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 Laura 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 -