Past and future European snow conditions as represented

Past and future European snow conditions as represented by the EURO-CORDEX ensemble Claas Teichmann 1 Sven Kotlarski 2 Katharina Bülow 1 Christian Steger 3 1 Climate Service Center Germany (GERICS), Hamburg 2 Federal Office of Meteorology and Climatology Meteo. Swiss, Zurich 3 Institute for Atmospheric and Climate Science, ETH Zurich, Zurich www. swissinfo. ch Water resource Recreation & tourism Natural hazards Ecology … Surface energy balance! Climate models www. nps. gov www. slf. ch

European snow cover already declined in the past. How will it evolve in the future? +8°C +6°C +40% +4°C Projected winter temperature change by end of Century +20% +2°C 0 +1°C (no mitigation) 0 -20% -1°C -40% -2°C less snowfall / snow cover ? more snowfall / snow cover Projected winter precipitation change by end of Century (no mitigation)

Snow Cover Change - Simulated winter surface snow water equivalent - Non-mitigation scenario Today Mid-Century End-Century

Snow Cover Change Alps - Simulated winter surface snow water equivalent - Non-mitigation scenario 500 - 1000 m 1000 - 1500 m Almost complete loss at low elevations Relative loss diminishes with elevation Similar results for Scandinavia -60 to -90 % 1500 - 2000 m -65 to -90 % High model agreement 2000 - 2500 m Higher elevations -60 to -85 % -40 to -70 % ?

Method Analyzing an ensemble of 42 regional climate model experiments Offline forcing of snow cover models Snow cover as part of climate model’s land surface scheme Fully interactive snow cover Large domains Global climate models 100 – 200 km Regional climate models 12 km Alps: up to ~3000 m Potentially biased atmospheric forcing Coarse resolution

Application in practice: Snow Cover Projections as a Climate Service Important media coverage Information already used in climate adaptation context www. climate-scenarios. ch