Increased probability of hot and dry weather extremes during the growing season threatens global crop yields

Although extreme weather events recur periodically everywhere, the impacts of their simultaneous occurrence on crop yields are globally unknown. In this study, we estimate the impacts of combined hot and dry extremes as well as cold and wet extremes on maize, rice, soybean, and wheat yields using gridded weather data and reported crop yield data at the global scale for 1980-2009. Our results show that co-occurring extremely hot and dry events have globally consistent negative effects on the yields of all inspected crop types. Extremely cold and wet conditions were observed to reduce crop yields globally too, although to a lesser extent and the impacts being more uncertain and inconsistent. Critically, we found that over the study period, the probability of co-occurring extreme hot and dry events during the growing season increased across all inspected crop types; wheat showing the largest, up to a six-fold, increase. Hence, our study highlights the potentially detrimental impacts that increasing climate variability can have on global food production.

Automated summary

In this study, the impacts of simultaneous extreme hot and dry events as well as extreme cold and wet events on crop yields were analyzed using global weather and yield data. The study found consistent negative effects of extreme hot and dry events on all inspected crop types globally. Extreme cold and wet conditions also reduced crop yields globally, but to a lesser extent and with more uncertainty. It was observed that the probability of co-occurring extreme hot and dry events during the growing season increased over the study period.