Extreme heat waves now pose a greater risk to global food systems, according to a joint report by the Food and Agriculture Organization (FAO) and the World Meteorological Organization (WMO).
Across regions, more frequent, longer, and more intense heat waves are often accompanied by prolonged droughts. These conditions are placing increasing strain on crop and livestock production, as well as on rural communities and the national economies that depend on them. The FAO and WMO estimate that about 1.23 billion people who rely directly on agriculture are already seeing their livelihoods affected, while food availability for hundreds of millions more is under pressure.
The report argues that heat waves are no longer just a climate hazard but a structural force reshaping global food systems. It describes them as a “risk multiplier” that amplifies existing vulnerabilities. When temperatures exceed certain thresholds – often around 30°C for major crops such as maize and wheat – yields begin to decline, plant structures weaken, and overall productivity falls.
Livestock is also highly sensitive to heat stress. Pigs and poultry are particularly vulnerable, with reduced growth and production, and in extreme cases, large-scale mortality.
The report notes that yields of key staple crops such as maize and wheat have already declined by 7.5% and 6.0%, respectively, for each degree Celsius of warming. These losses could deepen by up to 10% more per additional degree of warming. In aquatic systems, marine heat waves are causing repeated episodes of mass fish mortality and pushing fish stocks toward cooler waters. Fruit and nut orchards, as well as natural forests, are also facing declining output and increased exposure to more frequent and intense wildfires.
These impacts can reinforce a negative cycle. As yields fall, agricultural expansion often increases to compensate, leading to higher greenhouse gas emissions that further drive climate change.
Urgent need to adapt food systems
The FAO and WMO stress that building resilience to extreme heat will require coordinated, long-term action across entire food systems, from production to distribution.
Key priorities include promoting climate-resilient farming practices, improving water and land management, developing heat-tolerant crop varieties and livestock breeds, and strengthening risk governance. Adjusting planting calendars, adapting farming techniques, redesigning livestock housing and pasture shading, and diversifying production systems are also highlighted as critical measures.
Beyond these steps, the report underscores the importance of anticipation. Heat-related risks are still often underestimated in climate and development policies, yet they are largely predictable, offering opportunities to reduce losses and protect agricultural workers.
Reliable early warning systems, accessible weather and climate services, and tailored agro-meteorological advice can help farmers, herders, fishers, and foresters prepare for extreme conditions, adjust their activities, or temporarily suspend the most exposed operations.
