Extreme Heat Threatens Global Food Systems: UN Warns of Crisis and Solutions Within Reach

Extreme heat is pushing global agrifood systems to the brink, threatening the livelihoods and health of more than a billion people, according to a new report by the United Nations Food and Agriculture Organization (FAO) and the World Meteorological Organization (WMO).

The joint report finds that extreme heat is already causing half a trillion work hours to be lost each year in agricultural sectors, with impacts set to intensify as temperatures rise. WMO Secretary-General Celeste Saulo warned that extreme heat acts “as a compounding risk factor that magnifies existing weaknesses across agricultural systems.”

FAO Director-General Qu Dongyu described extreme heat as “a major risk multiplier,” exerting mounting pressure on crops, livestock, fisheries and forests, and on the communities and economies that depend upon them. The report highlights how heatwaves – prolonged periods of unusually high day and night temperatures – are affecting all components of agrifood systems.

For many major crops, yields begin to decline above 30°C (86°F), leading to weakened plant structures and reduced productivity. Livestock experience stress at even lower temperatures, particularly pigs and poultry, which cannot cool themselves efficiently, resulting in reduced growth, lower dairy yields and, in severe cases, organ failure.

In oceans, rising temperatures are lowering oxygen levels, putting fish under strain – with 91 per cent of the global ocean experiencing at least one marine heatwave in 2024. The report notes that higher temperatures are shrinking the safety margin that plants, animals and humans rely on to function, with yields for most major crops falling once temperatures exceed about 30°C.

Mr Kaveh Zahedi, head of the FAO’s climate change office, cited Morocco as an example where six years of drought were followed by record heatwaves, leading to a fall in cereal yields by over 40 per cent and decimating olive and citrus harvests. “Basically, those harvests failed,” he said.

Recent climate datasets show global warming is accelerating, with 2025 ranking among the three hottest years on record, triggering more frequent and severe weather extremes. Acting as a risk multiplier, extreme heat intensifies droughts, wildfires and pest outbreaks, and sharply cuts crop yields once critical temperature thresholds are breached.

The report warns that without urgent action to adapt agrifood systems to rising temperatures, the livelihoods of over a billion people who depend on agriculture, fisheries and forestry will face increasing threat. It calls for coordinated global efforts to build resilience through improved early warning systems, heat-adapted crop varieties and better protections for agricultural workers.