The resurgence of extreme heat pushes global agriculture to the limit

The resurgence of episodes of extreme heat is pushing agriculture to its limits around the world, threatening the health and livelihoods of over a billion people, cautioned the FAO and the World Meteorological Organization (WMO) on Wednesday.

The phenomenon, linked to climate change driven by human activities, already results in the loss of 500 billion hours of work in agriculture every year. Expected to worsen, it imperils global food security, as highlighted in the report “Extreme Heat and Agriculture.”

Extreme heat refers to temperatures that are significantly higher than normal, both during the day and at night. Experts predict that their intensity will double if the world reaches a warming of +2°C compared to pre-industrial levels (and quadruple at +4°C). These extreme temperatures also trigger cascading effects on humidity and solar radiation, leading to heavy rains, “flash” droughts, and other calamities.

“This is somewhat the trigger,” explained Kaveh Zahedi, Director of the FAO’s Climate Change Office to AFP. He cited an example from two years ago in Brazil, where prolonged extreme heat coupled with drought sparked fires in the Amazon and the drying up of tributaries of the river, impacting the entire food system, including fishing and aquaculture. Such occurrences highlight the compounding risks associated with extreme heat.

Cases of extreme heat are mounting in countries like the United States, Russia, and China, affecting all sectors. For livestock, extreme heat can lead to digestive or cardiovascular failures, reduce milk production, and lower protein content. Fish can suffer heart failure in waters with reduced oxygen levels due to elevated temperatures.

In 2024, 91% of the world’s oceans experienced at least one heatwave, with half being classified as “strong.” Heat stress affects the yield of most crops starting at temperatures below 30°C, including staples like potatoes and barley. The disappearance of pollinators, diseases, and food shortages escalate the risks, compounded by the homogeneity of crop varieties.

In Morocco, six years of drought followed by historic heat waves in 2023 and 2024 reduced cereal yields by 40% and devastated olive and citrus crops. Similar impacts were felt in mountainous regions, such as the Kyrgyz Fergana Valley, where temperatures soared, damaging fruits and cereals, and inviting locust invasions that led to a 25% drop in harvests.

Marine heatwaves have also shown devastating effects, with a marine heatwave in the eastern Bering Sea in 2018-2019 causing a 90% reduction in snow crab populations, forcing the closure of a profitable Arctic fishery.

To address these challenges, innovative actions are being explored, such as testing early-maturing rice varieties in India – a country heavily reliant on agriculture for sustenance and employment. Extreme heat impacts over a billion people, primarily farmers and their families, affecting health and productivity, contributing to already uncertain food security.

The report calls for the adoption of seeds and breeds adapted to new conditions and the establishment of warning systems for farmers, given that extreme heat events are among the most foreseeable phenomena.

While some actions are being taken, they may not be adequate. The report emphasizes that without a substantial reduction in greenhouse gas emissions, the severity of extreme heat will increasingly surpass the capacity to cope with it, and building resilience cannot replace decisive climate action.

Context: The article highlights the severe impacts of extreme heat on agriculture and food security worldwide, exacerbated by climate change.

Fact Check: The article reports data and insights from the FAO and the World Meteorological Organization, providing valuable information on the challenges posed by extreme heat episodes and their implications for global agriculture.