Extreme Heat Threatens Global Food Systems and Livelihoods of Billions, UN Warns

Extreme heat is rapidly emerging as one of the most dangerous and underestimated threats to global food security, with over one billion people at risk, particularly those working in agriculture, according to a major new joint report by the Food and Agriculture Organization (FAO) and the World Meteorological Organization (WMO).

Released on Earth Day (22 April), the report titled "Extreme Heat and Agriculture" paints a stark picture of a warming world where rising temperatures are not only damaging crops and ecosystems but also undermining livelihoods, labour productivity, and economic stability.

A Growing Climate Threat to Food Systems

Over the past 50 years, the frequency, intensity, and duration of extreme heat events have increased sharply, with projections indicating even more severe impacts ahead.

"This work highlights how extreme heat is a major risk multiplier," said FAO Director-General QU Dongyu. "It is placing mounting pressure on crops, livestock, fisheries, forests, and the communities that depend on them."

WMO Secretary-General Celeste Saulo echoed the urgency, noting that extreme heat is no longer an isolated weather event but a systemic risk.

"It is increasingly defining the conditions under which agrifood systems operate," she said. "It magnifies existing vulnerabilities across agriculture and ecosystems."

From Crops to Oceans: A System Under Stress

The report details how extreme heat is affecting every layer of the global food system:

• Crops: Yields of major crops begin to decline at temperatures above 30°C, with more sensitive crops like potatoes and barley affected at even lower thresholds.

• Livestock: Heat stress starts at around 25°C, reducing productivity and increasing mortality—particularly in animals like pigs and poultry that cannot sweat.

• Fisheries: Rising water temperatures reduce oxygen levels, forcing fish into physiological stress and, in extreme cases, cardiac failure. In 2025 alone, over 90% of the world's oceans experienced at least one marine heatwave.

• Forests: Heatwaves are strongly linked to longer and more intense wildfire seasons, threatening ecosystems and agricultural land alike.

Human Cost: Labour and Livelihoods at Risk

Beyond environmental impacts, extreme heat is taking a growing toll on agricultural workers—the backbone of global food production.

In some of the world's most vulnerable regions, including South Asia, tropical Sub-Saharan Africa, and parts of Central and South America, the number of days too hot to work could reach up to 250 days per year.

This has profound implications for:

• Rural incomes and poverty levels

• Food production and supply chains

• Migration and social stability

A 'Risk Multiplier' with Cascading Effects

The report emphasises that the danger of extreme heat lies not only in direct damage but in its ability to amplify other climate risks, including:

• Water scarcity and flash droughts

• Spread of pests and crop diseases

• Soil degradation

• Increased wildfire frequency

These compound effects can create cascading crises across food systems, particularly in already fragile regions.

Urgent Need for Adaptation and Innovation

To address these escalating risks, FAO and WMO call for immediate and coordinated action, highlighting key adaptation strategies:

• Climate-resilient crops and livestock through selective breeding

• Adjusting planting calendars and farming practices

• Expanding early warning systems and climate services

• Improving water management and soil conservation

Early warning systems, in particular, are identified as critical tools to help farmers anticipate and respond to extreme heat events.

Financing Resilience

The report also stresses the importance of financial support mechanisms to enable adaptation, including:

• Crop insurance schemes

• Cash transfers and social protection programmes

• Access to credit and risk-sharing tools

Such measures are essential to help farmers absorb shocks and invest in resilience.

A Call for Global Action

Ultimately, the report underscores that safeguarding global food systems will require collective international action.

"Protecting the future of agriculture will require building resilience on farms, strengthening global cooperation, and transitioning away from high-emissions pathways," the report concludes.

As climate change accelerates, the findings serve as a stark warning: without urgent intervention, extreme heat could reshape global agriculture—and the livelihoods of billions—within a generation.