Heatwaves and Yield Losses in Global Wheat, Maize and Rice, 2010–2025
Context—Wheat, maize and rice supply most human dietary energy, and their reproductive stages are highly sensitive to short periods of extreme heat. The 2010–2025 period combined record global temperatures with recurrent regional heatwaves in major breadbaskets. Findings—Evidence from observations, crop models and event analyses shows that heatwaves reduce yields by accelerating development, impairing pollination, shortening grain filling and intensifying water stress. Meta-analyses estimate mean yield declines per 1°C warming of about 6.0% for wheat, 7.4% for maize and 3.2% for rice without adaptation. Acute losses were most visible in the 2010 Russian wheat crisis, the 2012 United States maize drought-heat event, repeated South Asian wheat heat episodes, and hot-night rice stress in Asia. Implications—Adaptation through heat-tolerant cultivars, irrigation efficiency, altered sowing dates, early warning and diversified trade can reduce but not eliminate risks under continued warming.
Introduction
Heatwaves have become a central climate risk for global grain production. Wheat, maize and rice together provide a large share of human calories and livestock feed, so even regional heat shocks can transmit into food prices, trade restrictions and humanitarian stress [1]. Between 2010 and 2025, the world experienced repeated record-warm years and a rising frequency of compound hot-dry events in several agricultural regions [2]. This period is therefore a useful window for assessing how extreme heat has affected the three dominant cereal crops.
The relationship between heat and yield is not linear. Moderate warmth can accelerate crop development, while temperatures above…
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