Excess warming in Europe during Recent Decades: Drivers and physical processes

Oral Presentation

Observational analyses indicated that both winter and summer seasonal mean temperature over large part of Europe increased about 2.5 to 3.5 times higher than the global average during 1979-2022.  Here we defined excess European warming as the difference between the rate of European regional warming and the rate of global warming and showed that about 40% and 29% of excess European warming is induced by atmospheric circulation changes in winter and summer, respectively. Analysis of climate model simulations from the Coupled Model Intercomparison Project Phase 6 (CMIP6) suggests that models do a good job of simulating the magnitude of the thermodynamic component of excess European warming since 1979 in both winter and summer. Greenhouse Gases (GHG) induced warming makes the largest contribution in winter, followed by anthropogenic aerosols (AER). AER makes the largest contribution in summer, followed by GHG. But the dynamical contribution to warming is not simulated as a forced response in either season, with the observed trends in circulation since 1979 falling the outside the ranges of those in CMIP6 simulations. Our results show that the failure to simulate circulation trends matters for understanding excess mean warming in Europe as well as for extremes.