Extreme heat is rapidly emerging as one of the most serious threats to agriculture, both globally and in India, affecting production, livelihoods and food security. According to the Food and Agriculture Organization and World Meteorological Organization report, rising temperatures are no longer occasional disruptions but a structural risk that is reshaping agricultural systems worldwide.
India offers a stark example of this trend. The 2022 heatwave, analysed by the Indian Council of Agricultural Research and Central Research Institute for Dryland Agriculture, saw March and April become the hottest months on record, with temperatures 8-10.8°C above normal and rainfall deficits of up to 99% in several regions. The combined impact of heat and drought hit crops, livestock and farm incomes across northern and central India.
Crops Under Stress
Globally, the FAO-WMO report notes that most crops begin to suffer when temperatures cross 30°C. Heat reduces photosynthesis, shortens crop cycles and damages reproductive stages, leading to lower yields and poor quality produce.
In India, these impacts were clearly visible during the 2022 heatwave. Wheat yields declined by 9-34%, forcing the country to reassess export plans. Maize crops suffered stunted growth and pest attacks, reducing yields by up to 18%. Pulses like chickpea showed poor growth and shrivelled grains.
Horticulture crops were even more vulnerable. Vegetables such as cabbage, cauliflower and tomato recorded yield losses of up to 50%, while fruit crops like apple, plum and lemon saw flower drop, sunburn and pest attacks. These losses highlight how extreme heat can disrupt not just staple crops but also high-value agriculture.
Rice, which provides nearly 70% of India’s caloric intake, faces increasing risks. Globally, rice accounts for about 20% of dietary energy, making it critical for food security. Rising temperatures and erratic monsoons are expected to make rice farming more vulnerable, especially in densely populated regions like the Indo-Gangetic plains.
Livestock Productivity Declines
Heat stress is also affecting livestock systems worldwide. The FAO-WMO report warns that rising temperatures reduce feed intake, milk production and fertility in animals.
In India, the 2022 heatwave led to milk yield losses of up to 15%. Dairy animals experienced higher body temperatures, reduced appetite and increased disease incidence. Poultry farms also suffered, with egg production dropping by up to 10% initially and mortality rates rising significantly.
Globally, the report estimates that nearly half of the world’s cattle could face dangerous heat stress conditions by the end of the century if emissions remain high. This poses serious risks to dairy and meat production systems.
Fisheries and Aquaculture at Risk
Extreme heat is not limited to land-based agriculture. Marine heatwaves are increasing globally, affecting fish populations and aquatic ecosystems. Warmer waters reduce oxygen levels, disrupt food chains and force fish to migrate.
India’s fisheries sector is also vulnerable, particularly inland aquaculture systems where rising temperatures affect water quality and increase disease outbreaks. For a country where millions depend on fisheries for income and nutrition, these changes could have far-reaching consequences.
Forests and Plantations Under Pressure
Forests and plantation crops are increasingly exposed to heat stress. Globally, high temperatures are linked to increased wildfire risks, pest outbreaks and declining forest health.
In India, plantation crops and orchards have already shown signs of stress during extreme heat events. Fruit trees experienced lower productivity and higher pest incidence in 2022. Such impacts not only reduce farm incomes but also affect ecological balance and biodiversity.
Agricultural Workers Face Growing Risks
One of the most serious but often overlooked impacts of extreme heat is on agricultural workers. The FAO-WMO report states that labour productivity declines by 2-3% for every degree rise above 20°C.
India, where agriculture employs a large workforce, is particularly vulnerable. Rice farming alone employs millions of workers, often under open-field conditions. Climate projections suggest that wet-bulb temperatures in South Asia could approach dangerous thresholds for human survival by the end of the century.
During heatwaves, workers face dehydration, heatstroke and reduced working hours, directly affecting farm operations and rural incomes. In extreme scenarios, some regions could experience up to 250 unsafe working days annually.
Adaptation Strategies Offer Hope
Despite the growing risks, both global and Indian studies highlight several adaptation strategies to reduce the impact of extreme heat. Globally, the FAO-WMO report emphasizes the need for heat-tolerant crop varieties, improved irrigation systems, better soil management and climate-smart farming practices. Adjusting sowing dates and using early-maturing varieties can help farmers avoid peak heat periods.
In India, similar strategies are being explored. For rice cultivation, options include early-morning flowering varieties, changing planting schedules and using irrigation to reduce surface temperatures. Breeding heat-resistant crops is also gaining importance.
Institutional measures such as early warning systems, crop insurance schemes and climate advisory services are critical. However, experts warn that lack of awareness, limited access to finance and weak extension systems remain major barriers, especially for small and marginal farmers.
A Shared Global Challenge
The growing impact of extreme heat on agriculture underscores the interconnected nature of climate risks. While India’s 2022 heatwave demonstrated the immediate consequences, the FAO-WMO report makes it clear that such events will become more frequent and intense worldwide.
For India, where agriculture remains central to livelihoods and food security, the challenge is particularly urgent. Strengthening resilience through adaptation, investment and policy support will be key to safeguarding farmers and ensuring stable food supplies.
At the global level, the report stresses that adaptation alone is not enough. Reducing greenhouse gas emissions and limiting temperature rise will be essential to prevent long-term damage to agriculture and food systems. Extreme heat is no longer a distant threat, it is already reshaping the future of farming across the world.