EuroWire, ROME: Extreme heat is pushing global agrifood systems toward a breaking point, threatening the health and livelihoods of more than 1 billion people and cutting an estimated half a trillion work hours each year, according to a report released on Tuesday by the Food and Agriculture Organization of the United Nations and the World Meteorological Organization. The study says agricultural workers are on the front lines as hotter, longer and more frequent heat events disrupt production across crops, livestock, fisheries and forests.
The report, titled Extreme Heat and Agriculture, says the frequency, intensity and duration of extreme heat events have risen sharply over the past half century, increasing risks across food production systems and surrounding ecosystems. It defines extreme heat as periods when daytime and nighttime temperatures stay above usual levels long enough to create physiological stress and direct physical damage. The agencies said those conditions can weaken farm output directly and also intensify other hazards that already strain food security.
The report identifies clear biological limits across agriculture. For most major crops, yield declines begin above about 30 degrees Celsius, with some crops such as potatoes and barley affected at even lower thresholds. For common livestock species, heat stress begins above 25 degrees Celsius, and sooner for pigs and chickens, which cannot cool themselves by sweating. Prolonged exposure can reduce feed intake, dairy output and animal movement, and in severe cases lead to digestive failure, organ damage and cardiovascular shock.
Heat risks spread across farms and labor
The study says extreme heat also has major consequences for labor productivity, especially in rural economies that depend on outdoor work. In parts of South Asia, tropical sub-Saharan Africa, and Central and South America, the number of days each year that are too hot for safe work could rise to 250. That adds pressure on harvesting, irrigation, livestock care and other time-sensitive farm tasks, increasing the risk of income losses for households that rely on agricultural labor.
Beyond its direct effects, the report describes extreme heat as a risk multiplier that worsens water stress, triggers flash droughts, raises wildfire danger and creates conditions that favor pests and diseases. One case cited in the study showed that an unusually hot spring period in Kyrgyzstan’s Fergana mountain range in 2025 contributed to thermal shock on fruit and wheat crops, reduced irrigation capacity through faster evaporation, and was linked to a 25% drop in cereal harvests.
Adaptation measures gain urgency
FAO and WMO said the findings underscore the need for adaptation measures that are practical and timely for farmers, herders and fishing communities. The report points to seasonal outlooks, early warning systems, changes in planting windows, crop selection suited to hotter conditions, and management practices that can shield production from extreme heat. It also highlights selective breeding and better climate services as tools that can help producers respond before heat shocks translate into larger food system losses.
The two agencies said technical measures alone will not be enough without broader access to financial protection and stronger support systems in lower-income countries. The report highlights cash transfers, insurance, shock-responsive social protection and wider access to information, education and training as central to building resilience. It concludes that protecting agriculture and global food security will require stronger on-farm resilience as well as wider international action to reduce exposure to a hotter climate.