Extreme heat poses multiple risks for agrifood systems - damaging crops, stressing livestock and depleting fisheries - and threatens the livelihoods of an estimated 1.23 billion people. There is an urgent need for science-informed solutions to strengthen resilience and sustainability, according to a new report from the Food and Agriculture Organization and WMO on "Extreme Heat and Agriculture."
Agricultural communities are on the frontlines of the extreme heat crisis. Agricultural workers are 35 times more likely to die from occupational heat exposure than all workers combined in other sectors. In 2021, 470 billion labour hours were lost globally due to extreme heat, it says.
The new FAO-WMO Extreme Heat and Agriculture assessment was presented at a side-event on Transforming Agrifood Systems through Climate Science at COP30 at the Science for Climate Action pavilion .
Intergovernmental Panel on Climate Change chair Jim Skea stressed that the agrifood system is among the sectors most exposed to climate impacts, with droughts and extreme heat already pushing traditional risk management to its limits. Climate change is altering crop yields, livestock productivity, water availability, and ecosystem functioning, all of which have direct consequences for food security, livelihoods, nutrition, and biodiversity.
Kaveh Zahedi, Director of FAO's Office of Climate Change, Biodiversity and Environment, said climate science can guide the transformation of agrifood systems and clarify pathways that support mitigation, adaptation, and co-benefits for food security, nutrition, biodiversity, and land.
WMO Director of Water, Cryosphere and Hydrology Stefan Uhlenbrook noted that key hazards linked to low precipitation and heatwaves are already damaging crops and driving fire risks.
"Trusted climate science and services must inform climate smart practices in the agriculture sector," said Stefan Uhlenbrook.
"Extreme heat can be forecasted, highlighting the important role of the National Meteorological and Hydrological Services. Combining forecasts and Actionable Early warnings by NMHSs, with heat action plans for agricultural enterprises and farm workers, and longer-term heat mitigation measures can help safeguard people and agricultural produce," he said.
Extreme Heat and Agriculture Report key findings
- Extreme heat compounds other hazards - exacerbating crop failure and livestock mortality from drought and increasing vulnerability of ecosystems such as forests to wildfires.
- A single heatwave can cut agricultural productivity by up to 50%, and that agricultural workers are 35 times more likely to die from heat exposure.
- There are cascading impacts. For example, the 2014-2016 'blob' marine heatwave triggered a food chain collapse in the Pacific, leading to the starvation of millions of seabirds and the closure of major fisheries.
- On land, heat events have caused double-digit crop losses, suppressed forest productivity by up to 50 percent, and led to mass livestock mortality events involving hundreds of thousands of animals.
- Future projections, using a range of climate scenarios and models, indicate that these trends will continue to worsen. For every 1°C of additional warming, yields of staple crops such as maize and wheat are projected to decline by 4 to 10 percent.
Case studies
The report includes brief case studies from Pakistan, Morocco, Chile and Portugal on the cascading impacts.
In Brazil, the strong El Niño in 2023-2024 was followed by prolonged drought that was amplified by extreme heat. Daily maximum temperatures exceeded critical thresholds for crops like soy on a large number of days, causing flower abortion and poor grain formation. The Fire Weather Index was abnormally high, leading to early and catastrophic wildfires in the Pantanal. These factors combined led to a nearly 10% reduction in the national soy harvest and serious impacts on livestock, and farmer health.
Adaptation and risk governance
Building resilience to extreme heat requires effective adaptation such as developing heat-tolerant breeds and implementing sustainable irrigation, with knowledge-based management.
A key opportunity lies in leveraging the predictability of heat through anticipatory actions and agrometeorological advisories linked to early warning systems. This would mark a shift from reactive crisis management to proactive risk reduction.
Mitigation
Adaptation alone is not enough. Mitigation through climate-smart practices guided by climate science and information is crucial.
Agrifood systems account for one-third of global emissions across the value chain and 70% of freshwater withdrawals, said Martial Bernoux, Head of the Climate Change Team in FAO's Office of Climate Change, Biodiversity, and Environment.
He presented to the side event an FAO Update on scientific findings on the interactions between agriculture, food systems and climate change , which synthesizes material that could inform future IPCC assessments on the links between agriculture, food systems, and climate change.
IISD Earth Negotiations Bulletin story is here .
