Extreme heat threatens global food systems, UN agencies warn

The Food and Agriculture Organization (FAO) and the World Meteorological Organization (WMO) released a landmark joint report on World Earth Day 2026, warning...

What Happened

The Food and Agriculture Organization (FAO) and the World Meteorological Organization (WMO) released a landmark joint report on World Earth Day 2026, warning that extreme heat is "shrinking the safety margin" that plants, animals, and human agricultural labourers rely on to function.
The report characterises extreme heat not as an isolated climatic hazard but as a systemic, compounding risk factor that amplifies weaknesses already present in global food systems — including water scarcity, ecosystem degradation, and labour shortages.
Particular concern is raised for South Asia, tropical Sub-Saharan Africa, and Central and South America, where the interaction of rising temperatures with existing poverty and agricultural vulnerability creates highest-risk conditions for food insecurity.
The report calls for international solidarity and collective political will for risk-sharing, describing a "decisive transition away from a high-emissions future" as a prerequisite for protecting long-term food security.

Static Topic Bridges

FAO and WMO: Mandate and Role in Global Food and Climate Governance

The Food and Agriculture Organization (FAO) and the World Meteorological Organization (WMO) are both specialised agencies of the United Nations system, each with a distinct but complementary mandate in global food and climate governance.

FAO, established in 1945 and headquartered in Rome, leads international efforts on hunger eradication, agricultural development, and food systems sustainability. Its flagship publication is the annual State of Food Security and Nutrition in the World report.
WMO, established in 1950 and headquartered in Geneva, is the authoritative UN voice on weather, climate, and water. It coordinates the Global Framework for Climate Services (GFCS) and publishes the annual State of the Global Climate report.
The joint FAO-WMO Extreme Heat and Agriculture report represents a significant institutional coordination — combining WMO's physical climate science with FAO's agricultural systems expertise to produce a cross-sectoral risk assessment.
India is a member state of both FAO and WMO, and participates in the Inter-governmental Group on Grains, which FAO facilitates for global staple commodity monitoring.

Connection to this news: The authority of this warning derives directly from the institutional credibility and complementary expertise of FAO and WMO — representing the UN system's clearest declaration to date that extreme heat has become a structural threat to global food system stability.

Wet-Bulb Temperature and Human Heat Tolerance

Wet-bulb temperature (WBT) is the temperature measured by a thermometer wrapped in a water-soaked cloth — it accounts for the combined effect of heat and humidity on the human body's ability to cool itself through sweating. It is the most accurate indicator of when ambient heat becomes life-threatening.

The critical wet-bulb temperature threshold for human survival (with shade and rest) is approximately 35°C — a combination that effectively prevents the body from shedding heat even with maximum sweating.
At wet-bulb temperatures above 32°C, outdoor physical labour becomes medically hazardous; at 26–28°C WBT, labour productivity declines sharply even for acclimatised workers.
South Asian cities like Kolkata, Patna, and Karachi have already recorded wet-bulb temperatures approaching dangerous levels during recent heatwave events.
IPCC AR6 projects that wet-bulb temperatures exceeding 35°C — previously almost never recorded — will become regular occurrences in parts of South Asia and the Persian Gulf under 2°C warming scenarios.

Connection to this news: The FAO-WMO report's finding that up to 250 days per year may become too hot to work in South Asia is grounded in wet-bulb temperature thresholds — highlighting that the heat crisis is simultaneously an agricultural productivity crisis and a human health emergency for farming communities.

Heat as a Systemic Risk Multiplier in Food Systems

The concept of a risk multiplier refers to a hazard that, beyond its direct impacts, amplifies the severity of other, pre-existing vulnerabilities. The FAO-WMO report positions extreme heat explicitly in this role within food systems.

Heat accelerates evapotranspiration, intensifying soil moisture deficits and turning meteorological drought into agricultural drought faster — a mechanism linked to the emerging hazard of "flash drought."
Higher temperatures expand the geographic range of crop pests and plant pathogens, potentially nullifying the investment in high-yield varieties if pest management cannot keep pace.
Heat-wildfire interactions lengthen fire seasons in agricultural landscapes, destroying standing crops and damaging soil structure needed for subsequent seasons.
Marine heatwaves — in 2025, more than 90% of the global ocean experienced at least one — reduce dissolved oxygen in surface waters, causing fish cardiac failure and disrupting fisheries that hundreds of millions depend on for protein.

Connection to this news: By categorising extreme heat as a "risk multiplier," the report argues that conventional single-hazard risk frameworks used in agricultural planning and insurance are structurally inadequate — necessitating integrated, multi-hazard approaches to food system governance.

Paris Agreement and Food Security Linkages

The Paris Agreement (2015), adopted under the United Nations Framework Convention on Climate Change (UNFCCC), set a global target of limiting warming to well below 2°C and pursuing efforts to limit it to 1.5°C above pre-industrial levels. Food security is explicitly referenced in the agreement's preamble but is not a binding commitment.

Article 2.1(b) of the Paris Agreement calls for increasing the ability to adapt to climate impacts and fostering climate resilience and low-emissions development in a manner that does not threaten food production.
Nationally Determined Contributions (NDCs) submitted by countries under the Paris Agreement are the primary policy instrument through which food system adaptation is committed to at national level.
India's NDC commits to reducing emissions intensity of GDP by 45% by 2030 (compared to 2005 levels) and achieving 50% cumulative electric power from non-fossil sources — but agriculture-specific adaptation targets remain less precisely defined.
The FAO-WMO report's call for "international solidarity and collective political will" reflects growing concern that the gap between NDC commitments and actual adaptation investment is widening, particularly for the food and agriculture sector.

Connection to this news: The report reinforces the climate-food nexus that underpins the Paris Agreement's food security language — and implicitly critiques the slow pace of agricultural adaptation financing relative to the acceleration of heat impacts now being documented.

Key Facts & Data

Extreme heat is described as a "risk multiplier" that amplifies water stress, flash droughts, wildfires, pest spread, and marine ecosystem disruption.
Higher temperatures shrink the safety margin that plants, animals, and humans rely on to function in agricultural systems.
In 2025, more than 90% of the global ocean experienced at least one marine heatwave.
470 billion labour hours were lost globally to heat in 2021 alone.
Agricultural workers are 35 times more likely to die from heat-related occupational causes than workers in other sectors.
A single severe heatwave can reduce agricultural productivity in an affected area by up to 50%.
The number of working days too hot for outdoor labour could reach 250 per year in much of South Asia by mid-century.
IPCC AR6 projects wet-bulb temperatures exceeding 35°C will become regular occurrences in parts of South Asia under 2°C warming.
The Paris Agreement's Article 2.1(b) explicitly links climate adaptation to non-threatening food production — a linkage now under severe stress.
The report calls for a "decisive transition away from a high-emissions future" and international risk-sharing as prerequisites for food system protection.