Note: Single-source report; awaiting corroboration.
A joint report by the Food and Agriculture Organization (FAO) and the World Meteorological Organization (WMO) warns that extreme heat is increasingly shaping agri-food systems, causing half a trillion lost work hours each year and threatening global food systems. WMO Secretary-General Celeste Saulo noted that extreme heat intensifies existing vulnerabilities in agriculture and is a compounding risk factor.
The report calls extreme heat a major risk multiplier that pressures crops, livestock, fisheries, forests, and their dependent communities, according to FAO Director-General Qu Dongyu. Many major crop yields start to decline when temperatures exceed 30°C, negatively affecting plant structure and productivity. Livestock, especially pigs and poultry, experience stress at even lower temperatures, leading to reduced growth, lower milk production, and, in severe cases, organ failure.
Ocean conditions are also impacted; rising temperatures decrease oxygen levels and stress fish populations, with 91 percent of the global ocean experiencing at least one marine heatwave in 2024. Forests are hit by disrupted photosynthesis and higher wildfire risks related to heatwaves. The report adds that extreme heat worsens other climate threats such as droughts, water scarcity, wildfires, and pest and disease outbreaks, compounding ecosystem impacts.
Some areas have seen severe effects already. A 2025 heat event in Kyrgyzstan spiked 10°C above normal, causing a 25 percent drop in cereal harvests, locust swarms, and reduced irrigation capacity. In Brazil, extended heat and drought in 2023 and 2024 cut soybean yields by up to 20 percent. North America faced major fruit crop losses and more forest fires after a significant 2021 heatwave. In regions of South Asia, sub-Saharan Africa, and Latin America, the number of days too hot for agricultural work could reach 250 each year, putting millions of workers and food output at risk.