The joint report from the Food and Agriculture Organization (FAO) and the World Meteorological Organization (WMO) reveals that extreme heat already causes the loss of half a trillion work hours each year, and the impacts are expected to intensify as temperatures rise.
“Extreme heat increasingly defines the conditions under which agri-food systems operate,” said WMO Secretary-General Celeste Saulo, warning that it acts “as an aggravating risk factor that amplifies existing weaknesses in agricultural systems.”
The report highlights how heatwaves – prolonged periods of unusually high daytime and nighttime temperatures – affect crops, livestock, fisheries and forests, while also endangering agricultural workers.
A risk multiplier
Extreme heat is “a major risk multiplier,” said FAO Director-General Qu Dongyu, “putting increasing pressure on crops, livestock, fisheries and forests, as well as the communities and economies that depend on them.”
In all agricultural systems, the impacts are already visible. For many major crops, yields begin to decline above 30°C (86°F)leading to a weakening of factory structures and a reduction in productivity. Livestock are stressed at even lower temperatures, particularly pigs and poultry, which cannot cool themselves effectively, leading to reduced growth, lower milk yields and, in severe cases, organ failure.
In the oceans, rising temperatures are lowering oxygen levels, putting fish under strain – with 91% of the global ocean experiencing at least one marine heatwave in 2024. Forests are also affected, as extreme heat disrupts photosynthesis and increases the risk of wildfires.
Extreme heat also amplifies other climate risks. This can trigger droughts, worsen water scarcity, increase the risk of wildfires, and accelerate the spread of pests and diseases – creating what the report describes as “compound effects” that ripple across entire ecosystems.
“Severe impacts” are a reality
In some regions, these impacts are already serious.
A heat event in 2025 in Kyrgyzstan, for example, saw temperatures rise. about 10°C above normal, contributing to a 25 percent drop in cereal harvestswhile triggering swarms of locusts and reducing irrigation capacity.
Elsewhere, Prolonged heat and drought conditions in Brazil in 2023 and 2024 have reduced soybean yields by up to 20%.while a major heatwave across North America in 2021 led to significant losses of fruit crops and a sharp increase in wildfires.
The human toll is just as heavy. In parts of South Asia, sub-Saharan Africa and Latin America, the number of days too hot to work could reach 250 per year – putting millions of agricultural workers at risk and compromising food production.
Extreme heat is reshaping agricultural conditions globally, threatening food security and rural livelihoods. (archive photo)
Call to action
To address this, the report calls for urgent adaptation measures, including heat-tolerant crops, adjusted planting schedules and improved agricultural management practices.
Early warning systems and access to financial support – such as insurance and social protection – are also essential to help farmers cope with growing risks.
“Protecting the future of agriculture and ensuring global food security will require not only strengthening the resilience of farms, but also… making a decisive transition away from a high-emissions future.», conclude the UN agencies.
