AT THE END of March the India Meteorological Department predicted a warmer-than-usual April, the first month of India’s hot season. The forecast was soon proved right: in the first week of April temperatures in big cities were 3°C above normal. By the second, Delhi was suffering an intense heatwave. Even night-time minimums hit their highest in years. Heat-related illnesses soared.

India, always hot, has been getting hotter. The past decade was the warmest on record. Yet it has not been warming as quickly as the rest of the planet. In the past four decades temperatures over Earth’s land mass have risen by 0.30°C per decade, and by 0.23°C at comparable latitudes. The figure for India is a mere 0.09°C.

Two things are responsible for keeping India relatively cooler. One is the expansion of irrigated land, the area of which has doubled since 1980. Moisture in the air lowers temperatures, but comes at the cost of increasing humidity, sometimes to dangerous levels. In the baking Indo-Gangetic plain a combination of temperatures of just 37°C—a nice day for many—with 90% humidity can be fatal.

As we explain this week, the second cooling agent is horrific air pollution. During the day, particulate matter intercepts the sun’s rays, absorbing heat. It also makes clouds more reflective. The combined effects lead to a comparatively cooler surface. It follows that there is a tension: if India achieves cleaner air, an unintended effect would be higher daytime temperatures.

Some call for natural, energy-neutral methods to deal with rising heat, such as painting buildings white, using less concrete, and covering roofs in reflective tiles or second roofs. These low-cost solutions help somewhat, but they are no match for a north-Indian heatwave. More air-conditioning is necessary. Those who can afford it are already fuelling a boom: annual sales doubled between 2020 and 2024. Often these machines clean air as well as cool it.

One problem is that too few people yet have air-con: just one in ten households owns a unit, whereas two-thirds do in China and four-fifths in Malaysia. Air-con also creates even more pollution. During a heatwave last year, it accounted for a fifth of power demand, much of it met by dirty thermal-energy plants which provide three-quarters of generation. Air-conditioners throw heat into their immediate environment, making conditions worse for those without them. The hydrofluorocarbons they use as coolants are powerful greenhouse gases.

What to do? The only rational path is for India to push for cleaner energy and more air-con, simultaneously. The country is getting many things right. State and central pollution-control boards are responsible for cleaning up the air. Renewables, including hydro, make up 224GW of installed generation capacity of 472GW and there are ambitious plans for them to provide half of total capacity of 1,000GW by 2030. There are new efficiency standards for air-conditioners.

Yet the country needs to move faster. Pollution in the northern plains routinely exceeds the maximum readings of air-quality sensors. That means millions die from pollution-linked disease every year. And if the skies become clearer, temperatures will rise faster.

Speeding up land acquisition for solar projects, investing in the grid and reforming the market for purchasing and distributing power would accelerate private-sector investment in renewables. And a faster roll-out of air-conditioning could be encouraged by lowering the tax on machines from 28%, the highest-available rate (Apple’s iPhones are charged just 18%). The government should lead by example, air-conditioning offices where citizens meet public servants, not just those of politicians and elite bureaucrats.

Across Asia, the Middle East and the southern United States air-conditioning has helped make cities dynamic and more productive. There is a way for India to combine that goal with cleaner air. It should seize it.