Between booming populations across Asia and Africa, a mushrooming middle class and hotter average temperatures all over the planet each year, demand for cooling technology – chiefly single-room air conditioners – is on track to cause heat-trapping emissions to soar fifteenfold by the end of the century.

Of the 1.5 degrees Celsius – or 3.6 degrees Fahrenheit – that the planet's average temperature is expected to rise during this 80-year period, air conditioners alone are projected to be responsible for as much as a third of the increase. And a large portion of that will come from developing countries that are only now seeing the widespread proliferation of a technology first applied in the West more than a century ago.

Temperatures in India this week soared past 122 degrees this week in the northern city of Churu, forcing residents to remain indoors as much of the country baked in a brutal heat wave that's reportedly killed more than a dozen people in the last three weeks. Such events, only expected to become more frequent with climate change, are expected to be a big driver for air conditioning.

But the implications for climate change are staggering: Combined with surging populations in other nations around the globe, annual cooling emissions worldwide are set to almost triple by 2050 – even with improvements in building codes and equipment efficiency. India alone, home to about 16% of the world's population, will likely account for 20% of the global growth in sales of single-room air conditioners – 1 billion of the roughly 4.5 billion such units expected to be sold in the next few decades.

How to head off the resulting spike in emissions is a vexing question – and only partly because of the technological challenges. India, China and other developing nations have long chafed at being ordered around by developed countries – the ones historically most responsible for the current climate crisis. The U.S. and the member states of the European Union are two of the three largest sources of greenhouse gas emissions in the world.

A Chinese minister in December 2018, for example, called on developed nations to "pay their debts" on climate change and not just push developing countries to reduce their heat-trapping carbon emissions.

"This issue hits at a core tension that has existed in the global dialogue about climate change for quite some time," says Sarah Ladislaw, senior vice president and director and senior fellow of the Energy and National Security Program at the Center for Strategic and International Studies, a D.C.-based think tank. "It is unacceptable to conceive of climate change solutions that deprive developing countries of their basic right to achieve a higher standard of living. A lot of people tend to think of air conditioning or residential cooling as a luxury but it is not."

The Changing Climate View All 15 Images

The tension is most apparent in the world's fastest growing – and one of its hottest – nations.

"One country stands out above all else, not only having an impact in this sector but being impacted by a changing climate, and that is India," says Kartikeya Singh, senior fellow and deputy director at CSIS.

Successive heat waves in India in the past decade have killed thousands of people – more than 2,000 in 2018 alone. Temperatures in parts of the country climbed as high as 123.8 degrees Fahrenheit, and on April 24 New Delhi recorded temperatures of 109 degrees. India is among the countries that will experience the biggest leaps in temperatures associated with global warming, with devastating heat waves, once as short as five days, projected to stretch to 30 or 40 days, researchers say.

"We think of cooling being a luxury item. There are 2.8 billion people living in the Tropics today, and about 50% of the world's population will be there by 2050 – significant heat stress environments there, where cooling so much is not viewed as a luxury but a need for human health, human well-being, productivity and, even at the extreme, human prosperity," Iain Campbell, a senior fellow at the Rocky Mountain Institute, a nonprofit clean energy research and advocacy organization, said at a recent event in the nation's capital.

Unlike other environmental efforts, however, cooling technologies are one area where shifts in government policy – and advances in technology – promise not to raise costs or inhibit economic growth but instead to solve some of the toughest questions facing everyone from grid-planners to policymakers.

For every dollar someone spends buying an air conditioning unit, for example, energy utilities in India will need to spend at least 80 cents to upgrade the electric grid to meet that new demand. And under current trends, the country's electric grid – which only recently began providing power to the entire country – will need to double in size simply to meet expected demand from newly purchased air conditioners.

More efficient air conditioners, in other words, even if funded with government subsidies, could head off far more costly investments in electric infrastructure – and the benefits for the global climate are merely an added bonus.

"The Ministry of Power, Ministry of Finance, are the two primary drivers – they have a good understanding of the analysis as it pertains to their country, and it's like the climate impact and the emissions reduction opportunity is an add-on on top," Campbell says. "I'm not sure if we'd have gone and approached countries on a climate-impact perspective that it would've gotten very far. People would've been interested and there would've been good will and perhaps some good-faith efforts, but I'm not sure you would have mobilized the level or the depth of interest of government ministries to actually move the ball forward."

Simply overhauling and expanding India's electric grid, meanwhile, won't be enough: Even if policymakers decided to build only renewables like wind and solar, plus battery storage, it would come nowhere near meeting the expected surge demand from air conditioners: Solar, for example, saw a 100 GW increase in installed capacity last year – its best year ever. The energy demand for air conditioning worldwide, meanwhile, leapt by 130 GW.

"We all feel really good about that record year of solar – it isn't even keeping up with the new load associated with that year's sales of residential air conditioners," Campbell, whose job involves supporting clean energy projects, says. "So I just don't think we can move fast enough to be able to solve the cooling challenge with renewable energy, and we have to look at the other side of it and say, 'Is there a way to provide cooling much more efficiently than we do today?'"

The Indian government last year launched a competition with the Rocky Mountain Institute and a European clean energy nonprofit, Mission Innovation, to award $3 million to the developers of new cooling technologies that slash air conditioners' climate impact by five times. Finalists in the Global Cooling Prize will be announced in November and prototypes debuted next May, with some installed for testing in Delhi.

India's support for the endeavor – combined with other efforts to address climate impacts – may serve as an important bellwether, either a reflection of how other developing nations may take steps to address climate change or, more directly, spurring them to action.