TY  - JOUR
A1  - Palmer, Matthew D.
A1  - Gregory, Jonathan
A1  - Bagge, Meike
A1  - Calvert, Daley
A1  - Hagedoorn, Jan Marius
A1  - Howard, Tom
A1  - Klemann, Volker
A1  - Lowe, Jason A.
A1  - Roberts, Chris
A1  - Slangen, Aimee B. A.
A1  - Spada, Giorgio
T1  - Exploring the drivers of global and local sea‐level change over the 21st century and beyond
JF  - Earth's future
N2  - We present a new set of global and local sea‐level projections at example tide gauge locations under the RCP2.6, RCP4.5, and RCP8.5 emissions scenarios. Compared to the CMIP5‐based sea‐level projections presented in IPCC AR5, we introduce a number of methodological innovations, including (i) more comprehensive treatment of uncertainties, (ii) direct traceability between global and local projections, and (iii) exploratory extended projections to 2300 based on emulation of individual CMIP5 models. Combining the projections with observed tide gauge records, we explore the contribution to total variance that arises from sea‐level variability, different emissions scenarios, and model uncertainty. For the period out to 2300 we further breakdown the model uncertainty by sea‐level component and consider the dependence on geographic location, time horizon, and emissions scenario. Our analysis highlights the importance of local variability for sea‐level change in the coming decades and the potential value of annual‐to‐decadal predictions of local sea‐level change. Projections to 2300 show a substantial degree of committed sea‐level rise under all emissions scenarios considered and highlight the reduced future risk associated with RCP2.6 and RCP4.5 compared to RCP8.5. Tide gauge locations can show large ( > 50%) departures from the global average, in some cases even reversing the sign of the change. While uncertainty in projections of the future Antarctic ice dynamic response tends to dominate post‐2100, we see substantial differences in the breakdown of model variance as a function of location, time scale, and emissions scenario.
KW  - climate change
KW  - CMIP5 models
KW  - RCP scenarios
KW  - sea-level projections
KW  - tide gauge observations
Y1  - 2020
U6  - https://doi.org/10.1029/2019EF001413
SN  - 2328-4277
VL  - 8
IS  - 9
SP  - 1
EP  - 25
PB  - Wiley-Blackwell
CY  - Hoboken
ER  - 
TY  - GEN
A1  - Palmer, Matthew D.
A1  - Gregory, Jonathan
A1  - Bagge, Meike
A1  - Calvert, Daley
A1  - Hagedoorn, Jan Marius
A1  - Howard, Tom
A1  - Klemann, Volker
A1  - Lowe, Jason A.
A1  - Roberts, Chris
A1  - Slangen, Aimee B. A.
A1  - Spada, Giorgio
T1  - Exploring the drivers of global and local sea‐level change over the 21st century and beyond
T2  - Zweitveröffentlichungen der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe
N2  - We present a new set of global and local sea‐level projections at example tide gauge locations under the RCP2.6, RCP4.5, and RCP8.5 emissions scenarios. Compared to the CMIP5‐based sea‐level projections presented in IPCC AR5, we introduce a number of methodological innovations, including (i) more comprehensive treatment of uncertainties, (ii) direct traceability between global and local projections, and (iii) exploratory extended projections to 2300 based on emulation of individual CMIP5 models. Combining the projections with observed tide gauge records, we explore the contribution to total variance that arises from sea‐level variability, different emissions scenarios, and model uncertainty. For the period out to 2300 we further breakdown the model uncertainty by sea‐level component and consider the dependence on geographic location, time horizon, and emissions scenario. Our analysis highlights the importance of local variability for sea‐level change in the coming decades and the potential value of annual‐to‐decadal predictions of local sea‐level change. Projections to 2300 show a substantial degree of committed sea‐level rise under all emissions scenarios considered and highlight the reduced future risk associated with RCP2.6 and RCP4.5 compared to RCP8.5. Tide gauge locations can show large ( > 50%) departures from the global average, in some cases even reversing the sign of the change. While uncertainty in projections of the future Antarctic ice dynamic response tends to dominate post‐2100, we see substantial differences in the breakdown of model variance as a function of location, time scale, and emissions scenario.
T3  - Zweitveröffentlichungen der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe - 1353 
KW  - climate change
KW  - CMIP5 models
KW  - RCP scenarios
KW  - sea-level projections
KW  - tide gauge observations
Y1  - 2020
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-549881
SN  - 1866-8372
IS  - 9
ER  - 
TY  - JOUR
A1  - Leins, Johannes A.
A1  - Grimm, Volker
A1  - Drechsler, Martin
T1  - Large-scale PVA modeling of insects in cultivated grasslands
BT  - the role of dispersal in mitigating the effects of management schedules under climate change
JF  - Ecology and evolution
N2  - In many species, dispersal is decisive for survival in a changing climate. Simulation models for population dynamics under climate change thus need to account for this factor. Moreover, large numbers of species inhabiting agricultural landscapes are subject to disturbances induced by human land use. We included dispersal in the HiLEG model that we previously developed to study the interaction between climate change and agricultural land use in single populations. Here, the model was parameterized for the large marsh grasshopper (LMG) in cultivated grasslands of North Germany to analyze (1) the species development and dispersal success depending on the severity of climate change in subregions, (2) the additional effect of grassland cover on dispersal success, and (3) the role of dispersal in compensating for detrimental grassland mowing. Our model simulated population dynamics in 60-year periods (2020-2079) on a fine temporal (daily) and high spatial (250 x 250 m(2)) scale in 107 subregions, altogether encompassing a range of different grassland cover, climate change projections, and mowing schedules. We show that climate change alone would allow the LMG to thrive and expand, while grassland cover played a minor role. Some mowing schedules that were harmful to the LMG nevertheless allowed the species to moderately expand its range. Especially under minor climate change, in many subregions dispersal allowed for mowing early in the year, which is economically beneficial for farmers. More severe climate change could facilitate LMG expansion to uninhabited regions but would require suitable mowing schedules along the path. These insights can be transferred to other species, given that the LMG is considered a representative of grassland communities. For more specific predictions on the dynamics of other species affected by climate change and land use, the publicly available HiLEG model can be easily adapted to the characteristics of their life cycle.
KW  - bilinear interpolation
KW  - climate change
KW  - dispersal success
KW  - land use
KW  - large marsh grasshopper
KW  - spatially explicit model
Y1  - 2022
U6  - https://doi.org/10.1002/ece3.9063
SN  - 2045-7758
VL  - 12
IS  - 7
PB  - Wiley
CY  - Hoboken
ER  - 
TY  - GEN
A1  - Huber, Veronika
A1  - Krummenauer, Linda
A1  - Peña-Ortiz, Cristina
A1  - Lange, Stefan
A1  - Gasparrini, Antonio
A1  - Vicedo-Cabrera, Ana Maria
A1  - Garcia-Herrera, Ricardo
A1  - Frieler, Katja
T1  - Temperature-related excess mortality in German cities at 2 °C and higher degrees of global warming
T2  - Zweitveröffentlichungen der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe
N2  - Background: Investigating future changes in temperature-related mortality as a function of global mean temperature (GMT) rise allows for the evaluation of policy-relevant climate change targets. So far, only few studies have taken this approach, and, in particular, no such assessments exist for Germany, the most populated country of Europe.

Methods: We assess temperature-related mortality in 12 major German cities based on daily time-series of all-cause mortality and daily mean temperatures in the period 1993-2015, using distributed-lag non-linear models in a two-stage design. Resulting risk functions are applied to estimate excess mortality in terms of GMT rise relative to pre-industrial levels, assuming no change in demographics or population vulnerability.

Results: In the observational period, cold contributes stronger to temperature-related mortality than heat, with overall attributable fractions of 5.49% (95%CI: 3.82-7.19) and 0.81% (95%CI: 0.72-0.89), respectively. Future projections indicate that this pattern could be reversed under progressing global warming, with heat-related mortality starting to exceed cold-related mortality at 3 degrees C or higher GMT rise. Across cities, projected net increases in total temperature-related mortality were 0.45% (95%CI: -0.02-1.06) at 3 degrees C, 1.53% (95%CI: 0.96-2.06) at 4 degrees C, and 2.88% (95%CI: 1.60-4.10) at 5 degrees C, compared to today's warming level of 1 degrees C. By contrast, no significant difference was found between projected total temperature-related mortality at 2 degrees C versus 1 degrees C of GMT rise.

Conclusions: Our results can inform current adaptation policies aimed at buffering the health risks from increased heat exposure under climate change. They also allow for the evaluation of global mitigation efforts in terms of local health benefits in some of Germany's most populated cities.
T3  - Zweitveröffentlichungen der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe - 1430 
KW  - temperature-related mortality
KW  - climate change
KW  - Future projections
KW  - Germany
KW  - global mean temperature
Y1  - 2020
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-516511
SN  - 1866-8372
ER  - 
TY  - JOUR
A1  - Huber, Veronika
A1  - Krummenauer, Linda
A1  - Peña-Ortiz, Cristina
A1  - Lange, Stefan
A1  - Gasparrini, Antonio
A1  - Vicedo-Cabrera, Ana Maria
A1  - Garcia-Herrera, Ricardo
A1  - Frieler, Katja
T1  - Temperature-related excess mortality in German cities at 2 °C and higher degrees of global warming
JF  - Environmental Research
N2  - Background: Investigating future changes in temperature-related mortality as a function of global mean temperature (GMT) rise allows for the evaluation of policy-relevant climate change targets. So far, only few studies have taken this approach, and, in particular, no such assessments exist for Germany, the most populated country of Europe.

Methods: We assess temperature-related mortality in 12 major German cities based on daily time-series of all-cause mortality and daily mean temperatures in the period 1993-2015, using distributed-lag non-linear models in a two-stage design. Resulting risk functions are applied to estimate excess mortality in terms of GMT rise relative to pre-industrial levels, assuming no change in demographics or population vulnerability.

Results: In the observational period, cold contributes stronger to temperature-related mortality than heat, with overall attributable fractions of 5.49% (95%CI: 3.82-7.19) and 0.81% (95%CI: 0.72-0.89), respectively. Future projections indicate that this pattern could be reversed under progressing global warming, with heat-related mortality starting to exceed cold-related mortality at 3 degrees C or higher GMT rise. Across cities, projected net increases in total temperature-related mortality were 0.45% (95%CI: -0.02-1.06) at 3 degrees C, 1.53% (95%CI: 0.96-2.06) at 4 degrees C, and 2.88% (95%CI: 1.60-4.10) at 5 degrees C, compared to today's warming level of 1 degrees C. By contrast, no significant difference was found between projected total temperature-related mortality at 2 degrees C versus 1 degrees C of GMT rise.

Conclusions: Our results can inform current adaptation policies aimed at buffering the health risks from increased heat exposure under climate change. They also allow for the evaluation of global mitigation efforts in terms of local health benefits in some of Germany's most populated cities.
KW  - temperature-related mortality
KW  - climate change
KW  - Future projections
KW  - Germany
KW  - global mean temperature
Y1  - 2020
U6  - https://doi.org/10.1016/j.envres.2020.109447
SN  - 0013-9351
SN  - 1096-0953
VL  - 186
SP  - 1
EP  - 10
PB  - Elsevier
CY  - San Diego, California
ER  - 
TY  - GEN
A1  - Stoof-Leichsenring, Kathleen Rosemarie
A1  - Pestryakova, Luidmila Agafyevna
A1  - Epp, Laura Saskia
A1  - Herzschuh, Ulrike
T1  - Phylogenetic diversity and environment form assembly rules for Arctic diatom genera
BT  - a study on recent and ancient sedimentary DNA
T2  - Zweitveröffentlichungen der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe
N2  - Aim This study investigates taxonomic and phylogenetic diversity in diatom genera to evaluate assembly rules for eukaryotic microbes across the Siberian tree line. We first analysed how phylogenetic distance relates to taxonomic richness and turnover. Second, we used relatedness indices to evaluate if environmental filtering or competition influences the assemblies in space and through time. Third, we used distance-based ordination to test which environmental variables shape diatom turnover. Location Yakutia and Taymyria, Russia: we sampled 78 surface sediments and a sediment core, extending to 7,000 years before present, to capture the forest-tundra transition in space and time respectively. Taxon Arctic freshwater diatoms. Methods We applied metabarcoding to retrieve diatom diversity from surface and core sedimentary DNA. The taxonomic assignment binned sequence types (lineages) into genera and created taxonomic (abundance of lineages within different genera) and phylogenetic datasets (phylogenetic distances of lineages within different genera). Results Contrary to our expectations, we find a unimodal relationship between phylogenetic distance and richness in diatom genera. We discern a positive relationship between phylogenetic distance and taxonomic turnover in spatially and temporally distributed diatom genera. Furthermore, we reveal positive relatedness indices in diatom genera across the spatial environmental gradient and predominantly in time slices at a single location, with very few exceptions assuming effects of competition. Distance-based ordination of taxonomic and phylogenetic turnover indicates that lake environment variables, like HCO3- and water depth, largely explain diatom turnover. Main conclusion Phylogenetic and abiotic assembly rules are important in understanding the regional assembly of diatom genera across lakes in the Siberian tree line ecotone. Using a space-time approach we are able to exclude the influence of geography and elucidate that lake environmental variables primarily shape the assemblies. We conclude that some diatom genera have greater capabilities to adapt to environmental changes, whereas others will be putatively replaced or lost due to the displacement of the Arctic tundra biome under recent global warming.
T3  - Zweitveröffentlichungen der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe - 1442 
KW  - ancient sedimentary DNA
KW  - Arctic lakes
KW  - assembly rules
KW  - climate change
KW  - diatoms
KW  - environmental filtering
KW  - phylogenetic diversity
KW  - Siberian tree line
Y1  - 2020
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-515485
SN  - 1866-8372
IS  - 5
ER  - 
TY  - JOUR
A1  - Stoof-Leichsenring, Kathleen Rosemarie
A1  - Pestryakova, Luidmila Agafyevna
A1  - Epp, Laura Saskia
A1  - Herzschuh, Ulrike
T1  - Phylogenetic diversity and environment form assembly rules for Arctic diatom genera
BT  - a study on recent and ancient sedimentary DNA
JF  - Journal of Biogeography
N2  - Aim This study investigates taxonomic and phylogenetic diversity in diatom genera to evaluate assembly rules for eukaryotic microbes across the Siberian tree line. We first analysed how phylogenetic distance relates to taxonomic richness and turnover. Second, we used relatedness indices to evaluate if environmental filtering or competition influences the assemblies in space and through time. Third, we used distance-based ordination to test which environmental variables shape diatom turnover. Location Yakutia and Taymyria, Russia: we sampled 78 surface sediments and a sediment core, extending to 7,000 years before present, to capture the forest-tundra transition in space and time respectively. Taxon Arctic freshwater diatoms. Methods We applied metabarcoding to retrieve diatom diversity from surface and core sedimentary DNA. The taxonomic assignment binned sequence types (lineages) into genera and created taxonomic (abundance of lineages within different genera) and phylogenetic datasets (phylogenetic distances of lineages within different genera). Results Contrary to our expectations, we find a unimodal relationship between phylogenetic distance and richness in diatom genera. We discern a positive relationship between phylogenetic distance and taxonomic turnover in spatially and temporally distributed diatom genera. Furthermore, we reveal positive relatedness indices in diatom genera across the spatial environmental gradient and predominantly in time slices at a single location, with very few exceptions assuming effects of competition. Distance-based ordination of taxonomic and phylogenetic turnover indicates that lake environment variables, like HCO3- and water depth, largely explain diatom turnover. Main conclusion Phylogenetic and abiotic assembly rules are important in understanding the regional assembly of diatom genera across lakes in the Siberian tree line ecotone. Using a space-time approach we are able to exclude the influence of geography and elucidate that lake environmental variables primarily shape the assemblies. We conclude that some diatom genera have greater capabilities to adapt to environmental changes, whereas others will be putatively replaced or lost due to the displacement of the Arctic tundra biome under recent global warming.
KW  - ancient sedimentary DNA
KW  - Arctic lakes
KW  - assembly rules
KW  - climate change
KW  - diatoms
KW  - environmental filtering
KW  - phylogenetic diversity
KW  - Siberian tree line
Y1  - 2020
U6  - https://doi.org/10.1111/jbi.13786
SN  - 0305-0270
SN  - 1365-2699
VL  - 47
IS  - 5
SP  - 1166
EP  - 1179
PB  - Wiley-Blackwell
CY  - Oxford
ER  - 
TY  - JOUR
A1  - Hickmann, Thomas
A1  - Widerberg, Oscar
A1  - Lederer, Markus
A1  - Pattberg, Philipp H.
T1  - The United Nations Framework Convention on Climate Change Secretariat as an orchestrator in global climate policymaking
JF  - International review of administrative sciences : an international journal of comparative public administration
N2  - Scholars have recently devoted increasing attention to the role and function of international bureaucracies in global policymaking. Some of them contend that international public officials have gained significant political influence in various policy fields. Compared to other international bureaucracies, the political leeway of the Secretariat of the United Nations Framework Convention on Climate Change has been considered rather limited. Due to the specific problem structure of the policy domain of climate change, national governments endowed this intergovernmental treaty secretariat with a relatively narrow mandate. However, this article argues that in the past few years, the United Nations Framework Convention on Climate Change Secretariat has gradually loosened its straitjacket and expanded its original spectrum of activity by engaging different sub-national and non-state actors into a policy dialogue using facilitative orchestration as a mode of governance. The present article explores the recent evolution of the United Nations Framework Convention on Climate Change Secretariat and investigates the way in which it initiates, guides, broadens and strengthens sub-national and non-state climate actions to achieve progress in the international climate negotiations. <br /> Points for practitioners <br /> The Secretariat of the United Nations Framework Convention on Climate Change has lately adopted new roles and functions in global climate policymaking. While previously seen as a rather technocratic body that, first and foremost, serves national governments, the Climate Secretariat increasingly interacts with sub-national governments, civil society organizations and private companies to push the global response to climate change forward. We contend that the Climate Secretariat can contribute to global climate policymaking by coordinating and steering the initiatives of non-nation-state actors towards coherence and good practice.
KW  - climate change
KW  - environmental policymaking
KW  - intergovernmental relations
KW  - international bureaucracies
KW  - sub-national and non-state actors
Y1  - 2021
U6  - https://doi.org/10.1177/0020852319840425
SN  - 0020-8523
SN  - 1461-7226
VL  - 87
IS  - 1
SP  - 21
EP  - 38
PB  - Sage
CY  - Los Angeles, Calif. [u.a.]
ER  - 
TY  - THES
A1  - Windirsch-Woiwode, Torben
T1  - Permafrost carbon stabilisation by recreating a herbivore-driven ecosystem
T1  - Stabilisierung von Permafrostkohlenstoff durch die Wiedereinführung eines Herbivor-geprägten Ökosystems
N2  - With Arctic ground as a huge and temperature-sensitive carbon reservoir, maintaining low ground temperatures and frozen conditions to prevent further carbon emissions that contrib-ute to global climate warming is a key element in humankind’s fight to maintain habitable con-ditions on earth. Former studies showed that during the late Pleistocene, Arctic ground condi-tions were generally colder and more stable as the result of an ecosystem dominated by large herbivorous mammals and vast extents of graminoid vegetation – the mammoth steppe. Characterised by high plant productivity (grassland) and low ground insulation due to animal-caused compression and removal of snow, this ecosystem enabled deep permafrost aggrad-ation. Now, with tundra and shrub vegetation common in the terrestrial Arctic, these effects are not in place anymore. However, it appears to be possible to recreate this ecosystem local-ly by artificially increasing animal numbers, and hence keep Arctic ground cold to reduce or-ganic matter decomposition and carbon release into the atmosphere.
By measuring thaw depth, total organic carbon and total nitrogen content, stable carbon iso-tope ratio, radiocarbon age, n-alkane and alcohol characteristics and assessing dominant vegetation types along grazing intensity transects in two contrasting Arctic areas, it was found that recreating conditions locally, similar to the mammoth steppe, seems to be possible. For permafrost-affected soil, it was shown that intensive grazing in direct comparison to non-grazed areas reduces active layer depth and leads to higher TOC contents in the active layer soil. For soil only frozen on top in winter, an increase of TOC with grazing intensity could not be found, most likely because of confounding factors such as vertical water and carbon movement, which is not possible with an impermeable layer in permafrost. In both areas, high animal activity led to a vegetation transformation towards species-poor graminoid-dominated landscapes with less shrubs. Lipid biomarker analysis revealed that, even though the available organic material is different between the study areas, in both permafrost-affected and sea-sonally frozen soils the organic material in sites affected by high animal activity was less de-composed than under less intensive grazing pressure. In conclusion, high animal activity af-fects decomposition processes in Arctic soils and the ground thermal regime, visible from reduced active layer depth in permafrost areas. Therefore, grazing management might be utilised to locally stabilise permafrost and reduce Arctic carbon emissions in the future, but is likely not scalable to the entire permafrost region.
N2  - Mit dem arktischen Boden als riesigem und temperatursensiblen Kohlenstoffspeicher ist die Aufrechterhaltung niedriger Bodentemperaturen und gefrorener Bedingungen zur Verhinde-rung weiterer Kohlenstoffemissionen, die zum globalen Klimawandel beitragen, ein Schlüs-selelement im Kampf der Menschheit, die Erde weiterhin bewohnbar zu halten. Vorangehen-de Studien ergaben, dass die Bodenbedingungen in der Arktis während des späten Pleisto-zäns im Allgemeinen kälter und dadurch stabiler waren, als Ergebnis eines Ökosystems, das von großen pflanzenfressenden Säugetieren und weiten Flächen grasartiger Vegetation do-miniert wurde - der Mammutsteppe. Gekennzeichnet durch hohe Pflanzenproduktivität (Gras-land) und geringe Bodenisolierung aufgrund von Kompression und Schneeräumung durch Tiere, ermöglichte dieses Ökosystem eine tiefreichende Entwicklung des Permafrosts. Heut-zutage, mit der vorherrschenden Tundra- und Strauchvegetation in der Arktis, sind diese Ef-fekte nicht mehr präsent. Es scheint aber möglich, dieses Ökosystem lokal durch künstliche Erhöhung der Tierbestände nachzubilden und somit den arktischen Boden kühl zu halten, um den Abbau von organischem Material und die Freisetzung von Kohlenstoff in die Atmosphäre zu verringern.
Durch Messungen der Auftautiefe, des Gesamtgehalts des organischen Kohlenstoffs und Stickstoffs, des stabilen Kohlenstoff-Isotopenverhältnisses, des Radiocarbonalters, der 
n-Alkan- und Alkoholcharakteristika sowie durch Bestimmung der vorherrschenden Vegetati-onstypen entlang von Beweidungsgradienten in zwei unterschiedlichen arktischen Gebieten habe ich festgestellt, dass die Schaffung ähnlicher Bedingungen wie in der Mammutsteppe möglich sein könnte. Für durch Permafrost beeinflusste Böden konnte ich zeigen, dass eine intensive Beweidung im direkten Vergleich mit unbeweideten Gebieten die Tiefe der Auftau-schicht verringert und zu höheren Gehalten an organischem Kohlenstoff im oberen Bodenbe-reich führt. Für im Winter nur oberflächlich gefrorene Böden konnte kein Anstieg des organi-schen Kohlenstoffgehalts mit zunehmender Beweidungsintensität festgestellt werden, höchstwahrscheinlich aufgrund von Störfaktoren wie vertikalen Wasser- und Kohlenstoffbe-wegungen, die nicht durch eine undurchlässige Schicht wie beim Permafrost begrenzt sind. In beiden Gebieten führte eine hohe Tieraktivität zu einer Umwandlung der Vegetation hin zu artenarmen, von Gräsern dominierten Landschaften mit weniger Sträuchern. Die Analyse von Lipid-Biomarkern ergab, dass das verfügbare organische Material zwar zwischen den Unter-suchungsgebieten unterschiedlich war, aber sowohl in Permafrostgebieten als auch in saiso-nal gefrorenen Böden in Bereichen mit hoher Tieraktivität weniger stark zersetzt war als unter geringerer Beweidungsintensität. Zusammenfassend beeinflusst eine hohe Tieraktivität die Zersetzungsvorgänge in arktischen Böden und das thermische Regime des Bodens, was sich in einer reduzierten Tiefe der Auftauschicht in Permafrostgebieten widerspiegelt. Daher könn-te das Beweidungsmanagement in Zukunft aktiv eingesetzt werden, um den Permafrost lokal zu stabilisieren und gefroren zu halten sowie die Kohlenstoffemissionen in der Arktis zu ver-ringern. Aufgrund der Größe der Fläche, die in der terrestrischen Arktis von Permafrost be-einflusst ist, wird ein solches Beweidungsmanagement aber nicht als Maßnahme auf die ge-samte Permafrostregion ausgedehnt werden können.
KW  - permafrost
KW  - carbon
KW  - climate change
KW  - grazing
KW  - Arctic
KW  - Arktis
KW  - Kohlenstoff
KW  - Klimawandel
KW  - Beweidung
KW  - Permafrost
Y1  - 2024
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-624240
ER  - 
TY  - JOUR
A1  - Guzman Arias, Diego Alejandro
A1  - Samprogna Mohor, Guilherme
A1  - Mendiondo, Eduardo Mario
T1  - Multi-driver ensemble to evaluate the water utility business interruption cost induced by hydrological drought risk scenarios in Brazil
JF  - Urban water journal
N2  - Climate change and increasing water demand in urban environments necessitate planning water utility companies' finances. Traditionally, methods to estimate the direct water utility business interruption costs (WUBIC) caused by droughts have not been clearly established. We propose a multi-driver assessment method. We project the water yield using a hydrological model driven by regional climate models under radiative forcing scenarios. We project water demand under stationary and non-stationary conditions to estimate drought severity and duration, which are linked with pricing policies recently adopted by the Sao Paulo Water Utility Company. The results showed water insecurity. The non-stationary trend imposed larger differences in the drought resilience financial gap, suggesting that the uncertainties of WUBIC derived from demand and climate models are greater than those associated with radiative forcing scenarios. As populations increase, proactively controlling demand is recommended to avoid or minimize reactive policy changes during future drought events, repeating recent financial impacts.
KW  - Business interruption cost
KW  - water utility company
KW  - hydrological
KW  - droughts
KW  - water security
KW  - urban water
KW  - climate change
Y1  - 2022
U6  - https://doi.org/10.1080/1573062X.2022.2058564
SN  - 1573-062X
SN  - 1744-9006
PB  - Routledge, Taylor & Francis Group
CY  - Abingdon
ER  - 
TY  - JOUR
A1  - Warszawski, Lila
A1  - Kriegler, Elmar
A1  - Lenton, Timothy M.
A1  - Gaffney, Owen
A1  - Jacob, Daniela
A1  - Klingenfeld, Daniel
A1  - Koide, Ryu
A1  - Costa, María Máñez
A1  - Messner, Dirk
A1  - Nakicenovic, Nebojsa
A1  - Schellnhuber, Hans Joachim
A1  - Schlosser, Peter
A1  - Takeuchi, Kazuhiko
A1  - van der Leeuw, Sander
A1  - Whiteman, Gail
A1  - Rockström, Johan
T1  - All options, not silver bullets, needed to limit global warming to 1.5 °C
BT  - a scenario appraisal
JF  - Environmental research letters
N2  - Climate science provides strong evidence of the necessity of limiting global warming to 1.5 °C, in line with the Paris Climate Agreement. The IPCC 1.5 °C special report (SR1.5) presents 414 emissions scenarios modelled for the report, of which around 50 are classified as '1.5 °C scenarios', with no or low temperature overshoot. These emission scenarios differ in their reliance on individual mitigation levers, including reduction of global energy demand, decarbonisation of energy production, development of land-management systems, and the pace and scale of deploying carbon dioxide removal (CDR) technologies. The reliance of 1.5 °C scenarios on these levers needs to be critically assessed in light of the potentials of the relevant technologies and roll-out plans. We use a set of five parameters to bundle and characterise the mitigation levers employed in the SR1.5 1.5 °C scenarios. For each of these levers, we draw on the literature to define 'medium' and 'high' upper bounds that delineate between their 'reasonable', 'challenging' and 'speculative' use by mid century. We do not find any 1.5 °C scenarios that stay within all medium upper bounds on the five mitigation levers. Scenarios most frequently 'over use' CDR with geological storage as a mitigation lever, whilst reductions of energy demand and carbon intensity of energy production are 'over used' less frequently. If we allow mitigation levers to be employed up to our high upper bounds, we are left with 22 of the SR1.5 1.5 °C scenarios with no or low overshoot. The scenarios that fulfil these criteria are characterised by greater coverage of the available mitigation levers than those scenarios that exceed at least one of the high upper bounds. When excluding the two scenarios that exceed the SR1.5 carbon budget for limiting global warming to 1.5 °C, this subset of 1.5 °C scenarios shows a range of 15–22 Gt CO2 (16–22 Gt CO2 interquartile range) for emissions in 2030. For the year of reaching net zero CO2 emissions the range is 2039–2061 (2049–2057 interquartile range).
KW  - climate change
KW  - emissions scenarios
KW  - 1.5 ◦C
KW  - negative emissions
Y1  - 2021
U6  - https://doi.org/10.1088/1748-9326/abfeec
SN  - 1748-9326
N1  - Corrigendum: 10.1088/1748-9326/acbf6a
VL  - 16
IS  - 6
PB  - IOP Publishing
CY  - Bristol
ER  - 
TY  - THES
A1  - Schmidt, Lena Katharina
T1  - Altered hydrological and sediment dynamics in high-alpine areas – Exploring the potential of machine-learning for estimating past and future changes
N2  - Climate change fundamentally transforms glaciated high-alpine regions, with well-known cryospheric and hydrological implications, such as accelerating glacier retreat, transiently increased runoff, longer snow-free periods and more frequent and intense summer rainstorms. These changes affect the availability and transport of sediments in high alpine areas by altering the interaction and intensity of different erosion processes and catchment properties.
Gaining insight into the future alterations in suspended sediment transport by high alpine streams is crucial, given its wide-ranging implications, e.g. for flood damage potential, flood hazard in downstream river reaches, hydropower production, riverine ecology and water quality. However, the current understanding of how climate change will impact suspended sediment dynamics in these high alpine regions is limited. For one, this is due to the scarcity of measurement time series that are long enough to e.g. infer trends. On the other hand, it is difficult – if not impossible – to develop process-based models, due to the complexity and multitude of processes involved in high alpine sediment dynamics. Therefore, knowledge has so far been confined to conceptual models (which do not facilitate deriving concrete timings or magnitudes for individual catchments) or qualitative estimates (‘higher export in warmer years’) that may not be able to capture decreases in sediment export. Recently, machine-learning approaches have gained in popularity for modeling sediment dynamics, since their black box nature tailors them to the problem at hand, i.e. relatively well-understood input and output data, linked by very complex processes.
Therefore, the overarching aim of this thesis is to estimate sediment export from the high alpine Ötztal valley in Tyrol, Austria, over decadal timescales in the past and future – i.e. timescales relevant to anthropogenic climate change. This is achieved by informing, extending, evaluating and applying a quantile regression forest (QRF) approach, i.e. a nonparametric, multivariate machine-learning technique based on random forest.
The first study included in this thesis aimed to understand present sediment dynamics, i.e. in the period with available measurements (up to 15 years). To inform the modeling setup for the two subsequent studies, this study identified the most important predictors, areas within the catchments and time periods. To that end, water and sediment yields from three nested gauges in the upper Ötztal, Vent, Sölden and Tumpen (98 to almost 800 km² catchment area, 930 to 3772 m a.s.l.) were analyzed for their distribution in space, their seasonality and spatial differences therein, and the relative importance of short-term events. The findings suggest that the areas situated above 2500 m a.s.l., containing glacier tongues and recently deglaciated areas, play a pivotal role in sediment generation across all sub-catchments. In contrast, precipitation events were relatively unimportant (on average, 21 % of annual sediment yield was associated to precipitation events). Thus, the second and third study focused on the Vent catchment and its sub-catchment above gauge Vernagt (11.4 and 98 km², 1891 to 3772 m a.s.l.), due to their higher share of areas above 2500 m. Additionally, they included discharge, precipitation and air temperature (as well as their antecedent conditions) as predictors.
The second study aimed to estimate sediment export since the 1960s/70s at gauges Vent and Vernagt. This was facilitated by the availability of long records of the predictors, discharge, precipitation and air temperature, and shorter records (four and 15 years) of turbidity-derived sediment concentrations at the two gauges. The third study aimed to estimate future sediment export until 2100, by applying the QRF models developed in the second study to pre-existing precipitation and temperature projections (EURO-CORDEX) and discharge projections (physically-based hydroclimatological and snow model AMUNDSEN) for the three representative concentration pathways RCP2.6, RCP4.5 and RCP8.5.
The combined results of the second and third study show overall increasing sediment export in the past and decreasing export in the future. This suggests that peak sediment is underway or has already passed – unless precipitation changes unfold differently than represented in the projections or changes in the catchment erodibility prevail and override these trends. Despite the overall future decrease, very high sediment export is possible in response to precipitation events. This two-fold development has important implications for managing sediment, flood hazard and riverine ecology.
This thesis shows that QRF can be a very useful tool to model sediment export in high-alpine areas. Several validations in the second study showed good performance of QRF and its superiority to traditional sediment rating curves – especially in periods that contained high sediment export events, which points to its ability to deal with threshold effects. A technical limitation of QRF is the inability to extrapolate beyond the range of values represented in the training data. We assessed the number and severity of such out-of-observation-range (OOOR) days in both studies, which showed that there were few OOOR days in the second study and that uncertainties associated with OOOR days were small before 2070 in the third study. As the pre-processed data and model code have been made publically available, future studies can easily test further approaches or apply QRF to further catchments.
N2  - Der Klimawandel verändert vergletscherte Hochgebirgsregionen grundlegend, mit wohlbekannten Auswirkungen auf Kryosphäre und Hydrologie, wie beschleunigtem Gletscherrückgang, vorübergehend erhöhtem Abfluss, längeren schneefreien Perioden und häufigeren und intensiveren sommerlichen Starkniederschlägen. Diese Veränderungen wirken sich auf die Verfügbarkeit und den Transport von Sedimenten in hochalpinen Gebieten aus, indem sie die Interaktion und Intensität verschiedener Erosionsprozesse und Einzugsgebietseigenschaften verändern.
Eine Abschätzung der zukünftigen Veränderungen des Schwebstofftransports in hochalpinen Bächen ist von entscheidender Bedeutung, da sie weitreichende Auswirkungen haben, z. B. auf das Hochwasserschadenspotenzial, die Hochwassergefahr in den Unterläufen, sowie Wasserkraftproduktion, aquatische Ökosysteme und Wasserqualität. Das derzeitige Verständnis der Auswirkungen des Klimawandels auf die Schwebstoffdynamik in diesen hochalpinen Regionen ist jedoch begrenzt. Dies liegt zum einen daran, dass es kaum ausreichend lange Messzeitreihen gibt, um z.B. Trends ableiten zu können. Zum anderen ist es aufgrund der Komplexität und der Vielzahl der Prozesse, die an der hochalpinen Sedimentdynamik beteiligt sind, schwierig - wenn nicht gar unmöglich - prozessbasierte Modelle zu entwickeln. Daher beschränkte sich das Wissen bisher auf konzeptionelle Modelle (die es nicht ermöglichen, konkrete Zeitpunkte oder Größenordnungen für einzelne Einzugsgebiete abzuleiten) oder qualitative Schätzungen ("höherer Sedimentaustrag in wärmeren Jahren"), die möglicherweise nicht in der Lage sind, Rückgänge im Sedimentaustrag abzubilden. In jüngster Zeit haben Ansätze des maschinellen Lernens für die Modellierung der Sedimentdynamik an Popularität gewonnen, da sie aufgrund ihres Black-Box-Charakters auf das vorliegende Problem zugeschnitten sind, d. h. auf relativ gut verstandene Eingangs- und Ausgangsdaten, die durch sehr komplexe Prozesse verknüpft sind.
Das übergeordnete Ziel dieser Arbeit ist daher die Abschätzung des Sedimentaustrags am Beispiel des hochalpinen Ötztals in Tirol, Österreich, auf dekadischen Zeitskalen in der Vergangenheit und Zukunft – also Zeitskalen, die für den anthropogenen Klimawandel relevant sind. Dazu wird ein Quantile Regression Forest (QRF)-Ansatz, d.h. ein nichtparametrisches, multivariates maschinelles Lernverfahren auf der Basis von Random Forest, erweitert, evaluiert und angewendet.
Die erste Studie im Rahmen dieser Arbeit zielte darauf ab, die "gegenwärtige" Sedimentdynamik zu verstehen, d. h. in dem Zeitraum, für den Messungen vorliegen (bis zu 15 Jahre). Um die Modellierung für die beiden folgenden Studien zu ermöglichen, wurden in dieser Studie die wichtigsten Prädiktoren, Teilgebiete des Untersuchungsgebiets und Zeiträume ermittelt. Zu diesem Zweck wurden die Wasser- und Sedimenterträge von drei verschachtelten Pegeln im oberen Ötztal, Vent, Sölden und Tumpen (98 bis fast 800 km² Einzugsgebiet, 930 bis 3772 m ü.d.M.), auf ihre räumliche Verteilung, ihre Saisonalität und deren räumlichen Unterschiede, sowie die relative Bedeutung von Niederschlagsereignissen hin untersucht. Die Ergebnisse deuten darauf hin, dass die Gebiete oberhalb
von 2500 m ü. M., in denen sich Gletscherzungen und kürzlich entgletscherte Gebiete befinden, eine zentrale Rolle in der Sedimentdynamik in allen Teileinzugsgebieten spielen. Im Gegensatz dazu waren Niederschlagsereignisse relativ unbedeutend (im Durchschnitt wurden 21 % des jährlichen Austrags mit Niederschlagsereignissen in Verbindung gebracht). Daher konzentrierten sich die zweite und dritte Studie auf das Vent-Einzugsgebiet und sein Teileinzugsgebiet oberhalb des Pegels Vernagt (11,4 und 98 km², 1891 bis 3772 m ü. M.), da sie einen höheren Anteil an Gebieten oberhalb von 2500 m aufweisen. Außerdem wurden Abfluss, Niederschlag und Lufttemperatur (sowie deren Vorbedingungen) als Prädiktoren einbezogen.
Die zweite Studie zielte darauf ab, den Sedimentexport seit den 1960er/70er Jahren an den Pegeln Vent und Vernagt abzuschätzen. Dies wurde durch die Verfügbarkeit langer Aufzeichnungen der Prädiktoren Abfluss, Niederschlag und Lufttemperatur sowie kürzerer Aufzeichnungen (vier und 15 Jahre) von aus Trübungsmessungen abgeleiteten Sedimentkonzentrationen an den beiden Pegeln ermöglicht. Die dritte Studie zielte darauf ab, den zukünftigen Sedimentexport bis zum Jahr 2100 abzuschätzen, indem die in der zweiten Studie entwickelten QRF-Modelle auf bereits existierende Niederschlags- und Temperaturprojektionen (EURO-CORDEX) und Abflussprojektionen (des physikalisch basierten hydroklimatologischen und Schneemodells AMUNDSEN) in den drei repräsentativen Konzentrationspfaden RCP2.6, RCP4.5 und RCP8.5 angewendet wurden.
Die kombinierten Ergebnisse der zweiten und dritten Studie legen nahe, dass der Sedimentexport in der Vergangenheit insgesamt zugenommen hat und in der Zukunft abnehmen wird. Dies deutet darauf hin, dass der Höhepunkt des Sedimenteintrags erreicht ist oder bereits überschritten wurde - es sei denn, die Niederschlagsveränderungen entwickeln sich anders, als es in den Projektionen dargestellt ist, oder Veränderungen in der Erodierbarkeit des Einzugsgebiets setzen sich durch. Trotz des allgemeinen Rückgangs in der Zukunft sind sehr hohe Sedimentausträge als Reaktion auf Niederschlagsereignisse möglich. Diese zweifältige Entwicklung hat wichtige Auswirkungen auf das Sedimentmanagement, die Hochwassergefahr und die Flussökologie.
Diese Arbeit zeigt, dass QRF ein sehr nützliches Instrument zur Modellierung des Sedimentexports in hochalpinen Gebieten sein kann. Mehrere Validierungen in der zweiten Studie zeigten eine gute Modell-Performance und die Überlegenheit gegenüber traditionellen Sediment-Abfluss-Beziehungen – insbesondere in Zeiträumen, in denen es zu einem hohen Sedimentexport kam, was auf die Fähigkeit von QRF hinweist, mit Schwelleneffekten umzugehen. Eine technische Einschränkung von QRF ist die Unfähigkeit, über den Bereich der in den Trainingsdaten dargestellten Werte hinaus zu extrapolieren. Die Anzahl und den Schweregrad an solchen Tagen, in denen der Wertebereich der Trainingsdaten überschritten wurde, wurde in beiden Studien untersucht. Dabei zeigte sich, dass es in der zweiten Studie nur wenige solcher Tage gab und dass die mit den Überschreitungen verbundenen Unsicherheiten in der dritten Studie vor 2070 gering waren. Da die vorverarbeiteten Daten und der Modellcode öffentlich zugänglich gemacht wurden, können künftige Studien darauf aufbauend weitere Ansätze testen oder QRF auf weitere Einzugsgebiete anwenden.
KW  - suspended sediment
KW  - glacier melt
KW  - climate change
KW  - natural hazards
KW  - hydrology
KW  - geomorphology
KW  - Klimawandel
KW  - Geomorphologie
KW  - Gletscherschmelze
KW  - Hydrologie
KW  - Naturgefahren
KW  - suspendiertes Sediment
Y1  - 2024
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-623302
ER  - 
TY  - THES
A1  - Stiegler, Jonas
T1  - Mobile link functions in unpredictable agricultural landscapes
N2  - Animal movement is a crucial aspect of life, influencing ecological and evolutionary processes. It plays an important role in shaping biodiversity patterns, connecting habitats and ecosystems. Anthropogenic landscape changes, such as in agricultural environments, can impede the movement of animals by affecting their ability to locate resources during recurring movements within home ranges and, on a larger scale, disrupt migration or dispersal. Inevitably, these changes in movement behavior have far-reaching consequences on the mobile link functions provided by species inhabiting such extensively altered matrix areas. In this thesis, I investigate the movement characteristics and activity patterns of the European hare (Lepus europaeus), aiming to understand their significance as a pivotal species in fragmented agricultural landscapes. I reveal intriguing results that shed light on the importance of hares for seed dispersal, the influence of personality traits on behavior and space use, the sensitivity of hares to extreme weather conditions, and the impacts of GPS collaring on mammals' activity patterns and movement behavior. 
In Chapter I, I conducted a controlled feeding experiment to investigate the potential impact of hares on seed dispersal. By additionally utilizing GPS data of hares in two contrasting landscapes, I demonstrated that hares play a vital role, acting as effective mobile linkers for many plant species in small and isolated habitat patches. The analysis of seed intake and germination success revealed that distinct seed traits, such as density, surface area, and shape, profoundly affect hares' ability to disperse seeds through endozoochory. These findings highlight the interplay between hares and plant communities and thus provide valuable insights into seed dispersal mechanisms in fragmented landscapes. 
By employing standardized behavioral tests in Chapter II, I revealed consistent behavioral responses among captive hares while simultaneously examining the intricate connection between personality traits and spatial patterns within wild hare populations. This analysis provides insights into the ecological interactions and dynamics within hare populations in agricultural habitats. Examining the concept of animal personality, I established a link between personality traits and hare behavior. I showed that boldness, measured through standardized tests, influences individual exploration styles, with shy and bold hares exhibiting distinct space use patterns. In addition to providing valuable insights into the role of animal personality in heterogeneous environments, my research introduced a novel approach demonstrating the feasibility of remotely assessing personality types using animal-borne sensors without additional disturbance of the focal individual. 
While climate conditions severely impact the activity and, consequently, the fitness of wildlife species across the globe, in Chapter III, I uncovered the sensitivity of hares to temperature, humidity, and wind speed during their peak reproduction period. I found a strong response in activity to high temperatures above 25°C, with a particularly pronounced effect during temperature extremes of over 35°C. The non-linear relationship between temperature and activity was characterized by contrasting responses observed for day and night. These findings emphasize the vulnerability of hares to climate change and the potential consequences for their fitness and population dynamics with the ongoing rise of temperature. 
Since such insights can only be obtained through capturing and tagging free-ranging animals, I assessed potential impacts and the recovery process post-collar attachment in Chapter IV. For this purpose, I examined the daily distances moved and the temporal-associated activity of 1451 terrestrial mammals out of 42 species during their initial tracking period. The disturbance intensity and the speed of recovery varied across species, with herbivores, females, and individuals captured and collared in relatively secluded study areas experiencing more pronounced disturbances due to limited anthropogenic influences.
Mobile linkers are essential for maintaining biodiversity as they influence the dynamics and resilience of ecosystems. Furthermore, their ability to move through fragmented landscapes makes them a key component for restoring disturbed sites. Individual movement decisions determine the scale of mobile links, and understanding variations in space use among individuals is crucial for interpreting their functions. Climate change poses further challenges, with wildlife species expected to adjust their behavior, especially in response to high-temperature extremes, and comprehending the anthropogenic influence on animal movements will remain paramount to effective land use planning and the development of successful conservation strategies. 
This thesis provides a comprehensive ecological understanding of hares in agricultural landscapes. My research findings underscore the importance of hares as mobile linkers, the influence of personality traits on behavior and spatial patterns, the vulnerability of hares to extreme weather conditions, and the immediate consequences of collar attachment on mammalian movements. Thus, I contribute valuable insights to wildlife conservation and management efforts, aiding in developing strategies to mitigate the impact of environmental changes on hare populations. Moreover, these findings enable the development of methodologies aimed at minimizing the impacts of collaring while also identifying potential biases in the data, thereby benefiting both animal welfare and the scientific integrity of localization studies.
N2  - Die Bewegung von Tieren ist ein entscheidender Aspekt des Lebens, der ökologische und evolutionäre Prozesse beeinflusst. Sie spielt eine wichtige Rolle bei der Gestaltung der biologischen Vielfalt und verbindet Lebensräume und Ökosysteme miteinander. Anthropogene Landschaftsveränderungen, z.B. in der Landwirtschaft, können die Bewegung von Tieren behindern, indem sie ihre Fähigkeiten beeinträchtigen, Ressourcen innerhalb ihres täglichen Bewegungsradius zu lokalisieren und im größeren Maßstab, ihre Wanderung oder Ausbreitung limitieren. In dieser Thesis untersuche ich die Bewegungsmerkmale und Aktivitätsmuster des Feldhasen (Lepus europaeus), um seine Bedeutung als Schlüsselart in fragmentierten Agrarlandschaften zu verstehen. Ich lege faszinierende Ergebnisse vor, die die Bedeutung des Hasen für die Verbreitung von Saatgut, den Einfluss von Persönlichkeitsmerkmalen auf das Verhalten und die Raumnutzung, die Sensibilität des Hasen gegenüber extremen Witterungsbedingungen und die Auswirkungen von GPS-Empfängern auf die Aktivitätsmuster und das Bewegungsverhalten der Säugetiere beleuchten.
In Kapitel I führte ich ein kontrolliertes Fütterungsexperiment durch, um den potenziellen Einfluss von Hasen auf die Samenausbreitung zu analysieren. Durch die zusätzliche Verwendung von GPS-Daten von Hasen in zwei kontrastierenden Landschaften konnte ich nachweisen, dass Hasen eine wichtige Rolle spielen, da sie in kleinen und isolierten Habitatfeldern als effektive mobile Verbindungsglieder für viele Pflanzenarten fungieren. Die Analyse der Samenaufnahme und des Keimungserfolgs zeigte, dass verschiedene Eigenschaften der Samen, wie Dichte, Oberfläche und Form, die Fähigkeit der Hasen, Samen durch Endozoochorie zu verbreiten, stark beeinflussen. Diese Ergebnisse verdeutlichen die Wechselwirkung zwischen Hasen und Pflanzengemeinschaften und liefern somit wertvolle Erkenntnisse über die Mechanismen der Samenverbreitung in fragmentierten Landschaften.
Durch den Einsatz standardisierter Verhaltenstests in Kapitel II konnte ich konsistente Verhaltensreaktionen bei in Gefangenschaft lebenden Hasen aufdecken und zeitgleich den komplexen Zusammenhang zwischen Persönlichkeitsmerkmalen und räumlichen Mustern in Wildhasenpopulationen untersuchen. Diese Analyse bietet Einblicke in die ökologischen Interaktionen und die Dynamik von Hasenpopulationen in landwirtschaftlichen Lebensräumen. Indem ich das Konzept der Tierpersönlichkeit untersuchte, stellte ich eine Verbindung zwischen Persönlichkeitsmerkmalen und dem Verhalten von Hasen her. Ich habe gezeigt, dass die durch standardisierte Tests gemessene Kühnheit den individuellen Erkundungsstil beeinflusst, wobei schüchterne und kühne Hasen unterschiedliche Raumnutzungsmuster aufweisen. Meine Forschung liefert nicht nur wertvolle Einblicke in die Rolle der Tierpersönlichkeit in heterogenen Umgebungen, sondern stellt auch einen neuartigen Ansatz vor, der die Durchführbarkeit einer Fernbeurteilung von Persönlichkeitstypen mithilfe von am Tier angebrachten Sensoren ohne zusätzliche Störung des Zielindividuums demonstrierte.
Da die Klimabedingungen die Aktivität und folglich die Fitness von Wildtierarten auf der ganzen Welt stark beeinflussen, habe ich in Kapitel III die Sensibilität von Hasen gegenüber Temperatur, Luftfeuchtigkeit und Windgeschwindigkeit während ihrer Hauptfortpflanzungszeit ermittelt. Ich stellte fest, dass die Aktivität stark auf hohe Temperaturen über 25 °C reagiert, wobei die Auswirkungen bei extremen Temperaturen von über 35 °C besonders ausgeprägt sind. Die nicht lineare Beziehung zwischen Temperatur und Aktivität war durch gegensätzliche Reaktionen bei Tag und Nacht gekennzeichnet. Diese Ergebnisse unterstreichen die Anfälligkeit der Hasen für den Klimawandel und die möglichen Folgen für ihre Fitness und Populationsdynamik bei einem anhaltenden Temperaturanstieg.
Da solche Erkenntnisse nur durch Fangen und Besendern von Wildtieren ermöglicht werden können, habe ich in Kapitel IV die potenziellen negativen Auswirkungen auf das Individuuum, sowie den Erholungsprozess nach dem Anlegen des Halsbandes untersucht. Hierfür analysierte ich die zurückgelegten täglichen Entfernungen in Verbindung mit der Aktivität von 1451 terrestrischen Säugetieren aus 42 verschiedenen Arten während ihrer anfänglichen Verfolgung. Die Intensität der Störung sowie die Geschwindigkeit der Erholung variieren je nach Art, wobei Pflanzenfresser, Weibchen und Individuen, die in relativ abgelegenen Untersuchungsgebieten gefangen und mit Halsbändern versehen wurden, aufgrund bisher begrenzter anthropogener Einflüsse stärkere Störungen erfahren.
Mobile Verbindungsglieder sind essentiell für die Erhaltung der Biodiversität, indem sie eine wichtige Rolle in der Dynamik und Resilienz von Ökosystemen spielen. Weiterhin macht ihre Fähigkeit, sich durch zerstückelte Landschaften zu bewegen sie zu wichtigen Schlüsselkomponenten bei der Wiederherstellung von zerstörten Landschaften. Individuelle Bewegungsentscheidungen bestimmen den Maßstab der mobilen Verbindungen und die Schwankungen der Raumnutzung unter Individuen zu verstehen ist unerlässlich, um deren Funktion zu interpretieren. Der Klimawandel stellt eine weitere Herausforderung dar, indem Wildtiere dazu gezwungen werden, sich zu adaptieren, insbesondere an Hochtemperatur-Extreme. Den anthropogenen Einfluss auf Tierbewegungen aufzudecken bleibt von größter Bedeutung in der Landnutzungsplanung und die Entwicklung von erfolgreichen Strategien zum Schutz der Natur.
Diese Thesis liefert ein umfassendes ökologisches Verständnis von Feldhasen in Agrarlandschaften. Die Ergebnisse meiner Forschung unterstreichen die Bedeutung von Hasen als mobile Bindeglieder, den Einfluss von Persönlichkeitsmerkmalen auf Verhalten und räumliche Muster, die Anfälligkeit von Hasen gegenüber extremen Wetterbedingungen und die unmittelbaren Folgen der Halsbandanbringung auf Tierbewegungen. Damit leiste ich einen wertvollen Beitrag zum Schutz und zur Bewirtschaftung von Wildtieren, indem ich die Entwicklung von Strategien zur Abschwächung der Auswirkungen von Umweltveränderungen auf Hasenpopulationen unterstütze. Darüber hinaus ermöglichen diese Erkenntnisse die Entwicklung von Methoden, die darauf abzielen, die Folgen der Halsbandanbringung zu minimieren und gleichzeitig potenzielle Verzerrungen in den Daten zu identifizieren, was sowohl dem Tierschutz als auch der wissenschaftlichen Integrität von Lokalisierungsstudien zugutekommt.
KW  - European hare
KW  - mammals
KW  - ecology
KW  - animal personality
KW  - seed dispersal
KW  - movement ecology
KW  - tracking impacts
KW  - energy budget
KW  - climate change
KW  - accelerometry
KW  - GPS
KW  - tracking
KW  - Feldhase
KW  - GPS
KW  - Beschleunigungsmessungen
KW  - Tierpersönlichkeit
KW  - Klimawandel
KW  - Tierökologie
KW  - Energiebudget
KW  - Säugetiere
KW  - Bewegungsökologie
KW  - Samenausbreitung
KW  - Tierortung
KW  - Konsequenzen von Fang und Besenderung
Y1  - 2023
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-622023
ER  - 
TY  - JOUR
A1  - Böhnke, Denise
A1  - Krehl, Alice
A1  - Moermann, Kai
A1  - Volk, Rebekka
A1  - Lützkendorf, Thomas
A1  - Naber, Elias
A1  - Becker, Ronja
A1  - Norra, Stefan
T1  - Mapping urban green and its ecosystem services at microscale-a methodological approach for climate adaptation and biodiversity
JF  - Sustainability / Multidisciplinary Digital Publishing Institute (MDPI)
N2  - The current awareness of the high importance of urban green leads to a stronger need for tools to comprehensively represent urban green and its benefits. A common scientific approach is the development of urban ecosystem services (UES) based on remote sensing methods at the city or district level. Urban planning, however, requires fine-grained data that match local management practices. Hence, this study linked local biotope and tree mapping methods to the concept of ecosystem services. The methodology was tested in an inner-city district in SW Germany, comparing publicly accessible areas and non-accessible courtyards. The results provide area-specific [m(2)] information on the green inventory at the microscale, whereas derived stock and UES indicators form the basis for comparative analyses regarding climate adaptation and biodiversity. In the case study, there are ten times more micro-scale green spaces in private courtyards than in the public space, as well as twice as many trees. The approach transfers a scientific concept into municipal planning practice, enables the quantitative assessment of urban green at the microscale and illustrates the importance for green stock data in private areas to enhance decision support in urban development. Different aspects concerning data collection and data availability are critically discussed.
KW  - climate adaptation
KW  - urban green
KW  - mapping
KW  - ecosystem service cascade
KW  - model
KW  - surface type-function-concept
KW  - planning indicators
KW  - city district
KW  - level
KW  - urban planning practice
KW  - climate change
Y1  - 2022
U6  - https://doi.org/10.3390/su14159029
SN  - 2071-1050
VL  - 14
IS  - 15
PB  - MDPI
CY  - Basel
ER  - 
TY  - JOUR
A1  - Sedova, Barbora
A1  - Kalkuhl, Matthias
A1  - Mendelsohn, Robert
T1  - Distributional impacts of weather and climate in rural India
JF  - Economics of disasters and climate change
N2  - Climate-related costs and benefits may not be evenly distributed across the population. We study distributional implications of seasonal weather and climate on within-country inequality in rural India. Utilizing a first difference approach, we find that the poor are more sensitive to weather variations than the non-poor. The poor respond more strongly to (seasonal) temperature changes: negatively in the (warm) spring season, more positively in the (cold) rabi season. Less precipitation is harmful to the poor in the monsoon kharif season and beneficial in the winter and spring seasons. We show that adverse weather aggravates inequality by reducing consumption of the poor farming households. Future global warming predicted under RCP8.5 is likely to exacerbate these effects, reducing consumption of poor farming households by one third until the year 2100. We also find inequality in consumption across seasons with higher consumption during the harvest and lower consumption during the sowing seasons.
KW  - climate change
KW  - weather
KW  - inequality
KW  - household analysis
KW  - India
KW  - econometrics
Y1  - 2019
U6  - https://doi.org/10.1007/s41885-019-00051-1
SN  - 2511-1280
SN  - 2511-1299
VL  - 4
IS  - 1
SP  - 5
EP  - 44
PB  - Springer
CY  - Cham
ER  - 
TY  - JOUR
A1  - Kalkuhl, Matthias
A1  - Wenz, Leonie
T1  - The impact of climate conditions on economic production
BT  - evidence from a global panel of regions
JF  - Journal of Environmental Economics and Management
N2  - We present a novel data set of subnational economic output, Gross Regional Product (GRP), for more than 1500 regions in 77 countries that allows us to empirically estimate historic climate impacts at different time scales. Employing annual panel models, long-difference regressions and cross-sectional regressions, we identify effects on productivity levels and productivity growth. We do not find evidence for permanent growth rate impacts but we find robust evidence that temperature affects productivity levels considerably. An increase in global mean surface temperature by about 3.5°C until the end of the century would reduce global output by 7–14% in 2100, with even higher damages in tropical and poor regions. Updating the DICE damage function with our estimates suggests that the social cost of carbon from temperature-induced productivity losses is on the order of 73–142$/tCO2 in 2020, rising to 92–181$/tCO2 in 2030. These numbers exclude non-market damages and damages from extreme weather events or sea-level rise.
KW  - climate change
KW  - climate damages
KW  - climate impacts
KW  - growth regression
KW  - global warming
KW  - panel regression
KW  - cross-sectional regression
KW  - damage
KW  - function
KW  - social costs of carbon
Y1  - 2020
U6  - https://doi.org/10.1016/j.jeem.2020.102360
SN  - 0095-0696
SN  - 1096-0449
VL  - 103
PB  - Elsevier
CY  - San Diego
ER  - 
TY  - JOUR
A1  - Schultes, Anselm
A1  - Piontek, Franziska
A1  - Soergel, Bjoern
A1  - Rogelj, Joeri
A1  - Baumstark, Lavinia
A1  - Kriegler, Elmar
A1  - Edenhofer, Ottmar
A1  - Luderer, Gunnar
T1  - Economic damages from on-going climate change imply deeper near-term emission cuts
JF  - Environmental research letters
N2  - Pathways toward limiting global warming to well below 2 ∘C, as used by the IPCC in the Fifth Assessment Report, do not consider the climate impacts already occurring below 2 ∘C. Here we show that accounting for such damages significantly increases the near-term ambition of transformation pathways. We use econometric estimates of climate damages on GDP growth and explicitly model the uncertainty in the persistence time of damages. The Integrated Assessment Model we use includes the climate system and mitigation technology detail required to derive near-term policies. We find an optimal carbon price of $115 per tonne of CO2 in 2030. The long-term persistence of damages, while highly uncertain, is a main driver of the near-term carbon price. Accounting for damages on economic growth increases the gap between the currently pledged nationally determined contributions and the welfare-optimal 2030 emissions by two thirds, compared to pathways considering the 2 ∘C limit only.
KW  - climate change
KW  - climate mitigation
KW  - climate impacts
KW  - integrated assessment
Y1  - 2021
U6  - https://doi.org/10.1088/1748-9326/ac27ce
SN  - 1748-9326
VL  - 16
IS  - 10
PB  - IOP Publishing
CY  - Bristol
ER  - 
TY  - JOUR
A1  - Han, Sungju
A1  - Kuhlicke, Christian
T1  - Barriers and drivers for mainstreaming nature-based solutions for flood risks
BT  - the case of South Korea
JF  - International journal of disaster risk science
N2  - Nature-based solutions (NBS) are seen as a promising adaptation measure that sustainably deals with diverse societal challenges, while simultaneously delivering multiple benefits. Nature-based solutions have been highlighted as a resilient and sustainable means of mitigating floods and other hazards globally. This study examined diverging conceptualizations of NBS, as well as the attitudinal (for example, emotions and beliefs) and contextual (for example, legal and political aspects) barriers and drivers of NBS for flood risks in South Korea. Semistructured interviews were conducted with 11 experts and focused on the topic of flood risk measures and NBS case studies. The analysis found 11 barriers and five drivers in the attitudinal domain, and 13 barriers and two drivers in the contextual domain. Most experts see direct monetary benefits as an important attitudinal factor for the public. Meanwhile, the cost-effectiveness of NBS and their capacity to cope with flood risks were deemed influential factors that could lead decision makers to opt for NBS. Among the contextual factors, insufficient systems to integrate NBS in practice and the ideologicalization of NBS policy were found to be peculiar barriers, which hinder consistent realization of initiatives and a long-term national plan for NBS. Understanding the barriers and drivers related to the mainstreaming of NBS is critical if we are to make the most of such solutions for society and nature. It is also essential that we have a shared definition, expectation, and vision of NBS.
KW  - climate change
KW  - flood risk management
KW  - nature-based solutions (NBS)
KW  - South Korea
Y1  - 2021
U6  - https://doi.org/10.1007/s13753-021-00372-4
SN  - 2095-0055
SN  - 2192-6395
VL  - 12
IS  - 5
SP  - 661
EP  - 672
PB  - Springer
CY  - New York
ER  - 
TY  - JOUR
A1  - Li, Zhen
A1  - Spangenberg, Erik
A1  - Schicks, Judith Maria
A1  - Kempka, Thomas
T1  - Numerical Simulation of Coastal Sub-Permafrost Gas Hydrate Formation in the Mackenzie Delta, Canadian Arctic
JF  - Energies
N2  - The Mackenzie Delta (MD) is a permafrost-bearing region along the coasts of the Canadian Arctic which exhibits high sub-permafrost gas hydrate (GH) reserves. The GH occurring at the Mallik site in the MD is dominated by thermogenic methane (CH4), which migrated from deep conventional hydrocarbon reservoirs, very likely through the present fault systems. Therefore, it is assumed that fluid flow transports dissolved CH4 upward and out of the deeper overpressurized reservoirs via the existing polygonal fault system and then forms the GH accumulations in the Kugmallit-Mackenzie Bay Sequences. We investigate the feasibility of this mechanism with a thermo-hydraulic-chemical numerical model, representing a cross section of the Mallik site. We present the first simulations that consider permafrost formation and thawing, as well as the formation of GH accumulations sourced from the upward migrating CH4-rich formation fluid. The simulation results show that temperature distribution, as well as the thickness and base of the ice-bearing permafrost are consistent with corresponding field observations. The primary driver for the spatial GH distribution is the permeability of the host sediments. Thus, the hypothesis on GH formation by dissolved CH4 originating from deeper geological reservoirs is successfully validated. Furthermore, our results demonstrate that the permafrost has been substantially heated to 0.8-1.3 degrees C, triggered by the global temperature increase of about 0.44 degrees C and further enhanced by the Arctic Amplification effect at the Mallik site from the early 1970s to the mid-2000s.
KW  - gas hydrate
KW  - permafrost
KW  - methane
KW  - faults
KW  - climate change
KW  - Mallik
KW  - numerical simulations
Y1  - 2022
U6  - https://doi.org/10.3390/en15144986
SN  - 1996-1073
VL  - 15
IS  - 14
PB  - MDPI
CY  - Basel
ER  - 
TY  - THES
A1  - Middelanis, Robin
T1  - Global response to local extremes—a storyline approach on economic loss propagation from weather extremes
T1  - Globale Reaktion auf lokale Extreme — ein Storyline-Ansatz zu ökonomischer Schadensausbreitung aufgrund von Wetterextremen
N2  - Due to anthropogenic greenhouse gas emissions, Earth’s average surface temperature is steadily increasing. As a consequence, many weather extremes are likely to become more frequent and intense. This poses a threat to natural and human systems, with local impacts capable of destroying exposed assets and infrastructure, and disrupting economic and societal activity. Yet, these effects are not locally confined to the directly affected regions, as they can trigger indirect economic repercussions through loss propagation along supply chains. As a result, local extremes yield a potentially global economic response. To build economic resilience and design effective adaptation measures that mitigate adverse socio-economic impacts of ongoing climate change, it is crucial to gain a comprehensive understanding of indirect impacts and the underlying economic mechanisms. 
Presenting six articles in this thesis, I contribute towards this understanding. To this end, I expand on local impacts under current and future climate, the resulting global economic response, as well as the methods and tools to analyze this response. 
Starting with a traditional assessment of weather extremes under climate change, the first article investigates extreme snowfall in the Northern Hemisphere until the end of the century. Analyzing an ensemble of global climate model projections reveals an increase of the most extreme snowfall, while mean snowfall decreases. 
Assessing repercussions beyond local impacts, I employ numerical simulations to compute indirect economic effects from weather extremes with the numerical agent-based shock propagation model Acclimate. This model is used in conjunction with the recently emerged storyline framework, which involves analyzing the impacts of a particular reference extreme event and comparing them to impacts in plausible counterfactual scenarios under various climate or socio-economic conditions. Using this approach, I introduce three primary storylines that shed light on the complex mechanisms underlying economic loss propagation. 
In the second and third articles of this thesis, I analyze storylines for the historical Hurricanes Sandy (2012) and Harvey (2017) in the USA. For this, I first estimate local economic output losses and then simulate the resulting global economic response with Acclimate. The storyline for Hurricane Sandy thereby focuses on global consumption price anomalies and the resulting changes in consumption. I find that the local economic disruption leads to a global wave-like economic price ripple, with upstream effects propagating in the supplier direction and downstream effects in the buyer direction. Initially, an upstream demand reduction causes consumption price decreases, followed by a downstream supply shortage and increasing prices, before the anomalies decay in a normalization phase. A dominant upstream or downstream effect leads to net consumption gains or losses of a region, respectively. Moreover, I demonstrate that a longer direct economic shock intensifies the downstream effect for many regions, leading to an overall consumption loss. 
The third article of my thesis builds upon the developed loss estimation method by incorporating projections to future global warming levels. I use these projections to explore how the global production response to Hurricane Harvey would change under further increased global warming. The results show that, while the USA is able to nationally offset direct losses in the reference configuration, other countries have to compensate for increasing shares of counterfactual future losses. This compensation is mainly achieved by large exporting countries, but gradually shifts towards smaller regions. These findings not only highlight the economy’s ability to flexibly mitigate disaster losses to a certain extent, but also reveal the vulnerability and economic disadvantage of regions that are exposed to extreme weather events. 
The storyline in the fourth article of my thesis investigates the interaction between global economic stress and the propagation of losses from weather extremes. I examine indirect impacts of weather extremes — tropical cyclones, heat stress, and river floods — worldwide under two different economic conditions: an unstressed economy and a globally stressed economy, as seen during the Covid-19 pandemic. I demonstrate that the adverse effects of weather extremes on global consumption are strongly amplified when the economy is under stress. Specifically, consumption losses in the USA and China double and triple, respectively, due to the global economy’s decreased capacity for disaster loss compensation. An aggravated scarcity intensifies the price response, causing consumption losses to increase. 
Advancing on the methods and tools used here, the final two articles in my thesis extend the agent-based model Acclimate and formalize the storyline approach. With the model extension described in the fifth article, regional consumers make rational choices on the goods bought such that their utility is maximized under a constrained budget. In an out-of-equilibrium economy, these rational consumers are shown to temporarily increase consumption of certain goods in spite of rising prices. 
The sixth article of my thesis proposes a formalization of the storyline framework, drawing on multiple studies including storylines presented in this thesis. The proposed guideline defines eight central elements that can be used to construct a storyline. 
Overall, this thesis contributes towards a better understanding of economic repercussions of weather extremes. It achieves this by providing assessments of local direct impacts, highlighting mechanisms and impacts of loss propagation, and advancing on methods and tools used.
N2  - Mit dem kontinuierlichen Anstieg der globalen Mitteltemperatur aufgrund anthropogener Treibhausgasemissionen kann die Intensität und Häufigkeit vieler Wetterextreme zunehmen. Diese haben das Potential sowohl natürliche als auch menschliche Systeme stark zu beeinträchtigen. So hat die Zerstörung von Vermögenswerten und Infrastruktur sowie die Unterbrechung gesellschaftlicher und ökonomischer Abläufe oft negative wirtschaftliche Konsequenzen für direkt betroffene Regionen. Die Auswirkungen sind jedoch nicht lokal begrenzt, sondern können sich entlang von Lieferketten ausbreiten und somit auch indirekte Folgen in anderen Regionen haben – bis hin zu einer potenziell globalen wirtschaftlichen Reaktion. Daher sind Strategien zur Anpassung an veränderliche Klimabedingungen notwendig, um die Resilienz globaler Handelsketten zu stärken und dadurch negative sozioökonomische Folgen abzumildern. Hierfür ist ein besseres Verständnis lokaler Auswirkungen sowie ökonomischer Mechanismen zur Schadensausbreitung und deren Folgen erforderlich. 
Die vorliegende Dissertation umfasst insgesamt sechs Artikel, die zu diesem Verständnis beitragen. In diesen Studien werden zunächst lokale Auswirkungen von Wetterextremen unter gegenwärtigen und zukünftigen klimatischen Bedingungen untersucht. Weiterhin werden die globalen wirtschaftlichen Auswirkungen lokaler Wetterextreme sowie die darunterliegenden ökonomischen Effekte analysiert. In diesem Zusammenhang trägt diese Arbeit ferner zu der Weiterentwicklung der verwendeten Methoden und Ansätze bei. 
Der erste Artikel widmet sich zunächst der Betrachtung von extremem Schneefall in der nördlichen Hemisphäre unter dem Einfluss des Klimawandels. Zu diesem Zweck wird ein Ensemble von Projektionen globaler Klimamodelle bis zum Ende des Jahrhunderts analysiert. Die Projektionen zeigen dabei eine Verstärkung von extremen Schneefallereignissen, während die mittlere Schneefallintensität abnimmt. 
Um indirekte Auswirkungen von Wetterextremen zu erforschen, wird weiterhin das numerische agentenbasierte Modell Acclimate verwendet, welches die Ausbreitung ökonomischer Verlustkaskaden im globalen Versorgungsnetzwerk simuliert. In mehreren sogenannten Storylines werden die Auswirkungen eines historischen Referenzereignisses analysiert und mit den potentiellen Auswirkungen dieses Ereignisses unter plausiblen alternativen klimatischen oder sozioökonomischen Bedingungen verglichen. In dieser Dissertation werden drei zentrale Storylines vorgestellt, die jeweils unterschiedliche Aspekte der Schadensausbreitung von Wetterextremen untersuchen. 
Im zweiten und dritten Artikel dieser Arbeit werden dazu Storylines für die historischen Hurrikane Sandy (2012) und Harvey (2017) in den USA untersucht. Hierfür werden zunächst die lokalen ökonomischen Verluste durch diese Hurrikane ermittelt, welche als direkte wirtschaftliche Schockereignisse in Acclimate zur Berechnung der globalen Reaktion verwendet werden. Hierbei untersucht die Studie zu Hurricane Sandy globale Konsumpreisanomalien und damit einhergehende Auswirkungen auf das Konsumverhalten. Der direkte Schock löst hier eine wellenartige Veränderung globaler Konsumpreise mit drei Phasen aus, welche aus gegenläufigen Effekte aufwärts und abwärts der Lieferketten resultiert – sogenannten Upstream- und Downstream-Effekten. Zunächst steigt der Konsum aufgrund sinkender Preise durch Upstream-Effekte, bevor Preise aufgrund von Güterknappheit durch Downstream-Effekte wieder ansteigen und der Konsum abfällt. In einer Normalisierungsphase klingen diese Anomalien wieder ab. Ein länger anhaltender direkter wirtschaftlicher Schock verstärkt die Downstream-Phase und führt so in vielen Regionen insgesamt zu einem Konsumverlust. 
Die entwickelte Methode zur Berechnung direkter Verluste wird im dritten Artikel erweitert, indem Verstärkungen unter dem Einfluss des fortschreitenden Klimawandels berücksichtigt werden. Unter Nutzung dieser verstärkten direkten Verluste wird die Veränderung globaler Produktionsanomalien in Reaktion auf Hurricane Harvey simuliert. Die Ergebnisse zeigen, dass die USA bei zunehmender Erwärmung nicht mehr in der Lage sein werden, direkte Produktionsverluste auf nationaler Ebene auszugleichen. Stattdessen muss ein zunehmender Anteil dieser Verluste durch andere, insbesondere exportstarke Länder ausgeglichen werden. Der Anteil kleinerer Regionen an dieser ausgleichenden Produktion nimmt jedoch mit zunehmenden direkten Verlusten zu. Diese Produktionsverschiebungen verdeutlichen die Möglichkeit der globalen Wirtschaft, lokale Katastrophenverluste weitgehend flexibel abzumildern. Gleichzeitig veranschaulichen sie den Wettbewerbsnachteil direkt betroffener Wirtschaftsregionen. 
Die Storyline im vierten Artikel befasst sich mit dem Einfluss einer globalen wirtschaftlichen Krise auf die Schadensausbreitung von tropischen Wirbelstürmen, Hitzestress und Flussüberschwemmungen weltweit. Hierfür werden die indirekten Auswirkungen dieser Extreme unter dem Einfluss der global reduzierten wirtschaftlichen Aktivität während der Covid-19-Pandemie, sowie bei „normaler“ globaler Wirtschaftsleistung simuliert. Der Vergleich beider Szenarien zeigt bei global gestörter Wirtschaft eine deutliche Verstärkung negativer Konsumauswirkungen durch die simulierten Extreme. Konsumverluste steigen besonders stark in den USA und China an, wo sie sich verdoppeln bzw. verdreifachen. Diese Veränderungen resultieren aus der global verminderten wirtschaftlichen Kapazität, die für den Ausgleich der Produktionsverluste von Wetterextremen zur Verfügung steht. Dies verstärkt die Extremewetter-bedingte Güterknappheit, was zu Preisanstiegen und erhöhten Konsumverlusten führt. 
Abschließend werden in den letzten beiden Artikeln die in der Arbeit verwendeten Methoden und Ansätze erweitert. Hierfür wird das Modell Acclimate im fünften Artikel weiterentwickelt, indem Konsumenten als rational agierende Agenten modelliert werden. Mit dieser Erweiterung treffen lokale Verbraucher Entscheidungen über die konsumierten Güter so, dass diese den Nutzen eines begrenzten Budgets maximieren. Die entstehende Dynamik kann außerhalb eines wirtschaftlichen Gleichgewichts dazu führen, dass bestimmte Güter temporär trotz erhöhter Preise stärker nachgefragt werden. 
Der sechste Artikel formalisiert den Storyline-Ansatz und präsentiert einen Leitfaden für die Erstellung von Storylines. Dieser basiert auf den Ergebnissen mehrerer Studien, die diesen Ansatz verfolgen; einschließlich Storylines aus der vorliegenden Arbeit. Es werden insgesamt acht Elemente definiert, anhand derer eine Storyline-Studie erstellt werden kann. 
Insgesamt trägt diese Arbeit zu einem umfassenderen Verständnis der ökonomischen Auswirkungen von Wetterextremen bei. Hierfür werden lokale Auswirkungen von Extremen unter gegenwärtigen und zukünftigen klimatischen Bedingungen untersucht, sowie wichtige ökonomische Mechanismen und Auswirkungen der resultierenden Schadensausbreitung aufgedeckt. Neben diesen Erkenntnissen werden überdies Weiterentwicklungen der Methoden und Ansätze präsentiert, die weiterführende Analysen ermöglichen.
KW  - Klimawandel
KW  - Wetterextreme
KW  - indirekte ökonomische Effekte
KW  - makroökonomische Modellierung
KW  - climate change
KW  - weather extremes
KW  - indirect economic impacts
KW  - macro-economic modelling
Y1  - 2023
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-611127
ER  - 
TY  - JOUR
A1  - Rolph, Rebecca
A1  - Overduin, Pier Paul
A1  - Ravens, Thomas
A1  - Lantuit, Hugues
A1  - Langer, Moritz
T1  - ArcticBeach v1.0
BT  - a physics-based parameterization of pan-Arctic coastline erosion
JF  - Frontiers in Earth Science
N2  - In the Arctic, air temperatures are increasing and sea ice is declining, resulting in larger waves and a longer open water season, all of which intensify the thaw and erosion of ice-rich coasts. Climate change has been shown to increase the rate of Arctic coastal erosion, causing problems for Arctic cultural heritage, existing industrial, military, and civil infrastructure, as well as changes in nearshore biogeochemistry. Numerical models that reproduce historical and project future Arctic erosion rates are necessary to understand how further climate change will affect these problems, and no such model yet exists to simulate the physics of erosion on a pan-Arctic scale. We have coupled a bathystrophic storm surge model to a simplified physical erosion model of a permafrost coastline. This Arctic erosion model, called ArcticBeach v1.0, is a first step toward a physical parameterization of Arctic shoreline erosion for larger-scale models. It is forced by wind speed and direction, wave period and height, sea surface temperature, all of which are masked during times of sea ice cover near the coastline. Model tuning requires observed historical retreat rates (at least one value), as well as rough nearshore bathymetry. These parameters are already available on a pan-Arctic scale. The model is validated at three study sites at 1) Drew Point (DP), Alaska, 2) Mamontovy Khayata (MK), Siberia, and 3) Veslebogen Cliffs, Svalbard. Simulated cumulative retreat rates for DP and MK respectively (169 and 170 m) over the time periods studied at each site (2007-2016, and 1995-2018) are found to the same order of magnitude as observed cumulative retreat (172 and 120 m). The rocky Veslebogen cliffs have small observed cumulative retreat rates (0.05 m over 2014-2016), and our model was also able to reproduce this same order of magnitude of retreat (0.08 m). Given the large differences in geomorphology between the study sites, this study provides a proof-of-concept that ArcticBeach v1.0 can be applied on very different permafrost coastlines. ArcticBeach v1.0 provides a promising starting point to project retreat of Arctic shorelines, or to evaluate historical retreat in places that have had few observations.
KW  - permafrost
KW  - erosion
KW  - modelling
KW  - arctic
KW  - climate change
Y1  - 2022
U6  - https://doi.org/10.3389/feart.2022.962208
SN  - 2296-6463
VL  - 10
PB  - Frontiers Media
CY  - Lausanne
ER  - 
TY  - JOUR
A1  - Guzman, Diego A.
A1  - Samprogna Mohor, Guilherme
A1  - Mendiondo, Eduardo Mario
T1  - Multi-year index-based insurance for adapting Water Utility Companies to hydrological drought
BT  - case study of a water supply system of the Sao Paulo metropolitan region, Brazil
JF  - Water
N2  - The sustainability of water utility companies is threatened by non-stationary drivers, such as climate and anthropogenic changes. To cope with potential economic losses, instruments such as insurance are useful for planning scenarios and mitigating impacts, but data limitations and risk uncertainties affect premium estimation and, consequently, business sustainability. This research estimated the possible economic impacts of business interruption to the Sao Paulo Water Utility Company derived from hydrological drought and how this could be mitigated with an insurance scheme. Multi-year insurance (MYI) was proposed through a set of "change" drivers: the climate driver, through forcing the water evaluation and planning system (WEAP) hydrological tool; the anthropogenic driver, through water demand projections; and the economic driver, associated with recent water price policies adopted by the utility company during water scarcity periods. In our study case, the evaluated indices showed that MYI contracts that cover only longer droughts, regardless of the magnitude, offer better financial performance than contracts that cover all events (in terms of drought duration). Moreover, through MYI contracts, we demonstrate solvency for the insurance fund in the long term and an annual average actuarially fair premium close to the total expected revenue reduction.
KW  - multi-year insurance
KW  - climate change
KW  - hydrological drought
KW  - water
KW  - security and economy
Y1  - 2020
U6  - https://doi.org/10.3390/w12112954
SN  - 2073-4441
VL  - 12
IS  - 11
PB  - MDPI
CY  - Basel
ER  - 
TY  - JOUR
A1  - Sælen, Håkon
A1  - Hovi, Jon
A1  - Sprinz, Detlef F.
A1  - Underdal, Arild
T1  - How US withdrawal might influence cooperation under the Paris climate agreement
JF  - Environmental science & policy
N2  - Using a novel agent-based model, we study how US withdrawal might influence the political process established by the Paris Agreement, and hence the prospects for reaching the collective goal to limit warming below 2 degrees C. Our model enables us to analyze to what extent reaching this goal despite US withdrawal would place more stringent requirements on other core elements of the Paris cooperation process. We find, first, that the effect of a US withdrawal depends critically on the extent to which member countries reciprocate others' promises and contributions. Second, while the 2 degrees C goal will likely be reached only under a very small set of conditions in any event, even temporary US withdrawal will further narrow this set significantly. Reaching this goal will then require other countries to step up their ambition at the first opportunity and to comply nearly 100% with their pledges, while maintaining high confidence in the Paris Agreements institutions. Third, although a US withdrawal will first primarily affect the United States' own emissions, it will eventually prove even more detrimental to other countries' emissions.
KW  - climate change
KW  - Paris agreement
KW  - President Trump
KW  - 2 degrees C target
KW  - agent-based modeling
KW  - reciprocity
Y1  - 2020
U6  - https://doi.org/10.1016/j.envsci.2020.03.011
SN  - 1462-9011
SN  - 1873-6416
VL  - 108
SP  - 121
EP  - 132
PB  - Elsevier
CY  - Oxford
ER  - 
TY  - JOUR
A1  - Mogrovejo Arias, Diana Carolina
A1  - Brill, Florian H. H.
A1  - Wagner, Dirk
T1  - Potentially pathogenic bacteria isolated from diverse habitats in Spitsbergen, Svalbard
JF  - Environmental earth sciences
N2  - The Arctic ecosystem, a reservoir of genetic microbial diversity, represents a virtually unlimited source of microorganisms that could interact with human beings. Despite continuous exploration of Arctic habitats and description of their microbial communities, bacterial phenotypes commonly associated with pathogenicity, such as hemolytic activity, have rarely been reported. In this study, samples of snow, fresh and marine water, soil, and sediment from several habitats in the Arctic archipelago of Svalbard were collected during Summer, 2017. Bacterial isolates were obtained after incubation on oligotrophic media at different temperatures and their hemolytic potential was assessed on sheep blood agar plates. Partial (alpha) or true (beta) hemolysis was observed in 32 out of 78 bacterial species. Genes expressing cytolytic compounds, such as hemolysins, likely increase the general fitness of the producing microorganisms and confer a competitive advantage over the availability of nutrients in natural habitats. In environmental species, the nutrient-acquisition function of these compounds presumably precedes their function as toxins for mammalian erythrocytes. However, in the light of global warming, the presence of hemolytic bacteria in Arctic environments highlights the possible risks associated with these microorganisms in the event of habitat melting/destruction, ecosystem transition, and re-colonization.
KW  - Arctic
KW  - Svalbard
KW  - hemolysins
KW  - climate change
KW  - pathogens
KW  - virulence
Y1  - 2020
U6  - https://doi.org/10.1007/s12665-020-8853-4
SN  - 1866-6280
SN  - 1866-6299
VL  - 79
IS  - 5
PB  - Springer
CY  - Berlin ; Heidelberg
ER  - 
TY  - JOUR
A1  - Mtilatila, Lucy Mphatso Ng'ombe
A1  - Bronstert, Axel
A1  - Vormoor, Klaus Josef
T1  - Temporal evaluation and projections of meteorological droughts in the Greater Lake Malawi Basin, Southeast Africa
JF  - Frontiers in water
N2  - The study examined the potential future changes of drought characteristics in the Greater Lake Malawi Basin in Southeast Africa. This region strongly depends on water resources to generate electricity and food. Future projections (considering both moderate and high emission scenarios) of temperature and precipitation from an ensemble of 16 bias-corrected climate model combinations were blended with a scenario-neutral response surface approach to analyses changes in: (i) the meteorological conditions, (ii) the meteorological water balance, and (iii) selected drought characteristics such as drought intensity, drought months, and drought events, which were derived from the Standardized Precipitation and Evapotranspiration Index. Changes were analyzed for a near-term (2021-2050) and far-term period (2071-2100) with reference to 1976-2005. The effect of bias-correction (i.e., empirical quantile mapping) on the ability of the climate model ensemble to reproduce observed drought characteristics as compared to raw climate projections was also investigated. Results suggest that the bias-correction improves the climate models in terms of reproducing temperature and precipitation statistics but not drought characteristics. Still, despite the differences in the internal structures and uncertainties that exist among the climate models, they all agree on an increase of meteorological droughts in the future in terms of higher drought intensity and longer events. Drought intensity is projected to increase between +25 and +50% during 2021-2050 and between +131 and +388% during 2071-2100. This translates into +3 to +5, and +7 to +8 more drought months per year during both periods, respectively. With longer lasting drought events, the number of drought events decreases. Projected droughts based on the high emission scenario are 1.7 times more severe than droughts based on the moderate scenario. That means that droughts in this region will likely become more severe in the coming decades. Despite the inherent high uncertainties of climate projections, the results provide a basis in planning and (water-)managing activities for climate change adaptation measures in Malawi. This is of particular relevance for water management issues referring hydro power generation and food production, both for rain-fed and irrigated agriculture.
KW  - meteorological drought
KW  - drought intensity
KW  - climate change
KW  - drought
KW  - events
KW  - Lake Malawi
KW  - Shire River
KW  - drought projections
KW  - South-Eastern
KW  - Africa
Y1  - 2022
U6  - https://doi.org/10.3389/frwa.2022.1041452
SN  - 2624-9375
VL  - 4
PB  - Frontiers Media
CY  - Lausanne
ER  - 
TY  - THES
A1  - Riebold, Johannes
T1  - On the linkage between future Arctic sea ice retreat, the large-scale atmospheric circulation and temperature extremes over Europe
T1  - Untersuchung des Zusammenhangs zwischen zukünftigen Arktischen Meereisänderungen, der großskaligen atmosphärischen Zirkulation und Temperaturextremen über Europa
N2  - Extreme weather and climate events are  one of the greatest dangers for present-day society. Therefore,  it is important to provide reliable statements on what  changes in extreme events can be expected along with future global climate change. However, the  projected overall response to future climate change is generally a result of a complex interplay between individual physical mechanisms originated within the different climate subsystems. Hence, a profound understanding of these individual contributions is required in order to provide meaningful assessments of  future changes in extreme events. One aspect of  climate change is the recently observed phenomenon of Arctic Amplification and the related dramatic Arctic sea ice decline, which is expected to continue over the next decades. The question to what extent Arctic sea ice loss is able to affect atmospheric dynamics and extreme events over mid-latitudes has received a lot of attention over recent years and still remains a highly debated topic. 
In this respect, the objective of this  thesis is to contribute to a better understanding  on the impact of future Arctic sea ice retreat on European temperature extremes  and  large-scale atmospheric dynamics.
The  outcomes  are based  on model data from the atmospheric general circulation model ECHAM6.  Two different sea ice sensitivity  simulations from the Polar Amplification Intercomparison Project are employed and contrasted to a present day reference experiment: one experiment with prescribed future sea ice loss over the entire Arctic, as well as another one with sea ice reductions only locally prescribed over the Barents-Kara Sea.% prescribed over the entire Arctic, as well as only locally over the Barent/Karasea with a present day reference experiment. 

The first part of the thesis focuses on how future Arctic sea ice reductions affect large-scale atmospheric dynamics over the Northern Hemisphere in terms of occurrence frequency changes of five preferred Euro-Atlantic circulation regimes. When compared to circulation regimes computed from ERA5 it shows that ECHAM6 is able to realistically simulate the regime structures. Both ECHAM6 sea ice sensitivity experiments exhibit similar regime frequency changes. Consistent with tendencies found in ERA5, a more frequent occurrence of a Scandinavian blocking pattern in midwinter is for instance detected under future sea ice conditions in the sensitivity experiments. Changes in occurrence frequencies of circulation regimes  in summer season are however barely  detected. 
After identifying suitable regime storylines for the occurrence of European temperature extremes in winter, the previously detected regime frequency changes are used to quantify dynamically and thermodynamically driven contributions to sea ice-induced changes in European winter temperature extremes.
It is   for instance shown how the preferred occurrence of a Scandinavian blocking regime under low sea ice conditions dynamically contributes to more frequent midwinter cold extreme occurrences over Central Europe. In addition, a reduced occurrence frequency of a Atlantic trough regime is linked to reduced winter warm extremes over Mid-Europe. Furthermore, it is demonstrated how the overall thermodynamical warming effect due to sea ice loss can result in less (more) frequent winter cold (warm) extremes, and consequently counteracts the dynamically induced changes.

Compared to winter season, circulation regimes in summer are less suitable as storylines for the occurrence of summer heat extremes.  
Therefore, an approach based on circulation analogues is  employed in order to quantify thermodyamically and dynamically driven contributions to sea ice-induced changes of summer heat extremes over three different European sectors. Reduced occurrences of blockings over Western Russia are  detected in the ECHAM6 sea ice sensitivity experiments; however, arguing for dynamically and thermodynamically induced contributions to changes in summer heat extremes remains rather challenging.
N2  - Wetter- und Klimaextreme stellen eine der größten Gefahren für die heutige Gesellschaft dar. Daher ist es essentiell verlässliche Aussagen darüber zu treffen, welche Änderungen solcher Extremereignisse im Zuge des zukünftigen globalen Klimawandels zu erwarten sind. Die projizierten  Klimaänderungen, welche mit dem zukünftigen Klimawandel einhergehen, sind jedoch im Allgemeinen das Ergebnis komplexer Wechselwirkungen von verschiedenen physikalischen und dynamischen Prozessen in den verschiedenen Subsystemen des Klimasystems. Daher ist ein tiefgreifendes Verständnis dieser einzelnen Prozesse erforderlich, um aussagekräftige Einschätzungen für die Zukunft abgeben zu können. Ein Aspekt des globalen Klimawandels über die letzten Dekaden ist das Phänomen der arktischen Verstärkung und der damit verbundene dramatische Rückgang des Arktischen Meereises, welcher sich voraussichtlich in den nächsten Jahrzehnten auch fortsetzen wird. Die Frage, inwieweit der Rückgang des arktischen Meereises die atmosphärische Dynamik sowie Wetter- und Klimaextreme über den mittleren Breiten beeinflussen kann, wurde in den letzten Jahren von einer Vielzahl von Studien adressiert, bleibt jedoch bis zum heutigen Tage ein kontrovers diskutiertes Thema.
Aus diesem Grund zielt die vorliegende Arbeit darauf ab einen Beitrag zu einem besseren Verständnis  der Auswirkungen des zukünftigen arktischen Meereisrückgangs auf europäische Temperaturextreme, sowie auf Änderungen der relevanten großräumigen atmosphärischen Zirkulationsbedingungen zu leisten.
Die Ergebnisse dieser Arbeit basieren auf Modelldaten des atmosphärischen  Zirkulationsmodells ECHAM6. Zwei unterschiedliche Meereissensitivitätsexperimente aus dem Polar Amplification Intercomparison Project werden analysiert: ein Experiment  mit vorgeschriebener zukünftiger Meereisreduktion über der gesamten Arktis, sowie ein Weiteres, in dem jediglich das Meereis über der Barents- und Karasee verringert wird. Beide Experimente werden einer Referenzsimulation gegenübergestellt, welche  gegenwärtige Meereisbedingungen repräsentiert.

Zunächst wird analysiert, inwieweit der zukünftige arktische Meereisrückgang Einfluss auf die großräumige atmosphärische Zirkulation über der nördlichen Hemisphäre hat. Dazu werden im Rahmen dieser Arbeit die Häufigkeitsänderungen von fünf bevorzugten atmosphärischen Zirkulationsregimen bestimmt. Beide Sensitivitätsexperimente zeigen diesbezüglich ähnliche Änderungen in den Auftrittswahrscheinlichkeiten der Regime. In Übereinstimmung mit Ergebnissen, welche auf der ERA5-Reanalyse basieren, zeigt sich beispielsweise ein häufigeres Auftreten eines skandinavischen Blockierungsmusters im Mittwinter unter reduzierten Meereisbedingungen. Änderungen in der Auftrittswahrscheinlichkeit verschiedener Zirkulationsregime in der Sommersaison werden hingegen kaum detektiert. 
Anschließend werden jene Regime identifiziert, welche mit einem häufigerem Auftreten von winterlichen Temperaturextremen über Europa in Verbindung gebracht werden können.
In Kombination mit den zuvor erfassten meereisbedingten Änderungen in den Auftrittswahrscheinlichkeiten der Regime werden dann  dynamisch und thermodynamisch induzierte Beiträge zu  meereisbedingten Änderungen europäischer Temperaturextreme  quantifiziert.
Es zeigt sich beispielsweise, dass das bevorzugte Auftreten des skandinavischen Blockierungsmusters unter zukünftigen Meereisbedingungen dynamisch zu häufigeren  Kälteextremereignissen im Winter über Mitteleuropa beiträgt. Darüber hinaus kann eine reduzierte Häufigkeit des Auftretens eines Regimes, welches mit einem Trog über dem westlichen Atlantik assoziiert werden kann, mit einer verringerten Anzahl von sehr warmen Wintertagen über Mitteleuropa in Verbindung gebracht werden. Es wird zudem gezeigt,  wie der in den Modellsimulationen thermodynamisch induzierte Erwärmungseffekt infolge der reduzierten Meereisbedingungen zu einem häufigeren (weniger häufigeren) Auftreten von extrem warmen (kalten) Wintertagen führen kann. Dieser thermodynamische Effekt kann folglich den dynamisch induzierten Veränderungen entgegenwirken.

Zirkulationsregime in der Sommersaison können nur bedingt mit einem häufigeren Auftreten von europäischen Hitzeextremen im Sommer in Verbindung gebracht werden.
Aus diesem Grund  wird  ein zusätzlicher methodischer Ansatz verwendet, der  auf der Identifikation von Zirkulationsmustern basiert, welche große Ähnlichkeit zu typischen atmosphärischen Blockierungen während vergangener Hitzewellen über verschiedenen europäischen Regionen aufweisen. Dies ermöglicht es meereisbedingte Änderungen im Auftreten von Hitzeextremen über drei verschiedene europäische Sektoren in thermodynamisch und dynamisch induzierte Beiträge zu zerlegen. In den Meereissensitivitätsexperimenten kann beispielsweise ein selteneres Auftreten von Blockierungen über Westrussland detektiert werden. Eine in sich geschlossene physikalische Argumentation bezüglich der dynamisch und thermodynamisch induzierten Beiträge zu den detektierten Änderungen in der Häufigkeit von sommerlichen Hitzeextremen stellt jedoch weiterhin eine Herausforderung dar.

Im Vergleich zu anderen Aspekten des zukünftigen Klimawandels, wie beispielsweise dem thermodynamischen Einfluss global erhöhter Meeresoberflächentemperaturen, zeigt sich, dass die meereisinduzierten Auswirkungen auf europäische Temperaturextreme wahrscheinlich von untergeordneter Bedeutung sind.
Nichtsdestotrotz können die Ergebnisse dieser Arbeit zu einem besseren Verständnis gegenwärtiger und zeitnah zu erwartender Änderungen von Temperaturextremereignissen über Europa beitragen.
Zusätzlich dazu bietet die vorliegende Arbeit eine nützliche und ergänzende Perspektive auf die wissenschaftliche Fragestellung, inwieweit der Arktische Klimawandel mit Änderungen in der atmosphärischen Zirkulation und Extremereignissen über den mittleren Breiten in Verbindung gebracht werden kann. Folglich trägt diese Arbeit damit dazu bei einem allgemeinen Konsens in diesem  stark debattierten Forschungsgebiet einen Schritt näher zu kommen.
KW  - extreme events
KW  - Arctic sea ice
KW  - circulation regimes
KW  - atmosphere
KW  - climate change
KW  - Extremereignisse
KW  - arktisches Meereis
KW  - Zirkulationsregime
KW  - Klimawandel
KW  - Atmosphäre
KW  - large-scale circulation
KW  - großskalige Zirkulation
Y1  - 2023
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-604883
ER  - 
TY  - THES
A1  - Li, Zhen
T1  - Formation of Sub-Permafrost Methane Hydrate Reproduced by Numerical Modeling
BT  - Insights from LArge-scale Reservoir Simulator (LARS) to Mallik Site, Canadian Arctic
N2  - Natural gas hydrates are ice-like crystalline compounds containing water cavities that trap natural gas molecules like methane (CH4), which is a potent greenhouse gas with high energy density. The Mallik site at the Mackenzie Delta in the Canadian Arctic contains a large volume of technically recoverable CH4 hydrate beneath the base of the permafrost. Understanding how the sub-permafrost hydrate is distributed can aid in searching for the ideal locations for deploying CH4 production wells to develop the hydrate as a cleaner alternative to crude oil or coal. Globally, atmospheric warming driving permafrost thaw results in sub-permafrost hydrate dissociation, releasing CH4 into the atmosphere to intensify global warming. It is therefore crucial to evaluate the potential risk of hydrate dissociation due to permafrost degradation. To quantitatively predict hydrate distribution and volume in complex sub-permafrost environments, a numerical framework was developed to simulate sub-permafrost hydrate formation by coupling the equilibrium CH4-hydrate formation approach with a fluid flow and transport simulator (TRANSPORTSE). In addition, integrating the equations of state describing ice melting and forming with TRANSPORTSE enabled this framework to simulate the permafrost evolution during the sub-permafrost hydrate formation. A modified sub-permafrost hydrate formation mechanism for the Mallik site is presented in this study. According to this mechanism, the CH4-rich fluids have been vertically transported since the Late Pleistocene from deep overpressurized zones via geologic fault networks to form the observed hydrate deposits in the Kugmallit–Mackenzie Bay Sequences. The established numerical framework was verified by a benchmark of hydrate formation via dissolved methane. Model calibration was performed based on laboratory data measured during a multi-stage hydrate formation experiment undertaken in the LArge scale Reservoir Simulator (LARS). As the temporal and spatial evolution of simulated and observed hydrate saturation matched well, the LARS model was therefore validated. This laboratory-scale model was then upscaled to a field-scale 2D model generated from a seismic transect across the Mallik site. The simulation confirmed the feasibility of the introduced sub-permafrost hydrate formation mechanism by demonstrating consistency with field observations. The 2D model was extended to the first 3D model of the Mallik site by using well-logs and seismic profiles, to investigate the geologic controls on the spatial hydrate distribution. An assessment of this simulation revealed the hydraulic contribution of each geological element, including relevant fault networks and sedimentary sequences. Based on the simulation results, the observed heterogeneous distribution of sub-permafrost hydrate resulted from the combined factors of the source-gas generation rate, subsurface temperature, and the permeability of geologic elements. Analysis of the results revealed that the Mallik permafrost was heated by 0.8–1.3 °C, induced by the global temperature increase of 0.44 °C and accelerated by Arctic amplification from the early 1970s to the mid-2000s. This study presents a numerical framework that can be applied to study the formation of the permafrost-hydrate system from laboratory to field scales, across timescales ranging from hours to millions of years. Overall, these simulations deepen the knowledge about the dominant factors controlling the spatial hydrate distribution in sub-permafrost environments with heterogeneous geologic elements. The framework can support improving the design of hydrate formation experiments and provide valuable contributions to future industrial hydrate exploration and exploitation activities.
N2  - Gashydrate sind eisähnliche kristalline Verbindungen, die Moleküle wie Methan (CH4) in Hohlräumen einschließen. Die Mallik-Lagerstätte im Mackenzie-Delta in der kanadischen Arktis enthält ein großes Volumen an technisch förderbarem CH4-Hydrat unter dem Permafrostboden. Das Verständnis, wie die Hydrate verteilt sind, kann bei der Suche nach idealen Standorten für Förderbohrungen zu ihrer Erschließung als saubere Alternative zu Erdöl oder Kohle helfen. Weltweit führt die Erwärmung der Atmosphäre zum Auftauen des Permafrosts und zur Zersetzung der Hydrate, wodurch CH4 in die Atmosphäre freigesetzt und die globale Erwärmung verstärkt wird. Es ist also entscheidend, das potenzielle Risiko der Hydratauflösung aufgrund der Permafrostdegradation zu bewerten.
Um die Verteilung und das Volumen von Hydraten in komplexen Sub-Permafrost Umgebungen quantitativ vorherzusagen, wurde ein numerischer Ansatz zur Simulation entwickelt. Hierzu wurde der Gleichgewichtsansatz für die CH4-Hydratbildung mit einem Strömungs- und Transportsimulator (TRANSPORTSE) kombiniert. Die zusätzliche Integrierung der Zustandsgleichungen, die das Schmelzen und die Bildung von Eis beschreiben, ermöglichte die Simulation der Permafrostentwicklung während der Hydratbildung. Für den Standort Mallik wird ein modifizierter Bildungsmechanismus in dieser Studie beschrieben. Demzufolge wurden die CH4-reichen Fluide seit dem späten Pleistozän aus tiefen Überdruckszonen vertikal über geologische Verwerfungssysteme transportiert, und haben die Hydratvorkommen gebildet.
Der numerische Ansatz wurde anhand eines Benchmarks zur Hydratbildung verifiziert. Messdaten eines mehrstufigen Hydratbildungsexperiments im LArge scale Reservoir Simulator (LARS) dienten zur Kalibrierung. Basierend auf der guten Übereinstimmung zwischen der simulierten und beobachteten Hydratsättigung, wurde das LARS-Modell validiert. Im Anschluss erfolgte die Übertragung auf ein 2D-Modell im Feldmaßstab, das mithilfe einer seismischen Transekte durch den Mallik-Standort erstellt wurde. Die Übereinstimmung mit den Feldbeobachtungen bestätigte den beschriebenen Mechanismus zur Hydratbildung unterhalb des Permafrosts. Das 2D-Modell wurde basierend auf Bohrlochprotokollen und seismischen Profilen zum ersten 3D-Modell des Mallik-Standorts erweitert, um die geologischen Einflüsse auf die Hydratverteilung zu untersuchen. Die Auswertung verdeutlichte den Beitrag jedes geologischen Elements zum hydraulischen System, einschließlich relevanter Verwerfungssysteme und sedimentärer Abfolgen. Die beobachtete heterogene räumliche Verteilung der Hydrate ist auf die Gasproduktionsrate der Quelle, die Untergrundtemperatur und die Durchlässigkeit der geologischen Einheiten zurückzuführen. Die Analyse der Ergebnisse ergab, dass der Mallik-Permafrost um 0,8–1,3 °C erwärmt wurde, was durch den globalen Temperaturanstieg von 0,44 °C verursacht und durch die sogenannte polare Verstärkung seit Anfang der 1970er bis Mitte der 2000er Jahre beschleunigt wurde.
Der in dieser Studie entwickelte numerische Ansatz zur Bildung von Permafrost-Hydrat-Systemen kann vom Labor- bis zum Feldmaßstab und über Zeitskalen von Stunden bis zu Millionen von Jahren angewendet werden. Mit den Simulationen konnten die dominierenden Faktoren identifiziert werden, welche die räumliche Hydratverteilung in Umgebungen mit heterogenen geologischen Strukturen steuern. Der Ansatz kann die Planung von Hydratbildungsexperimenten verbessern und einen wertvollen Beitrag für zukünftige industrielle Hydraterkundungen- und -erschließungen leisten.
T2  - Bildung von Sub-Permafrost-Methanhydraten dargestellt durch numerische Modellierung: Erkenntnisse aus dem LArge-sclae Reservoir Simulator (LARS), angewandt auf den Mallik-Standort, Kanadische Arktis
KW  - methane hydrate
KW  - geologic fault
KW  - numerical simulation
KW  - hydrate formation
KW  - climate change
KW  - Mackenzie Delta
KW  - Mackenzie-Delta
KW  - Klimawandel
KW  - geologische Verwerfung
KW  - Hydratbildung
KW  - Methanhydrat
KW  - numerische Simulation
Y1  - 2023
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-603302
ER  - 
TY  - THES
A1  - Mtilatila, Lucy Mphatso Ng'ombe
T1  - Climate change effects on drought, freshwater availability and hydro-power generation in an African environment
T1  - Auswirkungen des Klimawandels auf Dürre, Wasserverfügbarkeit und Wasserkrafterzeugung in einer tropischen afrikanischen Region
BT  - observations and projections for the Lake Malawi and Shire River Basins in Malawi
BT  - Datenanalysen und Projektionen für die Einzugsgebiete des Malawi-Sees und des Shire-Flusses in Malawi
N2  - The work is designed to investigate the impacts and sensitivity of climate change on water resources, droughts and hydropower production in Malawi, the South-Eastern region which is highly vulnerable to climate change. It is observed that rainfall is decreasing and temperature is increasing which calls for the understanding of what these changes may impact the water resources, drought occurrences and hydropower generation in the region. The study is conducted in the Greater Lake Malawi Basin (Lake Malawi and Shire River Basins) and is divided into three projects. The first study is assessing the variability and trends of both meteorological and hydrological droughts from 1970-2013 in Lake Malawi and Shire River basins using the standardized precipitation index (SPI) and standardized precipitation and evaporation Index (SPEI) for meteorological droughts and the lake level change index (LLCI) for hydrological droughts. And later the relationship of the meteorological and hydrological droughts is established.
While the second study extends the drought analysis into the future by examining the potential future meteorological water balance and associated drought characteristics such as the drought intensity (DI), drought months (DM), and drought events (DE) in the Greater Lake Malawi Basin. The sensitivity of drought to changes of rainfall and temperature is also assessed using the scenario-neutral approach. The climate change projections from 20 Coordinated Regional Climate Downscaling Experiment (CORDEX) models for Africa based on two scenarios (RCP4.5 and RCP8.5) for the periods 2021–2050 and 2071–2100 are used. The study also investigates the effect of bias-correction (i.e., empirical quantile mapping) on the ability of the climate model ensemble in reproducing observed drought characteristics as compared to raw climate projections.
The sensitivity of key hydrologic variables and hydropower generation to climate change in Lake Malawi and Shire River basins is assessed in third study. The study adapts the mesoscale Hydrological Model (mHM) which is applied separately in the Upper Lake Malawi and Shire River basins. A particular Lake Malawi model, which focuses on reservoir routing and lake water balance, has been developed and is interlinked between the two basins. Similar to second study, the scenario-neutral approach is also applied to determine the sensitivity of climate change on water resources more particularly Lake Malawi level and Shire River flow which later helps to estimate the hydropower production susceptibility.
Results suggest that meteorological droughts are increasing due to a decrease in precipitation which is exacerbated by an increase in temperature (potential evapotranspiration). The hydrological system of Lake Malawi seems to have a >24-month memory towards meteorological conditions since the 36-months SPEI can predict hydrological droughts ten-months in advance. The study has found the critical lake level that would trigger hydrological drought to be 474.1 m.a.s.l.
Despite the differences in the internal structures and uncertainties that exist among the climate models, they all agree on an increase of meteorological droughts in the future in terms of higher DI and longer events (DM). DI is projected to increase between +25% and +50% during 2021-2050 and between +131% and +388% during 2071-2100. This translates into +3 to +5, and +7 to +8 more drought months per year during both periods, respectively. With longer lasting drought events, DE is decreasing. Projected droughts based on RCP8.5 are 1.7 times more severe than droughts based on RCP4.5.
It is also found that an annual temperature increase of 1°C decreases mean lake level and outflow by 0.3 m and 17%, respectively, signifying the importance of intensified evaporation for Lake Malawi’s water budget. Meanwhile, a +5% (-5%) deviation in annual rainfall changes mean lake level by +0.7 m (-0.6 m). The combined effects of temperature increase and rainfall decrease result in significantly lower flows on Shire River. The hydrological river regime may change from perennial to seasonal with the combination of annual temperature increase and precipitation decrease beyond 1.5°C (3.5°C) and -20% (-15%). The study further projects a reduction in annual hydropower production between 1% (RCP8.5) and 2.5% (RCP4.5) during 2021–2050 and between 5% (RCP4.5) and 24% (RCP8.5) during 2071–2100.
The findings are later linked to global policies more particularly the United Nations Framework Convention on Climate Change (UNFCCC)’s Paris Agreement and the United Nations (UN)’s Sustainable Development Goals (SDGs), and how the failure to adhere the restriction of temperature increase below the global limit of 1.5°C will affect drought and the water resources in Malawi consequently impact the hydropower production. As a result, the achievement of most of the SDGs will be compromised. 
The results show that it is of great importance that a further development of hydro energy on the Shire River should take into account the effects of climate change. The information generation is important for decision making more especially supporting the climate action required to fight against climate change. The frequency of extreme climate events due to climate change has reached the climate emergency as saving lives and livelihoods require urgent action.
N2  - Ziel der Arbeit ist es, die Auswirkungen und die Sensitivität des Klimawandels auf die Wasser¬ressourcen, Dürren und die Wasserkrafterzeugung in Malawi zu untersuchen, einer Region im Südosten Afrikas, die besonders anfällig für den Klimawandel ist. Es ist zu beobachten, dass die Niederschläge abnehmen und die Temperaturen steigen, was Untersuchungen nahelegt, inwiefern sich diese Veränderungen auf die Wasserressourcen, Dürren und die Wasserkraft¬erzeugung in der Region auswirken können. Die Studie wird im Flussgebiet des Malawi-Sees (Einzugsgebiet des Malawi-Sees und des Shire-Flusses) durchgeführt und ist in drei Projekte unterteilt. In der ersten Studie werden die Variabilität und die Trends von meteorologischen und hydrologischen Dürren im Zeitraum 1970-2013 im Malawi-See- und Shire-Flusseinzugs¬gebiet anhand des standardisierten Niederschlagsindexes (SPI) und des standardisierten Niederschlags- und Verdunstungsindexes (SPEI) für meteorologische Dürren und des Indexes für die Veränderung des Seespiegels (LLCI) für hydrologische Dürren untersucht. Anschließend wird der Zusammenhang zwischen meteorologischen und hydrologischen Dürren hergestellt. 
In der zweiten Studie wird die Dürreanalyse in die Zukunft ausgedehnt, indem die potenzielle künftige meteorologische Wasserbilanz und die damit verbundenen Dürremerkmale wie Dürre¬intensität (DI), Dürremonate (DM) und Dürreereignisse (DE) im Einzugsgebiet des Malawisees untersucht werden. Die Empfindlichkeit der Dürre gegenüber Veränderungen der Nieder¬schlags¬menge und der Temperatur wird anhand des „Szenario-neutralen“ Ansatzes bewertet. Es werden die Projektionen des Klimawandels aus 20 „Coordinated Regional Climate Downscaling Experiment“	 Modellen für Afrika auf der Grundlage von zwei Szenarien (RCP4.5 und RCP8.5) für die Zeiträume 2021-2050 und 2071-2100 verwendet. Die Studie untersucht auch die Auswirkung der Fehlerkorrektur (via „empirical quantile mapping) auf die Möglichkeit des Klimamodell-Ensembles, beobachtete Dürrecharakteristika im Vergleich zu den Originaldaten der Klimaprojektionen wieder¬zugeben. 
In der dritten Studie wird die Sensitivität der wichtigsten hydrologischen Variablen und der Wasserkrafterzeugung auf den Klimawandel in den Einzugsgebieten des Malawi-Sees und des Shire-Flusses untersucht. In der Studie wird das meso-skalige hydrologische Modell (mHM) angepasst, welches in den Einzugsgebieten des Malawisees und des Shire-Flusses getrennt angewendet wird. Ein spezielles Modell für den Malawisee, welches sich auf die Wellenver¬formung im See und dessen Wasserbilanz, wurde entwickelt und wurde mit den beiden Einzugsgebieten gekoppelt. Ähnlich wie in der zweiten Studie wird auch hier der Szenario-neutrale Ansatz angewandt, um die Sensitivität des Klimawandels auf die Wasserressourcen zu bestimmen, insbesondere auf den Wasserstand im Malawisee und den Durchfluss des Shire-Flusses, was später zur Abschätzung der Anfälligkeit der Wasserkraft-produktion nötig ist.

Die Ergebnisse lassen erwarten, dass meteorologische Dürren aufgrund von Niederschlags-rückgang zunehmen, was durch einen Temperaturanstieg (und dadurch erhöhte Verdunstung) noch verschärft wird. Das hydrologische System des Malawi-Sees scheint ein >24-monatiges „meteorologisches Gedächtnis“ zu haben, da mit den 36-monatigen SPEI-Indizes, hydrologische Dürren zehn Monate im Voraus vorhersagbar sind. Die Studie ergab zudem, dass der kritische Seespiegel zur Auslösung hydrologische Dürren bei 474,1 m+NN liegt. 
Trotz der Unterschiede in internen Strukturen und Unsicherheiten der verschiedenen Klimamodelle, stimmen sie darin überein, dass meteorologische Dürren in der Zukunft in Form von höheren DI und längeren Ereignissen (DM) zunehmen werden. Die DI würde im Zeitraum 2021-2050 um +25 % bis +50 % und im Zeitraum 2071-2100 um +131 % bis +388 % zunehmen. Dies bedeutet 3 bis 5 bzw. 7 bis 8 Dürremonate mehr pro Jahr in beiden Zeiträumen. Bei länger anhaltenden Dürreereignissen nehmen die DE ab. Die prognostizierten Dürren auf der Grundlage des RCP8.5 sind 1,7-mal schwerer als die Dürren auf der Grundlage des RCP4.5. 
Es wird auch festgestellt, dass ein jährlicher Temperaturanstieg von 1°C den mittleren See-spiegel und den Abfluss um 0,3 m bzw. 17 % verringert, was auf die Bedeutung einer verstärk¬ten Verdunstung für den Wasserhaushalt des Malawisees hinweist. Eine Abweichung von +5 % (-5 %) bei den jährlichen Niederschlägen verändert den mittleren Seespiegel um +0,7 m (-0,6 m). Die kombinierten Auswir¬kungen des Temperaturanstiegs und des Niederschlagsrück¬gangs führen zu einem deutlich geringeren Durchfluss im Shire River. Das hydrologische Regime des Flusses kann sich bei einer Kombination aus jährlicher Temperaturerhöhung und Niederschlagsabnahme um mehr als 1,5°C (3,5°C) und -20% (-15%) von mehrjährig zu saisonal ändern. Die Studie prognostiziert ferner einen Rückgang der jährlichen Wasserkraft¬produktion zwischen 1 % (RCP8.5) und 2,5 % (RCP4.5) im Zeitraum 2021-2050 und zwischen 5 % (RCP4.5) und 24 % (RCP8.5) im Zeitraum 2071-2100. 
Die Ergebnisse werden letztlich mit der globalen Politik in Verbindung gebracht, insbesondere mit dem Pariser Abkommen des Rahmenübereinkommens der Vereinten Nationen über Klima-änderungen (UNFCCC) und den Zielen für nachhaltige Entwicklung (SDGs) der Vereinten Nationen (UN). Zudem damit, wie sich die Nichteinhaltung der Begrenzung des Temperatur-anstiegs auf 1,5°C auf die Dürre und die Wasserressourcen in Malawi auswirken wird, was wiederum Auswirkungen auf die Wasserkraftproduktion hat. Infolgedessen wird die Erreichung der meisten SDGs gefährdet sein. 
Die Ergebnisse zeigen, dass es von großer Bedeutung ist, dass bei der weiteren Entwicklung der Wasserkraft am Shire River die Auswirkungen des Klimawandels berücksichtigt werden sollten. Die Generierung von Informationen ist wichtig für die Entscheidungsfindung, insbesondere für die Unterstützung von Klimaschutzmaßnahmen, die zur Bekämpfung des Klimawandels erforderlich sind. Die Häufigkeit extremer Klimaereignisse aufgrund des Klimawandels hat einen kritischen Punkt erreicht, so dass die Rettung von Leben und die Bewahrung der Lebensgrundlagen dringende Maßnahmen erfordert.
KW  - climate change
KW  - Klimaänderung
KW  - Malawi
KW  - water balance
KW  - Wasserbilanz
KW  - drought
KW  - Dürre
KW  - water resources
KW  - Wasserressourcen
Y1  - 2023
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-599298
ER  - 
TY  - JOUR
A1  - Marzetz, Vanessa
A1  - Spijkerman, Elly
A1  - Striebel, Maren
A1  - Wacker, Alexander
T1  - Phytoplankton community responses to interactions between light intensity, light variations, and phosphorus supply
JF  - Frontiers in Environmental Science
N2  - In a changing world, phytoplankton communities face a large variety of challenges including altered light regimes. These alterations are caused by more pronounced stratification due to rising temperatures, enhanced eutrophication, and browning of lakes. Community responses toward these effects can emerge as alterations in physiology, biomass, biochemical composition, or diversity. In this study, we addressed the combined effects of changes in light and nutrient conditions on community responses. In particular, we investigated how light intensity and variability under two nutrient conditions influence (1) fast responses such as adjustments in photosynthesis, (2) intermediate responses such as pigment adaptation and (3) slow responses such as changes in community biomass and species composition. Therefore, we exposed communities consisting of five phytoplankton species belonging to different taxonomic groups to two constant and two variable light intensity treatments combined with two levels of phosphorus supply. The tested phytoplankton communities exhibited increased fast reactions of photosynthetic processes to light variability and light intensity. The adjustment of their light harvesting mechanisms via community pigment composition was not affected by light intensity, variability, or nutrient supply. However, pigment specific effects of light intensity, light variability, and nutrient supply on the proportion of the respective pigments were detected. Biomass was positively affected by higher light intensity and nutrient concentrations while the direction of the effect of variability was modulated by light intensity. Light variability had a negative impact on biomass at low, but a positive impact at high light intensity. The effects on community composition were species specific. Generally, the proportion of green algae was higher under high light intensity, whereas the cyanobacterium performed better under low light conditions. In addition to that, the diatom and the cryptophyte performed better with high nutrient supply while the green algae as well as the cyanobacterium performed better at low nutrient conditions. This shows that light intensity, light variability, and nutrient supply interactively affect communities. Furthermore, the responses are highly species and pigment specific, thus to clarify the effects of climate change a deeper understanding of the effects of light variability and species interactions within communities is important.
KW  - phytoplankton communities
KW  - light variability
KW  - photosynthetic rate
KW  - climate change
KW  - resource competition
KW  - light intensity (irradiance)
KW  - pigment composition
KW  - nutrient supply
Y1  - 2020
U6  - https://doi.org/10.3389/fenvs.2020.539733
SN  - 2296-665X
VL  - 8
PB  - Frontiers Media
CY  - Lausanne
ER  - 
TY  - THES
A1  - Courtin, Jérémy
T1  - Biodiversity changes in Siberia between quaternary glacial and interglacial stages
T1  - Veränderungen der Biodiversität in Sibirien zwischen Quartären Glazial- und Interglazialphasen
BT  - exploring the potential of sedaDNA
BT  - das Potenzial von sedaDNA erforschen
N2  - Der vom Menschen verursachte Klimawandel wirkt sich auf die biologische Vielfalt der Erde und damit auf die Ökosysteme und ihre Leistungen aus. Die Ökosysteme in den hohen Breitengraden sind aufgrund der verstärkten Erwärmung an den Polen noch stärker betroffen als der Rest der nördlichen Hemisphäre. Dennoch ist es schwierig, die Dynamik von Ökosystemen in den hohen Breitengraden vorherzusagen, da die Wechselwirkungen zwischen abiotischen und biotischen Komponenten sehr komplex sind. Da die Vergangenheit der Schlüssel zur Zukunft ist, ist die Interpretation vergangener ökologischer Veränderungen möglich, um laufende Prozesse besser zu verstehen. Im Quartär durchlief das Pleistozän mehrere glaziale und interglaziale Phasen, welche die Ökosysteme der Vergangenheit beeinflussten. Während des letzten Glazials bedeckte die pleistozäne Steppentundra den größten Teil der unvergletscherten nördlichen Hemisphäre und verschwand parallel zum Aussterben der Megafauna am Übergang zum Holozän (vor etwa 11 700 Jahren). Der Ursprung des Rückgangs der Steppentundra ist nicht gut erforscht, und die Kenntnis über die Mechanismen, die zu den Veränderungen in den vergangenen Lebensgemeinschaften und Ökosystemen geführt haben, ist von hoher Priorität, da sie wahrscheinlich mit denen vergleichbar sind, die sich auf moderne Ökosysteme auswirken. Durch die Entnahme von See- oder Permafrostkernsedimenten kann die vergangene Artenvielfalt an den Übergängen zwischen Eis- und Zwischeneiszeiten untersucht werden. Sibirien und Beringia waren der Ursprung der Ausbreitung der Steppentundra, weshalb die Untersuchung dieses Gebiets hohe Priorität hat. Bis vor kurzem waren Makrofossilien und Pollen die gängigsten Methoden. Sie dienen der Rekonstruktion vergangener Veränderungen in der Zusammensetzung der Bevölkerung, haben aber ihre Grenzen und Schwächen. Seit Ende des 20. Jahrhunderts kann auch sedimentäre alte DNA (sedaDNA) untersucht werden. Mein Hauptziel war es, durch den Einsatz von sedaDNA-Ansätzen wissenschaftliche Beweise für Veränderungen in der Zusammensetzung und Vielfalt der Ökosysteme der nördlichen Hemisphäre am Übergang zwischen den quartären Eiszeiten und Zwischeneiszeiten zu liefern.
In dieser Arbeit liefere ich Momentaufnahmen ganzer alter Ökosysteme und beschreibe die Veränderungen in der Zusammensetzung zwischen Quartärglazialen und Interglazialen und bestätige die Vegetationszusammensetzung sowie die räumlichen und zeitlichen Grenzen der pleistozänen Steppentundra. Ich stelle einen allgemeinen Verlust der Pflanzenvielfalt fest, wobei das Aussterben der Pflanzen parallel zum Aussterben der Megafauna verlief. Ich zeige auf, wie der Verlust der biotischen Widerstandsfähigkeit zum Zusammenbruch eines zuvor gut etablierten Systems führte, und diskutiere meine Ergebnisse im Hinblick auf den laufenden Klimawandel. Mit weiteren Arbeiten zur Eingrenzung von Verzerrungen und Grenzen kann sedaDNA parallel zu den etablierteren Makrofossilien- und Pollenansätzen verwendet werden oder diese sogar ersetzen, da meine Ergebnisse die Robustheit und das Potenzial von sedaDNA zur Beantwortung neuer paläoökologischer Fragen wie Veränderungen der Pflanzenvielfalt und -verluste belegen und Momentaufnahmen ganzer alter Biota liefern.
N2  - Climate change of anthropogenic origin is affecting Earth’s biodiversity and therefore ecosystems and their services. High latitude ecosystems are even more impacted than the rest of Northern Hemisphere because of the amplified polar warming. Still, it is challenging to predict the dynamics of high latitude ecosystems because of complex interaction between abiotic and biotic components. As the past is the key to the future, the interpretation of past ecological changes to better understand ongoing processes is possible. In the Quaternary, the Pleistocene experienced several glacial and interglacial stages that affected past ecosystems. During the last Glacial, the Pleistocene steppe-tundra was covering most of unglaciated northern hemisphere and disappeared in parallel to the megafauna’s extinction at the transition to the Holocene (~11,700 years ago). The origin of the steppe-tundra decline is not well understood and knowledge on the mechanisms, which caused shifts in past communities and ecosystems, is of high priority as they are likely comparable to those affecting modern ecosystems. Lake or permafrost core sediments can be retrieved to investigate past biodiversity at transitions between glacial and interglacial stages. Siberia and Beringia were the origin of dispersal of the steppe-tundra, which make investigation this area of high priority. Until recently, macrofossils and pollen were the most common approaches. They are designed to reconstruct past composition changes but have limit and biases. Since the end of the 20th century, sedimentary ancient DNA (sedaDNA) can also be investigated. My main objectives were, by using sedaDNA approaches to provide scientific evidence of compositional and diversity changes in the Northern Hemisphere ecosystems at the transition between Quaternary glacial and interglacial stages.
In this thesis, I provide snapshots of entire ancient ecosystems and describe compositional changes between Quaternary glacial and interglacial stages, and confirm the vegetation composition and the spatial and temporal boundaries of the Pleistocene steppe-tundra. I identify a general loss of plant diversity with extinction events happening in parallel of megafauna’ extinction. I demonstrate how loss of biotic resilience led to the collapse of a previously well-established system and discuss my results in regards to the ongoing climate change. With further work to constrain biases and limits, sedaDNA can be used in parallel or even replace the more established macrofossils and pollen approaches as my results support the robustness and potential of sedaDNA to answer new palaeoecological questions such as plant diversity changes, loss and provide snapshots of entire ancient biota.
KW  - sedaDNA
KW  - pleistocene
KW  - paleoecology
KW  - climate change
KW  - holocene
KW  - Siberia
KW  - sedaDNA
KW  - Pleistozän
KW  - Paläoökologie
KW  - Holozän
KW  - Klimawandel
KW  - Sibirien
Y1  - 2023
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-595847
ER  - 
TY  - JOUR
A1  - Wolf, Sabina
A1  - Pham, My
A1  - Matthews, Nathanial
A1  - Bubeck, Philip
T1  - Understanding the implementation gap
BT  - policy-makers’ perceptions of ecosystem-based adaptation in Central Vietnam
JF  - Climate & development
N2  - In recent years, nature-based solutions are receiving increasing attention in the field of disaster risk reduction and climate change adaptation as inclusive, no regret approaches. Ecosystem-based adaptation (EbA) can mitigate the impacts of climate change, build resilience and tackle environmental degradation thereby supporting the targets set by the 2030 Agenda, the Paris Agreement and the Sendai Framework. Despite these benefits, EbA is still rarely implemented in practice. To better understand the barriers to implementation, this research examines policy-makers' perceptions of EbA, using an extended version of Protection Motivation Theory as an analytical framework. Through semi-structured interviews with policy-makers at regional and provincial level in Central Vietnam, it was found that EbA is generally considered a promising response option, mainly due to its multiple ecosystem-service benefits. The demand for EbA measures was largely driven by the perceived consequences of natural hazards and climate change. Insufficient perceived response efficacy and time-lags in effectiveness for disaster risk reduction were identified as key impediments for implementation. Pilot projects and capacity building on EbA are important means to overcome these perceptual barriers. This paper contributes to bridging the knowledge-gap on political decision-making regarding EbA and can, thereby, promote its mainstreaming into policy plans.
KW  - climate change
KW  - ecosystem-based adaptation
KW  - risk perception
KW  - protection
KW  - motivation theory
KW  - decision making
Y1  - 2020
U6  - https://doi.org/10.1080/17565529.2020.1724068
SN  - 1756-5529
SN  - 1756-5537
VL  - 13
IS  - 1
SP  - 81
EP  - 94
PB  - Taylor & Francis LTD
CY  - Abingdon
ER  - 
TY  - THES
A1  - Campos de Andrade, André Luiz
T1  - Governing climate change in Brazil
T1  - Steuerung des Klimawandels in Brasilien
BT  - a governance gap analysis of selected cases
BT  - eine Analyse von Governance-Lücken an ausgewählten Fällen
N2  - Enacted in 2009, the National Policy on Climate Change (PNMC) is a milestone in the institutionalisation of climate action in Brazil. It sets greenhouse gas (GHG) emission reduction targets and a set of principles and directives that are intended to lay the foundations for a cross-sectoral and multilevel climate policy in the country. However, after more than a decade since its establishment, the PNMC has experienced several obstacles related to its governance, such as coordination, planning and implementation issues. All of these issues pose threats to the effectiveness of GHG mitigation actions in the country.
By looking at the intragovernmental and intergovernmental relationships that have taken place during the lifetime of the PNMC and its sectoral plans on agriculture (the Sectoral Plan for Mitigation and Adaptation to Climate Change for the Consolidation of a Low-Carbon Economy in Agriculture [ABC Plan]), transport and urban mobility (the Sectoral Plan for Transportation and Urban Mobility for Mitigation and Adaption of Climate Change [PSTM]), this exploratory qualitative research investigates the Brazilian climate change governance guided by the following relevant questions: how are climate policy arrangements organised and coordinated among governmental actors to mitigate GHG emissions in Brazil? What might be the reasons behind how such arrangements are established? What are the predominant governance gaps of the different GHG mitigation actions examined? Why do these governance gaps occur? 
Theoretically grounded in the literature on multilevel governance and coordination of public policies, this study employs a novel analytical framework that aims to identify and discuss the occurrence of four types of governance gaps (i.e. politics, institutions and processes, resources and information) in the three GHG mitigation actions (cases) examined (i.e. the PNMC, ABC Plan and PSTM). The research results are twofold. First, they reveal that Brazil has struggled to organise and coordinate governmental actors from different policy constituencies and different levels of government in the implementation of the GHG mitigation actions examined. Moreover, climate policymaking has mostly been influenced by the Ministry of Environment (MMA) overlooking the multilevel and cross-sectoral approaches required for a country’s climate policy to mitigate and adapt to climate change, especially if it is considered an economy-wide Nationally Determined Contribution (NDC), as the Brazilian one is. 
Second, the study identifies a greater manifestation of gaps in politics (e.g. lack of political will in supporting climate action), institutions and processes (e.g. failures in the design of institutions and policy instruments, coordination and monitoring flaws, and difficulties in building climate federalism) in all cases studied. It also identifies that there have been important advances in the production of data and information for decision-making and, to a lesser extent, in the allocation of technical and financial resources in the cases studied; however, it is necessary to highlight the limitation of these improvements due to turf wars, a low willingness to share information among federal government players, a reduced volume of financial resources and an unequal distribution of capacities among the federal ministries and among the three levels of government.
A relevant finding is that these gaps tend to be explained by a combination of general and sectoral set aspects. Regarding the general aspects, which are common to all cases examined, the following can be mentioned: i) unbalanced policy capabilities existing among the different levels of government, ii) a limited (bureaucratic) practice to produce a positive coordination mode within cross-sectoral policies, iii) the socioeconomic inequalities that affect the way different governments and economic sectors perceive the climate issue (selective perception) and iv) the reduced dialogue between national and subnational governments on the climate agenda (poor climate federalism). The following sectoral aspects can be mentioned: i) the presence of path dependencies that make the adoption of transformative actions harder and ii) the absence of perceived co-benefits that the climate agenda can bring to each economic sector (e.g. reputational gains, climate protection and access to climate financial markets).
By addressing the theoretical and practical implications of the results, this research provides key insights to tackle the governance gaps identified and to help Brazil pave the way to achieving its NDCs and net-zero targets. At the theoretical level, this research and the current country’s GHG emissions profile suggest that the Brazilian climate policy is embedded in a cross-sectoral and multilevel arena, which requires the effective involvement of different levels of political and bureaucratic powers and the consideration of the country’s socioeconomic differences. Thus, the research argues that future improvements of the Brazilian climate policy and its governance setting must frame climate policy as an economic development agenda, the ramifications of which go beyond the environmental sector. An initial consequence of this new perspective may be a shift in the political and technical leadership from the MMA to the institutions of the centre of government (Executive Office of the President of Brazil) and those in charge of the country’s economic policy (Ministry of Economy). This change could provide greater capacity for coordination, integration and enforcement as well as for addressing certain expected gaps (e.g. financial and technical resources). It could also lead to greater political prioritisation of the agenda at the highest levels of government. Moreover, this shift of the institutional locus could contribute to greater harmonisation between domestic development priorities and international climate politics. Finally, the research also suggests that this approach would reduce bureaucratic elitism currently in place due to climate policy being managed by Brazilian governmental institutions, which is still a theme of a few ministries and a reason for the occurrence of turf wars.
N2  - Das 2009 verabschiedete nationale Klimagesetz (PNMC) war ein Meilenstein für die Institutionalisierung von Klimaschutzmaßnahmen in Brasilien. Es legt die Ziele für die Reduzierung der Treibhausgasemissionen (THG) sowie eine Reihe von Grundsätzen und Richtlinien fest, die die Grundlage für eine sektorübergreifende und mehrstufige Klimapolitik im Land bilden. Mehr als ein Jahrzehnt nach seiner in Kraftsetzung stößt das PNMC jedoch auf verschiedene Hindernisse in Zusammenhang mit seiner Ausführung, wie z. B. die Koordination, Planung und Umsetzung. All diese Probleme gefährden fortwährend die Wirksamkeit der Maßnahmen zur Verringerung der Treibhausgasemissionen im Land.
Durch die Untersuchung der inner- und zwischenstaatlichen Beziehungen, die seit des Bestehens des PNMC und den damit einhergehenden Sektorplänen für Landwirtschaft (Sektorplan zur Minderung und Anpassung an den Klimawandel für die Konsolidierung einer kohlenstoffarmen Wirtschaft in der Landwirtschaft - ABC-Plan)und für Verkehr und urbane Mobilität (Sektorplan für den Verkehr und die urbane Mobilität zur Minderung und Anpassung an den Klimawandel - PSTM) , untersucht die vorliegende  explorative qualitative Forschung die Governance der brasilianischen Klimapolitik anhand der folgenden relevanten Fragestellungen: Wie sind die klimapolitischen Maßnahmen zur Minderung der Treibhausgasemissionen in Brasilien organisiert und zwischen den staatlichen Akteuren koordiniert? Was könnten die Gründe für die Art und Weise der gewählten Organisationsform sein? Was sind die vorherrschenden Governance-Lücken bei den untersuchten THG-Minderungsmaßnahmen? Was sind die Gründe für die Entstehung dieser Lücken?  
Auf der theoretischen Grundlage der Literatur über Multi-Level-Governance und über die Koordinierung öffentlicher Maßnahmen wird in dieser Studie ein neuartiger analytischer Rahmen verwendet, der darauf abzielt, das Auftreten von vier Arten von Governance-Lücken (Politik, Institutionen & Prozesse, Ressourcen und Informationen) in den drei untersuchten THG-Minderungsmaßnahmenbündeln (PNMC, ABC-Plan und PSTM) zu identifizieren und zu diskutieren. Dabei konnten im Ergebnis zwei wesentliche Governance-Lücken identifiziert werden. 
Erstens zeigt die Studie, dass sich Brasilien schwer tut, Regierungsakteure aus verschiedenen Politikbereichen und von verschiedenen Regierungsebenen zu organisieren und zu koordinieren, um die betrachteten THG-Minderungsmaßnahmen umzusetzen. Gleichzeitig wird die Klimapolitik hauptsächlich vom Umweltministerium (MMA) gestaltet, das die für eine Klimapolitik erforderlichen Mehrebenen- und sektorübergreifenden Ansätze zur Minderung und Anpassung s Landes an den Klimawandel vernachlässigt, insbesondere da es sich - wie in Brasilien - um einen wirtschaftübergreifendes (economy wide), national festgelegten Beitrag (NDC) handelt. 
Zweitens stellt die Studie fest, dass sich in allen untersuchten Fällen immer größer werdende Lücken in der Politik (z. B. mangelnder politischer Wille zur Unterstützung von Klimaschutzmaßnahmen), in den Institutionen und Prozessen (z. B. Versäumnisse beim Design von Institutionen und politischen Instrumenten; Koordinierungs- und Überwachungsmängel; Schwierigkeiten beim Aufbau eines „Klimaföderalismus“) zu beobachten sind. Gleichwohl zeigen die Erkenntnisse aus den untersuchten Fällen, dass es auch wichtige Fortschritte bei der Erhebung von Daten und Informationen für eine Entscheidungsfindung und - in geringerem Maße - bei der Zuweisung technischer und finanzieller Ressourcen gegeben hat. Dennoch ist es notwendig, die Begrenztheit dieser Verbesserungen zu benennen, die auf Kompetenzstreitigkeiten, eine geringe Bereitschaft zum Informationsaustausch zwischen den Akteuren der Bundesregierung, ein geringes Volumen an finanziellen Ressourcen und eine ungleiche Verteilung der Personalkapazitäten zwischen den Bundesministerien und zwischen den drei Regierungsebenen zurückzuführen sind.
Eine wesentliche Erkenntnis der vorliegenden Arbeit ist, dass die zuvor beschriebenen Lücken vorwiegend durch eine Kombination von allgemeinen und sektoralen Aspekten zu erklären sind. Zu den allgemeinen Aspekten, die in allen untersuchten Fällen identifiziert wurden, gehören: i) unausgewogene politische Kapazitäten zwischen den verschiedenen Regierungsebenen; ii) eine mangelnde Verwaltungspraxis zur Schaffung eines positiven Koordinationsmodus innerhalb sektorübergreifender Politiken; iii) die sozioökonomischen Ungleichheiten, die sich auf die Art und Weise auswirken, wie verschiedene Regierungen und Wirtschaftssektoren das Klimaproblem wahrnehmen (selektive Wahrnehmung); iv) der eingeschränkte Dialog zwischen nationalen und subnationalen Regierungsebenen über die Klimaagenda (schwacher  „Klimaföderalismus“). Als sektorale Aspekte können genannt werden: i) das Vorhandensein von Pfadabhängigkeiten, die die Befürwortung von transformativen Maßnahmen erschweren; und ii) der (unzureichend) wahrgenommene Zusatznutzen, den die Klimaagenda jedem Wirtschaftssektor bringen kann (z. B. Reputationsgewinn, Klimaschutz, Zugang zu Klima-Finanzmärkten).
Indem die Forschungsarbeit die theoretischen und praktischen Implikationen der Ergebnisse anspricht, liefert sie wichtige Erkenntnisse, um die identifizierten Governance-Lücken zu schließen und Brasilien dabei zu helfen, den Weg zur Erreichung seiner NDCs und Netto-Null-Ziele zu gestalten. Auf theoretischer Ebene und vor dem Hintergrund des aktuellen Treibhausgasemissionsprofils des Landes empfiehlt die vorliegende Arbeit, dass die brasilianische Klimapolitik als eine sektorübergreifende und vielschichtige politische Agenda implementiert wird, die eine effektive Beteiligung verschiedener politischer und Verwaltungs- Ebenen sowie eine Berücksichtigung der sozioökonomischen Unterschiede des Landes erfordert. Daher argumentiert die Studie, dass künftige Verbesserungen der brasilianischen Klimapolitik und ihrer Rahmenbedingungen, die Klimapolitik als eine wirtschaftliche Entwicklungsagenda verstehen müssen, deren Auswirkungen über den Umweltsektor hinausgehen. Eine erste Konsequenz dieser neuen Perspektive ist eine Verlagerung der politischen und technischen Führung vom MMA zu den Institutionen des Regierungszentrums (Casa Civil) und der Wirtschaftspolitik des Landes (Wirtschaftsministerium). Dieser Wechsel könnte größere Kapazitäten für die Koordinierung, Integration und den Vollzug, sowie für die Schließung bestimmter erwarteter Lücken (z. B. finanzielle und technische Ressourcen) schaffen. Sie könnte auch zu einer stärkeren politischen Priorisierung der Agenda auf den höchsten Regierungsebenen führen. Außerdem könnte diese Veränderung der institutionellen Verankerung zu einer stärkeren Harmonisierung zwischen den nationalen Entwicklungsprioritäten und der internationalen Klimapolitik beitragen. Schließlich deutet die Untersuchung auch darauf hin, dass dieser Ansatz die bisherige verwaltungstechnische Zentralisierung reduzieren würde, da die Umsetzung der Klimapolitik in den brasilianischen Regierungsinstitutionen immer noch ein Thema einiger weniger Ministerien ist und mit Ressortstreitigkeiten einhergeht.
KW  - climate governance
KW  - climate policy
KW  - Brazil
KW  - climate change
KW  - Brasilien
KW  - Klimawandel
KW  - Klimagovernance
KW  - Klimapolitik
Y1  - 2023
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-587336
ER  - 
TY  - THES
A1  - Leins, Johannes A.
T1  - Combining model detail with large scales
T1  - Die Verbindung von Modelldetails und großen Skalen
BT  - a simulation framework for population viability analyses in changing and disturbed environments
BT  - ein Simulationswerkzeug zur Analyse der Überlebensfähigkeit von Populationen in einer sich verändernden und gestörten Umwelt
N2  - The global climate crisis is significantly contributing to changing ecosystems, loss of biodiversity and is putting numerous species on the verge of extinction. In principle, many species are able to adapt to changing conditions or shift their habitats to more suitable regions. However, change is progressing faster than some species can adjust, or potential adaptation is blocked and disrupted by direct and indirect human action. Unsustainable anthropogenic land use in particular is one of the driving factors, besides global heating, for these ecologically critical developments. Precisely because land use is anthropogenic, it is also a factor that could be quickly and immediately corrected by human action.
In this thesis, I therefore assess the impact of three climate change scenarios of increasing intensity in combination with differently scheduled mowing regimes on the long-term development and dispersal success of insects in Northwest German grasslands. The large marsh grasshopper (LMG, Stethophyma grossum, Linné 1758) is used as a species of reference for the analyses. It inhabits wet meadows and marshes and has a limited, yet fairly good ability to disperse. Mowing and climate conditions affect the development and mortality of the LMG differently depending on its life stage.
The specifically developed simulation model HiLEG (High-resolution Large Environmental
Gradient) serves as a tool for investigating and projecting viability and dispersal success under different climate conditions and land use scenarios. It is a spatially explicit, stage- and cohort-based model that can be individually configured to represent the life cycle and characteristics of terrestrial insect species, as well as high-resolution environmental data and the occurrence of external disturbances. HiLEG is a freely available and adjustable software that can be used to support conservation planning in cultivated grasslands.
In the three case studies of this thesis, I explore various aspects related to the structure of simulation models per se, their importance in conservation planning in general, and insights regarding the LMG in particular. It became apparent that the detailed resolution of model processes and components is crucial to project the long-term effect of spatially and temporally confined events. Taking into account conservation measures at the regional level has further proven relevant, especially in light of the climate crisis. I found that the LMG is benefiting from global warming in principle, but continues to be constrained by harmful mowing regimes. Land use measures could, however, be adapted in such a way that they allow the expansion and establishment of the LMG without overly affecting agricultural yields.
Overall, simulation models like HiLEG can make an important contribution and add value
to conservation planning and policy-making. Properly used, simulation results shed light
on aspects that might be overlooked by subjective judgment and the experience of individual stakeholders. Even though it is in the nature of models that they are subject to limitations and only represent fragments of reality, this should not keep stakeholders from using them, as long as these limitations are clearly communicated. Similar to HiLEG, models could further be designed in such a way that not only the parameterization can be adjusted as required, but also the implementation itself can be improved and changed as desired. This openness and flexibility should become more widespread in the development of simulation models.
N2  - Die globale Klimakrise trägt maßgeblich dazu bei, dass sich Ökosysteme verändern, die Artenvielfalt sinkt und zahlreiche Spezies vom Aussterben bedroht sind. Viele Arten sind prinzipiell in der Lage, sich wandelnden Bedingungen anzugleichen oder ihre Habitate in geeignetere Regionen zu verlagern. Allerdings schreitet der Wandel schneller voran als sich einige Spezies anpassen können oder die mögliche Anpassung wird durch direkte und indirekte menschliche Eingriffe blockiert und gestört. Gerade die nicht-nachhaltige Landnutzung durch den Menschen ist neben der Klimaerhitzung einer der treibenden Faktoren für diese ökologisch kritischen Entwicklungen. Gleichzeitig ist sie durch ihre unmittelbare menschliche Ursache ein Faktor, der sich kurzfristig und schnell korrigieren ließe.
Zu diesem Zweck untersuche ich in dieser Dissertation, wie sich drei Klimawandelszenarien ansteigender Intensität im Zusammenspiel mit unterschiedlich terminierten Mahdregimen im Nordwestdeutschen Grünland auf die langfristige Entwicklung und Ausbreitung von Insekten auswirken. In der Untersuchung fungiert die Sumpfschrecke (Stethophyma grossum, Linné 1758) als Bezugsspezies. Sie ist in Feucht- und Nasswiesen zu Hause und zu räumlicher Ausbreitung fähig, auch wenn sie nur eingeschränkt mobil ist. Mahd und Klimabedingungen wirken sich je nach Lebensstadium unterschiedlich stark auf die Entwicklung und Mortalität der Sumpfschrecke aus.
Das eigens entwickelte Simulationsmodell HiLEG (High-resolution Large Environmental Gradient) dient als Werkzeug zur Untersuchung und Projektion der Überlebens- und Ausbreitungswahrscheinlichkeit unter verschiedenen Klima- und Landnutzungsszenarien. Es ist ein räumlich explizites, stadien- und kohortenbasiertes Modell, das individuell konfiguriert werden kann, um den Lebenszyklus und die Charakteristiken terrestrischer Insektenarten sowie hochaufgelöste Umweltdaten und das zeitlich variierende Auftreten externer Störfaktoren abzubilden. HiLEG ist eine frei verfügbare Software und kann zur Unterstützung bei der Planung von Umweltschutzmaßnahmen in kultiviertem Grünland verwendet werden.
In den drei Fallstudien dieser Arbeit habe ich verschiedene Aspekte in Bezug auf die Struktur von Simulationsmodellen an sich, deren Bedeutung im Naturschutz im Allgemeinen und Erkenntnisse für die Sumpfschrecke im Speziellen untersucht. Es zeigte sich, dass die detaillierte Auflösung der Modellprozesse und -komponenten entscheidend ist, um den langfristigen Effekt räumlich und zeitlich begrenzter Ereignisse projizieren zu können. Insbesondere in Anbetracht der Klimakrise hat sich die gesteigerte Relevanz von Naturschutzmaßnahmen auf regionaler Ebene herausgestellt. Ich konnte außerdem bestätigen, dass die Sumpfschrecke zwar im Prinzip von der Klimaerwärmung profitiert, aber weiterhin durch ungeeignete Mahdregime beschränkt wird. Bewirtschaftungspläne könnten allerdings in dem Sinne angepasst werden, dass sie die Ausbreitung und Etablierung der Sumpfschrecke erlauben, ohne sich über die Maßen auf den Ertrag der Landwirtschaft auszuwirken.
Insgesamt können Simulationsmodelle wie HiLEG einen wichtigen Beitrag und Mehrwert für die Planung von Naturschutzmaßnahmen und Politikinstrument leisten. Richtig eingesetzt beleuchten die Simulationsergebnisse Aspekte, die durch subjektive Bewertung und Erfahrung einzelner Akteure möglicherweise übersehen würden. Auch wenn es in der Natur von Modellen liegt, dass sie Einschränkungen unterworfen sind und nur Ausschnitte der Realität abbilden, sollte dies kein Hindernis für ihren Einsatz sein, solange diese Limitierungen klar kommuniziert werden.
Analog zu HiLEG könnten Modelle so konzipiert werden, dass nicht nur ihre Parametrisierung nach Bedarf angepasst, sondern auch die Implementierung selbst beliebig verbessert und verändert werden kann. Diese Offenheit und Flexibilität sollte sich bei der Entwicklung von Simulationsmodelle stärker durchsetzen.
KW  - spatially explicit model
KW  - large marsh grasshopper
KW  - simulation framework
KW  - climate change
KW  - land use
KW  - Open Source
KW  - Open Access
KW  - dispersal
KW  - PVA (population viability analysis)
KW  - high resolution
KW  - scaling
KW  - grassland
KW  - disturbance timing
KW  - Klimawandel
KW  - Ausbreitung
KW  - Zeitpunkt von Störungen
KW  - Grünland
KW  - hohe Auflösung
KW  - Landnutzung
KW  - Sumpfschrecke
KW  - Open Access
KW  - Open Source
KW  - Populationsgefährdungsanalyse
KW  - Skalierung
KW  - Simulationsframework
KW  - räumlich explizites Modell
KW  - Stethophyma grossum
Y1  - 2023
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-582837
ER  - 
TY  - THES
A1  - Rikani, Albano
T1  - Modeling global human migration dynamics under climate change
N2  - International migration has been an increasing phenomenon during the past decades and has involved all the regions of the globe. Together with fertility and mortality rates, net migration rates represent the components that fully define the demographic evolution of the population in a country. Therefore, being able to capture the patterns of international migration flows and to produce projections of how they might change in the future is of relevant importance for demographic studies and for designing policies informed on the potential scenarios. Existing forecasting methods do not account explicitly for the main drivers and processes shaping international migration flows: existing migrant communities at the destination country, termed diasporas, would reduce the costs of migration and facilitate the settling for new migrants, ultimately producing a positive feedback; accounting for the heterogeneity in the type of migration flows, e.g. return and transit Ćows, becomes critical in some specific bilateral migration channels; in low- to middle- income countries economic development could relax poverty constraint and result in an increase of emigration rates.
Economic conditions at both origin and destination are identified as major drivers of international migration. At the same time, climate change impacts have already appeared on natural and human-made systems such as the economic productivity. These economic impacts might have already produced a measurable effect on international migration flows. Studies that provide a quantification of the number of migration moves that might have been affected by climate change are usually specific to small regions, do not provide a mechanistic understanding of the pathway leading from climate change to migration and restrict their focus to the effective induced flows, disregarding the impact that climate change might have had in inhibiting other flows.
Global climate change is likely to produce impacts on the economic development of the countries during the next decades too. Understanding how these impacts might alter future global migration patterns is relevant for preparing future societies and understanding whether the response in migration flows would reduce or increase population's exposure to climate change impacts.
This doctoral research aims at investigating these questions and fill the research gaps outlined above. First, I have built a global bilateral international migration model which accounts explicitly for the diaspora feedback, distinguishes between transit and return flows, and accounts for the observed non-linear effects that link emigration rates to income levels in the country of origin. I have used this migration model within a population dynamic model where I account also for fertility and mortality rates, producing hindcasts and future projections of international migration flows, covering more than 170 countries. Results show that the model reproduces past patterns and trends well. Future projections highlight the fact that,depending on the assumptions regarding future evolution of income levels and between-country inequality, migration at the end of the century might approach net zero or be still high in many countries. The model, parsimonious in the explanatory variables that includes, represents a versatile tool for assessing the impacts of different socioeconomic scenarios on international migration.
I consider then a counterfactual past without climate change impacts on the economic productivity. By prescribing these counterfactual economic conditions to the migration model I produce counterfactual migration flows for the past 30 years. I compare the counterfactual migration flows to factual ones, where historical economic conditions are used to produce migration flows. This provides an estimation of the recent international migration flows attributed to climate change impacts. Results show that a counterfactual world without climate change would have seen less migration globally. This effect becomes larger if I consider separately the increase and decrease in migration moves: a Ągure of net change in the migration flows is not representative of the effective magnitude of the climate change impact on migration. Indeed, in my results climate change produces a divergent effect on richer and poorer countries: by slowing down the economic development, climate change might have reduced international mobility from and to countries of the Global South, and increased it from and to richer countries in the Global North.
I apply the same methodology to a scenario of future 3℃ global warming above pre-industrial conditions. I Ąnd that climate change impacts, acting by reorganizing the relative economic attractiveness of destination countries or by affecting the economic growth in the origin, might produce a substantial effect in international migration flows, inhibiting some moves and inducing others.
Overall my results suggest that climate change might have had and might have in the future a significant effect on global patterns of international migration. It also emerges clearly that, for a comprehensive understanding of the effects of climate change on international migration, we need to go beyond net effects and consider separately induced and inhibited flows.
N2  - Die internationale Migration ist in den letzten Jahrzehnten ein zunehmendes Phänomen, das alle Regionen der Welt betrifft. Die wirtschaftlichen Bedingungen sowohl im Herkunftsals auch im Zielland gelten als wichtige Triebkräfte der internationalen Migration. Die wirtschaftlichen Auswirkungen des Klimawandels haben sich in der Vergangenheit bereits messbar auf die internationalen Migrationsströme ausgewirkt, und künftige Auswirkungen werden dies wahrscheinlich ebenfalls tun.
Diese Dissertation zielt darauf ab, dieses Thema zu untersuchen. Zunächst habe ich ein globales bilaterales internationales Migrationsmodell entwickelt, das explizit die wichtigsten Triebkräfte der internationalen Migration berücksichtigt. Ich habe dieses Migrationsmodell für die Erstellung retrospektiver und zukünftiger Projektionen der internationalen Migrationsströme weltweit verwendet. Die Ergebnisse zeigen, dass das Modell die Muster und Trends der Vergangenheit gut wiedergibt, und die Zukunftsprojektionen verdeutlichen, dass je nach den Annahmen über die künftige Entwicklung des Einkommensniveaus und der Ungleichheit zwischen den Ländern die Migration gegen Null gehen oder in vielen Ländern bis zum Ende des Jahrhunderts noch hoch sein könnte.
Anschließend betrachte ich eine kontrafaktische Vergangenheit, in der der Klimawandel keine Auswirkungen auf die wirtschaftliche Produktivität hat. Ich vergleiche die kontrafaktischen Migrationsströme mit den faktischen Strömen. Die Ergebnisse zeigen, dass es in einer kontrafaktischen Welt ohne Klimawandel weniger globale Migration gegeben hätte. Dieser Effekt wird sogar noch größer, wenn ich den Anstieg und den Rückgang der Migrationsströme getrennt betrachte.
Ich wende dieselbe Methodik auf ein Szenario einer zukünftigen globalen Erwärmung von 3℃ über den vorindustriellen Bedingungen an. Ich komme zu dem Schluss, dass die Folgen des Klimawandels erhebliche Auswirkungen auf die internationalen Migrationsströme haben könnten, indem sie die relative wirtschaftliche Attraktivität der Zielländer verändern oder das Wirtschaftswachstum in den Herkunftsländern beeinträchtigen, wodurch einige Wanderungen verhindert und andere ausgelöst werden.
Insgesamt deuten meine Ergebnisse darauf hin, dass der Klimawandel möglicherweise erhebliche Auswirkungen auf die globalen Muster der internationalen Migration hatte und auch weiterhin haben wird. Es wird auch deutlich, dass wir, um die Auswirkungen des Klimawandels auf die internationale Migration vollständig zu verstehen, über die Nettoeffekte hinausgehen und die induzierten und gehemmten Ströme getrennt betrachten müssen.
KW  - climate change
KW  - international migration
KW  - macroeconomic impacts
KW  - international migration modeling
KW  - Klimawandel
KW  - internationale Migration
KW  - Modellierung der internationalen Migration
KW  - makroökonomische Folgen
Y1  - 2023
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-583212
ER  - 
TY  - JOUR
A1  - Šedová, Barbora
A1  - Kalkuhl, Matthias
T1  - Who are the climate migrants and where do they go?
BT  - Evidence from rural India
JF  - World development
N2  - In this paper, we move from the large strand of research that looks at evidence of climate migration to the questions: who are the climate migrants? and where do they go? These questions are crucial to design policies that mitigate welfare losses of migration choices due to climate change. We study the direct and heterogeneous associations between weather extremes and migration in rural India. We combine ERAS reanalysis data with the India Human Development Survey household panel and conduct regression analyses by applying linear probability and multinomial logit models. This enables us to establish a causal relationship between temperature and precipitation anomalies and overall migration as well as migration by destination. We show that adverse weather shocks decrease rural-rural and international migration and push people into cities in different, presumably more prosperous states. A series of positive weather shocks, however, facilitates international migration and migration to cities within the same state. Further, our results indicate that in contrast to other migrants, climate migrants are likely to be from the lower end of the skill distribution and from households strongly dependent on agricultural production. We estimate that approximately 8% of all rural-urban moves between 2005 and 2012 can be attributed to weather. This figure might increase as a consequence of climate change. Thus, a key policy recommendation is to take steps to facilitate integration of less educated migrants into the urban labor market.
KW  - climate change
KW  - migration
KW  - household analysis
KW  - India
KW  - econometrics
Y1  - 2020
U6  - https://doi.org/10.1016/j.worlddev.2019.104848
SN  - 0305-750X
SN  - 1873-5991
VL  - 129
PB  - Elsevier Science
CY  - Amsterdam
ER  - 
TY  - JOUR
A1  - Vindas-Picado, José
A1  - Yaney-Keller, Adam
A1  - St. Andrews, Laura
A1  - Panagopoulou, Aliki
A1  - Santidrián Tomillo, Pilar
T1  - Effectiveness of shading to mitigate the impact of high temperature on sea turtle clutches considering the effect on primary sex ratios
JF  - Mitigation and adaptation strategies for global change : an international journal devoted to scientific, engineering, socio-economic and policy responses to environmental change
N2  - Developmental success of sea turtle clutches depends on incubation temperature, which also determines sex ratio of hatchlings. As global temperatures are rising, several studies have proposed mitigation strategies such as irrigation and shading to increase hatching success. Our study expands upon this research and measures the effects of using boxes with different degrees of shade coverage (50%, 80%, and 90%) on sand temperature and water content. Boxes were fully covered with fabric in 2017/2018 (top and sides) but were side open in 2018/2019. We took measurements at olive ridley (Lepidochelys olivacea) and leatherback (Dermochelys coriacea) turtle nest depths (45 and 75 cm) at Playa Grande, Costa Rica. Shading reduced temperature by up to 0.8 degrees C and up to 0.4 degrees C at 45 cm and 75 cm, respectively. There were statistically significant differences between shading and control treatments at both depths, but differences between shade treatments were only significant when using side open boxes, possibly due to air flow. Shading had no effect on water content. While the impact of using shaded boxes on temperature was low, the potential impact on primary sex ratios was large. If shading were applied to leatherback clutches, the percentage of female hatchlings could vary by up to 50%, with a maximum difference around the pivotal temperature (temperature with 1:1 sex ratio). Shading can be useful to increase hatching success, but we recommend avoiding it at temperatures within the transitional range (temperatures that produce both sexes), or using it only during the last third of incubation, when sex is already determined. As global warming will likely continue, understanding potential impact and effectiveness of mitigation strategies may be critical for the survival of threatened sea turtle populations.
KW  - climate mitigation
KW  - climate change
KW  - hatchery
KW  - hatching success
KW  - TSD
Y1  - 2020
U6  - https://doi.org/10.1007/s11027-020-09932-3
SN  - 1381-2386
SN  - 1573-1596
VL  - 25
IS  - 8
SP  - 1509
EP  - 1521
PB  - Springer
CY  - Dordrecht
ER  - 
TY  - JOUR
A1  - Ungelenk, Johannes
T1  - Émile Zola and the literary language of climate change
JF  - Nottingham French studies / University of Nottingham
N2  - On 7 February 1861, John Tyndall, professor of natural philosophy, delivered a historical lecture: he could prove that different gases absorb heat to a very different degree, which implies that the temperate conditions provided for by the Earth's atmosphere are dependent on its particular composition of gases. The theoretical foundation of climate science was laid.

Ten years later, on the other side of the Channel, a young and ambitious author was working on a comprehensive literary analysis of the French era under the Second Empire. Émile Zola had probably not heard or read of Tyndall's discovery. However, the article makes the case for reading Zola's Rougon-Macquart as an extensive story of climate change. Zola's literary attempts to capture the defining characteristic of the Second Empire led him to the insight that its various milieus were all part of the same ‘climate’: that of an all-encompassing warming. Zola suggests that this climate is man-made: the economic success of the Second Empire is based on heating, in a literal and metaphorical sense, as well as on stoking the steam-engines and creating the hypertrophic atmosphere of the hothouse that enhances life and maximises turnover and profit. In contrast to Tyndall and his audience, Zola sensed the catastrophic consequences of this warming: the Second Empire was inevitably moving towards a final débâcle, i.e. it was doomed to perish in local and ‘global’ climate catastrophes.

The article foregrounds the supplementary status of Tyndall's physical and Zola's literary knowledge. As Zola's striking intuition demonstrates, literature appears to have a privileged approach to the phenomenon of man-induced climate change.
N2  - Le 7 février 1861, le professeur de philosophie naturelle John Tyndall donna une communication historique: il pouvait prouver que des gaz différents absorbent la chaleur de manière différente, ce qui implique que les conditions tempérées fournies par l’atmosphère terrestre dépendent de sa composition particulière en gaz. Le fondement théorique de la science climatique était posé. Dix ans plus tard, de l'autre côté du Channel, un jeune auteur ambitieux était en train de faire une analyse littéraire globale de la France du Second Empire. Émile Zola n'avait probablement pas entendu parler de la découverte de Tyndall. Cependant, cet article propose de lire les Rougon Macquart de Zola comme une vaste histoire du changement climatique. Les tentatives littéraires entreprises par Zola pour capturer la caractéristique déterminante du Second Empire l'amena à réaliser que ses différents milieux faisaient tous partie du même « climat »: celui d'un réchauffement global. Zola suggère que ce climat est créé par l'humain et que le succès économique du Second Empire est basé sur l'action de chauffer dans un sens littéral et métaphorique, ainsi que sur l'alimentation des machines à vapeur et la création de l'atmosphère hypertrophiée d'une serre qui enrichit la vie et maximise l'écoulement et le profit. Contrairement à Tyndall et à son auditoire, Zola pressentit les conséquences catastrophiques d'un tel réchauffement: le Second Empire s'approchait inévitablement d'une débâcle finale, c'est-à-dire qu'il était voué à périr dans des catastrophes locales et « globales ».
KW  - Rougon-Macquart
KW  - climate change
KW  - John Tyndall
KW  - global warming
KW  - climate catastrophe
KW  - Second Empire
KW  - changement climatique
KW  - réchauffement planétaire
KW  - catastrophe climatique
KW  - Rougon-Macquart
KW  - Second Empire
KW  - John Tyndall
Y1  - 2021
U6  - https://doi.org/10.3366/nfs.2021.0331
SN  - 0029-4586
SN  - 2047-7236
VL  - 60
IS  - 3
SP  - 362
EP  - 373
PB  - Edinburgh University Press
CY  - Edinburgh
ER  - 
TY  - JOUR
A1  - Skålevåg, Amalie
A1  - Vormoor, Klaus Josef
T1  - Daily streamflow trends in Western versus Eastern Norway and their attribution to hydro-meteorological drivers
JF  - Hydrological processes : an international journal
N2  - Regional warming and modifications in precipitation regimes has large impacts on streamflow in Norway, where both rainfall and snowmelt are important runoff generating processes. Hydrological impacts of recent changes in climate are usually investigated by trend analyses applied on annual, seasonal, or monthly time series. None of these detect sub-seasonal changes and their underlying causes. This study investigated sub-seasonal changes in streamflow, rainfall, and snowmelt in 61 and 51 catchments respectively in Western (Vestlandet) and Eastern (ostlandet) Norway by applying the Mann-Kendall test and Theil-Sen estimator on 10-day moving averaged daily time series over a 30-year period (1983-2012). The relative contribution of rainfall versus snowmelt to daily streamflow and the changes therein have also been estimated to identify the changing relevance of these driving processes over the same period. Detected changes in 10-day moving averaged daily streamflow were finally attributed to changes in the most important hydro-meteorological drivers using multiple-regression models with increasing complexity. Earlier spring flow timing in both regions occur due to earlier snowmelt. ostlandet shows increased summer streamflow in catchments up to 1100 m a.s.l. and slightly increased winter streamflow in about 50% of the catchments. Trend patterns in Vestlandet are less coherent. The importance of rainfall has increased in both regions. Attribution of trends reveals that changes in rainfall and snowmelt can explain some streamflow changes where they are dominant processes (e.g., spring snowmelt in ostlandet and autumn rainfall in Vestlandet). Overall, the detected streamflow changes can be best explained by adding temperature trends as an additional predictor, indicating the relevance of additional driving processes such as increased glacier melt and evapotranspiration.
KW  - attribution
KW  - climate change
KW  - hydrological change
KW  - hydro-meteorological
KW  - driver
KW  - streamflow trend
KW  - trend analysis
Y1  - 2021
U6  - https://doi.org/10.1002/hyp.14329
SN  - 0885-6087
SN  - 1099-1085
VL  - 35
IS  - 8
PB  - Wiley
CY  - New York
ER  - 
TY  - GEN
A1  - Mtilatila, Lucy Mphatso Ng'ombe
A1  - Bronstert, Axel
A1  - Vormoor, Klaus Josef
T1  - Temporal evaluation and projections of meteorological droughts in the Greater Lake Malawi Basin, Southeast Africa
T2  - Zweitveröffentlichungen der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe
N2  - The study examined the potential future changes of drought characteristics in the Greater Lake Malawi Basin in Southeast Africa. This region strongly depends on water resources to generate electricity and food. Future projections (considering both moderate and high emission scenarios) of temperature and precipitation from an ensemble of 16 bias-corrected climate model combinations were blended with a scenario-neutral response surface approach to analyses changes in: (i) the meteorological conditions, (ii) the meteorological water balance, and (iii) selected drought characteristics such as drought intensity, drought months, and drought events, which were derived from the Standardized Precipitation and Evapotranspiration Index. Changes were analyzed for a near-term (2021–2050) and far-term period (2071–2100) with reference to 1976–2005. The effect of bias-correction (i.e., empirical quantile mapping) on the ability of the climate model ensemble to reproduce observed drought characteristics as compared to raw climate projections was also investigated. Results suggest that the bias-correction improves the climate models in terms of reproducing temperature and precipitation statistics but not drought characteristics. Still, despite the differences in the internal structures and uncertainties that exist among the climate models, they all agree on an increase of meteorological droughts in the future in terms of higher drought intensity and longer events. Drought intensity is projected to increase between +25 and +50% during 2021–2050 and between +131 and +388% during 2071–2100. This translates into +3 to +5, and +7 to +8 more drought months per year during both periods, respectively. With longer lasting drought events, the number of drought events decreases. Projected droughts based on the high emission scenario are 1.7 times more severe than droughts based on the moderate scenario. That means that droughts in this region will likely become more severe in the coming decades. Despite the inherent high uncertainties of climate projections, the results provide a basis in planning and (water-)managing activities for climate change adaptation measures in Malawi. This is of particular relevance for water management issues referring hydro power generation and food production, both for rain-fed and irrigated agriculture.
T3  - Zweitveröffentlichungen der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe - 1287 
KW  - meteorological drought
KW  - drought intensity
KW  - climate change
KW  - drought events
KW  - Lake Malawi
KW  - Shire River
KW  - drought projections
KW  - South-Eastern Africa
Y1  - 2022
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-571284
SN  - 1866-8372
IS  - 1287
ER  - 
TY  - JOUR
A1  - Mtilatila, Lucy Mphatso Ng'ombe
A1  - Bronstert, Axel
A1  - Vormoor, Klaus Josef
T1  - Temporal evaluation and projections of meteorological droughts in the Greater Lake Malawi Basin, Southeast Africa
JF  - Frontiers in Water
N2  - The study examined the potential future changes of drought characteristics in the Greater Lake Malawi Basin in Southeast Africa. This region strongly depends on water resources to generate electricity and food. Future projections (considering both moderate and high emission scenarios) of temperature and precipitation from an ensemble of 16 bias-corrected climate model combinations were blended with a scenario-neutral response surface approach to analyses changes in: (i) the meteorological conditions, (ii) the meteorological water balance, and (iii) selected drought characteristics such as drought intensity, drought months, and drought events, which were derived from the Standardized Precipitation and Evapotranspiration Index. Changes were analyzed for a near-term (2021–2050) and far-term period (2071–2100) with reference to 1976–2005. The effect of bias-correction (i.e., empirical quantile mapping) on the ability of the climate model ensemble to reproduce observed drought characteristics as compared to raw climate projections was also investigated. Results suggest that the bias-correction improves the climate models in terms of reproducing temperature and precipitation statistics but not drought characteristics. Still, despite the differences in the internal structures and uncertainties that exist among the climate models, they all agree on an increase of meteorological droughts in the future in terms of higher drought intensity and longer events. Drought intensity is projected to increase between +25 and +50% during 2021–2050 and between +131 and +388% during 2071–2100. This translates into +3 to +5, and +7 to +8 more drought months per year during both periods, respectively. With longer lasting drought events, the number of drought events decreases. Projected droughts based on the high emission scenario are 1.7 times more severe than droughts based on the moderate scenario. That means that droughts in this region will likely become more severe in the coming decades. Despite the inherent high uncertainties of climate projections, the results provide a basis in planning and (water-)managing activities for climate change adaptation measures in Malawi. This is of particular relevance for water management issues referring hydro power generation and food production, both for rain-fed and irrigated agriculture.
KW  - meteorological drought
KW  - drought intensity
KW  - climate change
KW  - drought events
KW  - Lake Malawi
KW  - Shire River
KW  - drought projections
KW  - South-Eastern Africa
Y1  - 2022
U6  - https://doi.org/10.3389/frwa.2022.1041452
SN  - 2624-9375
SP  - 1
EP  - 16
PB  - Frontiers Media S.A.
CY  - Lausanne, Schweiz
ER  - 
TY  - JOUR
A1  - van Rees, Charles B.
A1  - Waylen, Kerry A.
A1  - Schmidt-Kloiber, Astrid
A1  - Thackeray, Stephen J.
A1  - Kalinkat, Gregor
A1  - Martens, Koen
A1  - Domisch, Sami
A1  - Lillebo, Ana
A1  - Hermoso, Virgilio
A1  - Grossart, Hans-Peter
A1  - Schinegger, Rafaela
A1  - Decleer, Kris
A1  - Adriaens, Tim
A1  - Denys, Luc
A1  - Jaric, Ivan
A1  - Janse, Jan H.
A1  - Monaghan, Michael T.
A1  - De Wever, Aaike
A1  - Geijzendorffer, Ilse
A1  - Adamescu, Mihai C.
A1  - Jähnig, Sonja C.
T1  - Safeguarding freshwater life beyond 2020
BT  - recommendations for the new global biodiversity framework from the European experience
JF  - Conservation letters
N2  - Plans are currently being drafted for the next decade of action on biodiversity-both the post-2020 Global Biodiversity Framework of the Convention on Biological Diversity (CBD) and Biodiversity Strategy of the European Union (EU). Freshwater biodiversity is disproportionately threatened and underprioritized relative to the marine and terrestrial biota, despite supporting a richness of species and ecosystems with their own intrinsic value and providing multiple essential ecosystem services. Future policies and strategies must have a greater focus on the unique ecology of freshwater life and its multiple threats, and now is a critical time to reflect on how this may be achieved. We identify priority topics including environmental flows, water quality, invasive species, integrated water resources management, strategic conservation planning, and emerging technologies for freshwater ecosystem monitoring. We synthesize these topics with decades of first-hand experience and recent literature into 14 special recommendations for global freshwater biodiversity conservation based on the successes and setbacks of European policy, management, and research. Applying and following these recommendations will inform and enhance the ability of global and European post-2020 biodiversity agreements to halt and reverse the rapid global decline of freshwater biodiversity.
KW  - climate change
KW  - conservation
KW  - ecosystem services
KW  - rivers
KW  - sustainable
KW  - development goals
KW  - water resources
KW  - wetlands
Y1  - 2020
U6  - https://doi.org/10.1111/conl.12771
SN  - 1755-263X
VL  - 14
IS  - 1
PB  - Wiley
CY  - Hoboken
ER  - 
TY  - JOUR
A1  - Pan, Xiaohui
A1  - Wang, Weishi
A1  - Liu, Tie
A1  - Huang, Yue
A1  - De Maeyer, Philippe
A1  - Guo, Chenyu
A1  - Ling, Yunan
A1  - Akmalov, Shamshodbek
T1  - Quantitative detection and attribution of groundwater level variations in the Amu Darya Delta
JF  - Water
N2  - In the past few decades, the shrinkage of the Aral Sea is one of the biggest ecological catastrophes caused by human activity. To quantify the joint impact of both human activities and climate change on groundwater, the spatiotemporal groundwater dynamic characteristics in the Amu Darya Delta of the Aral Sea from 1999 to 2017 were analyzed, using the groundwater level, climate conditions, remote sensing data, and irrigation information. Statistics analysis was adopted to analyze the trend of groundwater variation, including intensity, periodicity, spatial structure, while the Pearson correlation analysis and principal component analysis (PCA) were used to quantify the impact of climate change and human activities on the variabilities of the groundwater level. Results reveal that the local groundwater dynamic has varied considerably. From 1999 to 2002, the groundwater level dropped from -189 cm to -350 cm. Until 2017, the groundwater level rose back to -211 cm with fluctuation. Seasonally, the fluctuation period of groundwater level and irrigation water was similar, both were about 18 months. Spatially, the groundwater level kept stable within the irrigation area and bare land but fluctuated drastically around the irrigation area. The Pearson correlation analysis reveals that the dynamic of the groundwater level is closely related to irrigation activity within the irrigation area (Nukus: -0.583), while for the place adjacent to the Aral Sea, the groundwater level is closely related to the Large Aral Sea water level (Muynak: 0.355). The results of PCA showed that the cumulative contribution rate of the first three components exceeds 85%. The study reveals that human activities have a great impact on groundwater, effective management, and the development of water resources in arid areas is an essential prerequisite for ecological protection.
KW  - groundwater level variation
KW  - climate change
KW  - human activities
KW  - statistical analysis
KW  - Amu Darya Delta
Y1  - 2020
U6  - https://doi.org/10.3390/w12102869
SN  - 2073-4441
VL  - 12
IS  - 10
PB  - MDPI
CY  - Basel
ER  - 
TY  - JOUR
A1  - Tesselaar, Max
A1  - Botzen, W. J. Wouter
A1  - Haer, Toon
A1  - Hudson, Paul
A1  - Tiggeloven, Timothy
A1  - Aerts, Jeroen C. J. H.
T1  - Regional inequalities in flood insurance affordability and uptake under climate change
JF  - Sustainability
N2  - Flood insurance coverage can enhance financial resilience of households to changing flood risk caused by climate change. However, income inequalities imply that not all households can afford flood insurance. The uptake of flood insurance in voluntary markets may decline when flood risk increases as a result of climate change. This increase in flood risk may cause substantially higher risk-based insurance premiums, reduce the willingness to purchase flood insurance, and worsen problems with the unaffordability of coverage for low-income households. A socio-economic tipping-point can occur when the functioning of a formal flood insurance system is hampered by diminishing demand for coverage. In this study, we examine whether such a tipping-point can occur in Europe for current flood insurance systems under different trends in future flood risk caused by climate and socio-economic change. This analysis gives insights into regional inequalities concerning the ability to continue to use flood insurance as an instrument to adapt to changing flood risk. For this study, we adapt the "Dynamic Integrated Flood and Insurance" (DIFI) model by integrating new flood risk simulations in the model that enable examining impacts from various scenarios of climate and socio-economic change on flood insurance premiums and consumer demand. Our results show rising unaffordability and declining demand for flood insurance across scenarios towards 2080. Under a high climate change scenario, simulations show the occurrence of a socio-economic tipping-point in several regions, where insurance uptake almost disappears. A tipping-point and related inequalities in the ability to use flood insurance as an adaptation instrument can be mitigated by introducing reforms of flood insurance arrangements.
KW  - climate change
KW  - flood risk management
KW  - insurance
KW  - socio-economic
KW  - tipping-point
KW  - adaptation
KW  - partial equilibrium modeling
Y1  - 2020
U6  - https://doi.org/10.3390/su12208734
SN  - 2071-1050
VL  - 12
IS  - 20
PB  - MDPI
CY  - Basel
ER  - 
TY  - JOUR
A1  - Reibold, Kerstin
T1  - Settler Colonialism, Decolonization, and Climate Change
JF  - Journal of applied philosophy
N2  - The article proposes that climate change makes enduring colonial injustices and structures visible. It focuses on the imposition and dominance of colonial concepts of land and self-determination on Indigenous peoples in settler states. It argues that if the dominance of these colonial frameworks remains unaddressed, the progressing climate change will worsen other colonial injustices, too. Specifically, Indigenous self-determination capabilities will be increasingly undermined, and Indigenous peoples will experience the loss of what they understand as relevant land from within their own ontologies of land. The article holds that even if settler states strive to repair colonial injustices, these efforts will be unsuccessful if climate change occurs and decolonization is pursued within the framework of a settler colonial ontology of land. Therefore, the article suggests, decolonization of the ontologies of land and concepts of self-determination is a precondition for a just response to climate change.
KW  - territorial rights
KW  - indigenous rights
KW  - climate change
KW  - colonialism
Y1  - 2022
U6  - https://doi.org/10.1111/japp.12573
SN  - 0264-3758
SN  - 1468-5930
PB  - Wiley-Blackwell
CY  - Oxford
ER  - 
TY  - THES
A1  - Krummenauer, Linda
T1  - Global heat adaptation among urban populations and its evolution under different climate futures
T1  - Globale Hitzeanpassung urbaner Bevölkerungen und deren Entwicklung unter verschiedenen klimatischen Zukünften
N2  - Heat and increasing ambient temperatures under climate change represent a serious threat to human health in cities. Heat exposure has been studied extensively at a global scale. Studies comparing a defined temperature threshold with the future daytime temperature during a certain period of time, had concluded an increase in threat to human health. Such findings however do not explicitly account for possible changes in future human heat adaptation and might even overestimate heat exposure. Thus, heat adaptation and its development is still unclear. Human heat adaptation refers to the local temperature to which populations are adjusted to. It can be inferred from the lowest point of the U- or V-shaped heat-mortality relationship (HMR), the Minimum Mortality Temperature (MMT). While epidemiological studies inform on the MMT at the city scale for case studies, a general model applicable at the global scale to infer on temporal change in MMTs had not yet been realised. The conventional approach depends on data availability, their robustness, and on the access to daily mortality records at the city scale. Thorough analysis however must account for future changes in the MMT as heat adaptation happens partially passively. Human heat adaptation consists of two aspects: (1) the intensity of the heat hazard that is still tolerated by human populations, meaning the heat burden they can bear and (2) the wealth-induced technological, social and behavioural measures that can be employed to avoid heat exposure. The objective of this thesis is to investigate and quantify human heat adaptation among urban populations at a global scale under the current climate and to project future adaptation under climate change until the end of the century. To date, this has not yet been accomplished. The evaluation of global heat adaptation among urban populations and its evolution under climate change comprises three levels of analysis. First, using the example of Germany, the MMT is calculated at the city level by applying the conventional method. Second, this thesis compiles a data pool of 400 urban MMTs to develop and train a new model capable of estimating MMTs on the basis of physical and socio-economic city characteristics using multivariate non-linear multivariate regression. The MMT is successfully described as a function of the current climate, the topography and the socio-economic standard, independently of daily mortality data for cities around the world. The city-specific MMT estimates represents a measure of human heat adaptation among the urban population. In a final third analysis, the model to derive human heat adaptation was adjusted to be driven by projected climate and socio-economic variables for the future. This allowed for estimation of the MMT and its change for 3 820 cities worldwide for different combinations of climate trajectories and socio-economic pathways until 2100. The knowledge on the evolution of heat adaptation in the future is a novelty as mostly heat exposure and its future development had been researched. In this work, changes in heat adaptation and exposure were analysed jointly. A wide range of possible health-related outcomes up to 2100 was the result, of which two scenarios with the highest socio-economic developments but opposing strong warming levels were highlighted for comparison. Strong economic growth based upon fossil fuel exploitation is associated with a high gain in heat adaptation, but may not be able to compensate for the associated negative health effects due to increased heat exposure in 30% to 40% of the cities investigated caused by severe climate change. A slightly less strong, but sustainable growth brings moderate gains in heat adaptation but a lower heat exposure and exposure reductions in 80% to 84% of the cities in terms of frequency (number of days exceeding the MMT) and intensity (magnitude of the MMT exceedance) due to a milder global warming. Choosing a 2 ° C compatible development by 2100 would therefore lower the risk of heat-related mortality at the end of the century. In summary, this thesis makes diverse and multidisciplinary contributions to a deeper understanding of human adaptation to heat under the current and the future climate. It is one of the first studies to carry out a systematic and statistical analysis of urban characteristics which are useful as MMT drivers to establish a generalised model of human heat adaptation, applicable at the global level. A broad range of possible heat-related health options for various future scenarios was shown for the first time. This work is of relevance for the assessment of heat-health impacts in regions where mortality data are not accessible or missing. The results are useful for health care planning at the meso- and macro-level and to urban- and climate change adaptation planning. Lastly, beyond having met the posed objective, this thesis advances research towards a global future impact assessment of heat on human health by providing an alternative method of MMT estimation, that is spatially and temporally flexible in its application.
N2  - Hitze und steigende Umgebungstemperaturen im Zuge des Klimawandels stellen eine ernsthafte Bedrohung für die menschliche Gesundheit in Städten dar. Die Hitzeexposition wurde umfassend auf globaler Ebene untersucht. Studien, die eine definierte Temperaturschwelle mit der zukünftigen Tagestemperatur während eines bestimmten Zeitraums verglichen, hatten eine Zunahme der Gefährdung der menschlichen Gesundheit ergeben. Solche Ergebnisse berücksichtigen jedoch nicht explizit mögliche Veränderungen der zukünftigen menschlichen Hitzeadaption und könnten daher sogar die Hitzeexposition überschätzen. Somit ist die menschliche Adaption an Hitze und ihre zukünftige Entwicklung noch unklar. Die menschliche Hitzeadaption bezieht sich auf die lokale Temperatur, an die sich die Bevölkerung angepasst hat. Sie lässt sich aus dem Tiefpunkt der U- oder V-förmigen Relation zwischen Hitze und Mortalität (HMR), der Mortalitätsminimaltemperatur (MMT), ableiten. Während epidemiologische Fallstudien über die MMT auf Stadtebene informieren, wurde ein auf globaler Ebene anwendbares allgemeines Modell, um auf die zeitliche Veränderung der MMTs zu schließen, bisher noch nicht realisiert. Der konventionelle Ansatz ist abhängig von der Datenverfügbarkeit, ihrer Robustheit und dem Zugang zu täglichen Mortalitätsdaten auf Stadtebene. Eine gründliche Analyse muss jedoch zukünftige Veränderungen in der MMT berücksichtigen, da die menschliche Hitzeanpassung teils passiv erfolgt. Die menschliche Hitzeanpassung besteht aus zwei Aspekten: (1) aus der Intensität der Hitze, die von der menschlichen Bevölkerung noch toleriert wird, also die Hitzebelastung, die sie ertragen kann, und (2) aus vermögensbedingten technologischen, sozialen und verhaltensbezogenen Maßnahmen, die zur Vermeidung von Hitzeexposition eingesetzt werden können. Das Ziel dieser Arbeit ist es, die menschliche Hitzeanpassung der städtischen Bevölkerung unter dem aktuellen Klima auf globaler Ebene zu untersuchen und zu quantifizieren und die zukünftige Anpassung an den Klimawandel bis zum Ende des Jahrhunderts zu projizieren. Dies wurde bis heute noch nicht erreicht. Die Bewertung der globalen Hitzeanpassung städtischer Bevölkerungen und ihrer Entwicklung unter dem Klimawandel umfasst drei Analyseebenen. Erstens wird am Beispiel Deutschlands die MMT auf Stadtebene nach der konventionellen Methode berechnet. Zweitens trägt diese Arbeit einen Datenpool von 400 städtischen MMTs zusammen, um auf dessen Basis ein neues Modell zu entwickeln und zu trainieren, welches in der Lage ist, MMTs auf der Grundlage von physischen und sozioökonomischen Stadtmerkmalen mittels multivariater nichtlinearer multivariater Regression zu schätzen. Es wird gezeigt, dass die MMT als Funktion des aktuellen Klimas, der Topographie und des sozioökonomischen Standards beschrieben werden kann, unabhängig von täglichen Sterblichkeitsdaten für Städte auf der ganzen Welt. Die stadtspezifischen MMT-Schätzungen stellen ein Maß für die menschliche Hitzeanpassung der städtischen Bevölkerung dar. In einer letzten dritten Analyse wurde das Modell zur Schätzung der menschlichen Hitzeadaption angepasst, um von für die Zukunft projizierten Klima- und sozioökonomischen Variablen angetrieben zu werden. Dies ermöglichte eine Schätzung des MMT und seiner Veränderung für 3 820 Städte weltweit für verschiedene Kombinationen aus Klimatrajektorien und sozioökonomischen Entwicklungspfaden bis 2100. Das Wissen über die Entwicklung der menschlichen Hitzeanpassung in der Zukunft ist ein Novum, da bisher hauptsächlich die Hitzeexposition und ihre zukünftige Entwicklung erforscht wurden. In dieser Arbeit wurden die Veränderungen der menschlichen Hitzeadaptation und der Hitzeexposition gemeinsam analysiert. Das Ergebnis ist ein breites Spektrum möglicher gesundheitsbezogener Zukünfte bis 2100, von denen zum Vergleich zwei Szenarienkombinationen mit den höchsten sozioökonomischen Entwicklungen, aber gegensätzlichen starken Erwärmungsniveaus hervorgehoben wurden. Ein starkes Wirtschaftswachstum auf der Grundlage der Nutzung fossiler Brennstoffe fördert zwar einen hohen Zugewinn an Hitzeanpassung, kann jedoch die damit verbundenen negativen gesundheitlichen Auswirkungen aufgrund der erhöhten Exposition in rund 30% bis 40% der untersuchten Städte aufgrund eines starken Klimawandels möglicherweise nicht ausgleichen. Ein etwas weniger starkes, dafür aber nachhaltiges Wachstum bringt aufgrund einer milderen globalen Erwärmung eine moderate Hitzeanpassung und eine geringere Hitzeexposition und sogar eine Abnahme der Exposition in 80% bis 84% der Städte in Bezug auf Häufigkeit (Anzahl der Tage über der MMT) und Intensität (Magnitude der MMT-Überschreitung). Die Wahl einer 2 ° C-kompatiblen Entwicklung bis 2100 würde daher das Risiko einer hitzebedingten Sterblichkeit am Ende des Jahrhunderts senken. Zusammenfassend liefert diese Dissertation vielfältige und multidisziplinäre Beiträge zu einem tieferen Verständnis der menschlichen Hitzeanpassung unter dem gegenwärtigen und zukünftigen Klima. Es ist eine der ersten Studien, die eine systematische und statistische Analyse städtischer Merkmale durchführt, die sich als MMT-Treiber verwenden lassen, um ein verallgemeinertes Modell der menschlichen Hitzeanpassung zu erarbeiten, das auf globaler Ebene anwendbar ist. Erstmals wurde ein breites Spektrum möglicher hitzebedingter Gesundheitsoptionen für verschiedene Zukunftsszenarien aufgezeigt. Diese Arbeit ist von Bedeutung für die Bewertung von hitzebezogener Gesundheitsauswirkungen in Regionen, in denen Mortalitätsdaten nicht zugänglich sind oder fehlen. Die Ergebnisse sind nützlich für die Gesundheitsplanung auf Meso- und Makroebene sowie für die Stadtplanung und die Planung der Anpassung an den Klimawandel. Über das Erreichen des gestellten Ziels hinaus treibt diese Dissertation die Forschung in Richtung einer globalen zukünftigen Folgenabschätzung von Hitze auf die menschliche Gesundheit voran, indem eine alternative Methode der MMT-Schätzung bereitgestellt wird, die in ihrer Anwendung räumlich und zeitlich flexibel ist.
KW  - heat
KW  - adaptation
KW  - global
KW  - populations
KW  - climate change
KW  - temperature
KW  - mortality
KW  - minimum mortality temperature
KW  - projection
KW  - future
KW  - health
KW  - model
KW  - socio-economy
KW  - wealth
KW  - acclimatisation
KW  - Akklimatisierung
KW  - Anpassung
KW  - Hitzeanpassung
KW  - Klimawandel
KW  - Zukunft
KW  - global
KW  - Gesundheit
KW  - Hitze
KW  - Mortalitäts-Minimal-Temperatur
KW  - Modell
KW  - Mortalität
KW  - Bevölkerung
KW  - Projektion
KW  - Sozioökonomie
KW  - Temperatur
KW  - Wohlstand
KW  - exposure
KW  - hazard
KW  - cities
KW  - Exposition
KW  - Naturgefahr
KW  - Städte
Y1  - 2022
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-559294
ER  - 
TY  - THES
A1  - Kemter, Matthias
T1  - River floods in a changing world
T1  - Flusshochwasser in einer sich ändernden Welt
N2  - River floods are among the most devastating natural hazards worldwide. As their generation is highly dependent on climatic conditions, their magnitude and frequency are projected to be affected by future climate change. Therefore, it is crucial to study the ways in which a changing climate will, and already has, influenced flood generation, and thereby flood hazard. Additionally, it is important to understand how other human influences - specifically altered land cover - affect flood hazard at the catchment scale.

The ways in which flood generation is influenced by climatic and land cover conditions differ substantially in different regions. The spatial variability of these effects needs to be taken into account by using consistent datasets across large scales as well as applying methods that can reflect this heterogeneity. Therefore, in the first study of this cumulative thesis a complex network approach is used to find 10 clusters of similar flood behavior among 4390 catchments in the conterminous United States. By using a consistent set of 31 hydro-climatological and land cover variables, and training a separate Random Forest model for each of the clusters, the regional controls on flood magnitude trends between 1960-2010 are detected. It is shown that changes in rainfall are the most important drivers of these trends, while they are regionally controlled by land cover conditions.

While climate change is most commonly associated with flood magnitude trends, it has been shown to also influence flood timing. This can lead to trends in the size of the area across which floods occur simultaneously, the flood synchrony scale. The second study is an analysis of data from 3872 European streamflow gauges and shows that flood synchrony scales have increased in Western Europe and decreased in Eastern Europe. These changes are attributed to changes in flood generation, especially a decreasing relevance of snowmelt. Additionally, the analysis shows that both the absolute values and the trends of flood magnitudes and flood synchrony scales are positively correlated. If these trends persist in the future and are not accounted for, the combined increases of flood magnitudes and flood synchrony scales can exceed the capacities of disaster relief organizations and insurers.

Hazard cascades are an additional way through which climate change can influence different aspects of flood hazard. The 2019/2020 wildfires in Australia, which were preceded by an unprecedented drought and extinguished by extreme rainfall that led to local flooding, present an opportunity to study the effects of multiple preceding hazards on flood hazard. All these hazards are individually affected by climate change, additionally complicating the interactions within the cascade. By estimating and analyzing the burn severity, rainfall magnitude, soil erosion and stream turbidity in differently affected tributaries of the Manning River catchment, the third study shows that even low magnitude floods can pose a substantial hazard within a cascade.

This thesis shows that humanity is affecting flood hazard in multiple ways with spatially and temporarily varying consequences, many of which were previously neglected (e.g. flood synchrony scale, hazard cascades). To allow for informed decision making in risk management and climate change adaptation, it will be crucial to study these aspects across the globe and to project their trajectories into the future. The presented methods can depict the complex interactions of different flood drivers and their spatial variability, providing a basis for the assessment of future flood hazard changes. The role of land cover should be considered more in future flood risk modelling and management studies, while holistic, transferable frameworks for hazard cascade assessment will need to be designed.
N2  - Flusshochwasser gehören zu den verheerendsten Naturkatastrophen weltweit. Ihre Entstehung hängt von klimatischen Bedingungen ab, weshalb vorhergesagt wird, dass sich ihre Magnituden und Häufigkeit durch den Klimawandel ändern werden. Daher ist es notwendig zu untersuchen, auf welche Art sich ein verändertes Klima - auch im Vergleich mit Effekten durch Landbedeckungsänderungen - auf Hochwasserentstehung und -gefahr auswirken könnte und das bereits getan hat.

Diese kumulative Arbeit beleuchtet drei Teilaspekte dieses Themas. In der ersten Studie werden mittels maschinellen Lernens die wichtigsten Variablen entdeckt und untersucht, die die Änderungen von Hochwassermagnituden in 4390 Einzugsgebieten in den USA von 1960-2010 kontrolliert haben. Es wird gezeigt, dass Änderungen der Regenmengen der entscheidende Faktor waren, während Landnutzung regional von großer Bedeutung war. Die zweite Studie untersucht von 1960-2010 Änderungen in der Distanz innerhalb welcher Hochwasser in verschiedenen Flüssen gleichzeitig auftreten. Daten von 3872 europäischen Flusspegeln zeigen, dass sich die Fläche der gleichzeitigen Überflutung in Westeuropa vergrößert und in Osteuropa verkleinert hat, was auf abnehmende Relevanz der Schneeschmelze bei der Hochwasserentstehung zurückzuführen ist. Die dritte Studie behandelt die Auswirkungen kaskadierender Naturkatastrophen auf Hochwasser am Beispiel der australischen Waldbrände 2019/2020. Die Untersuchung der verschieden stark betroffenen Nebenflüsse des Manning River zeigt, dass in einer Naturgefahrenkaskade selbst gewöhnliche Hochwasser substantielle Auswirkungen haben können.

Diese Arbeit zeigt, dass die Menschheit Hochwassergefahren auf verschiedene Arten und mit räumlich sowie zeitlich variablen Resultaten beeinflusst. Diese Aspekte müssen zukünftig global näher untersucht und ihre Entwicklung für die Zukunft modelliert werden, um fundierte Entscheidungen in Hochwasserschutz treffen zu können. Für Hochwassermagnituden und die Fläche gleichzeitiger Überflutung können hierfür die präsentierten Methoden adaptiert werden.
KW  - hydrology
KW  - climate change
KW  - flood
KW  - Hydrologie
KW  - Klimawandel
KW  - Hochwasser
Y1  - 2022
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-558564
ER  - 
TY  - THES
A1  - Kahl, Sandra
T1  - Evolutionary adaptive responses to rapid climate change in plants
T1  - Evolutionäre Anpassungsstrategien von Pflanzen an den Klimawandel
BT  - a case study of the widely distributed species Silene vulgaris
BT  - ein Fallbeispiel der weit verbreiteten Art Silene vulgaris
N2  - The ongoing climate change is altering the living conditions for many organisms on this planet at an unprecedented pace. Hence, it is crucial for the survival of species to adapt to these changing conditions. In this dissertation Silene vulgaris is used as a model organism to understand the adaption strategies of widely distributed plant species to the current climate change. Especially plant species that possess a wide geographic range are expected to have a high phenotypic plasticity or to show genetic differentiation in response to the different climate conditions they grow in. However, they are often underrepresented in research.
In the greenhouse experiment presented in this thesis, I examined the phenotypic responses and plasticity in S. vulgaris to estimate its’ adaptation potential. Seeds from 25 wild European populations were collected along a latitudinal gradient and grown in a greenhouse under three different precipitation (65 mm, 75 mm, 90 mm) and two different temperature regimes (18°C, 21°C) that resembled a possible climate change scenario for central Europe. Afterwards different biomass and fecundity-related plant traits were measured. 
The treatments significantly influenced the plants but did not reveal a latitudinal difference in response to climate treatments for most plant traits. The number of flowers per individual however, showed a stronger plasticity in northern European populations (e.g., Swedish populations) where numbers decreased more drastically with increased temperature and decreased precipitation. 
To gain an even deeper understanding of the adaptation of S. vulgaris to climate change it is also important to reveal the underlying phylogeny of the sampled populations. Therefore, I analysed their population genetic structure through whole genome sequencing via ddRAD. 
The sequencing revealed three major genetic clusters in the S. vulgaris populations sampled in Europe: one cluster comprised Southern European populations, one cluster Western European populations and another cluster contained central European populations. A following analysis of experimental trait responses among the clusters to the climate-change scenario showed that the genetic clusters significantly differed in biomass-related traits and in the days to flowering. However, half of the traits showed parallel response patterns to the experimental climate-change scenario.  
In addition to the potential geographic and genetic adaptation differences to climate change this dissertation also deals with the response differences between the sexes in S. vulgaris. As a gynodioecious species populations of S. vulgaris consist of female and hermaphrodite  

individuals and the sexes can differ in their morphological traits which is known as sexual dimorphism. As climate change is becoming an important factor influencing plant morphology it remains unclear if and how different sexes may respond in sexually dimorphic species. To examine this question the sex of each individual plant was determined during the greenhouse experiment and the measured plant traits were analysed accordingly. In general, hermaphrodites had a higher number of flowers but a lower number of leaves than females. With regards to the climate change treatment, I found that hermaphrodites showed a milder negative response to higher temperatures in the number of flowers produced and in specific leaf area (SLA) compared to females. 
Synthesis – The significant treatment response in Silene vulgaris, independent of population origin in most traits suggests a high degree of universal phenotypic plasticity. Also, the three European intraspecific genetic lineages detected showed comparable parallel response patterns in half of the traits suggesting considerable phenotypic plasticity.  Hence, plasticity might represent a possible adaptation strategy of this widely distributed species during ongoing and future climatic changes. The results on sexual dimorphism show that females and hermaphrodites are differing mainly in their number of flowers and females are affected more strongly by the experimental climate-change scenario. These results provide a solid knowledge basis on the sexual dimorphism in S. vulgaris under climate change, but further research is needed to determine the long-term impact on the breeding system for the species. 
In summary this dissertation provides a comprehensive insight into the adaptation mechanisms and consequences of a widely distributed and gynodioecious plant species and leverages our understanding of the impact of anthropogenic climate change on plants.
N2  - Der derzeitige Klimawandel verändert die Lebensbedingungen für viele Tiere und Pflanzen auf unserem Planeten in nie da gewesenem Maße. Damit Arten überleben, ist es von besonderer Wichtigkeit, dass sich diese an die sich ändernden Klimabedingungen anpassen können. Die vorliegende Dissertation befasst sich mit der Modellpflanze Silene vulgaris und versucht zu ergründen, wie sich solch weit verbreitete Pflanzenarten an den Klimawandel anpassen. Dabei ist zu erwarten, dass sie eine hohe phänotypische Plastizität besitzen, durch die sie sich gut anpassen können oder, dass sie sich durch eine genetische Differenzierung als Antwort auf die vorherrschenden Umweltbedingungen auszeichnen. Im experimentellen Ansatz dieser Dissertation untersuchte ich daher die phänotypischen Anpassungen und die phänotypische Plastizität von S. vulgaris an ein mögliches Klimawandelszenario für Zentraleuropa. Dabei wurden die Samen von 25 europäischen Populationen gesammelt und in einem Gewächshausexperiment unter drei verschiedenen Niederschlagsbedingungen (65 mm, 75 mm, 90 mm) und zwei verschiedenen Temperaturbedingungen (18°C, 21°C) herangezogen. Im Anschluss wurden verschiedene Biomasse- und Fertilitätsmerkmale gemessen. Für ein tiefergehendes Verständnis der Anpassungsmöglichkeiten von S. vulgaris an den Klimawandel ist es zudem wichtig, auch die zugrundeliegende Phylogenie der Populationen zu verstehen. In diesem Zusammenhang nutzte ich eine genomweite Sequenziermethode mittels ddRAD.
Die Bedingungen im Gewächshausexperiment beeinflussten die Pflanzen signifikant in ihren phänotypischen Merkmalen, jedoch ließ sich kein Unterschied zwischen Population unterschiedlicher Herkunft erkennen. Lediglich die Anzahl der Blüten zeigte eine größere Plastizität in nördlichen europäischen Populationen, wo sich die Blütenzahl stärker dezimierte unter höheren Temperaturen und stärkerer Trockenheit. Die populationsgenetische Analyse ergab drei distinkte phylogenetische Gruppen für die untersuchten europäischen Populationen von S. vulgaris: eine Gruppe beinhaltete südeuropäische Populationen aus Spanien und Südfrankreich, eine weitere Gruppe bestand aus den gesammelten Individuen der westfranzösischen Populationen, während die dritte Gruppe, die Populationen aus Mittel- und Nordeuropa enthielt. Diese genetischen Gruppen wurden anschließend ebenfalls der Merkmalsanalyse unter den Gewächshausbedingungen unterzogen. Dabei stellte sich heraus, dass sich die genetischen Gruppen in ihren phänotypischen Merkmalen unterschieden, jedoch  
eine ähnliche Anpassung ihrer Merkmale an die experimentellen Klimawandelbedingungen zeigten.
Der dritte Aspekt dieser Dissertation befasste sich mit möglichen Anpassungsunterschieden zwischen den Geschlechtern in S. vulgaris. Als gynodiözische Art bestehen ihre Populationen sowohl aus weiblichen, also auch aus zwittrigen Individuen. Die phänotypischen Merkmale beider Geschlechter können sich dabei unterscheiden, was man als Sexualdimorphismus bezeichnet. Es ist bereits bekannt, dass sich Pflanzenmerkmale durch den anhaltenden Klimawandel bereits verändern, jedoch ist es nicht gut erforscht, ob und wie sich die unterschiedlichen Geschlechter bei einer sexuell dimorphen Art unter diesem Selektionsdruck verhalten. Während des Gewächshausexperiments wurden daher die Geschlechter der Individuen bestimmt und die phänotypischen Unterschiede zwischen weiblichen und zwittrigen Pflanzen analysiert. Allgemein lässt sich sagen, dass zwittrige Individuen mehr Blüten aber weniger Blätter hatten als weibliche. Im Hinblick auf die experimentellen Klimawandelbedingungen konnte ich zudem feststellen, dass Hermaphroditen in ihrer spezifischen Blattfläche und der Blütenanzahl weniger stark negativ auf höhere Temperaturen reagierten. 
Synthese – Die signifikanten Merkmalsanpassungen an die Gewächshausbedingungen waren unabhängig von der geographischen Herkunft oder genetischen Gruppe der Individuen. Dies lässt ein hohes Maß an universeller, phänotypischer Plastizität vermuten. Dementsprechend kann davon ausgegangen werden, dass phänotypische Plastizität ein möglicher Anpassungsmechanismus für diese weit verbreitete Art an den Klimawandel sein könnte. Im Hinblick auf den Sexualdimorphismus in S. vulgaris lässt sich sagen, dass sich beide Geschlechter vornehmlich in der Anzahl der Blüten unterscheiden und dass weibliche Pflanzen stärker von den Bedingungen des Gewächshausexperiments beeinflusst wurden. Diese Dissertation konnte damit erstmals darüber Aufschluss geben, wie sich S. vulgaris im Hinblick auf ihren Sexualdimorphismus unter Klimawandelbedingungen verhält. Weitere Forschung wird nun benötigt, um auch den Langzeiteffekt des Klimawandels auf das Fortpflanzungssystem dieser Art abschätzen zu können. 
Zusammenfassend lässt sich sagen, dass die vorliegende Arbeit einen umfassenden Einblick in die Anpassungsmechanismen einer weit verbreiteten Pflanzenart an den anthropogenen Klimawandel gibt. Zudem bestärkt sie unser Verständnis der Auswirkungen, die sich daraus für eine gynodiözische Art, wie S. vulgaris ergeben.
KW  - Silene vulgaris
KW  - climate change
KW  - plant adaptation
KW  - Silene vulgaris
KW  - Klimawandel
KW  - Pflanzenanpassung
Y1  - 2022
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-556483
ER  - 
TY  - THES
A1  - Kuhla, Kilian
T1  - Impact, distribution, and adaptation
T1  - Auswirkung, Verteilung und Anpassung
BT  - how weather extremes threaten the economic network
BT  - wie Wetterextreme das ökonomische Netzwerk bedrohen
N2  - Weather extremes pose a persistent threat to society on multiple layers. Besides an average of ~37,000 deaths per year, climate-related disasters cause destroyed properties and impaired economic activities, eroding people's livelihoods and prosperity. While global temperature rises – caused by anthropogenic greenhouse gas emissions – the direct impacts of climatic extreme events increase and will further intensify without proper adaptation measures. Additionally, weather extremes do not only have local direct effects. Resulting economic repercussions can propagate either upstream or downstream along trade chains causing indirect effects. One approach to analyze these indirect effects within the complex global supply network is the agent-based model Acclimate. Using and extending this loss-propagation model, I focus in this thesis on three aspects of the relation between weather extremes and economic repercussions.

First, extreme weather events cause direct impacts on local economic performance. I compute daily local direct output loss time series of heat stress, river floods, tropical cyclones, and their consecutive occurrence using (near-future) climate projection ensembles. These regional impacts are estimated based on physical drivers and local productivity distribution. Direct effects of the aforementioned disaster categories are widely heterogeneous concerning regional and temporal distribution. As well, their intensity changes differently under future warming. Focusing on the hurricane-impacted capital, I find that long-term growth losses increase with higher heterogeneity of a shock ensemble. 

Second, repercussions are sectorally and regionally distributed via economic ripples within the trading network, causing higher-order effects. I use Acclimate to identify three phases of those economic ripples. Furthermore, I compute indirect impacts and analyze overall regional and global production and consumption changes. Regarding heat stress, global consumer losses double while direct output losses increase by a factor 1.5 between 2000 – 2039. In my research I identify the effect of economic ripple resonance and introduce it to climate impact research. This effect occurs if economic ripples of consecutive disasters overlap, which increases economic responses such as an enhancement of consumption losses. These loss enhancements can even be more amplified with increasing direct output losses, e.g. caused by climate crises.  

Transport disruptions can cause economic repercussions as well. For this, I extend the model Acclimate with a geographical transportation route and expand the decision horizon of economic agents. Using this, I show that policy-induced sudden trade restrictions (e.g. a no-deal Brexit) can significantly reduce the longer-term economic prosperity of affected regions. Analyses of transportation disruptions in typhoon seasons indicate that severely affected regions must reduce production as demand falls during a storm. Substituting suppliers may compensate for fluctuations at the beginning of the storm, which fails for prolonged disruptions.

Third, possible coping mechanisms and adaptation strategies arise from direct and indirect economic responses to weather extremes. Analyzing annual trade changes due to typhoon-induced transport disruptions depict that overall exports rise. This trade resilience increases with higher network node diversification. Further, my research shows that a basic insurance scheme may diminish hurricane-induced long-term growth losses due to faster reconstruction in disasters aftermaths. I find that insurance coverage could be an economically reasonable coping scheme towards higher losses caused by the climate crisis. Indirect effects within the global economic network from weather extremes indicate further adaptation possibilities. For one, diversifying linkages reduce the hazard of sharp price increases. Next to this, close economic interconnections with regions that do not share the same extreme weather season can be economically beneficial in the medium run. Furthermore, economic ripple resonance effects should be considered while computing costs. Overall, an increase in local adaptation measures reduces economic ripples within the trade network and possible losses elsewhere. In conclusion, adaptation measures are necessary and potential present, but it seems rather not possible to avoid all direct or indirect losses.

As I show in this thesis, dynamical modeling gives valuable insights into how direct and indirect economic impacts arise from different categories of weather extremes. Further, it highlights the importance of resolving individual extremes and reflecting amplifying effects caused by incomplete recovery or consecutive disasters.
N2  - Wetterextreme stellen für die Gesellschaft eine anhaltende Bedrohung auf mehreren Ebenen dar. Neben durchschnittlich ~37.000 Todesfällen pro Jahr verursachen meteorologische Katastrophen Eigentumsschäden und Wirtschaftsbeeinträchtigungen, wodurch die Lebensgrundlagen und der Wohlstand der Menschen untergraben werden. Während die globale Temperatur – verursacht durch anthropogene Treibhausgasemissionen – ansteigt, nehmen die direkten Auswirkungen klimatischer Extremereignisse zu und werden sich ohne geeignete Anpassungsmaßnahmen weiter verstärken. 
Hinzu kommt, dass Wetterextreme nicht nur lokal direkte Schäden anrichten, sondern sich wetterbedingte wirtschaftliche Auswirkungen auch entlang der Handelsketten ausbreiten und so indirekte Effekte nach sich ziehen. Ein Ansatz zur Analyse dieser indirekten Auswirkungen innerhalb des komplexen globalen Versorgungsnetzes ist das agentenbasierte Modell Acclimate. 
In meiner Dissertation verwende und erweitere ich dieses Schadenspropagationsmodell, um drei Aspekte der Beziehung zwischen Wetterextremen und wirtschaftlichen Auswirkungen zu untersuchen.

Erstens verursachen extreme Wetterereignisse direkte Schäden in lokaler Wirtschaftsleistung. Die regionalen Auswirkungen werden auf der Grundlage von physikalischen Faktoren und lokalen Produktivitätsverteilungen kalkuliert. Ich berechne tägliche Zeitreihen lokaler Produktionsverluste durch Hitzestress, Überschwemmungen, tropische Wirbelstürme und deren konsekutives Auftreten unter Verwendung von Klimaprojektionsensembles. Die direkten Auswirkungen der oben genannten Katastrophenkategorien sind sehr heterogen in Bezug auf die regionale und zeitliche Verteilung. Ebenso ändert sich ihre Stärke unterschiedlich unter zukünftiger Erwärmung. Meine Forschungsergebnisse zeigen, dass Kapitalstock, welcher von Wirbelstürmen beschädigt ist, langfristige Wachstumsverluste verursacht. Dabei nehmen die Verluste zu, wenn die Heterogenität der Schocks steigt.

Zweitens werden die wetterbedingten Auswirkungen durch wirtschaftliche Wellen innerhalb des Handelsnetzes auf verschiedene Wirtschaftssektoren und Regionen verteilt. In meiner Dissertation, untersuche ich die wirtschaftlichen Wellen mittels Acclimate und mache dabei drei Wellenphasen aus. Darüber hinaus berechne ich indirekte Auswirkungen und analysiere die regionalen und globalen Produktionsveränderungen sowie die Auswirkungen auf Konsumierende. Für letztere verdoppeln sich zwischen 2000 und 2039 die weltweiten Verluste durch Hitzestress, während im selben Zeitraum die direkten Produktionsverluste nur um den Faktor 1.5 steigen. Im Zuge meiner Forschung identifiziere ich den Effekt der ökonomischen Wellenresonanz und führe ihn in die Klimafolgenforschung ein. Dieser Effekt tritt auf, wenn sich die ökonomischen Wellen aufeinanderfolgender Katastrophen überlagern, was wirtschaftliche Reaktionen intensiviert wie beispielsweise eine Steigerung der Konsumverluste. Diese Dynamik der Verluste kann durch zunehmende direkte Produktionsverluste, hervorgerufen etwa durch den Klimawandel, noch verstärkt werden. 

Auch Handelsunterbrechungen können wirtschaftliche Auswirkungen haben. Um diese zu berechnen, erweitere ich das Modell Acclimate um ein geografisches Transportnetzwerk und weite den Entscheidungshorizont der Wirtschaftsakteure aus. Politisch bedingte plötzliche Handelsbeschränkungen (z. B. ein No-Deal-Brexit) können den längerfristigen wirtschaftlichen Wohlstand der betroffenen Regionen erheblich verringern. Analysen von Transportunterbrechungen in der Taifunsaison zeigen, dass stark betroffene Regionen ihre Produktionen reduzieren müssen, wenn die Nachfrage während eines Sturms sinkt. Zu Beginn eines Sturms können Handelsschwankungen durch alternative Lieferanten ausgeglichen werden, was jedoch bei längeren Unterbrechungen nicht mehr gelingt.

Drittens ergeben sich mögliche Anpassungsmechanismen und -strategien aus direkten und indirekten wirtschaftlichen Reaktionen auf Wetterextreme. Die Analyse der jährlichen Handelsveränderungen in der Taifunsaison zeigt, dass Exporte insgesamt zunehmen. Diese Widerstandsfähigkeit des Handels wächst mit einer höheren Diversifizierung der Handelspartner. Weiterhin zeigt meine Forschung an Wirtschaftswachstumsmodellen, dass ein Versicherungssystem langfristige Wachstumsverluste, verursacht durch Tropenstürme, durch schnelleren Wiederaufbau verringern kann. Ich komme zu dem Schluss, dass ein Versicherungsschutz eine wirtschaftlich sinnvolle Anpassungsstrategie gegenüber höheren Schäden durch die Klimakrise sein kann. Ebenso weisen indirekte Auswirkungen von Wetterextremen innerhalb des globalen Wirtschaftsnetzes auf weitere Anpassungsmöglichkeiten hin. Zunächst vermindert eine diversifizierte Vernetzung die Gefahr eines starken Preisanstiegs. Ebenso kann eine enge wirtschaftliche Verflechtung von Regionen, die nicht dieselbe Unwettersaison haben, mittelfristig wirtschaftlich vorteilhaft sein. Weiterhin sollten bei der Berechnung der Kosten wirtschaftliche Resonanzeffekte berücksichtigt werden. Eine Verstärkung der lokalen Anpassungsmaßnahmen verringert die Amplitude ökonomischer Wellen und damit auch potentielle Verluste in anderen Regionen. Insgesamt sind Anpassungsmaßnahmen notwendig, aber es scheint trotz dieser nicht möglich zu sein, alle direkten oder indirekten Verluste zu vermeiden.

Wie ich in meiner Arbeit darlege, gibt die dynamische Modellierung wertvolle Einblicke in die Art und Weise, wie direkte und indirekte wirtschaftliche Auswirkungen durch verschiedene Wetterextreme entstehen. Darüber hinaus wird deutlich, wie wichtig es ist, einzelne Extremereignisse aufzulösen und Verstärkungseffekte zu berücksichtigen, die durch unvollständigen Wiederaufbau oder aufeinanderfolgende Katastrophen verursacht werden.
KW  - climate change
KW  - weather extremes
KW  - macro-economic modelling
KW  - network theory
KW  - economic network
KW  - Klimawandel
KW  - Wetterextreme
KW  - Makroökonomische Modellierung
KW  - Netzwerktheorie
KW  - Ökonomisches Netzwerk
Y1  - 2022
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-552668
ER  - 
TY  - JOUR
A1  - Lecourieux, Fatma
A1  - Kappel, Christian
A1  - Pieri, Philippe
A1  - Charon, Justine
A1  - Pillet, Jeremy
A1  - Hilbert, Ghislaine
A1  - Renaud, Christel
A1  - Gomes, Eric
A1  - Delrot, Serge
A1  - Lecourieux, David
T1  - Dissecting the Biochemical and Transcriptomic Effects of a Locally Applied Heat Treatment on Developing Cabernet Sauvignon Grape Berries
JF  - Frontiers in plant science
N2  - Reproductive development of grapevine and berry composition are both strongly influenced by temperature. To date, the molecular mechanisms involved in grapevine berries response to high temperatures are poorly understood. Unlike recent data that addressed the effects on berry development of elevated temperatures applied at the whole plant level, the present work particularly focuses on the fruit responses triggered by direct exposure to heat treatment (HT). In the context of climate change, this work focusing on temperature effect at the microclimate level is of particular interest as it can help to better understand the consequences of leaf removal (a common viticultural practice) on berry development. HT (+8 degrees C) was locally applied to clusters from Cabernet Sauvignon fruiting cuttings at three different developmental stages (middle green, veraison and middle ripening). Samples were collected 1, 7, and 14 days after treatment and used for metabolic and transcriptomic analyses. The results showed dramatic and specific biochemical and transcriptomic changes in heat exposed berries, depending on the developmental stage and the stress duration. When applied at the herbaceous stage, HT delayed the onset of veraison. Heating also strongly altered the berry concentration of amino acids and organic acids (e.g., phenylalanine, raminobutyric acid and malate) and decreased the anthocyanin content at maturity. These physiological alterations could be partly explained by the deep remodeling of transcriptome in heated berries. More than 7000 genes were deregulated in at least one of the nine experimental conditions. The most affected processes belong to the categories "stress responses," protein metabolism" and "secondary metabolism," highlighting the intrinsic capacity of grape berries to perceive HT and to build adaptive responses. Additionally, important changes in processes related to "transport," "hormone" and "cell wall" might contribute to the postponing of veraison. Finally, opposite effects depending on heating duration were observed for genes encoding enzymes of the general phenylpropanoid pathway, suggesting that the HI induced decrease in anthocyanin content may result from a combination of transcript abundance and product degradation.
KW  - grapevine
KW  - berry development
KW  - microclimate
KW  - high temperature
KW  - microarrays
KW  - metabolomics/metabolite profiling
KW  - climate change
Y1  - 2017
U6  - https://doi.org/10.3389/fpls.2017.00053
SN  - 1664-462X
VL  - 8
PB  - Frontiers Research Foundation
CY  - Lausanne
ER  - 
TY  - JOUR
A1  - Meißl, Gertraud
A1  - Formayer, Herbert
A1  - Klebinder, Klaus
A1  - Kerl, Florian
A1  - Schöberl, Friedrich
A1  - Geitner, Clemens
A1  - Markart, Gerhard
A1  - Leidinger, David
A1  - Bronstert, Axel
T1  - Climate change effects on hydrological system conditions influencing generation of storm runoff in small Alpine catchments
JF  - Hydrological processes : an international journal
N2  - Floods and debris flows in small Alpine torrent catchments (<10km(2)) arise from a combination of critical antecedent system state conditions and mostly convective precipitation events with high precipitation intensities. Thus, climate change may influence the magnitude-frequency relationship of extreme events twofold: by a modification of the occurrence probabilities of critical hydrological system conditions and by a change of event precipitation characteristics. Three small Alpine catchments in different altitudes in Western Austria (Ruggbach, Brixenbach and Langentalbach catchment) were investigated by both field experiments and process-based simulation. Rainfall-runoff model (HQsim) runs driven by localized climate scenarios (CNRM-RM4.5/ARPEGE, MPI-REMO/ECHAM5 and ICTP-RegCM3/ECHAM5) were used in order to estimate future frequencies of stormflow triggering system state conditions. According to the differing altitudes of the study catchments, two effects of climate change on the hydrological systems can be observed. On one hand, the seasonal system state conditions of medium altitude catchments are most strongly affected by air temperature-controlled processes such as the development of the winter snow cover as well as evapotranspiration. On the other hand, the unglaciated high-altitude catchment is less sensitive to climate change-induced shifts regarding days with critical antecedent soil moisture and desiccated litter layer due to its elevation-related small proportion of sensitive areas. For the period 2071-2100, the number of days with critical antecedent soil moisture content will be significantly reduced to about 60% or even less in summer in all catchments. In contrast, the number of days with dried-out litter layers causing hydrophobic effects will increase by up to 8%-11% of the days in the two lower altitude catchments. The intensity analyses of heavy precipitation events indicate a clear increase in rain intensities of up to 10%.
KW  - climate change
KW  - hydrophobic effects
KW  - small Alpine catchments
KW  - soil moisture
KW  - storm runoff events
KW  - system conditions
Y1  - 2016
U6  - https://doi.org/10.1002/hyp.11104
SN  - 0885-6087
SN  - 1099-1085
VL  - 31
IS  - 6
SP  - 1314
EP  - 1330
PB  - Wiley
CY  - New York
ER  - 
TY  - JOUR
A1  - Rybski, Diego
A1  - Reusser, Dominik Edwin
A1  - Winz, Anna-Lena
A1  - Fichtner, Christina
A1  - Sterzel, Till
A1  - Kropp, Jürgen
T1  - Cities as nuclei of sustainability?
JF  - Environment and Planning B: Urban Analytics and City Science
N2  - We have assembled CO2 emission figures from collections of urban GHG emission estimates published in peer-reviewed journals or reports from research institutes and non-governmental organizations. Analyzing the scaling with population size, we find that the exponent is development dependent with a transition from super- to sub-linear scaling. From the climate change mitigation point of view, the results suggest that urbanization is desirable in developed countries. Further, we compare this analysis with a second scaling relation, namely the fundamental allometry between city population and area, and propose that density might be a decisive quantity too. Last, we derive the theoretical country-wide urban emissions by integration and obtain a dependence on the size of the largest city.
KW  - Scaling
KW  - cities
KW  - climate change
KW  - development process
KW  - allometry
Y1  - 2017
U6  - https://doi.org/10.1177/0265813516638340
SN  - 2399-8083
SN  - 2399-8091
VL  - 44
IS  - 3
SP  - 425
EP  - 440
PB  - Sage Publ.
CY  - London
ER  - 
TY  - GEN
A1  - Geiger, Tobias
A1  - Frieler, Katja
A1  - Levermann, Anders
T1  - Reply to Comment on: High-income does not protect against hurricane losses (Environmental research letters. -  12 (2017))
T2  - Environmental research letters
N2  - Recently a multitude of empirically derived damage models have been applied to project future tropical cyclone (TC) losses for the United States. In their study (Geiger et al 2016 Environ. Res. Lett. 11 084012) compared two approaches that differ in the scaling of losses with socio-economic drivers: the commonly-used approach resulting in a sub-linear scaling of historical TC losses with a nation's affected gross domestic product (GDP), and the disentangled approach that shows a sub-linear increase with affected population and a super-linear scaling of relative losses with per capita income. Statistics cannot determine which approach is preferable but since process understanding demands that there is a dependence of the loss on both GDP per capita and population, an approach that accounts for both separately is preferable to one which assumes a specific relation between the two dependencies. In the accompanying comment, Rybski et al argued that there is no rigorous evidence to reach the conclusion that high-income does not protect against hurricane losses. Here we affirm that our conclusion is drawn correctly and reply to further remarks raised in the comment, highlighting the adequateness of our approach but also the potential for future extension of our research.
KW  - climate change
KW  - tropical cyclones
KW  - damage
KW  - meteorological extremes
KW  - vulnerability
Y1  - 2017
U6  - https://doi.org/10.1088/1748-9326/aa88d6
SN  - 1748-9326
VL  - 12
PB  - IOP Publ. Ltd.
CY  - Bristol
ER  - 
TY  - THES
A1  - Šedová, Barbora
T1  - Heterogeneous effects of weather and climate change on human migration
T1  - Heterogene Auswirkungen von Wetter und Klimawandel auf menschliche Migration
N2  - While estimated numbers of past and future climate migrants are alarming, the growing empirical evidence suggests that the association between adverse climate-related events and migration is not universally positive. This dissertation seeks to advance our understanding of when and how climate migration emerges by analyzing heterogeneous climatic influences on migration in low- and middle-income countries. To this end, it draws on established economic theories of migration, datasets from physical and social sciences, causal inference techniques and approaches from systematic literature review. In three of its five chapters, I estimate causal effects of processes of climate change on inequality and migration in India and Sub-Saharan Africa. By employing interaction terms and by analyzing sub-samples of data, I explore how these relationships differ for various segments of the population. In the remaining two chapters, I present two systematic literature reviews. First, I undertake a comprehensive meta-regression analysis of the econometric climate migration literature to summarize general climate migration patterns and explain the conflicting findings. Second, motivated by the broad range of approaches in the field, I examine the literature from a methodological perspective to provide best practice guidelines for studying climate migration empirically. Overall, the evidence from this dissertation shows that climatic influences on human migration are highly heterogeneous. Whether adverse climate-related impacts materialize in migration depends on the socio-economic characteristics of the individual households, such as wealth, level of education, agricultural dependence or access to adaptation technologies and insurance. For instance, I show that while adverse climatic shocks are generally associated with an increase in migration in rural India, they reduce migration in the agricultural context of Sub-Saharan Africa, where the average wealth levels are much lower so that households largely cannot afford the upfront costs of moving. I find that unlike local climatic shocks which primarily enhance internal migration to cities and hence accelerate urbanization, shocks transmitted via agricultural producer prices increase migration to neighboring countries, likely due to the simultaneous decrease in real income in nearby urban areas. These findings advance our current understanding by showing when and how economic agents respond to climatic events, thus providing explicit contexts and mechanisms of climate change effects on migration in the future. The resulting collection of findings can guide policy interventions to avoid or mitigate any present and future welfare losses from climate change-related migration choices.
N2  - Während die geschätzten Zahlen zukünftiger Klimamigranten alarmierend sind, deuten die wachsenden empirischen Belege darauf hin, dass der Klimawandel nicht automatisch zu mehr Migration führt. Denn auch wenn klimabezogene Einflüsse die Entscheidung zur Migration zunehmend beeinflussen, wird diese durch eine Vielzahl von Faktoren, wie beispielsweise den sozioökonomischen und politischen Bedingungen, beeinflusst. Der Zusammenhang zwischen Klimawandel und Migration ist also stark kontextabhängig. Diese Dissertation besteht aus fünf Artikeln und zeigt, wann und wie Klimamigration entsteht, indem sie die heterogenen klimatischen Einflüsse in Entwicklungsländern untersucht. Gestützt auf ökonomische Migrationstheorien analysiere ich Datensätze aus den Natur- und Sozialwissenschaften mithilfe von Methodiken der ökonometrischen Kausalanalyse, der Geoinformationssysteme und der systematischen Literatursynthese.
In drei von fünf Kapiteln schätze ich die kausalen Auswirkungen des Klimawandels auf Ungleichheit und Migration in Indien und Subsahara Afrika. Durch die Verwendung von Interaktionstermen und die Analyse von Teilstichproben untersuche ich in Regressionsmodellen, wie sich diese Beziehungen für verschiedene Bevölkerungsgruppen unterscheiden. In den verbleibenden zwei Kapiteln fasse ich die ökonometrische Literatur zur Klimamigration systematisch zusammen. Zunächst führe ich eine umfassende Meta-Regressionsanalyse durch, um die allgemeine Klimamigrationsmuster zusammenzufassen und die widersprüchliche Evidenz zu erklären. In einem zweiten Schritt untersuche ich die ökonometrische Klimamigrationsliteratur aus einer methodologischen Perspektive, um Best-Practice-Leitlinien für künftige empirische Analysen von Klimamigration bereitzustellen.
Insgesamt bestätigen die Ergebnisse dieser Dissertation, dass die klimatischen Einflüsse auf menschliche Migration heterogen sind und von den sozioökonomischen Merkmalen der einzelnen Haushalte wie dem Wohlstand und Bildungsniveau, der Abhängigkeit von der Landwirtschaft oder dem Zugang zu Anpassungstechnologien und Versicherungen, mitbestimmt werden. Ich finde beispielsweise, dass ungünstige klimatische Schocks zu einem Migrationsanstieg im ländlichen Indien führen, sie aber die Migration im landwirtschaftlichen Subsahara Afrika, wo das durchschnittliche Einkommensniveau viel niedriger ist, verhindern. Ich habe zudem herausgefunden, dass im Gegensatz zu lokalen klimatischen Schocks, die in erster Linie die Binnenmigration in die Städte verstärken und damit die Urbanisierung beschleunigen, globale Schocks über landwirtschaftliche Erzeugerpreise die Abwanderung in benachbarte Länder antreiben. 
Diese Ergebnisse erweitern unser derzeitiges Verständnis, indem sie verdeutlichen, wann und wie Akteure auf unterschiedliche Klimaereignisse mit der Entscheidung zur Migration reagieren. Die daraus resultierenden Erkenntnisse können helfen, Entscheidungsträger auf drei wichtige Arten zu informieren. Erstens, wenn man weiß, wer die Klimamigranten sind und welche Destinationsziele sie wählen, wird Klimamigration vorhersehbarer und damit kontrollierbarer. Dies kann verhindern, dass sie zu einer humanitären Krise wird. Zweitens hilft die Identifizierung von Bevölkerungsgruppen, die nicht in der Lage sind, sich durch Migration an die veränderten klimatischen Bedingungen anzupassen, dabei, unfreiwillige Immobilität zu vermeiden, was wiederum auch eine potenzielle humanitären Krise verhindert. Drittens können all diese Informationen helfen, Kosten und Nutzen der Klima(im)mobilität genauer zu bewerten und so die Social Cost of Carbon genauer einzuschätzen.
KW  - migration
KW  - weather
KW  - climate change
KW  - agriculture
KW  - food prices
KW  - inequality
KW  - econometrics
KW  - Landwirtschaft
KW  - Klimawandel
KW  - Ökonometrie
KW  - Lebensmittelpreise
KW  - Ungleichheit
KW  - Migration
KW  - Wetter
Y1  - 2022
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-536733
ER  - 
TY  - JOUR
A1  - Ungelenk, Johannes
T1  - Émile Zola and the Literary Language of Climate Change
JF  - Nottingham French Studies
N2  - On 7 February 1861, John Tyndall, professor of natural philosophy, delivered a historical lecture: he could prove that different gases absorb heat to a very different degree, which implies that the temperate conditions provided for by the Earth's atmosphere are dependent on its particular composition of gases. The theoretical foundation of climate science was laid.

Ten years later, on the other side of the Channel, a young and ambitious author was working on a comprehensive literary analysis of the French era under the Second Empire. Émile Zola had probably not heard or read of Tyndall's discovery. However, the article makes the case for reading Zola's Rougon-Macquart as an extensive story of climate change. Zola's literary attempts to capture the defining characteristic of the Second Empire led him to the insight that its various milieus were all part of the same ‘climate’: that of an all-encompassing warming. Zola suggests that this climate is man-made: the economic success of the Second Empire is based on heating, in a literal and metaphorical sense, as well as on stoking the steam-engines and creating the hypertrophic atmosphere of the hothouse that enhances life and maximises turnover and profit. In contrast to Tyndall and his audience, Zola sensed the catastrophic consequences of this warming: the Second Empire was inevitably moving towards a final débâcle, i.e. it was doomed to perish in local and ‘global’ climate catastrophes.

The article foregrounds the supplementary status of Tyndall's physical and Zola's literary knowledge. As Zola's striking intuition demonstrates, literature appears to have a privileged approach to the phenomenon of man-induced climate change.
N2  - Le 7 février 1861, le professeur de philosophie naturelle John Tyndall donna une communication historique: il pouvait prouver que des gaz différents absorbent la chaleur de manière différente, ce qui implique que les conditions tempérées fournies par l’atmosphère terrestre dépendent de sa composition particulière en gaz. Le fondement théorique de la science climatique était posé. Dix ans plus tard, de l'autre côté du Channel, un jeune auteur ambitieux était en train de faire une analyse littéraire globale de la France du Second Empire. Émile Zola n'avait probablement pas entendu parler de la découverte de Tyndall. Cependant, cet article propose de lire les Rougon Macquart de Zola comme une vaste histoire du changement climatique. Les tentatives littéraires entreprises par Zola pour capturer la caractéristique déterminante du Second Empire l'amena à réaliser que ses différents milieux faisaient tous partie du même « climat »: celui d'un réchauffement global. Zola suggère que ce climat est créé par l'humain et que le succès économique du Second Empire est basé sur l'action de chauffer dans un sens littéral et métaphorique, ainsi que sur l'alimentation des machines à vapeur et la création de l'atmosphère hypertrophiée d'une serre qui enrichit la vie et maximise l'écoulement et le profit. Contrairement à Tyndall et à son auditoire, Zola pressentit les conséquences catastrophiques d'un tel réchauffement: le Second Empire s'approchait inévitablement d'une débâcle finale, c'est-à-dire qu'il était voué à périr dans des catastrophes locales et « globales ».
KW  - Rougon-Macquart
KW  - climate change
KW  - John Tyndall
KW  - global warming
KW  - climate catastrophe
KW  - Second Empire
KW  - changement climatique
KW  - réchauffement planétaire
KW  - catastrophe climatique
KW  - Second Empire
Y1  - 2021
U6  - https://doi.org/https://doi.org/10.3366/nfs.2021.0331
VL  - 60
IS  - 3
SP  - 362
EP  - 373
ER  - 
TY  - THES
A1  - Brugger, Julia
T1  - Modeling changes in climate during past mass extinctions
T1  - Modellierung von Klimaveränderungen während vergangener Massenaussterben
N2  - The evolution of life on Earth has been driven by disturbances of different types and magnitudes over the 4.6 million years of Earth’s history (Raup, 1994, Alroy, 2008). One example for such disturbances are mass extinctions which are characterized by an exceptional increase in the extinction rate affecting a great number of taxa in a short interval of geologic time (Sepkoski, 1986). During the 541 million years of the Phanerozoic, life on Earth suffered five exceptionally severe mass extinctions named the “Big Five Extinctions”. Many mass extinctions are linked to changes in climate
(Feulner, 2009). Hence, the study of past mass extinctions is not only intriguing, but can also provide insights into the complex nature of the Earth system. This thesis aims at deepening our understanding of the triggers of mass extinctions and how they affected life. To accomplish this, I investigate changes in climate during two of the Big Five extinctions using a coupled climate model.

During the Devonian (419.2–358.9 million years ago) the first vascular plants and vertebrates evolved on land while extinction events occurred in the ocean (Algeo et al., 1995). The causes of these formative changes, their interactions and their links to changes in climate are still poorly understood. Therefore, we explore the sensitivity of the Devonian climate to various boundary conditions using an intermediate-complexity climate model (Brugger et al., 2019). In contrast to Le Hir et al. (2011), we find only a minor biogeophysical effect of changes in vegetation cover due to unrealistically high soil albedo values used in the earlier study. In addition, our results cannot support the strong influence of orbital parameters on the Devonian climate, as simulated with a climate model with a strongly simplified ocean model (De Vleeschouwer et al., 2013, 2014, 2017). We can only reproduce the changes in Devonian climate suggested by proxy data by decreasing atmospheric CO2. Still, finding agreement between the evolution of sea surface temperatures reconstructed from proxy data (Joachimski et al., 2009) and our simulations remains challenging and suggests a lower δ18O ratio of Devonian seawater. Furthermore, our study of the sensitivity of the Devonian climate reveals a prevailing mode of climate variability on a timescale of decades to centuries. The quasi-periodic ocean temperature fluctuations are linked to a physical mechanism of changing sea-ice cover, ocean convection and overturning in high northern latitudes. 

In the second study of this thesis (Dahl et al., under review) a new reconstruction of atmospheric CO2 for the Devonian, which is based on CO2-sensitive carbon isotope fractionation in the earliest vascular plant fossils, suggests a much earlier drop of atmo- spheric CO2 concentration than previously reconstructed, followed by nearly constant CO2 concentrations during the Middle and Late Devonian. Our simulations for the Early Devonian with identical boundary conditions as in our Devonian sensitivity study (Brugger et al., 2019), but with a low atmospheric CO2 concentration of 500 ppm, show no direct conflict with available proxy and paleobotanical data and confirm that under the simulated climatic conditions carbon isotope fractionation represents a robust proxy for atmospheric CO2. To explain the earlier CO2 drop we suggest that early forms of vascular land plants have already strongly influenced weathering. This new perspective on the Devonian questions previous ideas about the climatic conditions and earlier explanations for the Devonian mass extinctions.

The second mass extinction investigated in this thesis is the end-Cretaceous mass extinction (66 million years ago) which differs from the Devonian mass extinctions in terms of the processes involved and the timescale on which the extinctions occurred. In the two studies presented here (Brugger et al., 2017, 2021), we model the climatic effects of the Chicxulub impact, one of the proposed causes of the end-Cretaceous extinction, for the first millennium after the impact. The light-dimming effect of stratospheric sulfate aerosols causes severe cooling, with a decrease of global annual mean surface air temperature of at least 26◦C and a recovery to pre-impact temperatures after more than 30 years. The sudden surface cooling of the ocean induces deep convection which brings nutrients from the deep ocean via upwelling to the surface ocean. Using an ocean biogeochemistry model we explore the combined effect of ocean mixing and iron-rich dust originating from the impactor on the marine biosphere. As soon as light levels have recovered, we find a short, but prominent peak in marine net primary productivity. This newly discovered mechanism could result in toxic effects for marine near-surface ecosystems. Comparison of our model results to proxy data (Vellekoop et al., 2014, 2016, Hull et al., 2020) suggests that carbon release from the terrestrial biosphere is required in addition to the carbon dioxide which can be attributed to the target material. Surface ocean acidification caused by the addition of carbon dioxide and sulfur is only moderate. Taken together, the results indicate a significant contribution of the Chicxulub impact to the end-Cretaceous mass extinction by triggering multiple stressors for the Earth system.

Although the sixth extinction we face today is characterized by human intervention in nature, this thesis shows that we can gain many insights into future extinctions from studying past mass extinctions, such as the importance of the rate of change (Rothman, 2017), the interplay of multiple stressors (Gunderson et al., 2016), and changes in the carbon cycle (Rothman, 2017, Tierney et al., 2020).
N2  - In den 4,6 Milliarden Jahren Erdgeschichte wurde die Entwicklung des Lebens durch Störungen unterschiedlichster Art geprägt (Raup, 1994, Alroy, 2008). Ein Beispiel für solche Störungen sind Massenaussterben. Diese sind durch einen außergewöhnlichen Anstieg der Aussterberate einer großen Anzahl von Taxa in einem kurzen geologischen Zeitintervall gekennzeichnet (Sepkoski, 1986). Während der 541 Millionen Jahre des Phanerozoikums traten fünf außergewöhnlich schwere Massenaussterben auf. Viele Massenaussterben stehen mit Klimaveränderungen im Zusammenhang (Feulner, 2009). Die Untersuchung vergangener Massenaussterben ist daher nicht nur faszinierend, sondern gibt auch Einblicke in die komplexen Prozesse des Erdsystems. Diese Dissertation möchte unser Verständnis für die Auslöser von Massenaussterben sowie deren Auswirkungen auf das Leben erweitern. Dazu untersuche ich die Klimaveränderungen während zwei der fünf großen Aussterbeereignisse mit Hilfe eines gekoppelten Klimamodells.

Während des Devons (vor 419,2-358,9 Millionen Jahren) entwickelten sich die ersten Gefäßpflanzen und Wirbeltiere an Land, während im Ozean Massenaussterben statt- fanden (Algeo et al., 1995). Die Ursachen dieser tiefgreifenden Veränderungen, ihre Wechselwirkungen und ihre Zusammenhänge mit Klimaveränderungen sind noch wenig verstanden. Daher untersuchen wir die Sensitivität des Klimas des Devons bezüglich verschiedener Randbedingungen mit einem Klimamodell mittlerer Komplexität (Brugger et al., 2019). Im Gegensatz zu Le Hir et al. (2011), die unrealistisch hohe Albedo Werte für den Boden verwenden, finden wir nur einen geringen biogeophysikalischen Einfluss von Änderungen der Vegetationsbedeckung. Außerdem können unsere Simulationen den starken Einfluss von Orbitalparametern, der mit einem Klimamodell mit stark vereinfachtem Ozeanmodell (De Vleeschouwer et al., 2013, 2014, 2017) simuliert wurde, nicht reproduzieren. Die in Proxydaten gefundenen klimatischen Veränderungen im Devon können wir nur durch eine Verringerung des atmosphärischen CO2 simulieren. Dennoch bleibt es eine Herausforderung, eine Übereinstimmung zwischen der aus Proxydaten
(Joachimski et al., 2009) rekonstruierten Entwicklung der Meeresoberflächentemperatu- ren und unseren Simulationen zu finden. Dies deutet auf ein niedrigeres δ18O-Verhältnis des Meerwassers im Devon hin. Außerdem finden wir im Rahmen unserer Sensitivitäts- studien eine Klimavariabilität auf einer Zeitskala von Jahrzehnten bis Jahrhunderten.
Die quasi-periodischen Schwankungen der Ozeantemperatur werden durch einen physikalischen Mechanismus aus sich verändernder Meereisbedeckung, Konvektion und Umwälzbewegung in den hohen nördlichen Breiten des Ozeans angetrieben.

In der zweiten Studie dieser Dissertation (Dahl et al., under review) präsentieren wir eine neue Rekonstruktion des atmosphärischen CO2 für das Devon, die auf CO2-sensitiver Kohlenstoffisotopenfraktionierung in den frühesten Gefäßpflanzenfossilien basiert. Diese zeigt einen viel früheren Abfall der atmosphärischen CO2-Konzentration als bisherige Rekonstruktionen, gefolgt von nahezu konstanten CO2-Konzentrationen während des Mittel- und Spätdevon. Unsere Simulationen für das frühe Devon mit identischen Rand- bedingungen wie in unserer Sensitivitätsstudie (Brugger et al., 2019), jedoch mit einer niedrigen atmosphärischen CO2-Konzentration von 500ppm, zeigen keinen direkten Konflikt mit verfügbaren Proxy- und paläobotanischen Daten. Zusätzlich bestätigen die Simulationen, dass unter den simulierten klimatischen Bedingungen die Kohlenstoff- Isotopenfraktionierung einen robusten Proxy für atmosphärisches CO2 darstellt. Um den früheren CO2-Abfall zu erklären, schlagen wir vor, dass frühe Formen von vaskulären Landpflanzen die Verwitterung bereits stark beeinflusst haben. Diese neue Sichtweise auf das Devon stellt bisherige Vorstellungen über die klimatischen Bedingungen und frühere Erklärungen für die devonischen Massenaussterben in Frage.

Das zweite in dieser Arbeit untersuchte Massenaussterben ist das Massenaussterben der späten Kreidezeit (vor 66 Millionen Jahren), das sich von denen im Devon in Bezug auf die beteiligten Prozesse und die Zeitskala der Aussterben unterscheidet. Eine der diskutierten Ursachen dieses Massenaussterbens ist der Chicxulub-Meteoriten-Einschlag. In den beiden hier vorgestellten Studien (Brugger et al., 2017, 2021) modellieren wir die klimatischen Auswirkungen des Chicxulub Einschlags für das erste Jahrtausend nach dem Einschlag. Die durch die stratosphärischen Sulfataerosole verringerte Son- neneinstrahlung verursacht eine starke Abkühlung: die global und jährlich gemittelte Oberflächenlufttemperatur nimmt um mindestens 26◦C ab und erholt sich erst nach mehr als 30 Jahren. Die plötzliche Abkühlung der Ozeanoberfläche löst bis in große Tiefen reichende Konvektion aus, die zum Nährstofftransport aus dem tiefen Ozean an die Ozea- noberfläche führt. Mit Hilfe eines biogeochemischen Modells des Ozeans untersuchen wir die kombinierte Wirkung dieser Durchmischung des Ozeans und eisenreichen Staubs aus dem Meteoriten auf die marine Biosphäre. Sobald wieder genügend Sonneneinstrahlung auf die Erdoberfläche trifft, erreicht die marine Nettoprimärproduktion ein kurzes, aber markantes Maximum. Dieser neu entdeckte Mechanismus könnte toxische Folgen für oberflächennahe Ökosysteme des Ozeans haben. Der Vergleich unserer Modellergebnisse mit Proxydaten (Vellekoop et al., 2014, 2016, Hull et al., 2020) deutet darauf hin, dass zusätzlich zum CO2 aus dem Gestein des Einschlagortes Kohlenstoff aus der terrest- rischen Biosphäre freigesetzt wird. Die Versauerung des Oberflächenozeans durch die
Zugabe von CO2 und Schwefel ist nur moderat. Insgesamt deuten die Ergebnisse darauf hin, dass der Chicxulub Einschlag einen wesentlichen Beitrag zum Massenaussterben der späten Kreidezeit leistete, indem er das Erdsystem multiplen Stressoren aussetzte.

Auch wenn das heutige sechste Aussterben durch menschliche Eingriffe in die Natur geprägt ist, zeigt diese Dissertation, dass wir aus dem Studium vergangener Massenaussterben viele Erkenntnisse über zukünftige Massenaussterben gewinnen können, wie z. B. die Bedeutung der Änderungsrate (Rothman, 2017), ein besseres Verständnis des Zusammenspiels multipler Stressoren (Gunderson et al., 2016) und die Rolle von Veränderungen im Kohlenstoffkreislauf (Rothman, 2017, Tierney et al., 2020).
KW  - earth system modeling
KW  - mass extinctions
KW  - paleoclimatology
KW  - climate change
KW  - Erdsystem Modellierung
KW  - Klimawandel
KW  - Massenaussterben
KW  - Paleoklimatologie
Y1  - 2022
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-532468
ER  - 
TY  - JOUR
A1  - Perring, Michael P.
A1  - Bernhardt-Roemermann, Markus
A1  - Baeten, Lander
A1  - Midolo, Gabriele
A1  - Blondeel, Haben
A1  - Depauw, Leen
A1  - Landuyt, Dries
A1  - Maes, Sybryn L.
A1  - De Lombaerde, Emiel
A1  - Caron, Maria Mercedes
A1  - Vellend, Mark
A1  - Brunet, Joerg
A1  - Chudomelova, Marketa
A1  - Decocq, Guillaume
A1  - Diekmann, Martin
A1  - Dirnboeck, Thomas
A1  - Doerfler, Inken
A1  - Durak, Tomasz
A1  - De Frenne, Pieter
A1  - Gilliam, Frank S.
A1  - Hedl, Radim
A1  - Heinken, Thilo
A1  - Hommel, Patrick
A1  - Jaroszewicz, Bogdan
A1  - Kirby, Keith J.
A1  - Kopecky, Martin
A1  - Lenoir, Jonathan
A1  - Li, Daijiang
A1  - Malis, Frantisek
A1  - Mitchell, Fraser J. G.
A1  - Naaf, Tobias
A1  - Newman, Miles
A1  - Petrik, Petr
A1  - Reczynska, Kamila
A1  - Schmidt, Wolfgang
A1  - Standovar, Tibor
A1  - Swierkosz, Krzysztof
A1  - Van Calster, Hans
A1  - Vild, Ondrej
A1  - Wagner, Eva Rosa
A1  - Wulf, Monika
A1  - Verheyen, Kris
T1  - Global environmental change effects on plant community composition trajectories depend upon management legacies
JF  - Global change biology
N2  - The contemporary state of functional traits and species richness in plant communities depends on legacy effects of past disturbances. Whether temporal responses of community properties to current environmental changes are altered by such legacies is, however, unknown. We expect global environmental changes to interact with land-use legacies given different community trajectories initiated by prior management, and subsequent responses to altered resources and conditions. We tested this expectation for species richness and functional traits using 1814 survey-resurvey plot pairs of understorey communities from 40 European temperate forest datasets, syntheses of management transitions since the year 1800, and a trait database. We also examined how plant community indicators of resources and conditions changed in response to management legacies and environmental change. Community trajectories were clearly influenced by interactions between management legacies from over 200 years ago and environmental change. Importantly, higher rates of nitrogen deposition led to increased species richness and plant height in forests managed less intensively in 1800 (i.e., high forests), and to decreases in forests with a more intensive historical management in 1800 (i.e., coppiced forests). There was evidence that these declines in community variables in formerly coppiced forests were ameliorated by increased rates of temperature change between surveys. Responses were generally apparent regardless of sites’ contemporary management classifications, although sometimes the management transition itself, rather than historic or contemporary management types, better explained understorey responses. Main effects of environmental change were rare, although higher rates of precipitation change increased plant height, accompanied by increases in fertility indicator values. Analysis of indicator values suggested the importance of directly characterising resources and conditions to better understand legacy and environmental change effects. Accounting for legacies of past disturbance can reconcile contradictory literature results and appears crucial to anticipating future responses to global environmental change.
KW  - biodiversity change
KW  - climate change
KW  - disturbance regime
KW  - forestREplot
KW  - herbaceous layer
KW  - management intensity
KW  - nitrogen deposition
KW  - plant functional traits
KW  - time lag
KW  - vegetation resurvey
Y1  - 2017
U6  - https://doi.org/10.1111/gcb.14030
SN  - 1354-1013
SN  - 1365-2486
VL  - 24
IS  - 4
SP  - 1722
EP  - 1740
PB  - Wiley
CY  - Hoboken
ER  - 
TY  - JOUR
A1  - Oguntunde, Philip G.
A1  - Abiodun, Babatunde Joseph
A1  - Lischeid, Gunnar
A1  - Abatan, Abayomi A.
T1  - Droughts projection over the Niger and Volta River basins of West Africa at specific global warming levels
JF  - International Journal of Climatology
N2  - This study investigates possible impacts of four global warming levels (GWLs: GWL1.5, GWL2.0, GWL2.5, and GWL3.0) on drought characteristics over Niger River basin (NRB) and Volta River basin (VRB). Two drought indices-Standardized Precipitation Index (SPI) and Standardized Precipitation-Evapotranspiration Index (SPEI)-were employed in characterizing droughts in 20 multi-model simulation outputs from the Coordinated Regional Climate Downscaling Experiment (CORDEX). The performance of the simulation in reproducing basic hydro-climatological features and severe drought characteristics (i.e., magnitude and frequency) in the basins were evaluated. The projected changes in the future drought frequency were quantified and compared under the four GWLs for two climate forcing scenarios (RCP8.5 and RCP4.5). The regional climate model (RCM) ensemble gives a realistic simulation of historical hydro-climatological variables needed to calculate the drought indices. With SPEI, the simulation ensemble projects an increase in the magnitude and frequency of severe droughts over both basins (NRB and VRB) at all GWLs, but the increase, which grows with the GWLs, is higher over NRB than over VRB. More than 75% of the simulations agree on the projected increase at GWL1.5 and all simulations agree on the increase at higher GWLs. With SPI, the projected changes in severe drought is weaker and the magnitude remains the same at all GWLs, suggesting that SPI projection may underestimate impacts of the GWLs on the intensity and severity of future drought. The results of this study have application in mitigating impact of global warming on future drought risk over the regional water systems.
KW  - climate change
KW  - drought index
KW  - global warming levels
KW  - river basins
KW  - West Africa
KW  - CORDEX data
Y1  - 2019
VL  - 40
IS  - 13
PB  - John Wiley & Sons, Inc.
CY  - New Jersey
ER  - 
TY  - GEN
A1  - Oguntunde, Philip G.
A1  - Abiodun, Babatunde Joseph
A1  - Lischeid, Gunnar
A1  - Abatan, Abayomi A.
T1  - Droughts projection over the Niger and Volta River basins of West Africa at specific global warming levels
T2  - Postprints der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe
N2  - This study investigates possible impacts of four global warming levels (GWLs: GWL1.5, GWL2.0, GWL2.5, and GWL3.0) on drought characteristics over Niger River basin (NRB) and Volta River basin (VRB). Two drought indices-Standardized Precipitation Index (SPI) and Standardized Precipitation-Evapotranspiration Index (SPEI)-were employed in characterizing droughts in 20 multi-model simulation outputs from the Coordinated Regional Climate Downscaling Experiment (CORDEX). The performance of the simulation in reproducing basic hydro-climatological features and severe drought characteristics (i.e., magnitude and frequency) in the basins were evaluated. The projected changes in the future drought frequency were quantified and compared under the four GWLs for two climate forcing scenarios (RCP8.5 and RCP4.5). The regional climate model (RCM) ensemble gives a realistic simulation of historical hydro-climatological variables needed to calculate the drought indices. With SPEI, the simulation ensemble projects an increase in the magnitude and frequency of severe droughts over both basins (NRB and VRB) at all GWLs, but the increase, which grows with the GWLs, is higher over NRB than over VRB. More than 75% of the simulations agree on the projected increase at GWL1.5 and all simulations agree on the increase at higher GWLs. With SPI, the projected changes in severe drought is weaker and the magnitude remains the same at all GWLs, suggesting that SPI projection may underestimate impacts of the GWLs on the intensity and severity of future drought. The results of this study have application in mitigating impact of global warming on future drought risk over the regional water systems.
T3  - Zweitveröffentlichungen der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe - 1203 
KW  - climate change
KW  - drought index
KW  - global warming levels
KW  - river basins
KW  - West Africa
KW  - CORDEX data
Y1  - 2019
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-525943
SN  - 1866-8372
IS  - 13
ER  - 
TY  - THES
A1  - Wunderling, Nico
T1  - Nichtlineare Dynamiken und Interaktionen von Kippelementen im Erdsystem
T1  - Nonlinear dynamics and interactions of tipping elements in the Earth system
N2  - With ongoing anthropogenic global warming, some of the most vulnerable components of the Earth system might become unstable and undergo a critical transition. These subsystems are the so-called tipping elements. They are believed to exhibit threshold behaviour and would, if triggered, result in severe consequences for the biosphere and human societies. Furthermore, it has been shown that climate tipping elements are not isolated entities, but interact across the entire Earth system. Therefore, this thesis aims at mapping out the potential for tipping events and feedbacks in the Earth system mainly by the use of complex dynamical systems and network science approaches, but partially also by more detailed process-based models of the Earth system.

In the first part of this thesis, the theoretical foundations are laid by the investigation of networks of interacting tipping elements. For this purpose, the conditions for the emergence of global cascades are analysed against the structure of paradigmatic network types such as Erdös-Rényi, Barabási-Albert, Watts-Strogatz and explicitly spatially embedded networks. Furthermore, micro-scale structures are detected that are decisive for the transition of local to global cascades. These so-called motifs link the micro- to the macro-scale in the network of tipping elements. Alongside a model description paper, all these results are entered into the Python software package PyCascades, which is publicly available on github.

In the second part of this dissertation, the tipping element framework is first applied to components of the Earth system such as the cryosphere and to parts of the biosphere. Afterwards it is applied to a set of interacting climate tipping elements on a global scale. Using the Earth system Model of Intermediate Complexity (EMIC) CLIMBER-2, the temperature feedbacks are quantified, which would arise if some of the large cryosphere elements disintegrate over a long span of time. The cryosphere components that are investigated are the Arctic summer sea ice, the mountain glaciers, the Greenland and the West Antarctic Ice Sheets. The committed temperature increase, in case the ice masses disintegrate, is on the order of an additional half a degree on a global average (0.39-0.46 °C), while local to regional additional temperature increases can exceed 5 °C. This means that, once tipping has begun, additional reinforcing feedbacks are able to increase global warming and with that the risk of further tipping events.

This is also the case in the Amazon rainforest, whose parts are dependent on each other via the so-called moisture-recycling feedback. In this thesis, the importance of drought-induced tipping events in the Amazon rainforest is investigated in detail. Despite the Amazon rainforest is assumed to be adapted to past environmental conditions, it is found that tipping events sharply increase if the drought conditions become too intense in a too short amount of time, outpacing the adaptive capacity of the Amazon rainforest. In these cases, the frequency of tipping cascades also increases to 50% (or above) of all tipping events. In the model that was developed in this study, the southeastern region of the Amazon basin is hit hardest by the simulated drought patterns. This is also the region that already nowadays suffers a lot from extensive human-induced changes due to large-scale deforestation, cattle ranching or infrastructure projects.

Moreover, on the larger Earth system wide scale, a network of conceptualised climate tipping elements is constructed in this dissertation making use of a large literature review, expert knowledge and topological properties of the tipping elements. In global warming scenarios, tipping cascades are detected even under modest scenarios of climate change, limiting global warming to 2 °C above pre-industrial levels. In addition, the structural roles of the climate tipping elements in the network are revealed. While the large ice sheets on Greenland and Antarctica are the initiators of tipping cascades, the Atlantic Meridional Overturning Circulation (AMOC) acts as the transmitter of cascades. Furthermore, in our conceptual climate tipping element model, it is found that the ice sheets are of particular importance for the stability of the entire system of investigated climate tipping elements.

In the last part of this thesis, the results from the temperature feedback study with the EMIC CLIMBER-2 are combined with the conceptual model of climate tipping elements. There, it is observed that the likelihood of further tipping events slightly increases due to the temperature feedbacks even if no further CO$_2$ would be added to the atmosphere.

Although the developed network model is of conceptual nature, it is possible with this work for the first time to quantify the risk of tipping events between interacting components of the Earth system under global warming scenarios, by allowing for dynamic temperature feedbacks at the same time.
N2  - Bei fortdauerndem anthropogenem Klimawandel, könnten einige der vulnerabelsten Komponenten des Erdsystem instabil werden und in einen anderen Zustand übergehen. Diese Komponenten des Erdsystems sind die sogenannten Kippelemente. Bei ihnen wird angenommen, dass sie einen Kipppunkt besitzen ab dem sie in einen qualitativ anderen Zustand übergehen können. Sollte das passieren, hätte das schwerwiegende Konsequenzen für die Biosphäre und menschliche Gesellschaften. Des Weiteren ist gezeigt worden, dass Kippelemente keine isolierte Reigionen oder Prozesse sind, sondern über das gesamte Erdsystem hinweg interagieren. Das Ziel dieser Arbeit ist es daher, die Wahrscheinlichkeit für Kippereignisse sowie deren Feedbacks im Erdsystem zu quantifizieren. Zu diesem Zweck kommen vor allem Frameworks aus der Wissenschaft komplexer Systeme und Netzwerke zum Einsatz. Für einige Teilaspekte dieser Arbeit wird aber auch ein detaillierteres und prozessbasierteres Erdsystemmodell verwendet.

Im ersten Teil dieser Arbeit werden die theoretischen Grundlagen gelegt, indem komplexe Netzwerke bestehend aus interagierenden Kippelementen untersucht werden. Hier werden Voraussetzungen für das Auftreten globaler Kippkaskaden anhand der Struktur paradigmatischer Netzwerktypen analysiert. Diese Typen sind Netzwerke wie Erdös-Rényi, Barabási-Albert, Watts-Strogatz Netzwerke oder auch explizit räumlich eingebettete Netzwerke. Darüber hinaus sind bestimmte Mikrostrukturen in Netzwerken dafür entscheidend, ob sich eine lokale Kaskaden auf das globale Netzwerk ausbreiten kann. Diese Strukturen sind das Bindeglied zwischen der Mikro- und der Makroebene des Netzwerks und werden Motive genannt. Zusammen mit einer Publikation zur Modellbeschreibung, werden alle diese Ergebnisse im Python-Softwarepaket PyCascades veröffentlicht, das auf github öffentlich verfügbar ist.

Im zweiten Teil dieser Dissertation wird das Kippelementframework zunächst auf Kompenenten des Erdsystems angewendet wie der Kryosphäre und Teilen der Biosphäre, und danach auf globaler Skala für interagierende Klimakippelemente. In einem ersten Schritt werden mit dem Erdsystemmodell mittlerer Komplexität CLIMBER-2 die Temperaturfeedbacks ermittelt, die entstehen würden, wenn große Gebiete der Kryosphäre auf lange Sicht eisfrei werden. In dieser Berechnung werden das arktische Sommermeereis, die Gebirgsgletscher, der grönländische und der westantarktische Eisschild berücksichtigt. Die quantifizierte Temperaturerhöhung liegt in der Größenordnung von einem halben Grad zusätzlicher globaler Erwärmung (0.39--0.46°C). Lokale bis regionale Temperaturerhöhungen können allerdings 5°C übersteigen. Wenn also das Kippen einiger Elemente begonnen hat, bedeutet dieses Ergebnis, dass Temperaturfeedbacks in der Lage sind, das Risiko weiterer Kippereignisse zu erhöhen.

Dies ist auch der Fall im Amazonasregenwald, dessen Unterregionen über den sogenannten Feuchtig-keits-Recycling-Feedback miteinander in Beziehung stehen und voneinander abhängen. In dieser Dissertation wird die Bedeutung von Kippereignissen im Detail untersucht, die aufgrund von Dürreperioden zustande kommen. Obwohl man davon ausgehen kann, dass der Regenwald sich an zurückliegende und gegenwärtige Klimabedingungen angepasst hat, kann festgestellt werden, dass die Häu-figkeit von Kippereignissen stark zunimmt, wenn die jeweilige Trockenperiode eine gewisse Intensität übersteigt und damit die Anpassungsfähigkeit des Amazonasregenwalds überschritten wird. In solchen Fällen steigt auch die Häufigkeit von Kippkaskaden unter allen Kippereignissen auf 50% (und mehr) an. In dem Modell, das in dieser Studie entwickelt wurde, zeigt sich, dass der Südosten des Amazonasbeckens am stärksten von den simulierten Trockenheitsmustern betroffen ist. Das ist gleichzeitig die Region, die bereits heute stark unter anthropogener Veränderung leidet, unter anderem aufgrund von großflächiger Abholzung, Viehzucht oder Infrastrukturprojekten.

Zudem wird in dieser Dissertation auf der größeren, erdsystemweiten Skala ein Netzwerk konzeptionalisierter Klimakippelemente aufgebaut. Zu diesem Zweck wird eine umfangreiche Literaturrecherche durchgeführt, die zusammen mit Expertenwissen und den topologischen Eigenschaften der Kippelemente in die Studien mit einfließt. In Klimawandelszenarien können dann Kippkaskaden beobachtet werden, selbst wenn die globale Erderwärmung auf 2°C über dem vorindustriellen Niveau begrenzt werden kann. Außerdem werden die strukturellen Rollen der Klimakippelemente im Netzwerk ermittelt. Während die großen Eisschilde auf Grönland und der Westantarktis viele Kippkaskaden initiieren, ist die Atlantische Umwälzzirkulation für die Weitergabe vieler dieser Kaskaden verantwortlich. In unserem konzeptionellen Modell für Klimakippelemente wird darüber hinaus festgestellt, dass die Eisschilde von besonderer Bedeutung für die Stabilität des Gesamtsystems sind.

Im letzen Teil dieser Dissertation werden die Ergebnisse der Feedbackstudie (CLIMBER-2-Studie) zusammengebracht mit dem konzeptionellen Klimakippelementmodell. Dabei zeigt sich, dass die Wahrscheinlichkeit zusätzlicher Kippereignisse aufgrund der berücksichtigten Temperaturfeedbacks auch ohne das Zuführen eines zusätzlichen CO2-Eintrags in die Atmosphäre leicht ansteigt.

Trotz der konzeptionellen Natur des entwickelten Netzwerkmodells, ist es mit dieser Arbeit erstmals möglich eine Risikoabschätzung über das Auftreten von Kippkaskaden im Erdsystem vorzunehmen. Darüber hinaus können, unter der Annahme globaler Erwärmungsszenarien, auch dynamische Temperaturfeedbacks berücksichtigt werden.
KW  - tipping element
KW  - nonlinear dynamics
KW  - tipping cascade
KW  - climate change
KW  - complex networks
KW  - Klimawandel
KW  - komplexe Netzwerke
KW  - nichtlineare Dynamiken
KW  - Kippkaskade
KW  - Kippelement
Y1  - 2021
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-525140
ER  - 
TY  - JOUR
A1  - Huang, Xiaozhong
A1  - Peng, Wei
A1  - Rudaya, Natalia
A1  - Grimm, Eric C.
A1  - Chen, Xuemei
A1  - Cao, Xianyong
A1  - Zhang, Jun
A1  - Pan, Xiaoduo
A1  - Liu, Sisi
A1  - Chen, Chunzhu
A1  - Chen, Fahu
T1  - Holocene vegetation and climate dynamics in the Altai Mountains and Surrounding Areas
JF  - Geophysical research letters
N2  - A comprehensive understanding of the regional vegetation responses to long-term climate change will help to forecast Earth system dynamics. Based on a new well-dated pollen data set from Kanas Lake and a review on the published pollen records in and around the Altai Mountains, the regional vegetation dynamics and forcing mechanisms are discussed. In the Altai Mountains, the forest optimum occurred during 10-7ka for the upper forest zone and the tree line decline and/or ecological shifts were caused by climatic cooling from around 7ka. In the lower forest zone, the forest reached an optimum in the middle Holocene, and then increased openness of the forest, possibly caused by both climate cooling and human activities, took place in the late Holocene. In the lower basins or plains around the Altai Mountains, the development of protograssland or forest benefited from increasing humidity in the middle to late Holocene. Plain Language Summary In the Altai Mountains and surrounding area of central Asia, the previous studies of the Holocene paleovegetation and paleoclimate studies did not discuss the different ecological limiting factors for the vegetation in high mountains and low-elevation areas due to limited data. With accumulating fossil pollen data and surface pollen data, it is possible to understand better the geomorphological effect on the vegetation and discrepancies of vegetation/forest responses to large-scale climate forcing, and it is also possible to get reliable quantitative reconstructions of climate. Here our new pollen data and review on the published fossil pollen data will help us to look into the past climate change and vertical evolution of vegetation in this important area of the Northern Hemisphere. Based on our study, it can be concluded that the growth of taiga forest in the wetter areas may be promoted under a future warmer climate, while the forest in the relatively dry areas is liable to decline, and the different vegetation dynamics will contribute to future high-resolution coupled vegetation-climate model for Earth system modelling.
KW  - climate change
KW  - Kanas Lake
KW  - Altai Mountains
KW  - vegetation dynamics
KW  - taiga forest
Y1  - 2018
U6  - https://doi.org/10.1029/2018GL078028
SN  - 0094-8276
SN  - 1944-8007
VL  - 45
IS  - 13
SP  - 6628
EP  - 6636
PB  - American Geophysical Union
CY  - Washington
ER  - 
TY  - JOUR
A1  - Grimm-Seyfarth, Annegret
A1  - Mihoub, Jean-Baptiste
A1  - Gruber, Bernd
A1  - Henle, Klaus
T1  - Some like it hot
BT  - from individual to population responses of an arboreal arid-zone gecko to local and distant climate
JF  - Ecological monographs
N2  - Accumulating evidence has demonstrated considerable impact of climate change on biodiversity, with terrestrial ectotherms being particularly vulnerable. While climate-induced range shifts are often addressed in the literature, little is known about the underlying ecological responses at individual and population levels. Using a 30-yr monitoring study of the long-living nocturnal gecko Gehyra variegata in arid Australia, we determined the relative contribution of climatic factors acting locally (temperature, rainfall) or distantly (La Nina induced flooding) on ecological processes ranging from traits at the individual level (body condition, body growth) to the demography at population level (survival, sexual maturity, population sizes). We also investigated whether thermoregulatory activity during both active (night) and resting (daytime) periods of the day can explain these responses. Gehyra variegata responded to local and distant climatic effects. Both high temperatures and high water availability enhanced individual and demographic parameters. Moreover, the impact of water availability was scale independent as local rainfall and La Nina induced flooding compensated each other. When water availability was low, however, extremely high temperatures delayed body growth and sexual maturity while survival of individuals and population sizes remained stable. This suggests a trade-off with traits at the individual level that may potentially buffer the consequences of adverse climatic conditions at the population level. Moreover, hot temperatures did not impact nocturnal nor diurnal behavior. Instead, only cool temperatures induced diurnal thermoregulatory behavior with individuals moving to exposed hollow branches and even outside tree hollows for sun-basking during the day. Since diurnal behavioral thermoregulation likely induced costs on fitness, this could decrease performance at both individual and population level under cool temperatures. Our findings show that water availability rather than high temperature is the limiting factor in our focal population of G.variegata. In contrast to previous studies, we stress that drier rather than warmer conditions are expected to be detrimental for nocturnal desert reptiles. Identifying the actual limiting climatic factors at different scales and their functional interactions at different ecological levels is critical to be able to predict reliably future population dynamics and support conservation planning in arid ecosystems.
KW  - behavioral adaptation
KW  - body condition
KW  - body growth rate
KW  - climate change
KW  - El Nino Southern Oscillation (ENSO)
KW  - Gehyra variegata
KW  - population dynamics
KW  - population size
KW  - survival
KW  - thermoregulation
Y1  - 2018
U6  - https://doi.org/10.1002/ecm.1301
SN  - 0012-9615
SN  - 1557-7015
VL  - 88
IS  - 3
SP  - 336
EP  - 352
PB  - Wiley
CY  - Hoboken
ER  - 
TY  - JOUR
A1  - van Kleunen, Mark
A1  - Essl, Franz
A1  - Pergl, Jan
A1  - Brundu, Giuseppe
A1  - Carboni, Marta
A1  - Dullinger, Stefan
A1  - Early, Regan
A1  - Gonzalez-Moreno, Pablo
A1  - Groom, Quentin J. M.
A1  - Hulme, Philip E.
A1  - Kueffer, Christoph
A1  - Kühn, Ingolf
A1  - Maguas, Cristina
A1  - Maurel, Noelie
A1  - Novoa, Ana
A1  - Parepa, Madalin
A1  - Pysek, Petr
A1  - Seebens, Hanno
A1  - Tanner, Rob
A1  - Touza, Julia
A1  - Verbrugge, Laura
A1  - Weber, Ewald
A1  - Dawson, Wayne
A1  - Kreft, Holger
A1  - Weigelt, Patrick
A1  - Winter, Marten
A1  - Klonner, Guenther
A1  - Talluto, Matthew V.
A1  - Dehnen-Schmutz, Katharina
T1  - The changing role of ornamental horticulture in alien plant invasions
JF  - Biological reviews
N2  - The number of alien plants escaping from cultivation into native ecosystems is increasing steadily. We provide an overview of the historical, contemporary and potential future roles of ornamental horticulture in plant invasions. We show that currently at least 75% and 93% of the global naturalised alien flora is grown in domestic and botanical gardens, respectively. Species grown in gardens also have a larger naturalised range than those that are not. After the Middle Ages, particularly in the 18th and 19th centuries, a global trade network in plants emerged. Since then, cultivated alien species also started to appear in the wild more frequently than non-cultivated aliens globally, particularly during the 19th century. Horticulture still plays a prominent role in current plant introduction, and the monetary value of live-plant imports in different parts of the world is steadily increasing. Historically, botanical gardens - an important component of horticulture - played a major role in displaying, cultivating and distributing new plant discoveries. While the role of botanical gardens in the horticultural supply chain has declined, they are still a significant link, with one-third of institutions involved in retail-plant sales and horticultural research. However, botanical gardens have also become more dependent on commercial nurseries as plant sources, particularly in North America. Plants selected for ornamental purposes are not a random selection of the global flora, and some of the plant characteristics promoted through horticulture, such as fast growth, also promote invasion. Efforts to breed non-invasive plant cultivars are still rare. Socio-economical, technological, and environmental changes will lead to novel patterns of plant introductions and invasion opportunities for the species that are already cultivated. We describe the role that horticulture could play in mediating these changes. We identify current research challenges, and call for more research efforts on the past and current role of horticulture in plant invasions. This is required to develop science-based regulatory frameworks to prevent further plant invasions.
KW  - botanical gardens
KW  - climate change
KW  - horticulture
KW  - naturalised plants
KW  - ornamental plants
KW  - pathways
KW  - plant invasions
KW  - plant nurseries
KW  - trade
KW  - weeds
Y1  - 2018
U6  - https://doi.org/10.1111/brv.12402
SN  - 1464-7931
SN  - 1469-185X
VL  - 93
IS  - 3
SP  - 1421
EP  - 1437
PB  - Wiley
CY  - Hoboken
ER  - 
TY  - JOUR
A1  - Steffen, Will
A1  - Röckstrom, Johan
A1  - Richardson, Katherine
A1  - Lenton, Timothy M.
A1  - Folke, Carl
A1  - Liverman, Diana
A1  - Summerhayes, Colin P.
A1  - Barnosky, Anthony D.
A1  - Cornell, Sarah E.
A1  - Crucifix, Michel
A1  - Donges, Jonathan Friedemann
A1  - Fetzer, Ingo
A1  - Lade, Steven J.
A1  - Scheffer, Marten
A1  - Winkelmann, Hilke Ricarda
A1  - Schellnhuber, Hans Joachim
T1  - Trajectories of the Earth System in the Anthropocene
JF  - Proceedings of the National Academy of Sciences of the United States of America
N2  - We explore the risk that self-reinforcing feedbacks could push the Earth System toward a planetary threshold that, if crossed, could prevent stabilization of the climate at intermediate temperature rises and cause continued warming on a "Hothouse Earth" pathway even as human emissions are reduced. Crossing the threshold would lead to a much higher global average temperature than any interglacial in the past 1.2 million years and to sea levels significantly higher than at any time in the Holocene. We examine the evidence that such a threshold might exist and where it might be. If the threshold is crossed, the resulting trajectory would likely cause serious disruptions to ecosystems, society, and economies. Collective human action is required to steer the Earth System away from a potential threshold and stabilize it in a habitable interglacial-like state. Such action entails stewardship of the entire Earth System-biosphere, climate, and societies-and could include decarbonization of the global economy, enhancement of biosphere carbon sinks, behavioral changes, technological innovations, new governance arrangements, and transformed social values.
KW  - Earth System trajectories
KW  - climate change
KW  - Anthropocene
KW  - biosphere feedbacks
KW  - tipping elements
Y1  - 2018
U6  - https://doi.org/10.1073/pnas.1810141115
SN  - 0027-8424
VL  - 115
IS  - 33
SP  - 8252
EP  - 8259
PB  - National Acad. of Sciences
CY  - Washington
ER  - 
TY  - JOUR
A1  - Tape, Ken D.
A1  - Jones, Benjamin M.
A1  - Arp, Christopher D.
A1  - Nitze, Ingmar
A1  - Grosse, Guido
T1  - Tundra be dammed
BT  - beaver colonization of the arctic
JF  - Global change biology
N2  - Increasing air temperatures are changing the arctic tundra biome. Permafrost is thawing, snow duration is decreasing, shrub vegetation is proliferating, and boreal wildlife is encroaching. Here we present evidence of the recent range expansion of North American beaver (Castor canadensis) into the Arctic, and consider how this ecosystem engineer might reshape the landscape, biodiversity, and ecosystem processes. We developed a remote sensing approach that maps formation and disappearance of ponds associated with beaver activity. Since 1999, 56 new beaver pond complexes were identified, indicating that beavers are colonizing a predominantly tundra region (18,293km(2)) of northwest Alaska. It is unclear how improved tundra stream habitat, population rebound following overtrapping for furs, or other factors are contributing to beaver range expansion. We discuss rates and likely routes of tundra beaver colonization, as well as effects on permafrost, stream ice regimes, and freshwater and riparian habitat. Beaver ponds and associated hydrologic changes are thawing permafrost. Pond formation increases winter water temperatures in the pond and downstream, likely creating new and more varied aquatic habitat, but specific biological implications are unknown. Beavers create dynamic wetlands and are agents of disturbance that may enhance ecosystem responses to warming in the Arctic.
KW  - arctic tundra
KW  - beaver
KW  - climate change
KW  - permafrost
KW  - population recovery
KW  - salmon
KW  - shrub expansion
KW  - stream
Y1  - 2018
U6  - https://doi.org/10.1111/gcb.14332
SN  - 1354-1013
SN  - 1365-2486
VL  - 24
IS  - 10
SP  - 4478
EP  - 4488
PB  - Wiley
CY  - Hoboken
ER  - 
TY  - THES
A1  - Nguyen, Van Khanh Triet
T1  - Flood dynamics in the Vietnamese Mekong Delta
T1  - Hochwasserdynamik im vietnamesischen Mekong-Delta
BT  - Current state and future projections
BT  - Aktueller Stand und künftige Prognosen
N2  - Today, the Mekong Delta in the southern of Vietnam is home for 18 million people. The delta also accounts for more than half of the country’s food production and 80% of the exported rice. Due to the low elevation, it is highly susceptible to the risk of fluvial and coastal flooding. Although extreme floods often result in excessive damages and economic losses, the annual flood pulse from the Mekong is vital to sustain agricultural cultivation and livelihoods of million delta inhabitants.
Delta-wise risk management and adaptation strategies are required to mitigate the adverse impacts from extreme events while capitalising benefits from floods. However, a proper flood risk management has not been implemented in the VMD, because the quantification of flood damage is often overlooked and the risks are thus not quantified. So far, flood management has been exclusively focused on engineering measures, i.e. high- and low- dyke systems, aiming at flood-free or partial inundation control without any consideration of the actual risks or a cost-benefit analysis. Therefore, an analysis of future delta flood dynamics driven these stressors is valuable to facilitate the transition from sole hazard control towards a risk management approach, which is more cost-effective and also robust against future changes in risk.
Built on these research gaps, this thesis investigates the current state and future projections of flood hazard, damage and risk to rice cultivation, the most important economic activity in the VMD. The study quantifies the changes in risk and hazard brought by the development of delta-based flood control measures in the last decades, and analyses the expected changes in risk driven by the changing climate, rising sea-level and deltaic land subsidence, and finally the development of hydropower projects in the Mekong Basin. For this purpose, flood trend analyses and comprehensive hydraulic modelling were performed, together with the development of a concept to quantify flood damage and risk to rice plantation.
The analysis of observed flood levels revealed strong and robust increasing trends of peak and duration downstream of the high-dyke areas with a step change in 2000/2001, i.e. after the disastrous flood which initiated the high-dyke development. These changes were in contrast to the negative trends detected upstream, suggested that high-dyke development has shifted flood hazard downstream. Findings of the trend’s analysis were later confirmed by hydraulic simulations of the two recent extreme floods in 2000 and 2011, where the hydrological boundaries and dyke system settings were interchanged.
However, the high-dyke system was not the only and often not the main cause for a shift of flood hazard, as a comparative analysis of these two extreme floods proved. The high-dyke development was responsible for 20–90% of the observed changes in flood level between 2000 and 2011, with large spatial variances. The particular flood hydrograph of the two events had the highest contribution in the northern part of the delta, while the tidal level had 2–3 times higher influence than the high-dyke in the lower-central and coastal areas downstream of high-dyke areas. The impact of the high-dyke development was highest in the areas closely downstream of the high-dyke area just south of the Cambodia-Vietnam border. The hydraulic simulations also validated that the concurrence of the flood peak with spring tides, i.e. high sea level along the coast, amplified the flood level and inundation in the central and coastal regions substantially.
The risk assessment quantified the economic losses of rice cultivation to USD 25.0 and 115 million (0.02–0.1% of the total GDP of Vietnam in 2011) corresponding to the 10-year and the 100-year floods, with an expected annual damage of about USD 4.5 million. A particular finding is that the flood damage was highly sensitive to flood timing. Here, a 10-year event with an early peak, i.e. late August-September, could cause as much damage as a 100-year event that peaked in October. This finding underlines the importance of a reliable early flood warning, which could substantially reduce the damage to rice crops and thus the risk. 
The developed risk assessment concept was furthermore applied to investigate two high-dyke development alternatives, which are currently under discussion among the administrative bodies in Vietnam, but also in the public. The first option favouring the utilization of the current high-dyke compartments as flood retention areas instead for rice cropping during the flood season could reduce flood hazard and expected losses by 5–40%, depending on the region of the delta. On the contrary, the second option promoting the further extension of the areas protected by high-dyke to facilitate third rice crop planting on a larger area, tripled the current expected annual flood damage. This finding challenges the expected economic benefit of triple rice cultivation, in addition to the already known reducing of nutrient supply by floodplain sedimentation and thus higher costs for fertilizers. 
The economic benefits of the high-dyke and triple rice cropping system is further challenged by the changes in the flood dynamics to be expected in future. For the middle of the 21st century (2036-2065) the effective sea-level rise an increase of the inundation extent by 20–27% was projected. This corresponds to an increase of flood damage to rice crops in dry, normal and wet year by USD 26.0, 40.0 and 82.0 million in dry, normal and wet year compared to the baseline period 1971-2000.
Hydraulic simulations indicated that the planned massive development of hydropower dams in the Mekong Basin could potentially compensate the increase in flood hazard and agriculture losses stemming from climate change. However, the benefits of dams as mitigation of flood losses are highly uncertain, because a) the actual development of the dams is highly disputed, b) the operation of the dams is primarily targeted at power generation, not flood control, and c) this would require international agreements and cooperation, which is difficult to achieve in South-East Asia. The theoretical flood mitigation benefit is additionally challenged by a number of negative impacts of the dam development, e.g. disruption of floodplain inundation in normal, non-extreme flood years. Adding to the certain reduction of sediment and nutrient load to the floodplains, hydropower dams will drastically impair rice and agriculture production, the basis livelihoods of million delta inhabitants.
In conclusion, the VMD is expected to face increasing threats of tidal induced floods in the coming decades. Protection of the entire delta coastline solely with “hard” engineering flood protection structures is neither technically nor economically feasible, adaptation and mitigation actions are urgently required. Better control and reduction of groundwater abstraction is thus strongly recommended as an immediate and high priority action to reduce the land subsidence and thus tidal flooding and salinity intrusion in the delta. Hydropower development in the Mekong basin might offer some theoretical flood protection for the Mekong delta, but due to uncertainties in the operation of the dams and a number of negative effects, the dam development cannot be recommended as a strategy for flood management. For the Vietnamese authorities, it is advisable to properly maintain the existing flood protection structures and to develop flexible risk-based flood management plans. In this context the study showed that the high-dyke compartments can be utilized for emergency flood management in extreme events. For this purpose, a reliable flood forecast is essential, and the action plan should be materialised in official documents and legislation to assure commitment and consistency in the implementation and operation.
N2  - Das Mekong-Delta im Süden Vietnams ist die Heimat von 18 Millionen Menschen. Im Delta werden mehr als die Hälfte der Nahrungsmittel des Landes und 80 % des exportierten Reises produziert. Aufgrund der geringen Höhen und Topographie ist das Delta sehr anfällig für Überflutungen, sowohl durch Fußhochwasser als auch durch gezeitenbedingte Rückstauüberflutungen. Obwohl extreme Überschwemmungen oft zu hohen Schäden und wirtschaftlichen Verlusten führen, ist der jährliche Hochwasserimpuls des Mekong lebenswichtig für die Aufrechterhaltung des landwirtschaftlichen Anbaus und des Lebensunterhalts von Millionen Deltabewohnern.
Ein deltaweites Risikomanagement bestehend aus Hochwasserschutzmaßnahmen und  Anpassungsstrategien ist erforderlich, um die negativen Auswirkungen von Extremereignissen zu mindern, zeitgleich aber auch die positiven Aspekte der Hochwasser beizubehalten. Ein Hochwasserrisikomanagement ist im VMD jedoch nicht implementiert, da die Quantifizierung von Hochwasserschäden typischerweise nicht vorgenommen wird. Bisher konzentriert sich das Hochwassermanagement ausschließlich auf ingenieurtechnische Maßnahmen zur Eindämmung der Gefährdung. Dies geschieht entweder durch Hoch- oder Niederdeichung, die auf eine hochwasserfreie oder teilweise Überflutungssteuerung abzielen. Eine risikobasierte Bewertung der Vor- und Nachteile zwischen Hoch- und Niederdeichansatz sowie Kosten-Nutzen-Rechnungen fehlen allerdings ebenfalls. Zudem ist zu erwarten, dass sich die Überschwemmungen Dynamik und das Hochwasserrisiko im Mekong Delta als Folge des Klimawandels und menschlicher Eingriffe in das Delta und das Mekong-Einzugsgebiet verändern werden. Die Analyse der zukünftigen Hochwasserdynamik in Abhängigkeit von diesen Stressoren ist notwendig, um den Übergang von einer alleinigen Gefahrenabwehr zu einem zukunftssicheren, probabilistischen Risikomanagement zu erleichtern.
Ausgehend von diesen Forschungslücken untersucht diese Arbeit den aktuelle Hochwassergefährdung und die zu erwartenden zukünftigen Änderungen, sowie der damit einhergehenden Schäden und Risiken für den Reisanbau im Mekong Delta unter Berücksichtigung existierender und möglicher Hochwasserschutzmaßnahmen, des sich ändernden Klimas, des steigenden Meeresspiegels in Kombination mit der Landabsenkung des Deltas und der geplanten Staudämme im Mekong Einzugsgebiet.
Eine Analyse der jährlichen Hochwasserpegel zeigte starke und robuste steigende Trends in den maximalen Wasserständen der Hochwasser und der Hochwasserdauer flussabwärts der Hochdeichgebiete, wobei eine sprunghafte Veränderung in den Jahren 2000/2001 nach. dem katastrophalen Hochwasser, das die Hochdeichentwicklung einleitete, festgestellt wurde. Diese Veränderungen stehen im Gegensatz zu den negativen Trends, oberstrom der Hocdeichgebiete, was darauf schließen lässt, dass die Hochdeichentwicklung die Hochwassergefahr flussabwärts verlagert hat. Die Ergebnisse der Trendanalyse wurden weiterhin durch hydraulische Simulationen der Überflutungsdynamiken der Hochwasser von 2000 und 2011 bestätigt. Allerdings waren die Hochdeiche nicht die Haupt- und einzige Ursache für den höheren Hochwasserpegel im Jahr 2011 im Vergleich zum Hochwasser im Jahr 2000. Die Hochwasserganglinie des Mekongs hatte den höchsten Beitrag im nördlichen Teil des Deltas oberstrom der Hochdeichgebiete, während der Tidenhub in den zentralen und küstennahen Gebieten stromabwärts des Hochdeichs einen 2-3 mal höheren Einfluss hatte als die Hochdeiche. 
Die wirtschaftlichen Verluste des Reisanbaus wurden rezent auf 25,0-115 Mio. USD geschätzt, für jeweils das 10- und 100-jährliche Hochwasser. Die Schäden sind hierbei sehr sensitiv gegenüber der Hochwasserganglinie, insbesondere dem Zeitpunkt des Auftretens des Hochwasserscheitels. Ein frühes 10-jährliches Hochwasser kann aufgrund des Zusammentreffens des Hochwassers mit der Ernte der Frühjahrsaussaat oder der Aussaat der Sommerfrucht ähnliche Verluste verursachen wie ein 100-jährliches Ereignis, das im Oktober seinen Höhepunkt erreicht. Neben dem Anbau einer dritten Frucht im Jahr könnten die existierenden Hochdeichabschnitte als Hochwasserrückhalteräume genutzt werden und so die Hochwassergefahr und die zu erwartenden Schäden um 5-40% reduzieren. Umgekehrt würde ein weiterer Ausbau der Hochdeiche die derzeit erwarteten jährlichen Hochwasserschäden verdreifachen.
Die Zukunftsprojektionen des Hochwasserrisikos ergaben, dass das Mekong Delta in den nächsten Jahrzehnten zunehmend von tidebedingten Überschwemmungen bedroht sein wird. Der Anstieg des Meeresspiegels in Kombination mit der Landabsenkung erhöht das Ausmaß der Überflutung des Deltas um 20% und den Schaden an der Reisernte um 40-85 Mio. USD. Technische Hochwasserschutzmaßnahmen können diesen Anstieg des Risikos nicht verhindern, da der Schutz des gesamten Deltas allein durch harte Hochwasserschutzbauten technisch und wirtschaftlich nicht realisierbar ist. Daher sind Maßnahmen zur Schadensminderung und zur Anpassung an das veränderte Risiko dringend erforderlich. Als erster und wichtiger Schritt wird hier eine bessere Kontrolle und Reduzierung der Grundwasserentnahme im Delta dringend empfohlen, um die Landabsenkung und dadurch die tidenbedingten Überflutungen sowie die Salzwasserintrusion zu verringern.
Der Klimawandel und die daraus resultierenden Veränderungen im Hochwasserregime des Mekong verursachen eine weitere, aber geringere Erhöhung des Hochwasserrisikos. Die geplanten Staudämme im Mekong Einzugsgebiet könnten die Zunahme der Hochwassergefahr und der landwirtschaftlichen Verluste aufgrund des Klimawandels in extremen Hochwasserjahren zumindest theoretisch abmildern. Der Nutzen von Dämmen zur Minderung des Hochwasserrisikos ist jedoch ungewiss, da die Realisierung der geplanten Dämme sehr umstritten und damit unsicher ist. Weiterhin spielt das Management der Staudämme eine wichtige Rolle für die Hochwasserregulierung. Da die Dämme in erste Linie zur Stromerzeugung gebaut werden, ist der Hochwasserschutz der unterliegenden Anrainerstaaten eher von untergeordneter Bedeutung. Für Vietnam bedeutet das, dass eine ordnungsgemäße Instandhaltung von Deichen und Hochwasserschutzbauten eine hohe Priorität haben sollte, um Abhängigkeiten von den Nachbarstaaten zu vermeiden. Weiterhin ist die Entwicklung von „weichen“ Hochwasserschutzmaßnahmen und -plänen dringend notwendig, da ein alleiniger Schutz durch technische Maßnahmen unmöglich ist. Aufgrund der in dieser Arbeit erzielten Ergebnisse wird daher empfohlen, die Hochdeichkompartimente für das Notfall-Hochwassermanagement bei Extremereignissen zu nutzen. Zu diesem Zweck ist eine verlässliche Hochwasservorhersage unerlässlich, und der Aktionsplan sollte in offiziellen Dokumenten und Gesetzen festgehalten werden, um die Verbindlichkeit und konsequente Umsetzung sicherzustellen.
KW  - Mekong Delta
KW  - flood hazard
KW  - flood risk
KW  - climate change
KW  - Mekong Delta
KW  - Klimawandel
KW  - Hochwassergefahr
KW  - Hochwasserrisiko
Y1  - 2021
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-512830
ER  - 
TY  - JOUR
A1  - Coch, Caroline
A1  - Lamoureux, Scott F.
A1  - Knoblauch, Christian
A1  - Eischeid, Isabell
A1  - Fritz, Michael
A1  - Obu, Jaroslav
A1  - Lantuit, Hugues
T1  - Summer rainfall dissolved organic carbon, solute, and sediment fluxes in a small Arctic coastal catchment on Herschel Island (Yukon Territory, Canada)
JF  - Artic science
N2  - Coastal ecosystems in the Arctic are affected by climate change. As summer rainfall frequency and intensity are projected to increase in the future, more organic matter, nutrients and sediment could bemobilized and transported into the coastal nearshore zones. However, knowledge of current processes and future changes is limited. We investigated streamflow dynamics and the impacts of summer rainfall on lateral fluxes in a small coastal catchment on Herschel Island in the western Canadian Arctic. For the summer monitoring periods of 2014-2016, mean dissolved organic matter flux over 17 days amounted to 82.7 +/- 30.7 kg km(-2) and mean total dissolved solids flux to 5252 +/- 1224 kg km(-2). Flux of suspended sediment was 7245 kg km(-2) in 2015, and 369 kg km(-2) in 2016. We found that 2.0% of suspended sediment was composed of particulate organic carbon. Data and hysteresis analysis suggest a limited supply of sediments; their interannual variability is most likely caused by short-lived localized disturbances. In contrast, our results imply that dissolved organic carbon is widely available throughout the catchment and exhibits positive linear relationship with runoff. We hypothesize that increased projected rainfall in the future will result in a similar increase of dissolved organic carbon fluxes.
KW  - permafrost
KW  - hydrology
KW  - lateral fluxes
KW  - hysteresis
KW  - climate change
Y1  - 2018
U6  - https://doi.org/10.1139/as-2018-0010
SN  - 2368-7460
VL  - 4
IS  - 4
SP  - 750
EP  - 780
PB  - Canadian science publishing
CY  - Ottawa
ER  - 
TY  - JOUR
A1  - Tabares Jimenez, Ximena del Carmen
A1  - Zimmermann, Heike Hildegard
A1  - Dietze, Elisabeth
A1  - Ratzmann, Gregor
A1  - Belz, Lukas
A1  - Vieth-Hillebrand, Andrea
A1  - Dupont, Lydie
A1  - Wilkes, Heinz
A1  - Mapani, Benjamin
A1  - Herzschuh, Ulrike
T1  - Vegetation state changes in the course of shrub encroachment in an African savanna since about 1850 CE and their potential drivers
JF  - Ecology and evolution
N2  - Shrub encroachment has far-reaching ecological and economic consequences in many ecosystems worldwide. Yet, compositional changes associated with shrub encroachment are often overlooked despite having important effects on ecosystem functioning. We document the compositional change and potential drivers for a northern Namibian Combretum woodland transitioning into a Terminalia shrubland. We use a multiproxy record (pollen, sedimentary ancient DNA, biomarkers, compound-specific carbon (delta C-13) and deuterium (delta D) isotopes, bulk carbon isotopes (delta(13)Corg), grain size, geochemical properties) from Lake Otjikoto at high taxonomical and temporal resolution. We provide evidence that state changes in semiarid environments may occur on a scale of one century and that transitions between stable states can span around 80 years and are characterized by a unique vegetation composition. We demonstrate that the current grass/woody ratio is exceptional for the last 170 years, as supported by n-alkane distributions and the delta C-13 and delta(13)Corg records. Comparing vegetation records to environmental proxy data and census data, we infer a complex network of global and local drivers of vegetation change. While our delta D record suggests physiological adaptations of woody species to higher atmospheric pCO(2) concentration and drought, our vegetation records reflect the impact of broad-scale logging for the mining industry, and the macrocharcoal record suggests a decrease in fire activity associated with the intensification of farming. Impact of selective grazing is reflected by changes in abundance and taxonomical composition of grasses and by an increase of nonpalatable and trampling-resistant taxa. In addition, grain-size and spore records suggest changes in the erodibility of soils because of reduced grass cover. Synthesis. We conclude that transitions to an encroached savanna state are supported by gradual environmental changes induced by management strategies, which affected the resilience of savanna ecosystems. In addition, feedback mechanisms that reflect the interplay between management legacies and climate change maintain the encroached state.
KW  - climate change
KW  - fossil pollen
KW  - land-use change
KW  - savanna ecology
KW  - sedimentary ancient DNA
KW  - state and transition
KW  - tree-grass interactions
Y1  - 2019
U6  - https://doi.org/10.1002/ece3.5955
SN  - 2045-7758
VL  - 10
IS  - 2
SP  - 962
EP  - 979
PB  - Wiley
CY  - Hoboken
ER  - 
TY  - JOUR
A1  - Maes, Sybryn L.
A1  - Perring, Michael P.
A1  - Vanhellemont, Margot
A1  - Depauw, Leen
A1  - Van den Bulcke, Jan
A1  - Brumelis, Guntis
A1  - Brunet, Jorg
A1  - Decocq, Guillaume
A1  - den Ouden, Jan
A1  - Härdtle, Werner
A1  - Hedl, Radim
A1  - Heinken, Thilo
A1  - Heinrichs, Steffi
A1  - Jaroszewicz, Bogdan
A1  - Kopecký, Martin
A1  - Malis, Frantisek
A1  - Wulf, Monika
A1  - Verheyen, Kris
T1  - Environmental drivers interactively affect individual tree growth across temperate European forests
JF  - Global change biology
N2  - Forecasting the growth of tree species to future environmental changes requires abetter understanding of its determinants. Tree growth is known to respond to global‐change drivers such as climate change or atmospheric deposition, as well as to localland‐use drivers such as forest management. Yet, large geographical scale studiesexamining interactive growth responses to multiple global‐change drivers are relativelyscarce and rarely consider management effects. Here, we assessed the interactiveeffects of three global‐change drivers (temperature, precipitation and nitrogen deposi-tion) on individual tree growth of three study species (Quercus robur/petraea, Fagus syl-vatica and Fraxinus excelsior). We sampled trees along spatial environmental gradientsacross Europe and accounted for the effects of management for Quercus. We collectedincrement cores from 267 trees distributed over 151 plots in 19 forest regions andcharacterized their neighbouring environment to take into account potentially confounding factors such as tree size, competition, soil conditions and elevation. Wedemonstrate that growth responds interactively to global‐change drivers, with species ‐specific sensitivities to the combined factors. Simultaneously high levels of precipita-tion and deposition benefited Fraxinus, but negatively affected Quercus’ growth, high-lighting species‐specific interactive tree growth responses to combined drivers. ForFagus, a stronger growth response to higher temperatures was found when precipita-tion was also higher, illustrating the potential negative effects of drought stress underwarming for this species. Furthermore, we show that past forest management canmodulate the effects of changing temperatures on Quercus’ growth; individuals in plotswith a coppicing history showed stronger growth responses to higher temperatures.Overall, our findings highlight how tree growth can be interactively determined by glo-bal‐change drivers, and how these growth responses might be modulated by past for-est management. By showing future growth changes for scenarios of environmentalchange, we stress the importance of considering multiple drivers, including past man-agement and their interactions, when predicting tree growth.
KW  - basal area increment
KW  - climate change
KW  - Fagus
KW  - Fraxinus
KW  - historical ecology
KW  - nitrogen deposition
KW  - Quercus
KW  - tree-ring analysis
Y1  - 2018
U6  - https://doi.org/10.1111/gcb.14493
SN  - 1354-1013
SN  - 1365-2486
VL  - 25
IS  - 1
SP  - 201
EP  - 217
PB  - Wiley
CY  - Hoboken
ER  - 
TY  - JOUR
A1  - Mielke, Jahel
T1  - Signals for 2 degrees C
BT  - the influence of policies, market factors and civil society actions on investment decisions for green infrastructure
JF  - Journal of Sustainable Finance & Investment
N2  - The targets of the Paris Agreement make it necessary to redirect finance flows towards sustainable, low-carbon infrastructures and technologies. Currently, the potential of institutional investors to help finance this transition is widely discussed. Thus, this paper takes a closer look at influence factors for green investment decisions of large European insurance companies. With a mix of qualitative and quantitative methods, the importance of policy, market and civil society signals is evaluated. In summary, respondents favor measures that promote green investment, such as feed-in tariffs or adjustments of capital charges for green assets, over ones that make carbon-intensive investments less attractive, such as the phase-out of fossil fuel subsidies or a carbon price. While investors currently see a low impact of the carbon price, they rank a substantial reform as an important signal for the future. Respondents also emphasize that policy signals have to be coherent and credible to coordinate expectations.
KW  - Green infrastructure investment
KW  - policy signals
KW  - green finance
KW  - climate change
KW  - institutional investors
Y1  - 2019
U6  - https://doi.org/10.1080/20430795.2018.1528809
SN  - 2043-0795
SN  - 2043-0809
VL  - 9
IS  - 2
SP  - 87
EP  - 115
PB  - Routledge, Taylor & Francis Group
CY  - Abingdon
ER  - 
TY  - THES
A1  - Mogrovejo Arias, Diana Carolina
T1  - Assessment of the frequency and relevance of potentially pathogenic phenotypes in microbial isolates from Arctic environments
N2  - The Arctic environments constitute rich and dynamic ecosystems, dominated by microorganisms extremely well adapted to survive and function under severe conditions. A range of physiological adaptations allow the microbiota in these habitats to withstand low temperatures, low water and nutrient availability, high levels of UV radiation, etc. In addition, other adaptations of clear competitive nature are directed at not only surviving but thriving in these environments, by disrupting the metabolism of neighboring cells and affecting intermicrobial communication. Since Arctic microbes are bioindicators which amplify climate alterations in the environment, the Arctic region presents the opportunity to study local microbiota and carry out research about interesting, potentially virulent phenotypes that could be dispersed into other habitats around the globe as a consequence of accelerating climate change. In this context, exploration of Arctic habitats as well as descriptions of the microbes inhabiting them are abundant but microbial competitive strategies commonly associated with virulence and pathogens are rarely reported. In this project, environmental samples from the Arctic region were collected and microorganisms (bacteria and fungi) were isolated. The clinical relevance of these microorganisms was assessed by observing the following virulence markers: ability to grow at a range of temperatures, expression of antimicrobial resistance and production of hemolysins. The aim of this project is to determine the frequency and relevance of these characteristics in an effort to understand microbial adaptations in habitats threatened by climate change. The isolates obtained and described here were able to grow at a range of temperatures, in some cases more than 30 °C higher than their original isolation temperature. A considerable number of them consistently expressed compounds capable of lysing sheep and bovine erythrocytes on blood agar at different incubation temperatures. Ethanolic extracts of these bacteria were able to cause rapid and complete lysis of erythrocyte suspensions and might even be hemolytic when assayed on human blood. In silico analyses showed a variety of resistance elements, some of them novel, against natural and synthetic antimicrobial compounds. In vitro experiments against a number of antimicrobial compounds showed resistance phenotypes belonging to wild-type populations and some non-wild type which clearly denote human influence in the acquisition of antimicrobial resistance. The results of this project demonstrate the presence of virulence-associated factors expressed by microorganisms of natural, non-clinical environments. This study contains some of the first reports, to the best of our knowledge, of hemolytic microbes isolated from the Arctic region. In addition, it provides additional information about the presence and expression of intrinsic and acquired antimicrobial resistance in environmental isolates, contributing to the understanding of the evolution of relevant pathogenic species and opportunistic pathogens. Finally, this study highlights some of the potential risks associated with changes in the polar regions (habitat melting and destruction, ecosystem transition and re-colonization) as important indirect consequences of global warming and altered climatic conditions around the planet.
N2  - Die Arktis ist ein reiches und dynamisches Ökosystem, welches von Mikroorganismen dominiert wird, die unter extremen Bedingungen überleben und funktionieren können. Eine Reihe physiologischer Anpassungen ermöglichen es der Mikrobiota, in diesem Lebensraum zu überdauern niedrige Temperaturen, geringe Wasser- und Nährstoffverfügbarkeit, hohe UV-Strahlung, usw. standzuhalten. Andere Fähigkeiten zielen darauf ab, sich einen Konkurrenzvorteil zu verschaffen, indem sie mit antimikrobiellen Substanzen benachbarte Mikroorganismen stören und die intermikrobielle Kommunikation beeinflussen. Arktische Mikroorganismen sind Bioindikatoren, die Klimaveränderungen anzeigen können. Die Arktis bietet Möglichkeiten, die lokale Mikrobiota zu untersuchen, um Rückschlüsse auf den Klimawandel zu ziehen. Insbesondere Forschung über potenziell pathogene Phänotypen, die infolge der Beschleunigung des Klimawandels in andere Lebensräume auf der ganzen Welt verteilt werden könnten, ist hier von herausragender Bedeutung. In diesem Zusammenhang gibt es zahlreiche Untersuchungen zur Erforschung arktischer Lebensräume sowie Beschreibungen der in ihnen lebenden Mikroben, während über bakterielle Konkurrenzstrategien, die üblicherweise mit Virulenz und Krankheitserregern verbunden sind, bisher wenig geforscht wurde. In diesem Projekt wurden Umweltproben aus der Arktis entnommen und Bakterien und Pilze isoliert. Die klinische Relevanz dieser Mikroorganismen wurde durch Untersuchung der folgenden Virulenzmarker bewertet: Fähigkeit, in einem bestimmten Temperaturbereich zu wachsen, Expression von Antibiotikaresistenz und Produktion von Hämolysinen. Ziel dieses Projekts war es, das Vorkommen dieser Eigenschaften zu bestimmen, um die mikrobiellen Anpassungen in vom Klimawandel bedrohten Lebensräumen zu verstehen. Die beschriebenen Bakterienisolate konnten in einem relevanten Temperaturbereich wachsen, in einigen Fällen von mehr als 30 °C höher als ihre ursprüngliche Isolationstemperatur. Eine beträchtliche Anzahl der Isolate exprimierte konsistent Verbindungen, die Schaf- und Rindererythrozyten auf Blutagar bei verschiedenen Inkubationstemperaturen lysieren können. Die Extrakte einiger dieser Bakterien konnten eine schnelle und vollständige Lyse von Schaf- und Rindererythrozytensuspensionen verursachen und sind möglicherweise sogar hämolytisch gegenüber humanem Blut. Darüber hinaus zeigten Genomanalysen eine Vielzahl von Resistenzgenen gegen natürliche und synthetische antimikrobielle Verbindungen, einige neuartige. In-vitro-Experimente zeigten, dass einige Resistenzphänotypen zu Wildtyp-Populationen während andere zu Nicht-Wildtyp gehören, was auf einen menschlichen Einfluss auf den Erwerb von Antibiotikaresistenzen in der Umwelt eindeutig hindeutet. Die Ergebnisse dieses Projekts zeigen das Vorhandensein von Virulenz-assoziierten Faktoren, die von Mikroorganismen natürlicher, nicht klinischer Umgebungen exprimiert werden. Diese Studie enthält nach unserem besten Wissen einige der ersten Berichte über hämolytische Mikroben, die aus der Arktis isoliert wurden. Darüber hinaus liefert es zusätzliche Informationen über das Vorhandensein und die Expression von intrinsischer und erworbener antimikrobieller Resistenz in Umweltisolaten und trägt zum Verständnis der Entwicklung relevanter pathogener Spezies und opportunistischer Pathogene bei. Schließlich beleuchtet diese Studie einige der potenziellen Risiken, die mit Veränderungen in den Polarregionen (Schmelzen und Zerstörung des Lebensraums, Übergang des Ökosystems und Wiederbesiedlung) als wichtige indirekte Folgen der globalen Erwärmung und veränderter klimatischer Bedingungen auf dem Planeten verbunden sind.
KW  - Arctic
KW  - pathogens
KW  - virulence
KW  - hemolysis
KW  - antimicrobial resistance
KW  - climate change
KW  - bacteria
KW  - fungi
KW  - thermotolerance
KW  - antibiotic resistance
KW  - Arktis
KW  - Krankheitserreger
KW  - Virulenz
KW  - Hämolyse
KW  - Antibiotikaresistenz
KW  - Klimawandel
KW  - Bakterien
KW  - Pilze
KW  - Thermotoleranz
Y1  - 2021
N1  - The author would like to acknowledge that the project leading to this doctoral dissertation has received funding from the European Union’s Horizon 2020 research and innovation programme under the Marie Skłodowska-Curie grant agreement No. 675546, research project “Microorganisms in Warming Arctic Environments - MicroArctic”.
ER  - 
TY  - JOUR
A1  - Hickmann, Thomas
A1  - Stehle, Fee
T1  - The Embeddedness of Urban Climate Politics in Multilevel Governance
BT  - a Case Study of South Africa’s Major Cities
JF  - The journal of environment & development : a review of international policy
N2  - Numerous scholars have lately highlighted the importance of cities in the global response to climate change. However, we still have little systematic knowledge on the evolution of urban climate politics in the Global South. In particular, we lack empirical studies that examine how local climate actions arise in political-administrative systems of developing and emerging economies. Therefore, this article adopts a multilevel governance perspective to explore the climate mitigation responses of three major cities in South Africa by looking at their vertical and horizontal integration in the wider governance framework. In the absence of a coherent national climate policy, Johannesburg, Cape Town, and Durban have developed distinct climate actions within their jurisdictions. In their effort to address climate change, transnational city networks have provided considerable technical support to these cities. Yet, substantial domestic political-economic obstacles hinder the three cities to develop a more ambitious stance on climate change.
KW  - climate change
KW  - developing and emerging economies
KW  - local climate policy making
KW  - multilevel governance
KW  - South Africa
KW  - transnational city networks
Y1  - 2018
U6  - https://doi.org/10.1177/1070496518819121
SN  - 1070-4965
SN  - 1552-5465
VL  - 28
IS  - 1
SP  - 54
EP  - 77
PB  - Sage Publ.
CY  - Thousand Oaks
ER  - 
TY  - THES
A1  - Steiglechner, Peter
T1  - Estimating global warming from anthropogenic heat emissions
T1  - Abschätzung der globalen Erwärmung durch anthropogene Abwärme
BT  - conceptual and numerical modelling approaches
BT  - konzeptionelle und numerische Modellierungsansätze
N2  - The forcing from the anthropogenic heat flux (AHF), i.e. the dissipation of primary energy consumed by the human civilisation, produces a direct climate warming. Today, the globally averaged AHF is negligibly small compared to the indirect forcing from greenhouse gas emissions. Locally or regionally, though, it has a significant impact. Historical observations show a constant exponential growth of worldwide energy production. A continuation of this trend might be fueled or even amplified by the exploration of new carbon-free energy sources like fusion power. In such a scenario, the impacts of the AHF become a relevant factor for anthropogenic post-greenhouse gas climate change on the global scale, as well.

This master thesis aims at estimating the climate impacts of such a growing AHF forcing. In the first part of this work, the AHF is built into simple and conceptual, zero- and one-dimensional Energy Balance Models (EBMs), providing quick order of magnitude estimations of the temperature impact. In the one-dimensional EBM, the ice-albedo feedback from enhanced ice melting due to the AHF increases the temperature impact significantly compared to the zero-dimensional EBM.

Additionally, the forcing is built into a climate model of intermediate complexity, CLIMBER-3α. This allows for the investigation of the effect of localised AHF and gives further insights into the impact of the AHF on processes like the ocean heat uptake, sea ice and snow pattern changes
and the ocean circulation.

The global mean temperature response from the AHF today is of the order of 0.010 − 0.016 K in all reasonable model configurations tested. A transient tenfold increase of this forcing heats up the Earth System additionally by roughly 0.1 − 0.2 K in the presented models. Further growth
can also affect the tipping probability of certain climate elements.

Most renewable energy sources do not or only partially contribute to the AHF forcing as the energy from these sources dissipates anyway. Hence, the transition to a (carbon-free) renewable energy mix, which, in particular, does not rely on nuclear power, eliminates the local and global climate impacts from the increasing AHF forcing, independent of the growth of energy production.
N2  - Das Forcing durch die Emission von anthropogener Abwärme (AHF), d.h. die Dissipation von konsumierter Primärenergie, stellt einen Beitrag zu einer direkten Klimaerwärmung dar.

Der global gemittelte AHF ist heutzutage vernachlässigbar klein im Vergleich zu dem indirekten Forcing durch Treibhausgasemissionen. Auf lokaler oder regionaler Ebene hat das Forcing jedoch einen signifikanten Einfluss. Die Energieproduktion hat in der Vergangenheit ein konstant exponentielles Wachstum aufgezeigt. Dieser Trend kann durch die Erschließung neuer CO2-neutraler Energiequellen, wie zum Beispiel Fusionsenergie, weiter bestärkt und angetrieben werden. In solch einem Szenario führt das AHF Forcing zu einem auch global relevanten Beitrag zum menschengemachten Klimawandel abseits der Treibhausgasemissionen.

In dieser Arbeit sollen die Auswirkungen eines wachsenden AHF auf das Klima abgeschätzt werden. Im ersten Teil wird das zusätzliche Forcing in einfache und konzeptionelle, null- und eindimensionale Energiebilanzmodelle (EBM) eingebaut. Diese bieten schnelle Größenordnungsabschätzungen des Temperaturanstiegs. Im eindimensionalen EBM erhöht die Eis-Albedo-Rückkopplung die Temperatur signifikant im Verlgeich zum nulldimensionalen Fall aufgrund von verstärkter Eisschmelze. Zusätzlich, wird das AHF Forcing in das Erdsystemmodell mittlerer Komplexität CLIMBER-3α eingebaut. Dieses erlaubt eine Analyse des Effekts eines heterogenen AHF Forcings und gibt weitere Einblicke in die Einflüsse auf Prozessse wie den Wärmefluss in den Ozean, Veränderungen in Meereis und Schneebedeckung und die Ozeanzirkulation.

Der global gemittelte Temperaturanstieg für das heutige AHF Forcing beträgt 0.010 − 0.016 K in allen realistischen, getesteten Modellkonfigurationen. Ein transienter Anstieg des Forcings auf den zehnfachen Wert erwärmt die Erde um weitere 0.1 − 0.2 K in den vorgestellten Modellen. Weiteres Wachstum kann zusätzlich auch das Kippen von bestimmten Klimaelementen beeinflussen. Die meisten erneuerbaren Energiequellen tragen nicht oder nur kaum zu der anthropogenen Abwärme bei, da deren Energie sowieso dissipiert. Daher beseitigt ein Wechsel auf einen CO2-neutralen, erneuerbaren Energiemix, der explizit nicht auf nuklearen Brennstoffen basiert, unabhängig von dem Wachstum der Energieproduktion die lokalen wie auch globalen Auswirkungen des AHF Effekts.
KW  - climate change
KW  - waste heat
KW  - heat island
KW  - energy balance model
KW  - climate model of intermediate complexity
KW  - Klimawandel
KW  - Abwärme
KW  - Wärmeinsel
KW  - Energiebilanzmodell
KW  - Klimamodell mittlerer Komplexität
Y1  - 2021
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-498866
ER  - 
TY  - RPRT
A1  - Šedová, Barbora
A1  - Čizmaziová, Lucia
A1  - Cook, Athene
T1  - A meta-analysis of climate migration literature
T2  - CEPA Discussion Papers
N2  - The large literature that aims to find evidence of climate migration delivers mixed findings. This meta-regression analysis i) summarizes direct links between adverse climatic events and migration, ii) maps patterns of climate migration, and iii) explains the variation in outcomes. Using a set of limited dependent variable models, we meta-analyze thus-far the most comprehensive sample of 3,625 estimates from 116 original studies and produce novel insights on climate migration. We find that extremely high temperatures and drying conditions increase migration. We do not find a significant effect of sudden-onset events. Climate migration is most likely to emerge due to contemporaneous events, to originate in rural areas and to take place in middle-income countries, internally, to cities. The likelihood to become trapped in affected areas is higher for women and in low-income countries, particularly in Africa. We uniquely quantify how pitfalls typical for the broader empirical climate impact literature affect climate migration findings. We also find evidence of different publication biases.
T3  - CEPA Discussion Papers - 29 
KW  - migration
KW  - climate change
KW  - meta-analysis
Y1  - 2021
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-499827
SN  - 2628-653X
IS  - 29
ER  - 
TY  - JOUR
A1  - Chan, Sander
A1  - Boran, Idil
A1  - van Asselt, Harro
A1  - Iacobuta, Gabriela
A1  - Niles, Navam
A1  - Rietig, Katharine
A1  - Scobie, Michelle
A1  - Bansard, Jennifer S.
A1  - Delgado Pugley, Deborah
A1  - Delina, Laurence L.
A1  - Eichhorn, Friederike
A1  - Ellinger, Paula
A1  - Enechi, Okechukwu
A1  - Hale, Thomas
A1  - Hermwille, Lukas
A1  - Hickmann, Thomas
A1  - Honegger, Matthias
A1  - Hurtado Epstein, Andrea
A1  - Theuer, Stephanie La Hoz
A1  - Mizo, Robert
A1  - Sun, Yixian
A1  - Toussaint, Patrick
A1  - Wambugu, Geoffrey
T1  - Promises and risks of nonstate action in climate and sustainability governance
JF  - Wiley interdisciplinary reviews : Climate change
KW  - climate change
KW  - governance
KW  - nonstate actions
KW  - SDGs
KW  - sustainable development
Y1  - 2019
U6  - https://doi.org/10.1002/wcc.572
SN  - 1757-7780
SN  - 1757-7799
VL  - 10
IS  - 3
PB  - Wiley
CY  - Hoboken
ER  - 
TY  - JOUR
A1  - Marzetz, Vanessa
A1  - Spijkerman, Elly
A1  - Striebel, Maren
A1  - Wacker, Alexander
T1  - Phytoplankton Community Responses to Interactions Between Light Intensity, Light Variations, and Phosphorus Supply
JF  - Frontiers in Environmental Science
N2  - In a changing world, phytoplankton communities face a large variety of challenges including altered light regimes. These alterations are caused by more pronounced stratification due to rising temperatures, enhanced eutrophication, and browning of lakes. Community responses toward these effects can emerge as alterations in physiology, biomass, biochemical composition, or diversity. In this study, we addressed the combined effects of changes in light and nutrient conditions on community responses. In particular, we investigated how light intensity and variability under two nutrient conditions influence (1) fast responses such as adjustments in photosynthesis, (2) intermediate responses such as pigment adaptation and (3) slow responses such as changes in community biomass and species composition. Therefore, we exposed communities consisting of five phytoplankton species belonging to different taxonomic groups to two constant and two variable light intensity treatments combined with two levels of phosphorus supply. The tested phytoplankton communities exhibited increased fast reactions of photosynthetic processes to light variability and light intensity. The adjustment of their light harvesting mechanisms via community pigment composition was not affected by light intensity, variability, or nutrient supply. However, pigment specific effects of light intensity, light variability, and nutrient supply on the proportion of the respective pigments were detected. Biomass was positively affected by higher light intensity and nutrient concentrations while the direction of the effect of variability was modulated by light intensity. Light variability had a negative impact on biomass at low, but a positive impact at high light intensity. The effects on community composition were species specific. Generally, the proportion of green algae was higher under high light intensity, whereas the cyanobacterium performed better under low light conditions. In addition to that, the diatom and the cryptophyte performed better with high nutrient supply while the green algae as well as the cyanobacterium performed better at low nutrient conditions. This shows that light intensity, light variability, and nutrient supply interactively affect communities. Furthermore, the responses are highly species and pigment specific, thus to clarify the effects of climate change a deeper understanding of the effects of light variability and species interactions within communities is important.
KW  - phytoplankton communities
KW  - light variability
KW  - photosynthetic rate
KW  - climate change
KW  - resource competition
KW  - light intensity (irradiance)
KW  - pigment composition
KW  - nutrient supply
Y1  - 2020
U6  - https://doi.org/10.3389/fenvs.2020.539733
SN  - 2296-665X
VL  - 8
PB  - Frontiers Media
CY  - Lausanne
ER  - 
TY  - GEN
A1  - Marzetz, Vanessa
A1  - Spijkerman, Elly
A1  - Striebel, Maren
A1  - Wacker, Alexander
T1  - Phytoplankton Community Responses to Interactions Between Light Intensity, Light Variations, and Phosphorus Supply
T2  - Postprints der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe
N2  - In a changing world, phytoplankton communities face a large variety of challenges including altered light regimes. These alterations are caused by more pronounced stratification due to rising temperatures, enhanced eutrophication, and browning of lakes. Community responses toward these effects can emerge as alterations in physiology, biomass, biochemical composition, or diversity. In this study, we addressed the combined effects of changes in light and nutrient conditions on community responses. In particular, we investigated how light intensity and variability under two nutrient conditions influence (1) fast responses such as adjustments in photosynthesis, (2) intermediate responses such as pigment adaptation and (3) slow responses such as changes in community biomass and species composition. Therefore, we exposed communities consisting of five phytoplankton species belonging to different taxonomic groups to two constant and two variable light intensity treatments combined with two levels of phosphorus supply. The tested phytoplankton communities exhibited increased fast reactions of photosynthetic processes to light variability and light intensity. The adjustment of their light harvesting mechanisms via community pigment composition was not affected by light intensity, variability, or nutrient supply. However, pigment specific effects of light intensity, light variability, and nutrient supply on the proportion of the respective pigments were detected. Biomass was positively affected by higher light intensity and nutrient concentrations while the direction of the effect of variability was modulated by light intensity. Light variability had a negative impact on biomass at low, but a positive impact at high light intensity. The effects on community composition were species specific. Generally, the proportion of green algae was higher under high light intensity, whereas the cyanobacterium performed better under low light conditions. In addition to that, the diatom and the cryptophyte performed better with high nutrient supply while the green algae as well as the cyanobacterium performed better at low nutrient conditions. This shows that light intensity, light variability, and nutrient supply interactively affect communities. Furthermore, the responses are highly species and pigment specific, thus to clarify the effects of climate change a deeper understanding of the effects of light variability and species interactions within communities is important.
T3  - Zweitveröffentlichungen der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe - 1109 
KW  - phytoplankton communities
KW  - light variability
KW  - photosynthetic rate
KW  - climate change
KW  - resource competition
KW  - light intensity (irradiance)
KW  - pigment composition
KW  - nutrient supply
Y1  - 2021
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-491041
SN  - 1866-8372
IS  - 1109
ER  - 
TY  - JOUR
A1  - Kahl, Sandra M.
A1  - Lenhard, Michael
A1  - Joshi, Jasmin Radha
T1  - Compensatory mechanisms to climate change in the widely distributed species Silene vulgaris
JF  - The journal of ecology
N2  - The adaptation of plants to future climatic conditions is crucial for their survival. Not surprisingly, phenotypic responses to climate change have already been observed in many plant populations. These responses may be due to evolutionary adaptive changes or phenotypic plasticity. Especially plant species with a wide geographic range are either expected to show genetic differentiation in response to differing climate conditions or to have a high phenotypic plasticity. We investigated phenotypic responses and plasticity as an estimate of the adaptive potential in the widespread species Silene vulgaris. In a greenhouse experiment, 25 European populations covering a geographic range from the Canary Islands to Sweden were exposed to three experimental precipitation and two temperature regimes mimicking a possible climate-change scenario for central Europe. We hypothesized that southern populations have a better performance under high temperature and drought conditions, as they are already adapted to a comparable environment. We found that our treatments significantly influenced the plants, but did not reveal a latitudinal difference in response to climate treatments for most plant traits. Only flower number showed a stronger plasticity in northern European populations (e.g. Swedish populations) where numbers decreased more drastically with increased temperature and decreased precipitation treatment. Synthesis. The significant treatment response in Silene vulgaris, independent of population origin - except for the number of flowers produced - suggests a high degree of universal phenotypic plasticity in this widely distributed species. This reflects the likely adaptation strategy of the species and forms the basis for a successful survival strategy during upcoming climatic changes. However, as flower number, a strongly fitness-related trait, decreased more strongly in northern populations under a climate-change scenario, there might be limits to adaptation even in this widespread, plastic species.
KW  - climate change
KW  - global change ecology
KW  - latitudinal gradient
KW  - local adaptation
KW  - phenotypic plasticity
KW  - plant performance
KW  - temperature increase
Y1  - 2019
U6  - https://doi.org/10.1111/1365-2745.13133
SN  - 0022-0477
SN  - 1365-2745
VL  - 107
IS  - 4
SP  - 1918
EP  - 1930
PB  - Wiley
CY  - Hoboken
ER  - 
TY  - GEN
A1  - Ayzel, Georgy
A1  - Izhitskiy, Alexander
T1  - Climate change impact assessment on freshwater inflow into the Small Aral Sea
T2  - Postprints der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe
N2  - During the last few decades, the rapid separation of the Small Aral Sea from the isolated basin has changed its hydrological and ecological conditions tremendously. In the present study, we developed and validated the hybrid model for the Syr Darya River basin based on a combination of state-of-the-art hydrological and machine learning models. Climate change impact on freshwater inflow into the Small Aral Sea for the projection period 2007–2099 has been quantified based on the developed hybrid model and bias corrected and downscaled meteorological projections simulated by four General Circulation Models (GCM) for each of three Representative Concentration Pathway scenarios (RCP). The developed hybrid model reliably simulates freshwater inflow for the historical period with a Nash–Sutcliffe efficiency of 0.72 and a Kling–Gupta efficiency of 0.77. Results of the climate change impact assessment showed that the freshwater inflow projections produced by different GCMs are misleading by providing contradictory results for the projection period. However, we identified that the relative runoff changes are expected to be more pronounced in the case of more aggressive RCP scenarios. The simulated projections of freshwater inflow provide a basis for further assessment of climate change impacts on hydrological and ecological conditions of the Small Aral Sea in the 21st Century.
T3  - Zweitveröffentlichungen der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe - 1071 
KW  - Small Aral Sea
KW  - hydrology
KW  - climate change
KW  - modeling
KW  - machine learning
Y1  - 2021
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-472794
SN  - 1866-8372
IS  - 1071
ER  - 
TY  - GEN
A1  - Metin, Ayse Duha
A1  - Dung, Nguyen Viet
A1  - Schröter, Kai
A1  - Guse, Björn
A1  - Apel, Heiko
A1  - Kreibich, Heidi
A1  - Vorogushyn, Sergiy
A1  - Merz, Bruno
T1  - How do changes along the risk chain affect flood risk?
T2  - Postprints der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe
N2  - Flood risk is impacted by a range of physical and socio-economic processes. Hence, the quantification of flood risk ideally considers the complete flood risk chain, from atmospheric processes through catchment and river system processes to damage mechanisms in the affected areas. Although it is generally accepted that a multitude of changes along the risk chain can occur and impact flood risk, there is a lack of knowledge of how and to what extent changes in influencing factors propagate through the chain and finally affect flood risk. To fill this gap, we present a comprehensive sensitivity analysis which considers changes in all risk components, i.e. changes in climate, catchment, river system, land use, assets, and vulnerability. The application of this framework to the mesoscale Mulde catchment in Germany shows that flood risk can vary dramatically as a consequence of plausible change scenarios. It further reveals that components that have not received much attention, such as changes in dike systems or in vulnerability, may outweigh changes in often investigated components, such as climate. Although the specific results are conditional on the case study area and the selected assumptions, they emphasize the need for a broader consideration of potential drivers of change in a comprehensive way. Hence, our approach contributes to a better understanding of how the different risk components influence the overall flood risk.
T3  - Zweitveröffentlichungen der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe - 1067 
KW  - global sensitivity analysis
KW  - climate change
KW  - river floods
KW  - frequency
KW  - Europe
KW  - model
KW  - vulnerability
KW  - adaptation
KW  - strategies
KW  - catchment
Y1  - 2021
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-468790
SN  - 1866-8372
IS  - 1067
ER  - 
TY  - GEN
A1  - Epp, Laura Saskia
A1  - Kruse, Stefan
A1  - Kath, Nadja J.
A1  - Stoof-Leichsenring, Kathleen Rosemarie
A1  - Tiedemann, Ralph
A1  - Pestryakova, Luidmila Agafyevna
A1  - Herzschuh, Ulrike
T1  - Temporal and spatial patterns of mitochondrial haplotype and species distributions in Siberian larches inferred from ancient environmental DNA and modeling
T2  - Postprints der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe
N2  - Changes in species' distributions are classically projected based on their climate envelopes. For Siberian forests, which have a tremendous significance for vegetation-climate feedbacks, this implies future shifts of each of the forest-forming larch (Larix) species to the north-east. However, in addition to abiotic factors, reliable projections must assess the role of historical biogeography and biotic interactions. Here, we use sedimentary ancient DNA and individual-based modelling to investigate the distribution of larch species and mitochondrial haplotypes through space and time across the treeline ecotone on the southern Taymyr peninsula, which at the same time presents a boundary area of two larch species. We find spatial and temporal patterns, which suggest that forest density is the most influential driver determining the precise distribution of species and mitochondrial haplotypes. This suggests a strong influence of competition on the species' range shifts. These findings imply possible climate change outcomes that are directly opposed to projections based purely on climate envelopes. Investigations of such fine-scale processes of biodiversity change through time are possible using paleoenvironmental DNA, which is available much more readily than visible fossils and can provide information at a level of resolution that is not reached in classical palaeoecology.
T3  - Zweitveröffentlichungen der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe - 1052 
KW  - ecological genetics
KW  - ecological modelling
KW  - palaeoecology
KW  - plant ecology
KW  - climate change
KW  - introgression
KW  - temperature
KW  - treeline
KW  - vegetation
KW  - mitochondrial haplotypes
KW  - Siberian larch
KW  - larch species
KW  - range shifts
KW  - vegetation-climate feedbacks
KW  - ecosystems
KW  - impacts
KW  - dynamics
Y1  - 2020
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-468352
SN  - 1866-8372
IS  - 1052
ER  - 
TY  - GEN
A1  - Smith, Taylor
A1  - Bookhagen, Bodo
T1  - Assessing Multi-Temporal Snow-Volume Trends in High Mountain Asia From 1987 to 2016 Using High-Resolution Passive Microwave Data
T2  - Postprints der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe
N2  - High Mountain Asia (HMA) is dependent upon both the amount and timing of snow and glacier meltwater. Previous model studies and coarse resolution (0.25° × 0.25°, ∼25 km × 25 km) passive microwave assessments of trends in the volume and timing of snowfall, snowmelt, and glacier melt in HMA have identified key spatial and seasonal heterogeneities in the response of snow to changes in regional climate. Here we use recently developed, continuous, internally consistent, and high-resolution passive microwave data (3.125 km × 3.125 km, 1987–2016) from the special sensor microwave imager instrument family to refine and extend previous estimates of changes in the snow regime of HMA. We find an overall decline in snow volume across HMA; however, there exist spatially contiguous regions of increasing snow volume—particularly during the winter season in the Pamir, Karakoram, Hindu Kush, and Kunlun Shan. Detailed analysis of changes in snow-volume trends through time reveal a large step change from negative trends during the period 1987–1997, to much more positive trends across large regions of HMA during the periods 1997–2007 and 2007–2016. We also find that changes in high percentile monthly snow-water volume exhibit steeper trends than changes in low percentile snow-water volume, which suggests a reduction in the frequency of high snow-water volumes in much of HMA. Regions with positive snow-water storage trends generally correspond to regions of positive glacier mass balances.
T3  - Zweitveröffentlichungen der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe - 1020 
KW  - snow
KW  - glacier
KW  - climate change
KW  - passive microwave
KW  - special sensor microwave imager
KW  - special sensor microwave imager/sounder
Y1  - 2020
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-484176
SN  - 1866-8372
IS  - 1020
ER  - 
TY  - JOUR
A1  - Smith, Taylor
A1  - Bookhagen, Bodo
T1  - Assessing Multi-Temporal Snow-Volume Trends in High Mountain Asia From 1987 to 2016 Using High-Resolution Passive Microwave Data
JF  - Frontiers in Earth Science
N2  - High Mountain Asia (HMA) is dependent upon both the amount and timing of snow and glacier meltwater. Previous model studies and coarse resolution (0.25° × 0.25°, ∼25 km × 25 km) passive microwave assessments of trends in the volume and timing of snowfall, snowmelt, and glacier melt in HMA have identified key spatial and seasonal heterogeneities in the response of snow to changes in regional climate. Here we use recently developed, continuous, internally consistent, and high-resolution passive microwave data (3.125 km × 3.125 km, 1987–2016) from the special sensor microwave imager instrument family to refine and extend previous estimates of changes in the snow regime of HMA. We find an overall decline in snow volume across HMA; however, there exist spatially contiguous regions of increasing snow volume—particularly during the winter season in the Pamir, Karakoram, Hindu Kush, and Kunlun Shan. Detailed analysis of changes in snow-volume trends through time reveal a large step change from negative trends during the period 1987–1997, to much more positive trends across large regions of HMA during the periods 1997–2007 and 2007–2016. We also find that changes in high percentile monthly snow-water volume exhibit steeper trends than changes in low percentile snow-water volume, which suggests a reduction in the frequency of high snow-water volumes in much of HMA. Regions with positive snow-water storage trends generally correspond to regions of positive glacier mass balances.
KW  - snow
KW  - glacier
KW  - climate change
KW  - passive microwave
KW  - special sensor microwave imager
KW  - special sensor microwave imager/sounder
Y1  - 2020
U6  - https://doi.org/10.3389/feart.2020.559175
SN  - 2296-6463
VL  - 8
PB  - Frontiers Media
CY  - Lausanne
ER  - 
TY  - JOUR
A1  - Grimm-Seyfarth, Annegret
A1  - Mihoub, Jean-Baptiste
A1  - Henle, Klaus
T1  - Functional traits determine the different effects of prey, predators, and climatic extremes on desert reptiles
JF  - Ecosphere : the magazine of the International Ecology University
N2  - Terrestrial reptiles are particularly vulnerable to climate change. Their highest density and diversity can be found in hot drylands, ecosystems which demonstrate extreme climatic conditions. However, reptiles are not isolated systems but part of a large species assemblage with many trophic dependencies. While direct relations among climatic conditions, invertebrates, vegetation, or reptiles have already been explored, to our knowledge, species’ responses to direct and indirect pathways of multiple climatic and biotic factors and their interactions have rarely been examined comprehensively. We investigated direct and indirect effects of climatic and biotic parameters on the individual (body condition) and population level (occupancy) of eight abundant lizard species with different functional traits in an arid Australian lizard community using a 30‐yr multi‐trophic monitoring study. We used structural equation modeling to disentangle single and interactive effects. We then assessed whether species could be grouped into functional groups according to their functional traits and their responses to different parameters. We found that lizard species differed strongly in how they responded to climatic and biotic factors. However, the factors to which they responded seemed to be determined by their functional traits. While responses on body condition were determined by habitat, activity time, and prey, responses on occupancy were determined by habitat specialization, body size, and longevity. Our findings highlight the importance of indirect pathways through climatic and biotic interactions, which should be included into predictive models to increase accuracy when predicting species’ responses to climate change. Since one might never obtain all mechanistic pathways at the species level, we propose an approach of identifying relevant species traits that help grouping species into functional groups at different ecological levels, which could then be used for predictive modeling.
KW  - Australia
KW  - climate change
KW  - Gekkonidae
KW  - periodic flooding
KW  - Scincidae
KW  - species functional traits
KW  - species interactions
KW  - structural equation modeling
Y1  - 2019
U6  - https://doi.org/10.1002/ecs2.2865
SN  - 2150-8925
VL  - 10
IS  - 9
PB  - Wiley
CY  - Hoboken
ER  - 
TY  - JOUR
A1  - Ayzel, Georgy
A1  - Izhitskiy, Alexander
T1  - Climate Change Impact Assessment on Freshwater Inflow into the Small Aral Sea
JF  - Water
N2  - During the last few decades, the rapid separation of the Small Aral Sea from the isolated basin has changed its hydrological and ecological conditions tremendously. In the present study, we developed and validated the hybrid model for the Syr Darya River basin based on a combination of state-of-the-art hydrological and machine learning models. Climate change impact on freshwater inflow into the Small Aral Sea for the projection period 2007-2099 has been quantified based on the developed hybrid model and bias corrected and downscaled meteorological projections simulated by four General Circulation Models (GCM) for each of three Representative Concentration Pathway scenarios (RCP). The developed hybrid model reliably simulates freshwater inflow for the historical period with a Nash-Sutcliffe efficiency of 0.72 and a Kling-Gupta efficiency of 0.77. Results of the climate change impact assessment showed that the freshwater inflow projections produced by different GCMs are misleading by providing contradictory results for the projection period. However, we identified that the relative runoff changes are expected to be more pronounced in the case of more aggressive RCP scenarios. The simulated projections of freshwater inflow provide a basis for further assessment of climate change impacts on hydrological and ecological conditions of the Small Aral Sea in the 21st Century.
KW  - Small Aral Sea
KW  - hydrology
KW  - climate change
KW  - modeling
KW  - machine learning
Y1  - 2019
U6  - https://doi.org/10.3390/w11112377
SN  - 2073-4441
VL  - 11
IS  - 11
PB  - MDPI
CY  - Basel
ER  - 
TY  - JOUR
A1  - Schwarzer, Christian
A1  - Joshi, Jasmin Radha
T1  - Ecotypic differentiation, hybridization and clonality facilitate the persistence of a cold-adapted sedge in European bogs
JF  - Biological journal of the Linnean Society : a journal of evolution
N2  - Recent research has shown that many cold-adapted species survived the last glacial maximum (LGM) in northern refugia. Whether this evolutionary history has had consequences for their genetic diversity and adaptive potential remains unknown. We sampled 14 populations of Carex limosa, a sedge specialized to bog ecosystems, along a latitudinal gradient from its Scandinavian core to the southern lowland range-margin in Germany. Using microsatellite and experimental common-garden data, we evaluated the impacts of global climate change along this gradient and assessed the conservation status of the southern marginal populations. Microsatellite data revealed two highly distinct genetic groups and hybrid individuals. In our common-garden experiment, the two groups showed divergent responses to increased nitrogen/phosphorus (N/P) availability, suggesting ecotypic differentiation. Each group formed genetically uniform populations at both northern and southern sampling areas. Mixed populations occurred throughout our sampling area, an area that was entirely glaciated during the LGM. The fragmented distribution implies allopatric divergence at geographically separated refugia that putatively differed in N/P availability. Molecular data and an observed low hybrid fecundity indicate the importance of clonal reproduction for hybrid populations. At the southern range-margin, however, all populations showed effects of clonality, lowered fecundity and low competitiveness, suggesting abiotic and biotic constraints to population persistence.
KW  - biogeography
KW  - bog/mire plants
KW  - Carex limosa
KW  - climate change
KW  - glacial divergence
KW  - global change
KW  - leading/trailing edge
KW  - population differentiation
KW  - sexual/asexual reproduction
Y1  - 2019
U6  - https://doi.org/10.1093/biolinnean/blz141
SN  - 0024-4066
SN  - 1095-8312
VL  - 128
IS  - 4
SP  - 909
EP  - 925
PB  - Oxford Univ. Press
CY  - Oxford
ER  - 
TY  - GEN
A1  - Jongejans, Loeka L.
A1  - Strauss, Jens
A1  - Lenz, Josefine
A1  - Peterse, Francien
A1  - Mangelsdorf, Kai
A1  - Fuchs, Matthias
A1  - Grosse, Guido
T1  - Organic matter characteristics in yedoma and thermokarst deposits on Baldwin Peninsula, west Alaska
T2  - Postprints der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe
N2  - As Arctic warming continues and permafrost thaws, more soil and sedimentary organic matter (OM) will be decomposed in northern high latitudes. Still, uncertainties remain in the quality of the OM and the size of the organic carbon (OC) pools stored in different deposit types of permafrost landscapes. This study presents OM data from deep permafrost and lake deposits on the Baldwin Peninsula which is located in the southern portion of the continuous permafrost zone in west Alaska. Sediment samples from yedoma and drained thermokarst lake basin (DTLB) deposits as well as thermokarst lake sediments were analyzed for cryostratigraphical and biogeochemical parameters and their lipid biomarker composition to identify the below-ground OC pool size and OM quality of ice-rich permafrost on the Baldwin Peninsula. We provide the first detailed characterization of yedoma deposits on Baldwin Peninsula. We show that three-quarters of soil OC in the frozen deposits of the study region (total of 68 Mt) is stored in DTLB deposits (52 Mt) and one-quarter in the frozen yedoma deposits (16 Mt). The lake sediments contain a relatively small OC pool (4 Mt), but have the highest volumetric OC content (93 kgm(-3)) compared to the DTLB (35 kgm(-3)) and yedoma deposits (8 kgm(-3)), largely due to differences in the ground ice content. The biomarker analysis indicates that the OM in both yedoma and DTLB deposits is mainly of terrestrial origin. Nevertheless, the relatively high carbon preference index of plant leaf waxes in combination with a lack of a degradation trend with depth in the yedoma deposits indi-cates that OM stored in yedoma is less degraded than that stored in DTLB deposits. This suggests that OM in yedoma has a higher potential for decomposition upon thaw, despite the relatively small size of this pool. These findings show that the use of lipid biomarker analysis is valuable in the assessment of the potential future greenhouse gas emissions from thawing permafrost, especially because this area, close to the discontinuous permafrost boundary, is projected to thaw substantially within the 21st century.
T3  - Zweitveröffentlichungen der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe - 985 
KW  - northern seward peninsula
KW  - deep permafrost carbon
KW  - Laptev Sea region
KW  - Arctic Siberia
KW  - climate change
KW  - gas production
KW  - Lena delta
KW  - soils
KW  - release
KW  - tundra
Y1  - 2020
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-446250
SN  - 1866-8372
IS  - 20
SP  - 6033
EP  - 6048
ER  - 
TY  - GEN
A1  - Alter, S. Elizabeth
A1  - Meyer, Matthias
A1  - Post, Klaas
A1  - Czechowski, Paul
A1  - Gravlund, Peter
A1  - Gaines, Cork
A1  - Rosenbaum, Howard C.
A1  - Kaschner, Kristin
A1  - Turvey, Samuel T.
A1  - van der Plicht, Johannes
A1  - Shapiro, Beth
A1  - Hofreiter, Michael
T1  - Climate impacts on transocean dispersal and habitat in gray whales from the Pleistocene to 2100
T2  - Postprints der Universität Potsdam : Mathematisch Naturwissenschaftliche Reihe
N2  - Arctic animals face dramatic habitat alteration due to ongoing climate change. Understanding how such species have responded to past glacial cycles can help us forecast their response to today's changing climate. Gray whales are among those marine species likely to be strongly affected by Arctic climate change, but a thorough analysis of past climate impacts on this species has been complicated by lack of information about an extinct population in the Atlantic. While little is known about the history of Atlantic gray whales or their relationship to the extant Pacific population, the extirpation of the Atlantic population during historical times has been attributed to whaling. We used a combination of ancient and modern DNA, radiocarbon dating and predictive habitat modelling to better understand the distribution of gray whales during the Pleistocene and Holocene. Our results reveal that dispersal between the Pacific and Atlantic was climate dependent and occurred both during the Pleistocene prior to the last glacial period and the early Holocene immediately following the opening of the Bering Strait. Genetic diversity in the Atlantic declined over an extended interval that predates the period of intensive commercial whaling, indicating this decline may have been precipitated by Holocene climate or other ecological causes. These first genetic data for Atlantic gray whales, particularly when combined with predictive habitat models for the year 2100, suggest that two recent sightings of gray whales in the Atlantic may represent the beginning of the expansion of this species' habitat beyond its currently realized range.
T3  - Zweitveröffentlichungen der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe - 965 
KW  - ancient DNA
KW  - climate change
KW  - last glacial maximum
KW  - marine mammal
Y1  - 2020
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-438920
SN  - 1866-8372
IS  - 965
SP  - 1510
EP  - 1522
ER  - 
TY  - GEN
A1  - Triet, Nguyen Van Khanh
A1  - Dung, Nguyen Viet
A1  - Merz, Bruno
A1  - Apel, Heiko
T1  - Towards risk-based flood management in highly productive paddy rice cultivation
BT  - concept development and application to the Mekong Delta
T2  - Postprints der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe
N2  - Flooding is an imminent natural hazard threatening most river deltas, e.g. the Mekong Delta. An appropriate flood management is thus required for a sustainable development of the often densely populated regions. Recently, the traditional event-based hazard control shifted towards a risk management approach in many regions, driven by intensive research leading to new legal regulation on flood management. However, a large-scale flood risk assessment does not exist for the Mekong Delta. Particularly, flood risk to paddy rice cultivation, the most important economic activity in the delta, has not been performed yet. Therefore, the present study was developed to provide the very first insight into delta-scale flood damages and risks to rice cultivation. The flood hazard was quantified by probabilistic flood hazard maps of the whole delta using a bivariate extreme value statistics, synthetic flood hydrographs, and a large-scale hydraulic model. The flood risk to paddy rice was then quantified considering cropping calendars, rice phenology, and harvest times based on a time series of enhanced vegetation index (EVI) derived from MODIS satellite data, and a published rice flood damage function. The proposed concept provided flood risk maps to paddy rice for the Mekong Delta in terms of expected annual damage. The presented concept can be used as a blueprint for regions facing similar problems due to its generic approach. Furthermore, the changes in flood risk to paddy rice caused by changes in land use currently under discussion in the Mekong Delta were estimated. Two land-use scenarios either intensifying or reducing rice cropping were considered, and the changes in risk were presented in spatially explicit flood risk maps. The basic risk maps could serve as guidance for the authorities to develop spatially explicit flood management and mitigation plans for the delta. The land-use change risk maps could further be used for adaptive risk management plans and as a basis for a cost-benefit of the discussed land-use change scenarios. Additionally, the damage and risks maps may support the recently initiated agricultural insurance programme in Vietnam.
T3  - Zweitveröffentlichungen der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe - 931 
KW  - climate change
KW  - hazard analysis
KW  - sea level
KW  - Tho city
KW  - Vietnam
KW  - damage
KW  - uncertainty
KW  - models
KW  - floodplains
KW  - hydrology
Y1  - 2020
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-446032
SN  - 1866-8372
IS  - 931
SP  - 2859
EP  - 2876
ER  - 
TY  - JOUR
A1  - Krol, Maarten
A1  - Jaeger, Annekathrin
A1  - Bronstert, Axel
A1  - Güntner, Andreas
T1  - Integrated modelling of climate, water, soil, agricultural and socio-economic processes: A general introduction of the methodology and some exemplary results from the semi-arid north-east of Brazil
JF  - Journal of hydrology
N2  - Many semi-arid regions are characterised by water scarcity and vulnerability of natural resources, pronounced climatic variability and social stress. Integrated studies including climatotogy, hydrology, and socio-econornic studies are required both for analysing the dynamic natural conditions and to assess possible strategies to make semi-arid regions Less vulnerable to the present and changing climate. The model introduced here dynamically describes the retationships between climate forcing, water availability, agriculture and selected societal processes. The model has been tailored to simulate the rather complex situation in the semi-and north-eastern Brazil in a quantitative manner including the sensitivity to external forcing, such as climate change. The selected results presented show the general functioning of the integrated model, with a primary focus on climate change impacts. It becomes evident that due to Large differences in regional climate scenarios, it is still impossible to give quantitative values for the most probable development, e.g., to assign probabilities to the simulated results. However, it becomes clear that water is a very crucial factor, and that an efficient and ecologically sound water management is a key question for the further development of that semi-arid region. The simulation results show that, independent of the differences in climate change scenarios, rain-fed farming is more vulnerable to drought impacts compared to irrigated farming. However, the capacity of irrigation and other water infrastructure systems to enhance resilience in respect to climatic fluctuations is significantly constrained given a significant negative precipitation trend. (c) 2005 Elsevier B.V. All rights reserved.
KW  - integrated modelling
KW  - integrated river basin management
KW  - water resources management
KW  - semi-arid hydrology
KW  - climate change
Y1  - 2006
U6  - https://doi.org/10.1016/j.jhydrol.2005.12.021
SN  - 0022-1694
VL  - 328
IS  - 3-4
SP  - 417
EP  - 431
PB  - Elsevier
CY  - Amsterdam
ER  - 
TY  - JOUR
A1  - Drewes, Julia
A1  - Moreiras, Stella
A1  - Korup, Oliver
T1  - Permafrost activity and atmospheric warming in the Argentinian Andes
JF  - Geomorphology : an international journal on pure and applied geomorphology
N2  - Rock glaciers are permafrost or glacial landforms of debris and ice that deform under the influence of gravity. Recent estimates hold that, in the semiarid Chilean Andes for example, active rock glaciers store more water than glaciers. However, little is known about how many rock glaciers might decay because of global warming and how much this decay might contribute to water and sediment release. We investigated an inventory of >6500 rock glaciers in the Argentinian Andes, spanning the climatic gradient from the Desert Andes to cold-temperate Tierra del Fuego. We used active rock glaciers as a diagnostic of permafrost, assuming that the toes mark the 0 degrees C isotherm in climate scenarios for the twenty-first century and their impact on freezing conditions near the rock glacier toes. We find that, under future worst case warming, up to 95% of rock glaciers in the southern Desert Andes and in the Central Andes will rest in areas above 0 degrees C and that this freezing level might move up more than twice as much (similar to 500 m) as during the entire Holocene (similar to 200 m). Many active rock glaciers are already well below the current freezing level and exemplify how local controls may confound regional prognoses. A Bayesian Multifactor Analysis of Variance further shows that only in the Central Andes are the toes of active rock glaciers credibly higher than those of inactive ones. Elsewhere in the Andes, active and inactive rock glaciers occupy indistinguishable elevation bands, regardless of aspect, the formation mechanism, or shape of rock glaciers. The state of rock glacier activity predicts differences in elevations of toes to 140 m at best so that regional inference of the distribution of discontinuous permafrost from rock-glacier toes cannot be more accurate than this in the Argentinian Andes. We conclude that the Central Andes-where rock glaciers are largest, cover the most area, and have a greater density than glaciers-is likely to experience the most widespread disturbance to the thermal regime of the twenty-first century. (C) 2018 Elsevier B.V. All rights reserved.
KW  - rock glacier
KW  - Argentina
KW  - permafrost
KW  - climate change
Y1  - 2018
U6  - https://doi.org/10.1016/j.geomorph.2018.09.005
SN  - 0169-555X
SN  - 1872-695X
VL  - 323
SP  - 13
EP  - 24
PB  - Elsevier
CY  - Amsterdam
ER  - 
TY  - JOUR
A1  - Colombo, Stefanie M.
A1  - Wacker, Alexander
A1  - Parrish, Christopher C.
A1  - Kainz, Martin J.
A1  - Arts, Michael T.
T1  - A fundamental dichotomy in long-chain polyunsaturated fatty acid abundance between and within marine and terrestrial ecosystems
JF  - Environmental reviews = Dossiers environnement
N2  - Polyunsaturated fatty acids (PUFA), especially long-chain (i.e., >= 20 carbons) polyunsaturated fatty acids (LC-PUFA), are fundamental to the health and survival of marine and terrestrial organisms. Therefore, it is imperative that we gain a better understanding of their origin, abundance, and transfer between and within these ecosystems. We evaluated the natural variation in PUFA distribution and abundance that exists between and within these ecosystems by amassing and analyzing, using multivariate and analysis of variance (ANOVA) methods, >3000 fatty acid (FA) profiles from marine and terrestrial organisms. There was a clear dichotomy in LC-PUFA abundance between organisms in marine and terrestrial ecosystems, mainly driven by the C-18 PUFA in terrestrial organisms and omega-3 (n-3) LC-PUFA in marine organisms. The PUFA content of an organism depended on both its biome (marine vs terrestrial) and taxonomic group. Within the marine biome, the PUFA content varied among taxonomic groups. PUFA content of marine organisms was dependent on both geographic zone (i.e., latitude, and thus broadly related to temperature) and trophic level (a function of diet). The contents of n-3 LC-PUFA were higher in polar and temperate marine organisms than those from the tropics. Therefore, we conclude that, on a per capita basis, high latitude marine organisms provide a disproportionately large global share of these essential nutrients to consumers, including terrestrial predators. Our analysis also hints at how climate change, and other anthropogenic stressors, might act to negatively impact the global distribution and abundance of n-3 LC-PUFA within marine ecosystems and on the terrestrial consumers that depend on these subsidies.
KW  - climate change
KW  - food webs
KW  - omega-3
KW  - polyunsaturated fatty acids
KW  - trophic ecology
Y1  - 2017
U6  - https://doi.org/10.1139/er-2016-0062
SN  - 1208-6053
SN  - 1181-8700
VL  - 25
SP  - 163
EP  - 174
PB  - NRC Research Press
CY  - Ottawa
ER  - 
TY  - JOUR
A1  - Markovic, Danijela
A1  - Carrizo, Savrina F.
A1  - Kaercher, Oskar
A1  - Walz, Ariane
A1  - David, Jonathan N. W.
T1  - Vulnerability of European freshwater catchments to climate change
JF  - Global change biology
N2  - Climate change is expected to exacerbate the current threats to freshwater ecosystems, yet multifaceted studies on the potential impacts of climate change on freshwater biodiversity at scales that inform management planning are lacking. The aim of this study was to fill this void through the development of a novel framework for assessing climate change vulnerability tailored to freshwater ecosystems. The three dimensions of climate change vulnerability are as follows: (i) exposure to climate change, (ii) sensitivity to altered environmental conditions and (iii) resilience potential. Our vulnerability framework includes 1685 freshwater species of plants, fishes, molluscs, odonates, amphibians, crayfish and turtles alongside key features within and between catchments, such as topography and connectivity. Several methodologies were used to combine these dimensions across a variety of future climate change models and scenarios. The resulting indices were overlaid to assess the vulnerability of European freshwater ecosystems at the catchment scale (18 783 catchments). The Balkan Lakes Ohrid and Prespa and Mediterranean islands emerge as most vulnerable to climate change. For the 2030s, we showed a consensus among the applied methods whereby up to 573 lake and river catchments are highly vulnerable to climate change. The anthropogenic disruption of hydrological habitat connectivity by dams is the major factor reducing climate change resilience. A gap analysis demonstrated that the current European protected area network covers <25% of the most vulnerable catchments. Practical steps need to be taken to ensure the persistence of freshwater biodiversity under climate change. Priority should be placed on enhancing stakeholder cooperation at the major basin scale towards preventing further degradation of freshwater ecosystems and maintaining connectivity among catchments. The catchments identified as most vulnerable to climate change provide preliminary targets for development of climate change conservation management and mitigation strategies.
KW  - catchment connectivity
KW  - climate change
KW  - exposure
KW  - freshwater biodiversity
KW  - gap analysis
KW  - resilience
KW  - sensitivity
KW  - vulnerability
Y1  - 2017
U6  - https://doi.org/10.1111/gcb.13657
SN  - 1354-1013
SN  - 1365-2486
VL  - 23
SP  - 3567
EP  - 3580
PB  - Wiley
CY  - Hoboken
ER  - 
TY  - JOUR
A1  - Wieczorek, Mareike
A1  - Kruse, Stefan
A1  - Epp, Laura Saskia
A1  - Kolmogorov, Alexei
A1  - Nikolaev, Anatoly N.
A1  - Heinrich, Ingo
A1  - Jeltsch, Florian
A1  - Pestryakova, Luidmila Agafyevna
A1  - Zibulski, Romy
A1  - Herzschuh, Ulrike
T1  - Dissimilar responses of larch stands in northern Siberia to increasing temperatures-a field and simulation based study
JF  - Ecology : a publication of the Ecological Society of America
N2  - Arctic and alpine treelines worldwide differ in their reactions to climate change. A northward advance of or densification within the treeline ecotone will likely influence climate-vegetation feedback mechanisms. In our study, which was conducted in the Taimyr Depression in the North Siberian Lowlands, w present a combined field-and model-based approach helping us to better understand the population processes involved in the responses of the whole treeline ecotone, spanning from closed forest to single-tree tundra, to climate warming. Using information on stand structure, tree age, and seed quality and quantity from seven sites, we investigate effects of intra-specific competition and seed availability on the specific impact of recent climate warming on larch stands. Field data show that tree density is highest in the forest-tundra, and average tree size decreases from closed forest to single-tree tundra. Age-structure analyses indicate that the trees in the closed forest and forest-tundra have been present for at least similar to 240 yr. At all sites except the most southerly ones, past establishment is positively correlated with regional temperature increase. In the single-tree tundra, however, a change in growth form from krummholz to erect trees, beginning similar to 130 yr ago, rather than establishment date has been recorded. Seed mass decreases from south to north, while seed quantity increases. Simulations with LAVESI (Larix Vegetation Simulator) further suggest that relative density changes strongly in response to a warming signal in the forest-tundra while intra-specific competition limits densification in the closed forest and seed limitation hinders densification in the single-tree tundra. We find striking differences in strength and timing of responses to recent climate warming. While forest-tundra stands recently densified, recruitment is almost non-existent at the southern and northern end of the ecotone due to autecological processes. Palaeo-treelines may therefore be inappropriate to infer past temperature changes at a fine scale. Moreover, a lagged treeline response to past warming will, via feedback mechanisms, influence climate change in the future.
KW  - climate change
KW  - closed forest
KW  - dendroecology
KW  - forest change
KW  - latitude
KW  - recruitment
KW  - tundra
KW  - vegetation model
Y1  - 2017
U6  - https://doi.org/10.1002/ecy.1887
SN  - 0012-9658
SN  - 1939-9170
VL  - 98
SP  - 2343
EP  - 2355
PB  - Wiley
CY  - Hoboken
ER  - 
TY  - JOUR
A1  - Wenz, Leonie
A1  - Levermann, Anders
A1  - Auffhammer, Maximilian
T1  - North-south polarization of European electricity consumption under future warming
JF  - Proceedings of the National Academy of Sciences of the United States of America
N2  - There is growing empirical evidence that anthropogenic climate change will substantially affect the electric sector. Impacts will stem both from the supply sidethrough the mitigation of greenhouse gasesand from the demand sidethrough adaptive responses to a changing environment. Here we provide evidence of a polarization of both peak load and overall electricity consumption under future warming for the worlds third-largest electricity marketthe 35 countries of Europe. We statistically estimate country-level doseresponse functions between daily peak/total electricity load and ambient temperature for the period 2006-2012. After removing the impact of nontemperature confounders and normalizing the residual load data for each country, we estimate a common doseresponse function, which we use to compute national electricity loads for temperatures that lie outside each countrys currently observed temperature range. To this end, we impose end-of-century climate on todays European economies following three different greenhouse-gas concentration trajectories, ranging from ambitious climate-change mitigationin line with the Paris agreementto unabated climate change. We find significant increases in average daily peak load and overall electricity consumption in southern and western Europe (similar to 3 to similar to 7% for Portugal and Spain) and significant decreases in northern Europe (similar to-6 to similar to-2% for Sweden and Norway). While the projected effect on European total consumption is nearly zero, the significant polarization and seasonal shifts in peak demand and consumption have important ramifications for the location of costly peak-generating capacity, transmission infrastructure, and the design of energy-efficiency policy and storage capacity.
KW  - electricity consumption
KW  - peak load
KW  - climate change
KW  - adaptation
Y1  - 2017
U6  - https://doi.org/10.1073/pnas.1704339114
SN  - 0027-8424
VL  - 114
SP  - E7910
EP  - E7918
PB  - National Acad. of Sciences
CY  - Washington
ER  - 
TY  - JOUR
A1  - Wenz, Leonie
A1  - Kalkuhl, Matthias
A1  - Steckel, Jan Christoph
A1  - Creutzig, Felix
T1  - Teleconnected food supply shocks
JF  - Environmental research letters
N2  - The 2008-2010 food crisis might have been a harbinger of fundamental climate-induced food crises with geopolitical implications. Heat-wave-induced yield losses in Russia and resulting export restrictions led to increases in market prices for wheat across the Middle East, likely contributing to the Arab Spring. With ongoing climate change, temperatures and temperature variability will rise, leading to higher uncertainty in yields for major nutritional crops. Here we investigate which countries are most vulnerable to teleconnected supply-shocks, i.e. where diets strongly rely on the import of wheat, maize, or rice, and where a large share of the population is living in poverty. We find that the Middle East is most sensitive to teleconnected supply shocks in wheat, Central America to supply shocks in maize, and Western Africa to supply shocks in rice. Weighing with poverty levels, Sub-Saharan Africa is most affected. Altogether, a simultaneous 10% reduction in exports of wheat, rice, and maize would reduce caloric intake of 55 million people living in poverty by about 5%. Export bans in major producing regions would put up to 200 million people below the poverty line at risk, 90% of which live in Sub-Saharan Africa. Our results suggest that a region-specific combination of national increases in agricultural productivity and diversification of trade partners and diets can effectively decrease future food security risks.
KW  - food security
KW  - trade shocks
KW  - vulnerability
KW  - climate change
KW  - teleconnections
Y1  - 2016
U6  - https://doi.org/10.1088/1748-9326/11/3/035007
SN  - 1748-9326
VL  - 11
PB  - IOP Publ. Ltd.
CY  - Bristol
ER  - 
TY  - JOUR
A1  - Kellermann, Patric
A1  - Bubeck, Philip
A1  - Kundela, Guenther
A1  - Dosio, Alessandro
A1  - Thieken, Annegret Henriette
T1  - Frequency Analysis of Critical Meteorological Conditions in a Changing ClimateAssessing Future Implications for Railway Transportation in Austria
JF  - Climate : open access journal
N2  - Meteorological extreme events have great potential for damaging railway infrastructure and posing risks to the safety of train passengers. In the future, climate change will presumably have serious implications on meteorological hazards in the Alpine region. Hence, attaining insights on future frequencies of meteorological extremes with relevance for the railway operation in Austria is required in the context of a comprehensive and sustainable natural hazard management plan of the railway operator. In this study, possible impacts of climate change on the frequencies of so-called critical meteorological conditions (CMCs) between the periods 1961-1990 and 2011-2040 are analyzed. Thresholds for such CMCs have been defined by the railway operator and used in its weather monitoring and early warning system. First, the seasonal climate change signals for air temperature and precipitation in Austria are described on the basis of an ensemble of high-resolution Regional Climate Model (RCM) simulations for Europe. Subsequently, the RCM-ensemble was used to investigate changes in the frequency of CMCs. Finally, the sensitivity of results is analyzed with varying threshold values for the CMCs. Results give robust indications for an all-season air temperature rise, but show no clear tendency in average precipitation. The frequency analyses reveal an increase in intense rainfall events and heat waves, whereas heavy snowfall and cold days are likely to decrease. Furthermore, results indicate that frequencies of CMCs are rather sensitive to changes of thresholds. It thus emphasizes the importance to carefully define, validate, andif neededto adapt the thresholds that are used in the weather monitoring and warning system of the railway operator. For this, continuous and standardized documentation of damaging events and near-misses is a pre-requisite.
KW  - climate change
KW  - critical meteorological condition
KW  - frequency analysis
KW  - natural hazard management
KW  - railway transportation
Y1  - 2016
U6  - https://doi.org/10.3390/cli4020025
SN  - 2225-1154
VL  - 4
SP  - 914
EP  - 931
PB  - MDPI
CY  - Basel
ER  - 
TY  - JOUR
A1  - Schneider, Birgit
T1  - Burning worlds of cartography: a critical approach to climate cosmograms of the Anthropocene
JF  - Geo : geography and environment
N2  - Climate science today makes use of a variety of red globes to explore and communicate findings. These transform the iconography which informs this image: the idealised, even mythical vision of the blue, vulnerable and perfect marble is impaired by the application of the colours yellow and red. Since only predictions that employ a lot of red seem to exist, spectators are confronted with the message that the future Earth that might turn out as envisaged here is undesirable. Here intuitively powerful narrations of the end of the world may connect. By employing methods of art history and visual analysis, and building on examples from current Intergovernmental Panel on Climate Change reports and future scenario maps, this article explores how burning world images bear - intentionally or not - elements of horror and shock. My question explored here is as follows: should 'burning world' images be understood as a new and powerful cosmology?
KW  - cartography
KW  - visualisation
KW  - climate change
KW  - whole Earth images
Y1  - 2016
U6  - https://doi.org/10.1002/geo2.27
SN  - 2054-4049
VL  - 3
PB  - Wiley
CY  - Hoboken
ER  - 
TY  - JOUR
A1  - Geiger, Tobias
A1  - Frieler, Katja
A1  - Levermann, Anders
T1  - High-income does not protect against hurricane losses
JF  - Environmental research letters
N2  - Damage due to tropical cyclones accounts for more than 50% of all meteorologically-induced economic losses worldwide. Their nominal impact is projected to increase substantially as the exposed population grows, per capita income increases, and anthropogenic climate change manifests. So far, historical losses due to tropical cyclones have been found to increase less than linearly with a nation's affected gross domestic product (GDP). Here we show that for the United States this scaling is caused by a sub-linear increase with affected population while relative losses scale super-linearly with per capita income. The finding is robust across a multitude of empirically derived damage models that link the storm's wind speed, exposed population, and per capita GDP to reported losses. The separation of both socio-economic predictors strongly affects the projection of potential future hurricane losses. Separating the effects of growth in population and per-capita income, per hurricane losses with respect to national GDP are projected to triple by the end of the century under unmitigated climate change, while they are estimated to decrease slightly without the separation.
KW  - climate change
KW  - tropical cyclones
KW  - damage
KW  - meteorological extremes
KW  - vulnerability
Y1  - 2016
U6  - https://doi.org/10.1088/1748-9326/11/8/084012
SN  - 1748-9326
VL  - 11
PB  - IOP Publ. Ltd.
CY  - Bristol
ER  - 
TY  - JOUR
A1  - Di Capua, Giorgia
A1  - Coumou, Dim
T1  - Changes in meandering of the Northern Hemisphere circulation
JF  - Environmental research letters
N2  - Strong waves in the mid-latitude circulation have been linked to extreme surface weather and thus changes in waviness could have serious consequences for society. Several theories have been proposed which could alter waviness, including tropical sea surface temperature anomalies or rapid climate change in the Arctic. However, so far it remains unclear whether any changes in waviness have actually occurred. Here we propose a novel meandering index which captures the maximum waviness in geopotential height contours at any given day, using all information of the full spatial position of each contour. Data are analysed on different time scale (from daily to 11 day running means) and both on hemispheric and regional scales. Using quantile regressions, we analyse how seasonal distributions of this index have changed over 1979-2015. The most robust changes are detected for autumn which has seen a pronounced increase in strongly meandering patterns at the hemispheric level as well as over the Eurasian sector. In summer for both the hemisphere and the Eurasian sector, significant downward trends in meandering are detected on daily timescales which is consistent with the recently reported decrease in summer storm track activity. The American sector shows the strongest increase in meandering in the warm season: in particular for 11 day running mean data, indicating enhanced amplitudes of quasi-stationary waves. Our findings have implications for both the occurrence of recent cold spells and persistent heat waves in the mid-latitudes.
KW  - Rossby waves
KW  - climate change
KW  - extreme events
KW  - mid-latitudes flow
Y1  - 2016
U6  - https://doi.org/10.1088/1748-9326/11/9/094028
SN  - 1748-9326
VL  - 11
PB  - IOP Publ. Ltd.
CY  - Bristol
ER  - 
TY  - THES
A1  - Hanschmann, Raffael Tino
T1  - Stalling the engine? EU climate politics after the ‘Great Recession’
T1  - Den Motor abgewürgt? EU-Klimapolitik nach der Großen Rezession
BT  - investigating the impact of economic shocks on EU climate policy-making in three case studies
BT  - eine Untersuchung des Einflusses von Wirtschaftskrisen auf Prozesse in der EU-Klimapolitik in drei Fallstudien
N2  - This dissertation investigates the impact of the economic and fiscal crisis starting in 2008 on EU climate policy-making. While the overall number of adopted greenhouse gas emission reduction policies declined in the crisis aftermath, EU lawmakers decided to introduce new or tighten existing regulations in some important policy domains. Existing knowledge about the crisis impact on EU legislative decision-making cannot explain these inconsistencies. In response, this study develops an actor-centred conceptual framework based on rational choice institutionalism that provides a micro-level link to explain how economic crises translate into altered policy-making patterns. The core theoretical argument draws on redistributive conflicts, arguing that tensions between ‘beneficiaries’ and ‘losers’ of a regulatory initiative intensify during economic crises and spill over to the policy domain. To test this hypothesis and using social network analysis, this study analyses policy processes in three case studies: The introduction of carbon dioxide emission limits for passenger cars, the expansion of the EU Emissions Trading System to aviation, and the introduction of a regulatory framework for biofuels. The key finding is that an economic shock causes EU policy domains to polarise politically, resulting in intensified conflict and more difficult decision-making. The results also show that this process of political polarisation roots in the industry that is the subject of the regulation, and that intergovernmental bargaining among member states becomes more important, but also more difficult in times of crisis.
N2  - Diese Dissertation untersucht den Einfluss der in 2008 beginnenden globalen Wirtschaftskrise auf die Prozesse der EU-Klimapolitik. Während die Zahl der verabschiedeten Gesetze zur Treibhausgasreduktion nach Krisenausbruch insgesamt sank, entschieden die EU-Gesetzgeber, in mehreren wichtigen Politikfeldern neue Regulierungen einzuführen oder existierende zu verschärfen. Bestehendes Wissen zum Einfluss der Krise auf EU-Gesetzgebungsprozesse kann diese Inkonsistenzen nicht erklären. Daher entwickelt diese Arbeit ein auf Rational-Choice-Institutionalismus basierendes konzeptionelles Gerüst, das auf der Mikro-Ebene eine kausale Verbindung zwischen Wirtschaftskrise und veränderten Politikprozessen herstellt. Das zentrale theoretische Argument beruht auf Verteilungskonflikten innerhalb der regulierten Wirtschaftsbranchen: Die Spannung zwischen „Nutznießern“ und „Verlierern“ einer geplanten Regulierung intensiviert sich in Krisenzeiten und setzt sich im politischen Raum fort. Diese Hypothese wird an drei Fallstudien mittels sozialer Netzwerkanalyse getestet. Die drei Fallstudien untersuchen politische Entscheidungsprozesse in den folgenden EU-Politikfeldern: Kohlenstoffdioxid-Emissionsgrenzen für PKW, die Ausweitung des Emissionshandels auf Flugverkehr und die Einführung eines Regulierungsrahmens für Biokraftstoffe. Die wichtigste Erkenntnis der Untersuchung ist, dass makroökonomische Schocks eine Polarisierung der politischen Interessen innerhalb eines Politikfeldes auslösen, dadurch Konflikte intensivieren und letztlich Entscheidungsfindungen erschweren. Die Ergebnisse zeigen zudem, dass dieser Polarisierungsprozess in der regulierten Wirtschaftsbranche wurzelt. Außerdem werden Verhandlungen zwischen den Regierungen der Mitgliedsstaaten in Krisenzeiten wichtiger, aber auch schwieriger. 
KW  - EU
KW  - European Union
KW  - policy-making
KW  - network analysis
KW  - policy preferences
KW  - economic crisis
KW  - crisis
KW  - climate
KW  - climate change
KW  - climate policy
KW  - climate politics
KW  - environmental policy
KW  - EU
KW  - Europäische Union
KW  - Politikgestaltung
KW  - Netzwerkanalyse
KW  - Politikpräferenzen
KW  - Wirtschaftskrise
KW  - Krise
KW  - Klima
KW  - Klimawandel
KW  - Klimapolitik
KW  - Umweltpolitik
Y1  - 2019
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-440441
ER  -