With the planet’s average temperature continually rising and phenomena such as heat waves becoming more frequent, longer-lasting, and more intense, air conditioning (AC) units are increasingly regarded as central to mitigating the impacts of extreme heat on human health.
A study published recently in the journal Nature Health estimates that the use of AC in homes prevented about 58,000 heat-related premature deaths between 2010 and 2020 in the United States of America. According to the investigators’ calculations, if Americans did not use AC, the number of annual deaths due to extreme temperatures would be more than double what is currently recorded.
However, the team, led by the Yale School of Public Health, also says that beyond a certain point, using more AC does not save more lives, and the costs begin to outweigh the benefits.
“Everyone agrees that air conditioning works,” says Kai Chen, the article’s lead co-author. “But knowing that it works for one person is not the same as knowing how many deaths are prevented across an entire population,” he adds.
The researchers explain that, when air conditioning is already a well-diffused solution, continuing to expand it does not bring significant gains in reducing heat-related deaths. But it does bring, indeed, an increase in energy use, greater pressure on the power grid, and more greenhouse gas emissions, which in turn amplify extreme heat phenomena.
Therefore, the team argues that air conditioning should primarily serve the people most vulnerable to the effects of heat and that policies to expand the use of this cooling solution help save more lives in communities where it remains underdeveloped or where economic power does not allow the purchase of such equipment.
“While some choose to turn on their AC, others make the difficult decision to endure the heat in order to save money for food,” says Narasimha Rao, coauthor of the study.
