ALBERT

Description: Der vorliegende Kolloquiumsband der ”Blauen Bände“ umfasst 41 Beiträge. Dem diesjährigen Kolloquiumsband wurde ein neues Format hinzugefügt. Der sogenannte 1-Pager bietet die Möglichkeit eines einseitigen Beitrages, bestehend aus einer Zusammenfassung, einer Abbildung und einer Referenz zu weiterführender Information. In der Vergangenheit haben sich immer wieder Diskussionen zur Publikation von wissenschaftlichen Arbeiten in den ”Blauen Bänden“ ergeben. Mit diesem neuen niederschwelligen 1-Pager Format wollen wir alle EMTF Kolloquiums Teilnehmer*innen motivieren, ihren Beitrag in diesem traditionellen Kolloquiumsband sichtbar zu machen. Das ist mit einer vergleichsweise großen Anzahl von Beitr¨agen gut gelungen. In diesem Band sind Extended Abstracts (4), Vortragsfolien (8), Postern (19) sowie der neu eingeführte 1-Pager (10) zusammengefasst. Als weitere Neuerung wurde dem Band erstmalig das Tagungsprogramm als Anhang beigefügt. Wir danken allen Teilnehmern, die mit ihren Beiträgen dazu beitragen, die Breite des Kolloquiums auch in den ”Blauen Bänden“ zu dokumentieren.

Description: The geometry and evolution of fluvial systems are thought to be related to surface uplift. In eastern Tibet, rivers exhibit peculiar drainage patterns but how these patterns were established and their connection with the plateau uplift are still under debate. Here, we use detrital zircon U-Pb dating, bedrock (U-Th)/He thermochronometry, topographic analysis and numerical modeling to explore the paleo-drainage pattern of the Dadu and Anning Rivers, eastern Tibet. Our detrital data indicate that the Pliocene sources of sediments to the Anning River are different from the modern ones and they include a source similar to that of the modern Dadu River, implying a paleo-connection between the Dadu and the Anning Rivers and a subsequent cutoff of this connection after the deposition of the Pliocene sediments. Bedrock thermochronometric data along the Dadu River reveal rapid cooling at ∼10 Ma and a possible enhanced cooling at ∼2 Ma, which we interpret as a response to the regional plateau uplift in eastern Tibet and to the Dadu-Anning capture, respectively. Combined with topographic analysis and numerical modeling, our results indicate an Early Pleistocene capture between the Dadu and Anning Rivers, resulting in the changes in the sediment sources of the Anning River, enhanced incision of the Dadu, and the transience of the Dadu River profile. The Dadu-Anning capture is related to the motion along the active sinistral strike-slip Daliangshan fault that locally disrupts the river network. This event does not date the plateau uplift; rather, it indicates how river reorganization can effectively enhance river incision and affect landscape development independently from regional-scale uplift.

Description: Many physical, biological, and social systems exhibit emergent properties arising from their components’ interactions (cells). In this study, we systematically treat every-pair interactions (a) that exhibit power-law dependence on the Euclidean distance and (b) act in structures that can be characterized using fractal geometry. It can represent the two-body interaction potential, the heat flux between two parts of a structure, friendship strength between two people, etc.. We analytically derive the average intensity of influence that one cell has on the others or, conversely, receives from them. This quantity is referred to as the mean interaction field of the cells, and we find that (i) in a long-range interaction regime, the mean interaction field increases following a power-law with the size of the system, (ii) in a short-range interaction regime, the field saturates, and (iii) in the intermediate range it follows a logarithmic behavior. To validate our analytical solution, we perform numerical simulations. For long-range interactions, the theoretical calculations align closely with the numerical results. However, for short-range interactions, we observe that discreteness significantly impacts the continuum approximation used in the derivation, leading to incorrect asymptotic behavior in this regime. To address this issue, we propose an expansion that substantially improves the accuracy of the analytical expression. We discuss applications of the every-pair interactions system proposed, and one of them is to explore a framework for estimating the fractal dimension of unknown structures. This approach offers an alternative to established methods such as box-counting or sandbox methods. Overall, we believe that our analytical work will have broad applicability in systems where every-pair interactions play a role.

Description: The article evidences to what extent rights-based climate litigation is applied as a strategy to enhance the recognition and protection of climate-induced migrants. Adopting a deduc- tive approach and desk review, the study, illustrates how climate-induced migration has been addressed by International Human Rights Law, with some attention also paid to the growing application of the right to a safe climate and climate justice. The study highlights the duties of both States and private actors in tackling the emerging climate crisis under the human rights agenda. Relevant responsibilities are framed in particular within the scope of rights-based litiga- tion dealing with the topic. We present an analysis of litigation linked to climate-induced migration that was filed before distinct international, regional, and national jurisdictions and, in doing so, propose a chronology of cases—structured in three generations—of how population movements as a result of climate change have been discussed by judicial means. The first generation relates to cases that consider the issue from the perspective of protection—in both national, regional, and international jurisdictions. The second generation emerges within general climate litigation claims, involving commitments linked to the climate agenda. In addition to raising (forced) pop- ulation movements as one of the expected impacts of climate change, such cases frequently call upon a rights-based approach. The third generation encompasses rights-based cases cen- tred on climate-induced migrants per se. The strengths and limitations of rights-based litigation to respond to the topic are finally highlighted: we conclude that litigation remains a blunt but not unpromising tool to respond to climate-induced migration. Generic references to the risk of (forced) population movements largely prevail; nevertheless, strategic rights-based litigation can facilitate the visibility of climate-induced migrants to the international community, fostering the development of legal solutions in the longer term.

Description: Process-based forest models combine biological, physical, and chemical process understanding to simulate forest dynamics as an emergent property of the system. As such, they are valuable tools to investigate the effects of climate change on forest ecosystems. Specifically, they allow testing of hypotheses regarding long-term ecosystem dynamics and provide means to assess the impacts of climate scenarios on future forest development. As a consequence, numerous local-scale simulation studies have been conducted over the past decades to assess the impacts of climate change on forests. These studies apply the best available models tailored to local conditions, parameterized and evaluated by local experts. However, this treasure trove of knowledge on climate change responses remains underexplored to date, as a consistent and harmonized dataset of local model simulations is missing. Here, our objectives were (i) to compile existing local simulations on forest development under climate change in Europe in a common database, (ii) to harmonize them to a common suite of output variables, and (iii) to provide a standardized vector of auxiliary environmental variables for each simulated location to aid subsequent investigations. Our dataset of European stand- and landscape-level forest simulations contains over 1.1 million simulation runs representing 135 million simulation years for more than 13,000 unique locations spread across Europe. The data were harmonized to consistently describe forest development in terms of stand structure (dominant height), composition (dominant species, admixed species), and functioning (leaf area index). Auxiliary variables provided include consistent daily climate information (temperature, precipitation, radiation, vapor pressure deficit) as well as information on local site conditions (soil depth, soil physical properties, soil water holding capacity, plant-available nitrogen). The present dataset facilitates analyses across models and locations, with the aim to better harness the valuable information contained in local simulations for large-scale policy support, and for fostering a deeper understanding of the effects of climate change on forest ecosystems in Europe.

Description: The Texas power grid on the Gulf Coast of the United States is frequently hit by tropical cyclones (TCs) causing widespread power outages, a risk that is expected to substantially increase under global warming. Here we introduce a new approach that combines a probabilistic line failure model with a network model of the Texas grid to simulate the spatio-temporal co-evolution of wind-induced failures of high-voltage transmission lines and the resulting cascading power outages from seven major historical TCs. The approach allows reproducing observed supply failures. In addition, compared to existing static approaches, it provides a notable advantage in identifying critical lines whose failure can trigger large supply shortages. We show that hardening only 1% of total lines can reduce the likelihood of the most destructive type of outage by a factor of between 5 and 20. The proposed modelling approach could represent a so far missing tool for identifying effective options to strengthen power grids against future TC strikes, even under limited knowledge.

Description: Media inform the public, thereby influencing societal debates and political decisions. Despite climate change’s importance, drivers of media attention to climate change remain differently understood. Here we assess how different sociopolitical and extreme weather events affect climate change media coverage, both immediately and in the weeks following the event. To this end, we construct a data set of over 90,000 climate change articles published in nine major German newspapers over the past three decades and apply fixed effects panel regressions to control for confounders. We find that United Nations Climate Change Conferences affect coverage most strongly and most persistently. Climate protests incite climate coverage that extends well beyond the reporting on the event itself, whereas many articles on weather extremes do not mention climate change. The influence of all events has risen over time, increasing the media prominence of climate change.

Description: The Greenland Ice Sheet and Atlantic Meridional Overturning Circulation are considered tipping elements in the climate system, where global warming exceeding critical threshold levels in forcing can lead to large-scale and nonlinear reductions in ice volume and overturning strength, respectively. The positive-negative feedback loop governing their interaction (with a destabilizing effect on the AMOC due to ice loss and subsequent freshwater flux into the North Atlantic as well as a stabilizing effect of a net-cooling around Greenland with an AMOC weakening) may determine the long-term stability of both tipping elements. Here we explore the potential dynamic regimes arising from this positive-negative tipping feedback loop in a process-based conceptual model. Under idealized forcing scenarios we identify conditions under which different kinds of tipping cascades can occur: Herein, we distinguish between overshoot tipping cascades (leading to tipping of both GIS and AMOC) and rate-induced tipping cascades (where the AMOC despite not having crossed its own intrinsic tipping point tips nonetheless due to the fast rate of ice loss from Greenland). These different cascades occur within corridors of distinct tipping pathways that are affected by the GIS melting patterns and thus eventually by the imposed forcing and its time scales. Our results suggest that it is not only necessary to avoid breaching the respective critical levels of the environmental drivers for the Greenland Ice Sheet and Atlantic Meridional Overturning Circulation, but also to respect safe rates of environmental change to mitigate potential domino effects.

Description: Pyrite is a ubiquitous sulfide mineral found in diverse geological settings and holds great significance in the formation of Au deposits as well as the safe utilization of groundwater due to its remarkable ability to incorporate substantial amounts of As. However, despite its importance, there remains a dearth of fundamental data on the partitioning of As between pyrite and fluid, which is key for accurately modeling the As distribution in these environments. Here, we present new insights into the partitioning behavior of As between pyrite and fluid at conditions that mimic natural fluid systems. Pyrite was synthesized by replacement of natural siderite in hydrothermal experiments at 200 °C and pH 5 applying a wide range of fluid As concentrations, spanning from 0.001 to 100 µg/g. The As distribution and concentration in synthetic pyrite was analyzed by quantitative LA-ICP-MS mapping providing a high spatial resolution and sensitivity at 2–3 µm image pixel size at a detection limit of ∼1 µg/g at the single pixel scale. Pyrite-fluid partitioning coefficients (DAs(py/fluid)) between synthetic pyrite and experimental fluid agree with previously published data for high fluid As concentrations of 1 µg/g to 100 µg/g (DAs 〈 2000). However, at low As concentrations in the experimental fluid (〈1 µg/g), a steep increase in the DAs(py/fluid) values of up to ∼30,000 was detected, demonstrating even stronger As partitioning into pyrite. This is confirmed by the analyses of natural pyrite that precipitated from As-poor fluids (0.3–0.4 ng/g) within a deep anoxic aquifer in SE Sweden. The discovery holds significant implications for the mobility and scavenging of As, which in turn is important for understanding the formation and fingerprinting of mineral deposits as well as for the secure utilization of groundwater resources.

Description: Important features of Sn mineralization are the heterogeneous geographic distribution and frequent regional separation from W mineralization in spite some similarities of Sn and W behavior during magmatic processes. Major Sn and W mineralization is often spatially associated with peraluminous granites, which are derived from partial melting of metasediments. Several concepts have been suggested to explain those features, such as a weathering-related Sn-enriched source, Sn redistribution between melts and restite during protolith melting, and extensive fractional crystallization. We demonstrate the importance of protolith composition for the formation of Sn (and W) granites by using a comprehensive bulk-rock composition dataset from Precambrian metasediments of the South China Sn-W province and employing a thermodynamic modeling approach. We used four compositional proxies for phase equilibria calculations, which are the metasediments of the Mengdong, Sibao, Pingbian, and Shuangqiaoshan Groups. It is well documented that those Precambrian metasediments are important protoliths of Sn granites in South China. We present quantitative evaluation of the control of protolith composition in the generation of Sn-enriched granitic melts using South China as example, but our conclusions may also be applicable to worldwide Sn–enriched granites. Our results indicate that the protolith major-element geochemistry controls the anatectic reactions and melt productivity at specific melting conditions, and consequently the partitioning behavior of Sn. Further, pre-enrichment of Sn is crucial to the fertility of granitic melt and may be a prerequisite, particularly for the formation of giant Sn deposits. We propose that the heterogeneous distribution of favorable source rocks is one of the important factors that control the spatial distribution of major Sn (and W) districts in South China and other regions worldwide.