ALBERT

Beschreibung: The aim of this study is to contribute to a learning process about innovative and successful approaches to overcoming problems and challenges of urban environmental protection. To this end, a detailed overview of the importance of environmental challenges, political priorities and successful solutions in selected countries and cities is given. Based on this, the study analyzes specific success factors and discusses the extent to which these can be transferred and replicated to other cities. Finally, recommendations are made for cities, countries and the international community on how environmental protection at the urban level can be further strengthened. The role of German cities and institutions will also be discussed. The case studies analyzed include Belo Horizonte in Brazil, Moscow in Russia, Kochi in India, Beijing in China, Cape Town in South Africa and Jakarta in Indonesia. These cities were selected because they have already implemented successful policies, measures and other initiatives in the past. For each city, the study analyzes relevant policy documents in order to present the respective challenges and political priorities. The analysis aims to understand the effectiveness of the plans and instruments taking into account the national political environment. Despite the cross-sectoral approach, the analysis of each case study focuses on specific sectors in order to produce well-founded results. The success factors that are worked out based on this sectoral analysis are placed in a holistic context in order to be able to make generalizable statements about success factors.

Beschreibung: With a growing concern over rapid Antarctic ice loss in recent years, the Amundsen Sea, one of the fastest-melting areas in Antarctica, currently becomes a hotspot for the Earth sciences in the context of its linkage to global climate. As a center of strong physical and biological coupling processes, polynyas of the Amundsen Sea could act as sentinels of changes in atmosphere–ice–ocean interactions, offering a unique perspective into its sensitivity to climate variability. Here, we present a new, multiproxy-based high-resolution sedimentary record from the Amundsen Sea polynya, which provides new insights into environmental conditions of the region over the last 350 years and their linkages to climatic factors. Our results show that the polynya witnessed step-wise environmental shifts in parallel with the phases and strength of large-scale climate patterns, i.e., the Southern Annular Mode (SAM) and El Niño–Southern Oscillation (ENSO). Notably, intersite correlation of on-shelf Circumpolar Deep Water (CDW) intrusion signals at different locals suggests that the CDW may have gained increased access to the shelves at the time of a strong coupling of positive SAM and El Niño states. We tentatively speculate that anomalous large-scale atmospheric and oceanic circulation patterns over the Southern Hemisphere, forced by increasing greenhouse gas levels, were strongly involved in the mid-20th century CDW invigoration, which may be greater in scale that goes well beyond the Amundsen Sea region. This result is relevant to the current debate on spatial heterogeneity in the timing and phasing of major climatic events in Antarctica, underscoring an unambiguous connection of the Antarctic climate state to the large-scale ocean–atmosphere reorganizations. Our study also extends a growing evidence that today's global warming trend is expected to have a severe effect on future configuration of Antarctic continental ice-shelf environment.

Beschreibung: We investigate the late Cretaceous blueschist-facies (480 °C-1.8 GPa) segment of the Zagros suture zone, a well-preserved block-in-matrix paleo-subduction channel. We aim to determine the relative chronology, conditions of deformation, and potential fluid sources and processes associated with the widespread occurrence of lawsonite + clinopyroxene + glaucophane veins and aragonite-bearing hydraulic breccias. We use a multi-scale approach methodology to provide new insights into deep fluid flow mechanisms as well as to constrain possible sinks of CO2-bearing fluids in the subducting slab. Petrological analyses suggest that silicate-rich vein systems began precipitating during early burial and evolved with ongoing burial and shearing-related deformation in the blueschist-facies, while most carbonate-rich veins and hydrofractures formed at near-peak P-T conditions. In situ LA-ICP-MS trace element analyses reveal that: (i) individual silicate host-vein pairs have similar REE signatures, reflecting local-scale fluid-mediated element redistribution, (ii) carbonate-bearing veins and metasediments also have similar trace element signatures and (iii) lawsonite in blueschist-hosted veins exhibit REE enrichments along their rims, suggesting an increasing contribution of metasedimentary-derived fluids upon approaching peak P-T. Carbonate Osingle bondC isotope compositions of the veins and metasedimentary rocks range from +13.6 to +17.9‰ (δ18OVSMOW) and − 1.0 to +3.1‰ (δ13CVPDB), demonstrating metasedimentary-derived fluid sources related to large-scale H2O homogenization with far-traveled mafic- ultramafic-derived fluids. Srsingle bondNd isotopic ratios in carbonate veins and the adjacent host resemble their host composition indicating that host rock-buffered isotopic homogenization occurred between the infiltrating fluids and the rock matrix, possibly during episodic porous flow. Thermodynamic modeling predicts that decarbonation via fluid-assisted reactions is inefficient at blueschist-facies and that carbon release likely occurs deeper along the subduction interface (i.e., at eclogite-facies). We propose that deeply produced H2O-rich fluids interacted with the carbonate-bearing lithologies along the subduction interface facilitating fluid-mediated decarbonation and further fluid transport as hydraulic pulses (e.g., porosity waves) that traveled at the kilometer-scale parallel to the subduction interface, (i) contributing to the isotopic homogenization herein observed and (ii) triggering episodic hydrofracturing in the lawsonite-blueschist-facies (≈50-60 km depth). Veinsets in exhumed subducted rocks hence provide a unique opportunity to understand fluid-rock interaction processes in the region at which episodic tremor and slow slip events phenomena occur.