Global Economic Growth and the Environmental Impact

Cool homes, hot planet: How air conditioning explains the world

Washington Post, April 27, 2015. Image credit: PublicDomanArchive

Air conditioners in the United States are commonplace — they’re in some 90 percent of our homes, where they consume 5 percent of total U.S. electricity. But we’re not where the growth will happen. Rather, it’s in warm or tropical countries with large populations, like India and Brazil. And you can’t really blame them: As incomes rise, people everywhere seek more comfort — and more and more, they’ll be able to afford it.

China, for instance, has seen a doubling of air conditioner sales in just a half decade — 64 million of them were sold in the year 2013, according to the study. Demand will also be huge in India, the paper finds, where there are “more than three times as many cooling degree days per person” than in the United States. (A “cooling degree day” is a measurement used to determine the demand for air conditioning by calculating how many degrees the average temperature is over 65 —and thus how much cooling you’d need to maintain your home at 65.)

The study looked in particular at Mexico, where air conditioning penetration is currently only at about 13 percent. It found that as people get richer, those living in warm areas will flock to air conditioning. “In warm areas … we find a close relationship between household income and air conditioner adoption, with ownership increasing 2.7 percentage points per $1,000 of annual household income,” write Davis and his colleague Paul Gertler, also based at U.C. Berkeley.

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