ALBERT

Description: The atmospheric concentration of CO2 at which global glaciation (snowball) bifurcation occurs, changes throughout Earth's history, most notably because of the slowly increasing solar luminosity. Quantifying this critical CO2 concentration is not only interesting from a climate dynamics perspective, but also an important prerequisite for understanding past Snowball Earth episodes as well as the conditions for habitability on Earth and other planets. Here we use the coupled climate model CLIMBER-3α in an Aquaplanet configuration to scan for the Snowball bifurcation point for time slices spanning the last 4 billion years, thus quantifying the time evolution of the bifurcation and identifying a qualitative shift in critical state dynamics.

Description: The new climate dataset, BASD-CMIP6-PE, for Peru and Ecuador is based on bias-adjusted and statistically downscaled CMIP6 climate projections from 10 GCMs. It addresses the need for reliable high-resolution (1d, 10km) climate data covering Peru and Ecuador. This dataset includes historical simulations (1850-2014) and future projections (2015-2100) for precipitation and minimum, mean, and maximum temperature under three Shared Socioeconomic Pathways (SSPs:SSP1-2.6, SSP3-7.0, and SSP5-8.5). The BASD-CMIP6-PE climate data were generated using the trend-preserving Bias Adjustment and Statistical Downscaling (BASD) method (Lange, 2019, 2021) and data from regional observational datasets such as RAIN4PE (Fernandez-Palomino et al., 2021a,b) for precipitation and PISCO-temperature (Huerta et al., 2018) for temperatures as reference data. The reliability of the BASD-CMIP6-PE was evaluated using observational data and through hydrological modeling across Peruvian and Ecuadorian river basins in the historical period. The evaluation demonstrated the dataset’s reliability in describing spatial patterns of atmospheric variables and streamflow simulation, including mean, low, and high flows. This suggests the usefulness of the new dataset for assessing regional climate change impacts on agriculture, water resources, and hydrological extremes. The BASD-CMIP6-PE data are available for the domain covering Peru and Ecuador, located between 19°S and 2°N and 82°W to 67°W, with a spatial resolution of 0.1° and a daily temporal resolution. The unit for precipitation is millimeters (mm), and for temperature, it is degrees Celsius (°C). The BASD-CMIP6-PE dataset is organized within a "daily" folder, denoting its availability at a 1 daily temporal resolution. Within this directory, four subfolders are present: "historical" containing historical data, "ssp126" for SSP1-2.6, "ssp370" for SSP3-7.0, and "ssp585" for SSP5-8.5. Each of these subfolders further includes ten distinct folders, corresponding to different GCMs: CanESM5, IPSL–CM6A–LR, UKESM1–0–LL, CNRM–CM6–1, CNRM–ESM2–1, MIROC6, GFDL–ESM4, MRI–ESM2–0, MPI–ESM1–2–HR, and EC–Earth3. These folders store the data in the NetCDF format arranged by model, model member, experiment, variable, temporal resolution, and subset period, resulting in file names like "canesm5_r1i1p1f1_ssp126_pr_daily_2015_2020.nc". For a detailed description of the BASD-CMIP6-PE development and evaluation, readers are advised to read Fernandez-Palomino et al. (2023), for which this dataset is supplementary material.

Description: The atmosphere model of the Geophysical Fluid Dynamics Laboratory (GFDL-AM2) is coupled to a slab ocean in order to analyse the monsoon's sensitivity to changes in various forcing parameters on a planet with idealized topography. This monsoon planet design of a water planet with a zonal circumglobal land stripe allows to extract the relevant monsoon behaviour and reduces the influence of topography. Besides the width and location of the land stripe, the atmospheric CO2 concentration, incoming solar radiation, sulfate aerosol concentration and surface albedo are variied. Horizontal grid resolution is 2° latitude x 2.5° longitude. For the vertical grid, a hybrid coordinate grid with 24 vertical levels is implemented. The lowest model level starts about 30 m above the surface and the top level is at about 3 hPa. The vertical resolution is decreasing towards higher altitudes. Advective and physics time steps are 10 minutes and 0.5 hours, for atmopsheric radiation 3 hours time steps are used. Instead of an ocean general circulation model, a mixed-layer slab ocean is used.

Description: Unter dem Label "Transition Management" ist in den Niederlanden in den letzten zehn Jahren ein Forschungsfeld entstanden, das sich insbesondere dem "Wie" nachhaltiger Systemübergänge widmet. Obwohl die niederländischen Ansätze teilweise adaptiert wurden, steht ein geschlossenes Forschungsprogramm für die deutsche Nachhaltigkeitsdebatte noch aus.

Description: Die multilaterale Politik bekennt sich zum Zwei-Grad-Ziel, um den Klimawandel zu begrenzen. Sie stützt sich dazu explizit auf Empfehlungen "der Wissenschaft". Bemerkenswert ist, dass sie sich dabei nicht - was doch naheläge - auf das IPCC beruft. Dieses Gremium hat sich nämlich explizit versagt, "Werturteile" wie das Zwei-Grad-Ziel zu formulieren. Da die Politik aber nach solchen Urteilen verlangt, bedient sie sich pragma tisch an anderer Stelle - bei einer Wissenschaft, die nicht strikt zwischen Fakten und Werturteilen trennt. Letzteres sollte auch ein Kennzeichen einer Wissenschaft von der Nachhaltigkeit (sustainability science) sein.

Description: Since the 1970s, climate change has dominated the international scientific and political agenda. In particular, the foundation of the Intergovernmental Panel on Climate Change at the end of the 1980s played a major role for the further enhancement of efforts in the field of climate change sciences. However, to understand the interaction of the worldwide coordination of climate change sciences as well as the role of the Intergovernmental Panel on Climate Change and its consequences, it is worthwhile to take a look at the self-conception of the Intergovernmental Panel on Climate Change's tasks and work. This paper gives an idea of the history of international climate change science, its representation in public discourse and the role of the Intergovernmental Panel on Climate Change by comprehensively illustrating its tasks, organization and self-image. Furthermore, the article tries to argue that the hitherto accepted concept of science followed within this body fails to integrate the idea of scientific ethics. It can be concluded that the conception of science represented by the Intergovernmental Panel on Climate Change has heavily influenced worldwide attention to climate change, its becoming part of the political agenda as well as the ethical consequences.

Description: Transdisziplinäre Nachhaltigkeitswissenschaften institutionell zu etablieren ist eine große Herausforderung. Hier setzt die neue NaWis-Runde an; sie möchte zur Transformation im Wissenschaftssystem beitragen.

Description: This contribution presents the state of the art of economy-wide material flow accounting. Starting from a brief recollection of the intellectual and policy history of this approach, we outline system definition, key methodological assumptions, and derived indicators. The next section makes an effort to establish data reliability and uncertainty for a number of existing multinational (European and global) material flow accounting (MFA) data compilations and discusses sources of inconsistencies and variations for some indicators and trends. The results show that the methodology has reached a certain maturity: Coefficients of variation between databases lie in the range of 10% to 20%, and correlations between databases across countries amount to an average R2 of 0.95. After discussing some of the research frontiers for further methodological development, we conclude that the material flow accounting framework and the data generated have reached a maturity that warrants material flow indicators to complement traditional economic and demographic information in providing a sound basis for discussing national and international policies for sustainable resource use.

Description: Die Entwicklung zu einer nachhaltigen Wirtschaftsweise wird insbesondere durch Veränderungsprozesse in einzelnen Schlüsselbranchen vorangetrieben. Zu einer solchen Schlüsselbranche gehört der Energiesektor. Ein nachhaltiger Branchenwandel basiert dabei auf einem differenzierten Zusammenspiel von technologischen Entwicklungen, von politischer Rahmensetzung, von allgemeinen Umfeldveränderungen und von der Entwicklung neuer Geschäftsstrategien, die diese Elemente aufgreifen.