Extreme heat is threatening global food systems, with farmers unable to work outdoors, livestock under stress, and crop yields falling, according to a joint report by the Food and Agriculture Organization (FAO) and the World Meteorological Organization (WMO). The UN warns that the livelihoods of more than a billion people are at risk as food supply in some areas is being pushed to the brink.
In already hot regions such as much of India, South Asia, tropical sub-Saharan Africa, and parts of Central and South America, farmers could face up to 250 unsafe working days per year. Livestock mortality rates are rising as heat stress begins at around 25°C, reducing dairy yields and affecting pigs and chickens, which cannot sweat. Crop yields start declining above 30°C, with maize down by about 10% and wheat falling nearly as much, projected to decline further with rising temperatures.
Ocean heatwaves are also killing fish by reducing dissolved oxygen levels. The report, published on Wednesday, emphasises that more could be done to warn farmers using weather forecasts and mobile phones. Experts call for adaptation measures, including early warnings, tools, and knowhow to help farmers protect against extreme weather.
Richard Waite of the World Resources Institute warned that without adaptation, extreme heat will cut yields, forcing more land into agriculture and driving higher emissions. Morgan Ody of La Via Campesina highlighted risks to farmers and fishers, calling for compensation, debt relief, public investment, and worker safety rules. Molly Anderson of Middlebury College urged a shift to more diverse, nature-friendly food systems to withstand shocks.
