Food, water and livelihoods: How extreme heat is reshaping India's agrifood system

For farmers, heat is no longer just a matter of rising temperatures. It is increasingly becoming a water crisis. Across India, hotter days and warmer nights are altering how crops grow, how livestock survive, and how people work.

Heat is drying soils faster, intensifying droughts, reducing water availability, and making agriculture more vulnerable to shocks. The consequences are already visible in shrinking harvests, falling milk production, rising food prices, and growing risks to millions of workers who depend on agriculture for their livelihoods.

A new joint report, “Extreme heat and agriculture,” by the Food and Agriculture Organisation (FAO) and the World Meteorological Organisation (WMO), provides a stark assessment of these risks, highlighting that for India, extreme heat is no longer a distant threat but an immediate disruptor of the entire agrifood value chain.

The report describes extreme heat as a "risk multiplier" that magnifies existing vulnerabilities across food, water, health, and livelihoods. Its findings highlight an urgent need to rethink how India manages its farms, water resources, and rural economies in an increasingly warmer world.

Why is extreme heat becoming more dangerous?

Human-induced climate change has already increased global average temperatures by 1.24°C above pre-industrial levels. According to the report, the period from 2015 to 2025 has been the warmest on record.

The WMO estimates a 70 percent probability that average global temperatures between 2025 and 2029 will exceed the 1.5°C warming threshold. Natural climate cycles such as the El Niño Southern Oscillation (ENSO) can further amplify these warming trends, increasing the likelihood of severe heatwaves and droughts across South Asia.

In India, these conditions manifest as heatwaves—prolonged periods of abnormally hot weather where both daytime and nighttime temperatures exceed regional averages. High nighttime temperatures are particularly damaging as they prevent essential physiological cooling in crops and livestock, prolonging heat accumulation into the following day. Furthermore, extreme heat is the primary driver of "flash droughts", which intensify rapidly over days or weeks, depleting topsoil moisture and forcing a dangerous feedback loop where dry soil radiates more sensible heat, further baking the surrounding air.

The water connection: How heat affects agriculture, especially rice and wheat

India’s agricultural stability is built on grain production, yet the major staples—rice and wheat—are highly sensitive to thermal thresholds. Rice, which provides 70 percent of India’s caloric intake, is increasingly vulnerable as high-temperature extremes are projected to become more frequent throughout the subcontinent. Most major crops exhibit negative yield responses at temperatures exceeding 30 °C, and for every 1 °C of warming, global maize and wheat yields have already declined by 7.5 and 6.0 percent, respectively.

The 2022 heatwave in India stands as a "classic example" of the devastating compound impact of high temperatures and rainfall deficits. During March and April 2022, temperatures were 8 to 10.8 °C higher than normal, while rainfall was 60 to 99 percent below average in many regions.

The results were catastrophic for farmers across Northern and Central India:

• Wheat yields plummeted by 9 to 34 percent across affected states like Punjab and Haryana.

• Vegetable production saw massive losses, with tomato yields reduced by 40 to 50 percent due to sunscald and flower drop.

• Legumes like chickpeas suffered from poor pod set and wilting, while maize faced stunted growth and increased pest pressure.

At a physiological level, extreme heat reaches a "temperature failure point" (typically above 35 °C for most crops), where plants experience failures in photosynthesis and reproductive functioning. High heat can render pollen sterile, cause embryos to be aborted, and shorten the grain-filling period, leading to shriveled, low-quality harvests with reduced nutritional value.

Livestock are feeling the heat too 

India’s massive livestock sector is equally under siege. Most livestock species show negative responses to heat above 25 °C, and unacclimated cattle, swine, and chickens are particularly susceptible to cardiovascular shock and organ failure when temperatures rise. During the 2022 heatwave, Indian dairy animals suffered from a loss of appetite and higher body temperatures, leading to milk yield reductions of up to 15 percent. Increased calf mortality and skin infections were also reported.

The poultry industry faces even more acute risks. Heatwave-induced deaths in poultry can soar into the millions, as birds have a limited ability to dissipate heat through panting and wing spreading. In 2022, egg production in laying hens dropped by up to 10 percent during the onset of the heat, while mortality rates for layers spiked to nearly eight times the regular monthly average. Furthermore, chronic heat stress suppresses the immune systems of animals, making them more vulnerable to disease outbreaks and infections.

The human cost: Farmers on the frontline Farmers at the Indo-Gangetic Basin

Perhaps the most critical concern for India is the health and productivity of its millions of agricultural workers. The report identifies the Indo-Gangetic Basin as one of the most intense global risk zones for future heatwaves. By the late twenty-first century, extremes of wet-bulb temperature (a measure of heat and humidity) in South Asia are projected to exceed critical thresholds for human safety under high-emission scenarios.

Worker productivity is estimated to drop by 2 to 3 percent for every degree above 20 °C. In low-income regions where manual labour is the norm, the vast majority of labour-hour losses occur in the agricultural sector. Agricultural workers are found to be 35 times more likely to die from occupational heat exposure than other workers. For those performing intensive manual labour, piece-rate payment structures often induce workers to push beyond safe limits, increasing the risk of dehydration and chronic kidney disease.

Women bear a disproportionate share of this burden. Rural women are often deeply involved in harvesting and water collection, facing high exposure to heat and increased risks of heat-related illnesses. Research indicates that heatwaves significantly increase the likelihood of preterm birth, and social inequalities often limit women’s access to credit or climate information that could aid adaptation.

Building resilience in a hotter future: Why finance and governance matter

Building the resilience of agrifood systems requires coordinated action that keeps pace with the rate of climatic change. The report outlines a matrix of technical adaptation options categorised by their timescale:

1. Tactical (short-term): These include intra-seasonal adjustments like altering sowing dates, using irrigation for surface cooling, and shifting field activities to early morning hours. Agrometeorological advisories and early warning systems are essential for informing these quick-fix responses.

2. Strategic (medium-term): India has begun exploring cultivars that flower early in the morning and breeding genetically resistant varieties that better tolerate heat stress. Investments in climate services and improved water management infrastructure fall into this category.

3. Transformative (long-term): This involves large-scale shifts in production zones, switching to entirely different, heat-tolerant species, and investing in landscape-level rehydration and restoration projects.

However, technical solutions alone are insufficient if pervasive socioeconomic barriers are not addressed. Agrifood systems currently receive only 4 percent of total climate-related development finance. Closing this gap is essential to support small-scale producers who lack the risk finance needed to invest in heat-resilient technologies.

Effective risk governance must move beyond "siloed" responses. Extreme heat is a systemic risk that demands coordinated policy development across ministries of agriculture, health, water, labour, and disaster management. Integrating agricultural resilience into national heat action plans is a critical step towards protecting the lives and livelihoods of those on the frontlines.

Adapting to heat means adapting to water stress 

The evidence is clear: business-as-usual is no longer an option for India’s agrifood system. While adaptation can provide a critical line of defense, there are profound physiological and ecological limits to what it can achieve. As global temperatures approach the 1.5°C limit, the urgency for both adaptation and ambitious multilateral climate change mitigation grows. For India, the transition to a heat-resilient future is not just an agricultural challenge but a prerequisite for national food security, economic stability, and the health of its people.

“Protecting the future of agriculture and ensuring global food security will require not only building on-farm resilience but also exercising international solidarity and collective political will for risk sharing and a decisive transition away from a high-emissions future,” the report says.