ALBERT

Description: Die Bundesregierung hat den Kohleausstieg bis zum Jahr 2038 beschlossen und beschleunigt so die Transformation in den Kohleregionen. Die Ausgangslagen für den Wandel in den Revieren und umliegende Gemeinden der Lausitz und des Rheinlands sind dabei sehr unterschiedlich. In beiden Regionen stehen Politik, Zivilgesellschaft, Wirtschaft und Wissenschaft vor der Aufgabe, Lösungspfade und Transformationskorridore zu finden, die ökologisch verantwortlich, sozial gerecht, wirtschaftlich vielversprechend und demokratisch getragen sind. Das IASS Potsdam veranstaltete im Frühjahr 2020 gemeinsam mit dem Kulturwissenschaftlichen Institut Essen einen Workshop, um demokratiepolitische Gemeinsamkeiten und Unterschiede im Strukturwandel der Braunkohleregionen herauszuarbeiten. Die Zwischenergebnisse werden in dieser Studie dargestellt.

Description: Submarine groundwater discharge (SGD) into coastal areas is a common global phenomenon and is rapidly gaining scientific interest due to its influence on marine ecology, the coastal sedimentary environment and its potential as a future freshwater resource. We conducted an integrated study of hydroacoustic surveys combined with geochemical porewater and water column investigations at a well‐known groundwater seep site in Eckernförde Bay (Germany). We aim to better constrain the effects of shallow gas and SGD on high frequency multibeam backscatter data and to present acoustic indications for submarine groundwater discharge. Our high‐quality hydroacoustic data reveal hitherto unknown internal structures within the pockmarks in Eckernförde Bay. Using precisely positioned sediment core samples, our hydroacoustic‐geochemical approach can differentiate intra‐pockmark regimes that were formerly assigned to pockmarks of a different nature. We demonstrate that high‐frequency multibeam data, in particular the backscatter signals, can be used to detect shallow free gas in areas of enhanced groundwater advection in muddy sediments. Intriguingly, our data reveal relatively small (typically 〈15 m across) pockmarks within the much larger, previously mapped, pockmarks. The small pockmarks, which we refer to as “intra‐pockmarks”, have formed due to the localized ascent of gas and groundwater; they manifest themselves as a new type of ‘eyed’ pockmarks, revealed by their acoustic backscatter pattern. Our data suggest that, in organic‐rich muddy sediments, morphological lows combined with a strong multibeam backscatter signal can be indicative of free shallow gas and subsequent advective groundwater flow.

Description: Aerosols interact with radiation and clouds. Substantial progress made over the past 40 years in observing, understanding, and modeling these processes helped quantify the imbalance in the Earth's radiation budget caused by anthropogenic aerosols, called aerosol radiative forcing, but uncertainties remain large. This review provides a new range of aerosol radiative forcing over the industrial era based on multiple, traceable, and arguable lines of evidence, including modeling approaches, theoretical considerations, and observations. Improved understanding of aerosol absorption and the causes of trends in surface radiative fluxes constrain the forcing from aerosol-radiation interactions. A robust theoretical foundation and convincing evidence constrain the forcing caused by aerosol-driven increases in liquid cloud droplet number concentration. However, the influence of anthropogenic aerosols on cloud liquid water content and cloud fraction is less clear, and the influence on mixed-phase and ice clouds remains poorly constrained. Observed changes in surface temperature and radiative fluxes provide additional constraints. These multiple lines of evidence lead to a 68% confidence interval for the total aerosol effective radiative forcing of -1.6 to -0.6 W m−2, or -2.0 to -0.4 W m−2 with a 90% likelihood. Those intervals are of similar width to the last Intergovernmental Panel on Climate Change assessment but shifted toward more negative values. The uncertainty will narrow in the future by continuing to critically combine multiple lines of evidence, especially those addressing industrial-era changes in aerosol sources and aerosol effects on liquid cloud amount and on ice clouds. Key Points: - An assessment of multiple lines of evidence supported by a conceptual model provides ranges for aerosol radiative forcing of climate change - Aerosol effective radiative forcing is assessed to be between -1.6 and -0.6 W m−2 at the 16–84% confidence level - Although key uncertainties remain, new ways of using observations provide stronger constraints for models

Description: A major surface circulation feature of the Arctic Ocean is the Transpolar Drift (TPD), a current that transports river‐influenced shelf water from the Laptev and East Siberian Seas toward the center of the basin and Fram Strait. In 2015, the international GEOTRACES program included a high‐resolution pan‐Arctic survey of carbon, nutrients, and a suite of trace elements and isotopes (TEIs). The cruises bisected the TPD at two locations in the central basin, which were defined by maxima in meteoric water and dissolved organic carbon concentrations that spanned 600 km horizontally and ~25‐50 m vertically. Dissolved TEIs such as Fe, Co, Ni, Cu, Hg, Nd, and Th, which are generally particle‐reactive but can be complexed by organic matter, were observed at concentrations much higher than expected for the open ocean setting. Other trace element concentrations such as Al, V, Ga, and Pb were lower than expected due to scavenging over the productive East Siberian and Laptev shelf seas. Using a combination of radionuclide tracers and ice drift modeling, the transport rate for the core of the TPD was estimated at 0.9 ± 0.4 Sv (106 m3 s‐1). This rate was used to derive the mass flux for TEIs that were enriched in the TPD, revealing the importance of lateral transport in supplying materials beneath the ice to the central Arctic Ocean and potentially to the North Atlantic Ocean via Fram Strait. Continued intensification of the Arctic hydrologic cycle and permafrost degradation will likely lead to an increase in the flux of TEIs into the Arctic Ocean.

Description: This summary for decision makers is based on the report ‘Ecological Baselines of the Southeast Atlantic and Southeast Pacific – Status of Marine Biodiversity and Anthropogenic Pressures in Areas Beyond National Jurisdiction’ and provides consolidated information on key biological and ecological features of Areas Beyond National Jurisdiction (ABNJ) in the Southeast Atlantic as well as highlights key pressures placed upon it by human activities. ABNJ include the water column (the high seas) and the seabed (the Area) outside of the Exclusive Economic Zone (EEZ) of coastal States and cover about half of the Earth’s surface. This summary is intended to inform relevant actors and stakeholders to support their understanding of the function and importance of marine biological diversity in ABNJ and the need to for appropriate conservation and management measures. The report was prepared as part of the Strengthening Regional Ocean Governance for the High Seas (‘STRONG High Seas’) project – funded by the German Federal Ministry for the Environment, Nature Conservation and Nuclear Safety (BMU) through the International Climate Initiative (IKI).

Description: Este resumen para los tomadores de decisiones está basado en el informe “Ecological Baselines of the Southeast Atlantic and Southeast Pacific – Status of Marine Biodiversity and Anthropogenic Pressures in Areas Beyond National Jurisdiction” y proporciona información consolidada sobre las principales características biológicas y ecológicas de las zonas fuera de la jurisdicción nacional (ABNJ, por sus siglas en inglés) en el Pacífico Sudeste, así como, destaca las principales presiones que ejercen sobre ellas las actividades humanas. Las ABNJ incluyen la columna de agua (alta mar) y el lecho marino (la Zona) fuera de la Zona Económica Exclusiva (ZEE) de los estados ribereños y cubren aproximadamente la mitad de la superficie de la Tierra. El presente resumen tiene por objeto informar a los agentes e interesados pertinentes para reforzar su conocimiento de la función e importancia de la diversidad biológica marina en las ABNJ y la necesidad de adoptar medidas apropiadas de conservación y gestión. El informe se preparó como parte del proyecto Strengthening Regional Ocean Governance for the High Seas (‘STRONG High Seas’) – financiado por el Ministerio Federal Alemán de Medio Ambiente, Protección de la Naturaleza y Seguridad Nuclear (BMU) a través de la Iniciativa Internacional sobre el Clima (IKI).

Description: Ce résumé à l’intention des décideurs se fonde sur le rapport Ecological Baselines of the Southeast Atlantic and Southeast Pacific – Status of Marine Biodiversity and Anthropogenic Pressures in Areas Beyond National Jurisdiction. Il fournit des informations consolidées sur les particularités biologiques et écologiques clés des zones situées au-delà de la juridiction nationale (ZAJN) dans l’Atlantique du Sud-Est et met également en évidence les pressions principales qu’imposent à ces dernières les activités anthropiques. Les ZAJN comprennent la colonne d’eau (la haute mer) et les fonds marins (la « Zone ») en dehors de la zone économique exclusive (ZEE) des États côtiers et couvrent près de la moitié de la surface de la Terre. Ce résumé a pour but d’éclairer les acteurs et les parties prenantes concernés afin de les aider à mieux comprendre la fonction et l’importance de la diversité biologique marine dans les ZAJN et la nécessité de mesures de conservation et de gestion appropriées. Ce rapport a été élaboré dans le cadre du projet Strengthening Regional Ocean Governance for the High Seas (« STRONG High Seas ») – financé par le Ministère fédéral allemand de l'Environnement, de la Protection de la nature et de la Sûreté nucléaire (BMU) par le biais de l’Initiative internationale pour la protection du climat (International Climate Initiative – IKI).

Description: This summary for decision makers is based on the report ‘Ecological Baselines of the Southeast Atlantic and Southeast Pacific – Status of Marine Biodiversity and Anthropogenic Pressures in Areas Beyond National Jurisdiction’ and provides consolidated information on key biological and ecological features of Areas Beyond National Jurisdiction (ABNJ) in the Southeast Pacific as well as highlights key pressures placed upon it by human activities. ABNJ include the water column (the high seas) and the seabed (the Area) outside of the Exclusive Economic Zone (EEZ) of coastal States and cover about half of the Earth’s surface. This summary is intended to inform relevant actors and stakeholders to support their understanding of the function and importance of marine biological diversity in ABNJ and the need to for appropriate conservation and management measures. The report was prepared as part of the Strengthening Regional Ocean Governance for the High Seas (‘STRONG High Seas’) project – funded by the German Federal Ministry for the Environment, Nature Conservation and Nuclear Safety (BMU) through the International Climate Initiative (IKI).

Description: The Arctic Ocean is particularly vulnerable to ocean acidification, a process that is mainly driven by the uptake of anthropogenic carbon (Cant) from the atmosphere. Although Cant concentrations cannot be measured directly in the ocean, they have been estimated using data‐based methods such as the transient time distribution (TTD) approach, which characterizes the ventilation of water masses with inert transient tracers, such as CFC‐12. Here, we evaluate the TTD approach in the Arctic Ocean using an eddying ocean model as a test bed. When the TTD approach is applied to simulated CFC‐12 in that model, it underestimates the same model's directly simulated Cant concentrations by up to 12%, a bias that stems from its idealized assumption of gas equilibrium between atmosphere and surface water, both for CFC‐12 and anthropogenic CO2. Unlike the idealized assumption, the simulated partial pressure of CFC‐12 (p CFC‐12) in Arctic surface waters is undersaturated relative to that in the atmosphere in regions and times of deep‐water formation, while the simulated equivalent for Cant is supersaturated. After accounting for the TTD approach's negative bias, the total amount of Cant in the Arctic Ocean in 2005 increases by 8% to 3.3 ± 0.3 Pg C. By combining the adjusted TTD approach with scenarios of future atmospheric CO2, it is estimated that all Arctic waters, from surface to depth, would become corrosive to aragonite by the middle of the next century even if atmospheric CO2 could be stabilized at 540 ppm.