Future change of precipitation extremes in Europe: Intercomparison of scenarios from regional climate models

TLDR

The study analyzes precipitation extremes from six European regional climate models to quantify future changes and assess inter‑model differences. Using the same ensemble of global climate model boundary conditions for 1961–1990 and 2071–2100 under the IPCC A2 scenario, the authors compute multiyear return values of daily precipitation totals via extreme‑value analysis. The models exhibit modest biases, with winter extremes increasing north of 45°N and remaining stable or decreasing south, northern Europe’s 20‑yr future return matching 40‑100‑yr present values, and overall agreement suggesting changes largely follow a scaling of present extremes, though summer shows larger inter‑model spread driven by precipitation frequency and intensity, revealing a consistent component that alters extremes beyond simple scaling.

Abstract

An analysis of the climate of precipitation extremes as simulated by six European regional climate models (RCMs) is undertaken in order to describe/quantify future changes and to examine/interpret differences between models. Each model has adopted boundary conditions from the same ensemble of global climate model integrations for present (1961–1990) and future (2071–2100) climate under the Intergovernmental Panel on Climate Change A2 emission scenario. The main diagnostics are multiyear return values of daily precipitation totals estimated from extreme value analysis. An evaluation of the RCMs against observations in the Alpine region shows that model biases for extremes are comparable to or even smaller than those for wet day intensity and mean precipitation. In winter, precipitation extremes tend to increase north of about 45°N, while there is an insignificant change or a decrease to the south. In northern Europe the 20‐year return value of future climate corresponds to the 40‐ to 100‐year return value of present climate. There is a good agreement between the RCMs, and the simulated change is similar to a scaling of present‐day extremes by the change in average events. In contrast, there are large model differences in summer when RCM formulation contributes significantly to scenario uncertainty. The model differences are well explained by differences in the precipitation frequency and intensity process, but in all models, extremes increase more or decrease less than would be expected from the scaling of present‐day extremes. There is evidence for a component of the change that affects extremes specifically and is consistent between models despite the large variation in the total response.