Reductions in the future agricultural workday due to climate change

Agricultural workers are vital to global food security, yet their vulnerability to climate change remains understudied. Here, we integrate high-resolution hourly heat stress projections with new gridded global data on the agricultural workforce to quantify reductions in the agricultural workday from climate change. By 2050, the global agricultural workforce is projected to rise from 1.30 to 1.33 billion, with workers exposed to over 100 days of heat stress annually increasing from 359 to 663 million. Under SSP2-4.5, 3\% of the harvest season and 8\% of a standard workday (9am-5pm) will be lost globally to unsafe conditions, rising to 4\% and 11\% under SSP5-8.5. In tropical and coastal regions of South Asia, East Asia, and Sub-Saharan Africa, extreme heat will infringe evening hours, challenging adaptation strategies like shifting work to cooler times. This highlights an urgent need to improve policy with enhanced climate-resilient strategies to protect the world's agricultural workforce.