Extreme heat threatens global agrifood systems: UN report

Livestock begin to experience heat stress above 25 degrees Celsius, while yields of major crops start to decline above 30 degrees, the report said. Fish exposed to high water temperatures risk cardiac failure. In 2024, 91 percent of the global ocean experienced at least one marine heatwave. Extreme heat can also be deadly for farm workers. In parts of South Asia, tropical sub-Saharan Africa and Central and South America, there may be up to 250 days a year when it is too hot to work, the report said. It added that extreme heat leads to an estimated annual loss of around 500 billion working hours globally. The report said extreme heat acts as a risk multiplier, worsening droughts, wildfires and the spread of pests and diseases. It called for measures including crop breeding, adjusting crop choices and planting schedules, and improved farm management to reduce exposure to heat. This work highlights how extreme heat is a major risk multiplier, exerting mounting pressure on crops, livestock, fisheries and forests, and on the communities and economies that depend upon them, FAO Director-General Qu Dongyu said. WMO Secretary-General Celeste Saulo said that extreme heat is more than simply an isolated climate hazard, but acts as a compounding risk factor that magnifies existing weaknesses across agricultural systems. The report said addressing the impact of extreme heat will also require tackling socio-economic barriers in low- and middle-income countries, alongside technical solutions, and called for international cooperation to safeguard food security and support a transition to low-emission development.