ALT A map showing projected future megadrought risk. On the map, regions of ‘high risk’ in the late twenty-first century (red circles) experience mean shifts in the multi-model ensemble towards drier conditions (for example, western North America, Europe, Central America), whereas those with ‘moderate risk’ (orange circles) typically experience small increases in megadrought risk associated with subsets of models rather than any coherent ensemble-mean shift (for example, West Africa, northern China). Anthropogenic climate change has intensified ongoing megadroughts in south-western North America and across Chile and Argentina. Future megadroughts will be substantially warmer than past events, with this warming driving projected increases in megadrought risk and severity across many regions, including western North America, Central America, Europe and the Mediterranean, extratropical South America, and Australia.