Increasing risk of 2022-like droughts in Europe under climate change: evidence from Large Ensembles using flow analogs

The 2022 European drought was exceptional in spatial extent, intensity, and duration, with severe impacts on society and ecosystems. Its primary dynamical driver was a persistent anticyclonic anomaly over the eastern North Atlantic and western Europe. While anthropogenic climate change (ACC) is known to intensify droughts thermodynamically by enhancing evaporation, its impact on atmospheric circulation patterns remains uncertain due to strong internal variability. Using seven Single Model Initial-condition Large Ensembles (SMILEs) and a flow analog approach, we assess the influence of ACC on both dynamical and thermodynamical aspects of the 2022 drought. Specifically, we examine changes in the spatial structure and frequency of circulation analogs, as well as the conditional probability of drought occurrence. Our findings indicate that ACC did not significantly alter the pattern or frequency of the circulation drivers linked to the 2022 drought, even under higher levels of global warming. However, it markedly increases the likelihood of severe drought given such circulation patterns, resulting in broader spatial extent, greater intensity, and reduced intra-analog variability. These results suggest a shift in drought causation under global warming, with thermodynamic factors increasingly dominating over dynamical drivers.