Evident decrease in future European soil moisture in the Kiel Climate Model grand ensemble

Abstract The focus of this study is the European soil moisture trends following an increase in atmospheric CO2 concentrations. A single model-grand ensemble of 100 members, where CO2 levels increase by 1% per year for 140 years with the Kiel Climate Model, is used. A strong soil drying over most of Central Europe and the Mediterranean region when CO2 is quadrupled is found, with virtually all of the ensemble members agreeing on the sign of the change. This strong loss in soil moisture over Europe is driven mainly by a reduction in precipitation and, to a lesser degree, an increase in evaporation. Results also suggest that the precipitation pattern changes are partly linked to the response of the storm track to CO2 increases. Such soil moisture changes could have far-reaching impacts on extreme weather and climate events such as droughts or heat waves, with important implications for climate adaptation.