UN Warns Extreme Heat Pushing Global Food Systems to the Brink of Collapse
The United Nations has issued a stark warning that extreme heat is severely threatening the world's food systems, putting the livelihoods of more than a billion people in peril. A major joint report by the Food and Agriculture Organization (FAO) and the World Meteorological Organization (WMO) highlights how increasingly common and severe heatwaves are pushing food supply in some areas to the brink.
Farmers and Livestock Under Unprecedented Stress
In already hot regions such as much of India, south Asia, tropical sub-Saharan Africa, and parts of Central and South America, farmers could find it impossible to work safely for up to 250 days a year—more than two-thirds of the time. This poses a direct threat to agricultural productivity and food security.
Livestock are also suffering, with mortality rates expected to rise as heat stress begins for common species at around 25°C. Extreme heat reduces yields from dairy cows and diminishes the fat and protein content of milk. Animals like pigs and chickens, which cannot sweat, face severe health issues including digestive tract breakdowns, organ failure, and cardiovascular shock as temperatures climb.
Crop Yields Declining Amid Rising Temperatures
Agricultural crops are highly vulnerable to heat, with yields beginning to decline at temperatures above 30°C. Damage includes weakened cell walls and the production of toxins. Specifically, maize yields in some areas have decreased by approximately 10%, while wheat has fallen by nearly as much. Projections indicate further declines as global temperatures rise to more than 1.5°C above preindustrial levels.
Ocean heatwaves are exacerbating the crisis by killing fish, as heat reduces dissolved oxygen levels in water, leading to mass population declines. This adds another layer of complexity to the global food supply chain.
Urgent Calls for Adaptation and Systemic Change
The report emphasizes that more could be done to warn farmers, as heatwaves are often predictable. Utilizing weather forecasts and mobile phone communications could alert farmers to impending extreme weather, helping them take protective measures.
Richard Waite, director of agriculture initiatives at the World Resources Institute, stressed the importance of adaptation. "Without adaptation, extreme heat will cut crop and livestock yields, forcing more land into agriculture to maintain food production. That would drive even higher emissions from land use change, which in turn would make climate impacts on agriculture even worse," he said. "What's needed is scaling solutions that help farmers maintain and sustainably increase productivity, even in a changing climate, to break that vicious cycle."
Morgan Ody, general coordinator of La Via Campesina, highlighted the risks to agricultural workers, calling for compensation for losses, debt relief, public investment in adaptive measures, and safety rules to limit exposure to high temperatures. She advocated for replacing intensive farming with nature-friendly methods to build resilience.
Systemic Vulnerabilities and Long-Term Solutions
Modern industrialised food systems, reliant on a narrow range of staple crops and inputs like fertiliser, are highly vulnerable to shocks such as extreme heat. Molly Anderson, professor of food studies at Middlebury College, called for developing a more diverse food system better equipped to withstand shocks and reversing trends in intensive agriculture that have stripped farms of trees, shade, and crop-livestock mixtures.
"The risk of simultaneous crop failures from extreme heat could ripple through food prices, supply chains, and economies," Anderson warned. "Adaptation has limits—the only durable response is to tackle fossil fuels, accelerate the shift to renewable energy, and invest massively in adaptation."
Tim Lang, emeritus professor of food policy at the University of London, noted that while the worst effects will be felt in already hot countries, temperate regions like the British Isles are not immune. "Places we've got food from will dry up. Land use here will be changed. Water dependencies are exposed. Crops that started off well will fail to thrive. Productivity will be disrupted. Regular patterns of growing and consuming will be forced to change," he said. "Anyone who thinks climate change won't affect us should think again."
