India is affected by climate change like other countries, but it is warming at a slower rate.

An article — in a compilation published earlier this month by Harvard University’s Salata Institute for Climate and Sustainability — showed that monthly maximum temperature rose, on average, by “about 0.28 degree C per decade since 1980”. The average change for 2015–24 reached 0.88 degree C compared with the 1980–90 period, with 2025 the warmest year on record.

Significantly, India’s average increase in temperature is lower than the global average of about 1.4 degree C during the period. This is not just surprising but also important, as this difference may not continue to serve us. Here’s why.

The rise in temperature differs across not just regions but also time, in terms of months, and the time of day. Winter daytime temperatures in northern India show weaker warming than the national average. Some regions, in fact, see a clear cooling trend.

This could potentially be dismissed as natural short-term climate fluctuations. But this variability is not enough to explain the “widespread and significant winter daytime cooling” observed across large parts of northern India since 1980.

Role of aerosols

The study attributes the cooling to “aerosol forcing” and irrigation. Aerosols are small particles that are emitted when crop residue is burnt, or result from industrial pollution, traffic, and cooking. Now how can aerosols — generally seen as harmful to lungs — be beneficial?

The sun’s light comes to earth in the form of shortwave radiation. Aerosols help bounce the light back into space or absorb the energy.

On the flip side, at night the earth releases the heat absorbed during daytime in the form of longwave radiation. Aerosols obstruct the escape of this heat and send it back to the earth’s surface.

Northern India is heavily irrigated. Plants and the soil use up the sun’s energy to convert the irrigation water into vapour, preventing it from heating the air. This results in some cooling. The report points out that this is similar to the natural cooling effect seen earlier in the American Midwest, which has large-scale irrigation.

But this trend is unlikely to persist. Both factors — aerosol loading and irrigation — can change and result in accelerated warming over northern India.

“Aerosol loading may decline under a clean air policy. India’s National Clean Air Programme and related State-level initiatives are designed to reduce ambient particulate matter,” the paper observes. Reduction in aerosols will certainly improve the health of the populace even if it nullifies the masking effect on greenhouse warming. This could lead to some increase in winter daytime temperatures over northern India. During nights, cleaner air could lead to cooler nights as the absence of aerosols would allow the heat absorbed during the day to escape back into space. This will widen the temperature range.

Loss of groundwater

Irrigation is determined by groundwater availability, and the Indo-Gangetic plain is perched above one of the most rapidly depleting groundwater systems on earth.

Irrigation patterns may change due to groundwater depletion, or from efficiency improvements, or even crop diversification. The transpiration — loss of moisture to the air from plants — and evaporation of water from the soil will reduce, as will the related cooling. As a result, the warming of the northern plains could accelerate much more than seen since 1980.

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Published on April 27, 2026