Abstract
<title>Abstract</title> <p>Drought poses a major threat to agriculture, water supply, and ecosystems in Europe. Regional climate model projections provide future scenarios and internal variability, an irreducible uncertainty, essential to assess drought risk under global warming. Here, we reveal that under +3 °C global warming, isolated drought clusters are near-certain to merge into a single southeastern hotspot. By constructing variability bounds on the Standardized Precipitation Evapotranspiration Index of a regional single-model large ensemble, we show that climate shifts into a drier state in which the Iberian Peninsula, the Mediterranean, and Eastern Europe are almost certain to face a recurrent, large-scale drought hotspot. Mountain ranges mark the boundary between this hotspot and the wetter northern continent. Nevertheless, the area covered by local drought hotspots in the North increases sharply under +3 °C of global warming. Increasing variability across most drought hotspots indicates that amplified and possibly unprecedented extremes are likely to emerge.</p>