Abstract
Climate change is intensifying drought risk, yet it is unclear which regions will be most vulnerable in the future. Here we investigate emerging hotspots of agricultural drought across the tropics and Northern Hemisphere extratropics using climate reanalysis and model simulations under a range of Shared Socioeconomic Pathways. Our analysis accounts for soil moisture at the onset of the growing season, as well as variability during the season itself, linking climate change to the land-surface water balance by classifying the dominant controls on evapotranspiration, including a newly defined state governed by plant extraction of water from the root zone. We show that much of Europe, southern Africa, northern South America and western North America are emerging hotspots of agricultural drought, with mechanisms of observed drying consistent with future projections. Drought trends are identified even where precipitation projections diverge. By focusing on growing seasons, our approach captures hotspots overlooked by annual metrics and shows that increasing drought frequency is compounded by shifts towards more severe and intense events. These findings have strong implications for food security and highlight the need for drought-resilient adaptation not only in the global south but also in extratropical regions where risk is already escalating.
