Future Changes of European Windstorm Losses in EURO-CORDEX Simulations

Windstorms are one of the most important natural hazards affecting Europe. This article investigates the potential impacts of climate change on windstorm losses in Europe employing the Loss Index (LI) method. A large EURO-CORDEX multi-model ensemble at 12 km resolution with 20 different general circulation model to regional climate model (GCM-RCM) chains following the historical plus RCP8.5 scenario is considered. A comparison between the simulated historical 10 m wind gusts and ERA5 reanalysis reveals substantial model biases. An Empirical Quantile Mapping method is employed to bias-correct the daily wind gust speeds, leading to the effective reduction of these biases. Considering different global warming levels (GWLs), our results show an increase in windstorm intensity for Western, Central and Eastern Europe in a warming world, and a general decrease in windstorm frequency for large parts of Europe. While the ensemble mean changes are mostly moderate for +2°C world, signals are more pronounced for +3°C. The projected changes in windstorm losses are small and mostly non-robust, with negative trends for Central Europe and positive trends for Eastern Europe. For the most extreme loss events, the EURO-CORDEX ensemble projects shorter return periods for Eastern Europe independent of the GWL, while no clear trends for Core Europe emerge. Our results show a large spread between the individual ensemble members, without a clear dominance of a single GCM or RCM. In summary, the projected changes in windstorm losses are subtle, but important particularly for Central and Eastern Europe, which should be considered in the mid- and long-term planning of the insurance industry.