Air Conditioning Saves Thousands of Lives, but Worsens Global Warming

Air conditioners offer protection from deadly heat, yet the electricity they consume can deepen the climate problem that makes cooling increasingly necessary.

A study published in Nature Health found that air-conditioning use saved nearly 58,000 lives in the United States between 2010 and 2020. Current estimates put the annual figure at about 5,000 lives in the country. The United Nations estimates that almost half a million people die each year from hot weather worldwide, increasing the need for cooling as heatwaves strike every continent.

The climate cost is substantial. The International Energy Agency and the U.N. Environment Programme estimate that rising air-conditioner use could push electricity demand up threefold. Because fossil fuels still generate much of the world’s electricity, they project emissions from air-conditioning use will increase from 4.5 billion to 7.2 billion tons over the next 25 years.

“Everyone knows that air conditioning cools, but from the perspective of climate change, air conditioning is not ideal, it produces more carbon emissions and accelerates the problems of climate warming,” said Kai Chen, a professor of epidemiology at the Yale School of Public Health and a study author. Energy concerns have led Bangladesh, Cambodia, Jordan, Malaysia, the Philippines, Seychelles, Singapore and Sri Lanka to restrict air-conditioning use in offices, with some governments requiring public offices to switch it off for one or two working days.

Scientists track cooling demand through “cooling degree days,” a measure of the energy needed to cool buildings when outdoor temperatures rise. The U.S. figure has increased 28% since 1990, with 2024 recording the sharpest rise. Data indicated that the pace of increase by March 2026 had already exceeded the pace seen in 2024. Europe’s figure has doubled since 1990 while air-conditioner use rose 44%. Experts meeting in Singapore under the Global Cooling Pledge will seek ways to cool people without adding to warming.

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Everyone knows that air conditioning cools, but from the perspective of climate change, air conditioning is not ideal, it produces more carbon emissions and accelerates the problems of climate warming.