Adaptation to climate change: Regional sea surface temperature scenarios for the North Sea and the Baltic Sea

The German Strategy for Adaptation to Climate Change (Deutsche Anpassungsstrategie - DAS) is the political framework to climate change adaptation in Germany and laid the foundation to prepare for the impacts of climate change and reduce climate risks in a continuous process. The DAS core service “Climate and Water” provides monitoring and projection data to evaluate requirements for climate change adaptation.

An ensemble of regional climate ocean simulations is provided to tackle a large number of questions on the topics of sea level, water temperature, salinity and currents. The regional climate ocean simulation ensemble is based on atmospheric forcing from five members of the EURO-CORDEX ensemble. The simulations were calculated for a thirty-year ”historical” period (1971-2000), a thirty-year ”near future” period (2031-2060) and one for the ”far future” (2071-2100) for the RCP8.5 scenario.In this study, we focus on the evaluation of the sea surface temperature (SST), which has a major impact on the ecosystem and therefore must be part of the adaptation strategy. A comparison of all SST model results with observational data provides a bias correction of the individual ensemble members, which than is also applied to the projected data. The ensemble approach is examined with respect to substantial uncertainties and different types of ensemble representation are discussed. The results are prepared for policymakers and practitioners engaged in coastal risk assessment and adaptation planning and will be available on the internet at https://das.bsh.de.