TY - THES A1 - Jiménez Álvaro, Eliana T1 - Análisis neotectónico y lito-tefroestratigráfico de los grandes movimientos en masa asociados al fallamiento activo de la cuenca intermontana Quito-Guayllabamba, Ecuador T1 - Neotectonic and litho-tephrostratigraphic analysis of large mass movements associated with active faulting in the Quito-Guayllabamba intermontane basin, Ecuador T1 - Neotektonische und litho-tephrostratigraphische Auswertung der großen Massenbewegungen im Zusammenhang mit dem aktiven Verwerfungen im intermontanen Quito-Guayllabamba-Becken, Ecuador N2 - Within the Quito-Guayllabamba intermontane basin of Ecuador, five unusually large colluvial deposits of ancient landslides have been identified and analyzed in this study. The voluminous rotational MM-5 Guayllabamba landslide is the largest one, with a volume of 1183 million m3. The mega debris-avalanches MM-1 Conocoto, MM-3 Oyacoto, and MM-4 San Francisco were originally triggered by an initial rupture that was associated with a rotational landslide, the corresponding deposits have volumes between 399 to 317 million m3. Finally, the deposit with the smallest volume, the MM-2 Batán rotational landslide and debris fall, has a volume of 8,7 million m3. In this thesis, a detailed study of these large mass movements was carried out using neotectonic and litho-tephrostratigraphic methods to understand the geological and geomorphological boundary conditions that might have been relevant for triggering such mass movements. The neotectonic part of the study was based on the qualitative and quantitative geomorphic analysis of these large mass-movement deposits through the structural characterization of anticlines located east of the Quito sub-basin and their collapsed flanks that constitute the break-off areas. This part of the analysis was furthermore supported by the application of different morphometric indices to reveal tectonically forced landscape evolution processes that may have aided mass-movement generation. The litho-tephrostratigraphic part of the study was based on the analysis of petrographic, geochemical, and geochronological characteristics of soil horizons and intercalated volcanic ashes with the aim to constrain the timing of individual mass-movement events and their potential correlation. The results were integrated into chronostratigraphic schemes using break-off surfaces, cross-cutting and superposition relationships of landslide deposits and subsequently deposited strata to understand the mass movements in the tectonic and temporal context of the intermontane basin setting, as well as to identify the triggering mechanisms for each event. The MM-5 Guayllabamba mass movement is the result of the collapse of the southwestern slope of the Mojanda volcano and was triggered by the interaction of geologic and morphologic conditions approximately 0,81 Ma. The first debris-avalanche episode of the MM-3 Oyacoto and MM-4 San Francisco mass movements could be related to both geological and morphological conditions, given the highly fractured rocks and uplift of the Bellavista-Catequilla anticline that was subsequently incised at the foot of the slope by fluvial erosion. This first episode of collapse most likely occurred around 0,8 Ma. The MM-2 Batán mass movement was possibly also facilitated by a combination of geological and morphological conditions, most likely associated with a reduction in the lithostatic stresses affecting the Chiche and Machángara formations and an increase of shear stresses during lateral fluvial scouring processes at the flanks of the source areas. This points to a linked process between river erosion and uplift processes associated with the evolution of the El Batán-La Bota anticline that could have occurred between 0,5 and 0,25 Ma. The voluminous MM-1 Conocoto debris avalanche, as well as the second debris avalanche episode that generated the MM-3 Oyacoto and MM-4 San Francisco mass movements, were caused by the gravitational collapse of the Mojanda and Cangahua formations that are characterized by the intercalation of volcanic ashes. The failure of the eastern flank of the anticlines probably was associated with increased available humidity related to regional Holocene climatic variations. The results of paleosol chronology combined with regional chronostratigraphic and paleoclimate data suggests that these debris avalanches were triggered between 5 and 4 ka. Active tectonics has shaped the morphological features of the Quito-Guayllabamba intermontane basin. The triggering of mass movements in this environment is associated with failure of Pleistocene lithologies (lake sediments, alluvial and volcanic deposits) subjected to ongoing deformation processes, seismic activity, and superposed episodes of climate variability. The Metropolitan District of Quito is an integral part of this complex environment and the geological, climatic, and topographic conditions that continue to influence the urban geographic space within this intermontane basin. The city of Quito comprises the area with the largest urban consolidation including the sub-basins of Quito and San Antonio, with a population of 2,872 million inhabitants, reflecting the importance of studying the inherent geological and climatic hazards that this region is confronted with. N2 - Innerhalb des intermontanen Beckens von Quito-Guayllabamba in Ecuador wurden fünf ungewöhnlich große alte Erdrutschablagerungen identifiziert und in dieser Studie analysiert. Die voluminöse, mit einer Rotationsbewegung verbundene Ablagerung MM-5 von Guayllabamba ist mit einem Volumen von 1183 Mio. m3 die größte dieser Massenbewegungsablagerungen. Die Megaschuttlawinen MM-1 von Conocoto, MM-3 Oyacoto und MM-4 von San Francisco wurden ursprünglich durch eine Ruptur an den oberen Hängen ausgelöst, die ebenfalls mit Rotationsbewegungen verbunden waren, die entsprechenden Ablagerungen haben ein Volumen zwischen 399 und 317 Mio. m3. Die kleinste Ablagerung, die Ablagerung MM-2 von Batán, hat ein Volumen von 8,7 Mio. m3. In dieser Arbeit wurde eine detaillierte Untersuchung dieser großen Massenbewegungen mit neotektonischen, litho-tephrostratigraphischen und geomorphologischen Methoden durchgeführt, um die geologischen und geomorphologischen Randbedingungen zu verstehen, die für die Auslösung solcher Massenbewegungen relevant gewesen sein könnten. Der neotektonische Teil der Studie basierte auf der qualitativen und quantitativen geomorphologischen Analyse dieser voluminösen Ablagerungen über eine strukturelle Charakterisierung der Antiklinalen und ihrer kollabierten Flanken östlich des Quito-Subbbeckens, die Abrisszonen bilden. Dieser Teil der Analyse wurde durch die Anwendung verschiedener morphometrischer Indizes unterstützt, um tektonisch bedingte Landschaftsentwicklungsprozesse aufzuzeigen, welche die Entstehung der Massenbewegungen begünstigt haben könnten. Der litho-tephrostratigraphische Teil der Studie basierte auf der Analyse petrographischer, geochemischer und geochronologischer Merkmale von Paläo-Bodenhorizonten und zwischengeschalteten vulkanischen Aschen mit dem Ziel, die Chronologie einzelner Massenbewegungsereignisse zunächst einzugrenzen und Ablagerungen eventuell miteinander zu korrelieren. Die Ergebnisse wurden in chronostratigraphische Schemata integriert, die Abrisskanten, Aufschlüsse und stratigraphische Überlappungsbeziehungen von Erdrutschablagerungen und später abgelagerten Schichten verwenden, um die Massenbewegungen im tektonischen und zeitlichen Kontext der intermontanen, sowie die Auslösemechanismen der einzelnen Ereignisse zu identifizieren. Die Massenbewegung MM-5 von Guayllabamba ist das Ergebnis des Kollapses des Südwesthangs des Vulkans Mojanda und wurde durch das Zusammenspiel geologischer und morphologischer Bedingungen vor etwa 0,81 Ma ausgelöst. Die erste Schuttlawinen-Episode MM-3 Oyacoto und MM-4 San Francisco könnte sowohl mit den geologischen als auch mit den morphologischen Bedingungen zusammenhängen, da das Gestein stark zerklüftet ist und die Bellavista-Catequilla-Antiklinale angehoben wurde, die anschließend am Fuß des Hanges durch fluviale Erosion eingeschnitten wurde. Höchstwahrscheinlich ereignete sich diese erste Massenbewegungsphase um 0,8 Ma. Die Massenbewegung der Ablagerung von MM-2 Batán wurde möglicherweise auch durch eine Kombination von geologischen und morphologischen Bedingungen begünstigt, die vermutlich mit einer Verringerung des lithostatischen Druckes in den Formationen Chiche und Machángara sowie einer Zunahme der Scherspannungen im Zuge der seitlichen fluvialen Kolkprozesse an den Flanken der Abrissregionen verbunden waren. Dies deutet auf einen verknüpften Prozess zwischen fluvialer Erosion und Hebungsprozessen im Zusammenhang mit der Entwicklung der El Batán-La Bota-Antiklinale hin, der zwischen 0,5 und 0,25 Ma stattgefunden haben könnte. Die voluminöse Schuttlawine MM-1 von Conocoto sowie die zweite Schuttlawine, welche die Ablagerungen von MM-3 Oyacoto und MM-4 San Francisco generierte, wurden durch den gravitativen Kollaps der Mojanda- und Cangahua-Formationen ausgelöst, der durch die zwischengeschalteten vulkanischen Aschen begünstigt wurde. Das Versagen der Bergflanken war möglicherweise auch begünstigt durch die Zunahme der verfügbaren Feuchtigkeit und des erhöhten Porendruckes im Zusammenhang mit regionalen klimatischen Schwankungen während des Holozäns. Die Ergebnisse der Chronologie der Paläoböden in Verbindung mit regionalen chronostratigraphischen und paläoklimatischen Daten legen nahe, dass diese Schuttlawinen zwischen 5 und 4 ka ausgelöst wurden. Die aktive Tektonik hat die morphologischen Merkmale des intermontanen Quito-Guayllabamba-Beckens fundamental geprägt. Die Auslösung von Massenbewegungen in diesem Gebiet steht im Zusammenhang mit Verwerfungen in den pleistozänen Ablagerungen (lakustrische Sedimente, alluviale und vulkanische Ablagerungen), die laufenden Deformationsprozessen, seismischer Aktivität sowie überlagerten Episoden klimatischer Variabilität ausgesetzt sind. Der Stadtbezirk Quito ist ein integraler Bestandteil dieser komplexen Region und der geologischen, klimatischen und topografischen Bedingungen, die den städtischen Siedlungsraum in diesem intermontanen Becken weiterhin beeinflussen werden. Die Stadt Quito umfasst das Gebiet mit der größten urbanen Konsolidierung, einschließlich der Teileinzugsgebiete von Quito und San Antonio, mit einer Bevölkerung von 2,872 Millionen Einwohnern, was die Bedeutung der Untersuchung der inhärenten geologischen und klimatischen Gefahren widerspiegelt, mit denen diese Region konfrontiert ist. N2 - Dentro de la cuenca intermontana de Quito-Guay llabamba de Ecuador, se han identificado y analizado en este estudio, cinco depósitos coluviales inusualmente grandes de antiguos deslizamientos. El gran deslizamiento rotacional MM-5 Guayllabamba es el más extenso, con un volumen de 1183 millones de m3. Las mega avalanchas de escombros MM-1 Conocoto, MM-3 Oyacoto, y MM-4 San Francisco fueron desencadenadas originalmente por una ruptura inicial que estuvo asociada a un deslizamiento rotacional, los depósitos correspondientes tienen volúmenes entre 399 a 317 millones de m3. Finalmente, el depósito de menor volumen, el deslizamiento rotacional y caída de detritos MM-2 Batán, tiene un volumen de 8,7 millones de m3. En esta tesis, se realizó un estudio detallado de estos grandes movimientos en masa utilizando métodos neotectónicos y lito-tefrostratigráficos para comprender las condiciones geológicas y geomorfológicas de contorno que podrían ser relevantes para desencadenar estos movimientos en masa. La parte neotectónica del estudio se basó en el análisis geomorfológico cualitativo y cuantitativo de estos grandes depósitos de movimientos en masa, a través de la caracterización estructural de anticlinales ubicados al este de la subcuenca de Quito y sus flancos colapsados que constituyen las áreas de ruptura. Esta parte del análisis fue además apoyada por la aplicación de diferentes índices morfométricos para revelar procesos de evolución del paisaje forzados tectónicamente que pueden haber contribuido a la generación de movimientos en masa. La parte lito-tefrostratigráfica del estudio se basó en el análisis de las características petrográficas, geoquímicas y geocronológicas de los horizontes del suelo y de las cenizas volcánicas intercaladas, con el objetivo de restringir la cronología de los eventos individuales de movimientos en masa y su posible de correlación. Los resultados se integraron en esquemas cronoestratigráficos utilizando superficies de ruptura, relaciones transversales y de superposición de depósitos de deslizamiento y estratos posteriores para comprender los movimientos en masa en el contexto tectónico y temporal del entorno de la cuenca intermontana, así como para identificar los mecanismos desencadenantes de cada evento. El movimiento en masa MM-5 Guayllabamba es el resultado del colapso de la ladera suroeste del volcán Mojanda y fue desencadenado por la interacción de condiciones geológicas y morfológicas hace aproximadamente 0,81 Ma. El primer episodio de avalancha de escombros de los movimientos en masa MM-3 Oyacoto y MM-4 San Francisco podría estar relacionado con condiciones tanto geológicas como morfológicas, dadas las rocas altamente fracturadas y el levantamiento del anticlinal Bellavista-Catequilla que posteriormente fue inciso al pie de la ladera por la erosión fluvial. Este primer episodio de colapso probablemente ocurrió alrededor de los 0,8 Ma. El movimiento en masa MM-2 Batán posiblemente también fue desencadenado por una combinación de condiciones geológicas y morfológicas, asociadas a una reducción de los esfuerzos litostáticos que afectaron a las formaciones Chiche y Machángara y a un aumento de los esfuerzos de cizalla durante procesos de socavación fluvial lateral en los flancos de las áreas de origen. Esto apunta a un proceso vinculado entre la erosión fluvial y los procesos de levantamiento asociados a la evolución del anticlinal El Batán-La Bota que podría haber ocurrido entre 0,5 y 0,25 Ma. La voluminosa avalancha de escombros MM-1 Conocoto, así como el segundo episodio de avalancha de escombros que generó los movimientos en masa MM-3 Oyacoto y MM-4 San Francisco, fueron provocados por el colapso gravitacional de las formaciones Mojanda y Cangahua que se caracterizan por la intercalación de cenizas volcánicas. La falla del flanco oriental de los anticlinales probablemente estuvo asociada al incremento de la humedad disponible relacionada con las variaciones climáticas regionales del Holoceno. Los resultados de la cronología de los paleosuelos combinados con los datos cronoestratigráficos y paleoclimáticos regionales sugieren que estas avalanchas de escombros se desencadenaron entre 5 y 4 ka. La tectónica activa ha modelado los rasgos morfológicos de la cuenca intermontana Quito-Guayllabamba. El desencadenamiento de movimientos en masa en este ambiente está asociado a rupturas en litologías del Pleistoceno (sedimentos lacustres, depósitos aluviales y volcánicos) sometidas a procesos de deformación, actividad sísmica y episodios superpuestos de variabilidad climática. El Distrito Metropolitano de Quito es parte integral de este complejo entorno y de las condiciones geológicas, climáticas y topográficas que continúan influyendo en el espacio geográfico urbano dentro de esta cuenca intermontana. La ciudad de Quito comprende el área de mayor consolidación urbana incluyendo las subcuencas de Quito y San Antonio, con una población de 2,872 millones de habitantes, lo que refleja la importancia del estudio de las amenazas geológicas y climáticas inherentes a esta región. KW - große Massenbewegungen KW - intermontane Becken KW - aktive Verwerfungen KW - Auslösemechanismus KW - Klima KW - large mass movements KW - intermontane basin KW - active faulting KW - trigger mechanism KW - climate KW - grandes movimientos en masa KW - cuenca intermontana KW - fallamiento activo KW - mecanismos de disparo KW - clima Y1 - 2023 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-622209 ER - TY - GEN A1 - Horton, Benjamin P. A1 - Khan, Nicole S. A1 - Cahill, Niamh A1 - Lee, Janice S. H. A1 - Shaw, Timothy A. A1 - Garner, Andra J. A1 - Kemp, Andrew C. A1 - Engelhart, Simon E. A1 - Rahmstorf, Stefan T1 - Estimating global mean sea-level rise and its uncertainties by 2100 and 2300 from an expert survey T2 - Zweitveröffentlichungen der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe N2 - Sea-level rise projections and knowledge of their uncertainties are vital to make informed mitigation and adaptation decisions. To elicit projections from members of the scientific community regarding future global mean sea-level (GMSL) rise, we repeated a survey originally conducted five years ago. Under Representative Concentration Pathway (RCP) 2.6, 106 experts projected a likely (central 66% probability) GMSL rise of 0.30-0.65 m by 2100, and 0.54-2.15 m by 2300, relative to 1986-2005. Under RCP 8.5, the same experts projected a likely GMSL rise of 0.63-1.32 m by 2100, and 1.67-5.61 m by 2300. Expert projections for 2100 are similar to those from the original survey, although the projection for 2300 has extended tails and is higher than the original survey. Experts give a likelihood of 42% (original survey) and 45% (current survey) that under the high-emissions scenario GMSL rise will exceed the upper bound (0.98 m) of the likely range estimated by the Fifth Assessment Report of the Intergovernmental Panel on Climate Change, which is considered to have an exceedance likelihood of 17%. Responses to open-ended questions suggest that the increases in upper-end estimates and uncertainties arose from recent influential studies about the impact of marine ice cliff instability on the meltwater contribution to GMSL rise from the Antarctic Ice Sheet. T3 - Zweitveröffentlichungen der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe - 1437 KW - projections KW - Greenland KW - consequences KW - climate Y1 - 2020 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-516788 SN - 1866-8372 IS - 1 ER - TY - JOUR A1 - Horton, Benjamin P. A1 - Khan, Nicole S. A1 - Cahill, Niamh A1 - Lee, Janice S. H. A1 - Shaw, Timothy A. A1 - Garner, Andra J. A1 - Kemp, Andrew C. A1 - Engelhart, Simon E. A1 - Rahmstorf, Stefan T1 - Estimating global mean sea-level rise and its uncertainties by 2100 and 2300 from an expert survey JF - npj Climate and Atmospheric Science N2 - Sea-level rise projections and knowledge of their uncertainties are vital to make informed mitigation and adaptation decisions. To elicit projections from members of the scientific community regarding future global mean sea-level (GMSL) rise, we repeated a survey originally conducted five years ago. Under Representative Concentration Pathway (RCP) 2.6, 106 experts projected a likely (central 66% probability) GMSL rise of 0.30-0.65 m by 2100, and 0.54-2.15 m by 2300, relative to 1986-2005. Under RCP 8.5, the same experts projected a likely GMSL rise of 0.63-1.32 m by 2100, and 1.67-5.61 m by 2300. Expert projections for 2100 are similar to those from the original survey, although the projection for 2300 has extended tails and is higher than the original survey. Experts give a likelihood of 42% (original survey) and 45% (current survey) that under the high-emissions scenario GMSL rise will exceed the upper bound (0.98 m) of the likely range estimated by the Fifth Assessment Report of the Intergovernmental Panel on Climate Change, which is considered to have an exceedance likelihood of 17%. Responses to open-ended questions suggest that the increases in upper-end estimates and uncertainties arose from recent influential studies about the impact of marine ice cliff instability on the meltwater contribution to GMSL rise from the Antarctic Ice Sheet. KW - projections KW - Greenland KW - consequences KW - climate Y1 - 2020 U6 - https://doi.org/10.1038/s41612-020-0121-5 SN - 2397-3722 VL - 3 IS - 1 SP - 1 EP - 8 PB - Springer Nature CY - London ER - TY - JOUR A1 - Ganguli, Poulomi A1 - Paprotny, Dominik A1 - Hasan, Mehedi A1 - Güntner, Andreas A1 - Merz, Bruno T1 - Projected changes in compound flood hazard from riverine and coastal floods in northwestern Europe JF - Earth's future N2 - Compound flooding in coastal regions, that is, the simultaneous or successive occurrence of high sea levels and high river flows, is expected to increase in a warmer world. To date, however, there is no robust evidence on projected changes in compound flooding for northwestern Europe. We combine projected storm surges and river floods with probabilistic, localized relative sea-level rise (SLR) scenarios to assess the future compound flood hazard over northwestern coastal Europe in the high (RCP8.5) emission scenario. We use high-resolution, dynamically downscaled regional climate models (RCM) to drive a storm surge model and a hydrological model, and analyze the joint occurrence of high coastal water levels and associated river peaks in a multivariate copula-based approach. The RCM-forced multimodel mean reasonably represents the observed spatial pattern of the dependence strength between annual maxima surge and peak river discharge, although substantial discrepancies exist between observed and simulated dependence strength. All models overestimate the dependence strength, possibly due to limitations in model parameterizations. This bias affects compound flood hazard estimates and requires further investigation. While our results suggest decreasing compound flood hazard over the majority of sites by 2050s (2040-2069) compared to the reference period (1985-2005), an increase in projected compound flood hazard is limited to around 34% of the sites. Further, we show the substantial role of SLR, a driver of compound floods, which has frequently been neglected. Our findings highlight the need to be aware of the limitations of the current generation of Earth system models in simulating coastal compound floods. KW - compound flood KW - storm surge KW - river floods KW - sea level rise KW - climate KW - change KW - Europe Y1 - 2020 U6 - https://doi.org/10.1029/2020EF001752 SN - 2328-4277 VL - 8 IS - 11 PB - Wiley-Blackwell CY - Hoboken, NJ ER - TY - JOUR A1 - Kalkuhl, Matthias A1 - Schwerhoff, Gregor A1 - Waha, Katharina T1 - Land tenure, climate and risk management JF - Ecological economics N2 - We analyze to what extent climate conditions affect the prevalence of sharecropping as a form of traditional land tenure. We investigate how sharecropping tenure is related to climate risk and how it interacts with fertilizer use and livestock ownership that both influence production risk. We first develop a stylized theoretical model to illustrate the role of climate for land tenure and production. Our empirical analysis is based on more than 9000 households with considerable heterogeneity in climate conditions across several African countries. We find that farmers in areas with low precipitation are more likely to be sharecroppers. We further find evidence for risk management interaction effects as sharecropping farmers are less likely to own livestock and more likely to use fertilizer. In economies where formal kinds of insurance are unavailable, sharecropping thus functions as a form of insurance and reduces the need for potentially costly risk management strategies. KW - traditional land tenure KW - climate KW - risk management KW - agriculture KW - Africa KW - sharecropping Y1 - 2020 U6 - https://doi.org/10.1016/j.ecolecon.2019.106573 SN - 0921-8009 SN - 1873-6106 VL - 171 PB - Elsevier Science CY - Amsterdam [u.a.] ER - TY - JOUR A1 - Streck, Charlotte T1 - Strengthening the Paris Agreement by holding non-state actors accountable BT - establishing normative links between transnational partnerships and treaty implementation JF - Transnational environmental law N2 - While the intergovernmental climate regime increasingly recognizes the role of non-state actors in achieving the goals of the Paris Agreement (PA), the normative linkages between the intergovernmental climate regime and the non-state dominated 'transnational partnership governance' remain vague and tentative. A formalized engagement of the intergovernmental climate regime with transnational partnerships can increase the effectiveness of partnerships in delivering on climate mitigation and adaptation, thereby complementing rather than replacing government action. The proposed active engagement with partnerships would include (i) collecting and analyzing information to develop and prioritize areas for transnational and partnership engagement; (ii) defining minimum criteria and procedural requirements to be listed on an enhanced Non-state Actor Zone for Climate Action platform; (iii) actively supporting strategic initiatives; (iv) facilitating market or non-market finance as part of Article 6 PA; and (v) evaluating the effectiveness of partnerships in the context of the enhanced transparency framework (Article 13 PA) and the global stocktake (Article 14 PA). The UNFCCC Secretariat could facilitate engagement and problem solving by actively orchestrating transnational partnerships. Constructing effective implementation partnerships, recording their mitigation and adaptation goals, and holding them accountable may help to move climate talks from rhetoric to action. KW - transnational partnerships KW - non-state actors KW - Paris Agreement KW - climate KW - governance KW - transnational governance Y1 - 2021 U6 - https://doi.org/10.1017/S2047102521000091 SN - 2047-1025 SN - 2047-1033 VL - 10 IS - 3 SP - 493 EP - 515 PB - Cambridge Univ. Press CY - Cambridge ER - TY - JOUR A1 - Bürger, Gerd T1 - A counterexample to decomposing climate shifts and trends by weather types JF - International Journal of Climatology N2 - The literature contains a sizable number of publications where weather types are used to decompose climate shifts or trends into contributions of frequency and mean of those types. They are all based on the product rule, that is, a transformation of a product of sums into a sum of products, the latter providing the decomposition. While there is nothing to argue about the transformation itself, its interpretation as a climate shift or trend decomposition is bound to fail. While the case of a climate shift may be viewed as an incomplete description of a more complex behaviour, trend decomposition indeed produces bogus trends, as demonstrated by a synthetic counterexample with well-defined trends in type frequency and mean. Consequently, decompositions based on that transformation, be it for climate shifts or trends, must not be used. KW - analysis KW - climate KW - statistical methods Y1 - 2018 U6 - https://doi.org/10.1002/joc.5519 SN - 0899-8418 SN - 1097-0088 VL - 38 IS - 9 SP - 3732 EP - 3735 PB - Wiley CY - Hoboken ER - TY - RPRT A1 - Ludolph, Lars A1 - Šedová, Barbora T1 - Global food prices, local weather and migration in Sub-Saharan Africa T2 - CEPA Discussion Papers N2 - In this paper, we study the effect of exogenous global crop price changes on migration from agricultural and non-agricultural households in Sub-Saharan Africa. We show that, similar to the effect of positive local weather shocks, the effect of a locally-relevant global crop price increase on household out-migration depends on the initial household wealth. Higher international producer prices relax the budget constraint of poor agricultural households and facilitate migration. The order of magnitude of a standardized price effect is approx. one third of the standardized effect of a local weather shock. Unlike positive weather shocks, which mostly facilitate internal rural-urban migration, positive income shocks through rising producer prices only increase migration to neighboring African countries, likely due to the simultaneous decrease in real income in nearby urban areas. Finally, we show that while higher producer prices induce conflict, conflict does not play a role for the household decision to send a member as a labor migrant. T3 - CEPA Discussion Papers - 26 KW - labour migration KW - food prices KW - climate KW - Africa Y1 - 2021 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-494946 SN - 2628-653X IS - 26 ER - TY - GEN A1 - Pauly, Maren A1 - Helle, Gerhard A1 - Miramont, Cécile A1 - Büntgen, Ulf A1 - Treydte, Kerstin A1 - Reinig, Frederick A1 - Guibal, Frédéric A1 - Sivan, Olivier A1 - Heinrich, Ingo A1 - Riedel, Frank A1 - Kromer, Bernd A1 - Balanzategui, Daniel A1 - Wacker, Lukas A1 - Sookdeo, Adam Sookdeo A1 - Brauer, Achim T1 - Subfossil trees suggest enhanced Mediterranean hydroclimate variability at the onset of the Younger Dryas T2 - Postprints der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe N2 - Nearly 13,000 years ago, the warming trend into the Holocene was sharply interrupted by a reversal to near glacial conditions. Climatic causes and ecological consequences of the Younger Dryas (YD) have been extensively studied, however proxy archives from the Mediterranean basin capturing this period are scarce and do not provide annual resolution. Here, we report a hydroclimatic reconstruction from stable isotopes (delta O-18, delta C-13) in subfossil pines from southern France. Growing before and during the transition period into the YD (12 900-12 600 cal BP), the trees provide an annually resolved, continuous sequence of atmospheric change. Isotopic signature of tree sourcewater (delta O-18(sw)) and estimates of relative air humidity were reconstructed as a proxy for variations in air mass origin and precipitation regime. We find a distinct increase in inter-annual variability of sourcewater isotopes (delta O-18(sw)), with three major downturn phases of increasing magnitude beginning at 12 740 cal BP. The observed variation most likely results from an amplified intensity of North Atlantic (low delta O-18(sw)) versus Mediterranean (high delta O-18(sw)) precipitation. This marked pattern of climate variability is not seen in records from higher latitudes and is likely a consequence of atmospheric circulation oscillations at the margin of the southward moving polar front. T3 - Zweitveröffentlichungen der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe - 1135 KW - annually laminated sediments KW - lake Meerfelder Maar KW - isotopic composition KW - oxygen isotope KW - climate KW - cellulose KW - radiocarbon KW - temperature KW - record KW - model Y1 - 2021 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-459169 SN - 1866-8372 IS - 1135 ER - TY - GEN A1 - Licht, Alexis A1 - Dupont-Nivet, Guillaume A1 - Pullen, Alex A1 - Kapp, Paul A1 - Abels, Hemmo A. A1 - Lai, Zulong A1 - Guo, ZhaoJie A1 - Abell, Jordan A1 - Giesler, Dominique T1 - Resilience of the Asian atmospheric circulation shown by paleogene dust provenance T2 - Postprints der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe N2 - The onset of modern central Asian atmospheric circulation is traditionally linked to the interplay of surface uplift of the Mongolian and Tibetan-Himalayan orogens, retreat of the Paratethys sea from central Asia and Cenozoic global cooling. Although the role of these players has not yet been unravelled, the vast dust deposits of central China support the presence of arid conditions and modern atmospheric pathways for the last 25 million years (Myr). Here, we present provenance data from older (42-33 Myr) dust deposits, at a time when the Tibetan Plateau was less developed, the Paratethys sea still present in central Asia and atmospheric pCO(2) much higher. Our results show that dust sources and near-surface atmospheric circulation have changed little since at least 42 Myr. Our findings indicate that the locus of central Asian high pressures and concurrent aridity is a resilient feature only modulated by mountain building, global cooling and sea retreat. T3 - Zweitveröffentlichungen der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe - 1114 KW - Chinese Loess Plateau KW - last glacial maximum KW - Tibetan Plateau KW - Yellow-River KW - climate KW - basin KW - evolution KW - ardification KW - monsoons KW - desert Y1 - 2021 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-436381 SN - 1866-8372 IS - 1114 ER -