Surface energy balance! Climate models 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 MeteoSwiss, Zurich 3 Institute for Atmospheric and Climate Science, ETH Zurich, Zurich www.swissinfo.ch Water resource Recreation & tourism Natural hazards Ecology … www.nps.gov www.slf.ch Surface energy balance! Climate models

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

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 Almost complete loss at low elevations Relative loss diminishes with elevation Similar results for Scandinavia High model agreement 500 - 1000 m 1000 - 1500 m 1500 - 2000 m 2000 - 2500 m -60 to -90 % -65 to -90 % -60 to -85 % -40 to -70 % Higher elevations ?

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 Potentially biased atmospheric forcing Coarse resolution Global climate models Regional climate models 100 – 200 km 12 km Alps: up to ~3000m

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