Edited By Shilpy Bisht

Heat stress, caused by global warming, leads to significant changes in the development of wheat, leading to a reduction in grain production and quality.

The month of March, which is also India’s wheat harvest season, will experience abnormal temperatures and unusual number of heatwave days, the India Meteorological Department has warned.

With 2025 being the warmest February in 124 years, India’s changing climate pattern poses a serious threat to its wheat and rice production.

According to officials from the Ministry of Earth Sciences, quoted by news agency PTI, the rice and wheat production could see a decline of 6-10% due to climate change.

In 2023-24, the country harvested 113.29 million tonnes of wheat and 137 million tonnes of rice for its 1.4 billion population, with 80% depending on government-subsidised grains.

India’s average temperature has risen by 0.7-degree Celsius since 1901. The year 2024 was the hottest on record, with the average minimum temperature 0.90-degree Celsius above the long-term average.

How Extreme Heat Impacts Harvest

Global warming is weakening Western Disturbances including weather systems that bring winter rains to northwest India. This could lead to severe water shortages for billions living in the Himalayan region and surrounding plains, according to M Ravichandran, Secretary, Ministry of Earth Sciences.

Wheat yields may see a drop of 6-25% by 2100, while irrigated rice yields could fall by 7% by 2050 and 10% by 2080, according to the data from the National Innovations in Climate Resilient Agriculture (NICRA).

Heat stress, caused by increasing global warming, “triggers significant changes in the biological and developmental process of wheat, leading to a reduction in grain production and grain quality”, as per a 2022 study in the International Journal of Molecular Sciences.

Rising sea temperatures are forcing fish to migrate to cooler, deeper waters, impacting coastal fishing communities and their livelihoods.

Climate change is increasing the frequency of extreme weather events and reducing the lead time for predicting heavy rainfall. “The time to predict such events has decreased from three days to just one and a half days,” Mrutyunjay Mohapatra, director general of the India Meteorological Department, told PTI.

Melting of Himalayan glaciers would mean decreased snowfall and less water for people living in India. The Himalayan and Hindukush mountain ranges, known as the Third Pole, provide water resources vital to one-seventh of the world’s population.

Why Indian Ocean Is The Real Problem

According to the United Nations Food and Agriculture Organisation, there are three stages of a wheat growth — From germination to appearance of shoots, and reproductive stage to the maturity.

Experts believe the warming of the Indian Ocean at an accelerated speed will “likely put it in a near-permanent heatwave state” by the end of the century, according to a study conducted by the Indian Institute of Tropical Meteorology in Pune in 2024.

This in turn will alter India’s monsoon, on which the country’s agriculture depends. For example, if the kharif or summer crop is ending late, it will delay the beginning of rabi season.

Wheat is a rabi crop. If it sowing starts late, the later stages of plant growth will coincide with early heat waves in India. “Extreme heat causes wheat to develop higher protein content but lower starch, making the grain harder and affecting milling quality. Farmers may face lower market prices due to reduced grain weight and quality issues,” Prakash Jha, assistant professor of agricultural climatology at the Mississippi State University, told The Hindu.

How To Lower The Impact Of Heat Stress On Crops

Experts believe the larger question is to be able to guarantee food security. For which, India needs to focus on addressing yield gaps by efficient management of resources like fertilisers, and pest control.

Agricultural policy management strategies to support early sowing of crops in areas that are likely to see heatwaves can alleviate heat stress on wheat.

By combing scientific research, financial support, technological solution and farmer education, wheat crops can be protected from rising heat.

Unprecedented Heatwave Warning For 2025

The IMD has warned that India is set to witness one of the warmest March months on the record, with above-average temperatures to last for most of the month.

According to the official, daytime temperatures are predicted to start increasing in the second week of March, with maximum temperatures in many states predicted to surpass 40 degrees Celsius (104°F) by the end of the month.

Mumbai was under a heatwave warning for February 25 and 26, according to the IMD. Its maximum temperature on February 26 was 38.7°C, 5.9 degrees higher than the average.

Heatwaves with temperatures above 37 degrees Celsius were also reported in Goa and Coastal Maharashtra.

India had to restrict its wheat exports to safeguard the domestic supply after heatwave in February and March destroyed wheat fields. According to the IMD, temperatures in wheat-producing states of northern and central India are expected to rise sharply in mid-March, possibly reaching 6 degrees Celsius over average.

Published Date: March 11, 2025