July 12, 2010
You know you’re in a heat wave when a high of 92 degrees comes as a relief. But at least heat waves this hot—temperatures reached an official high of 102 degrees last week here in Washington—don’t happen every year. Right?
Well, that break between years of extremely high-temperature summers may get shorter and heat waves may become more common, say climate scientists writing in the journal Geophysical Research Letters. The researchers used more than 20 computer models to simulate what will happen with hot temperature extremes in the continental United States between now and 2039. Over that time, the average global temperature is likely to increase by about 1.8 degrees Fahrenheit due to climate change from rising carbon dioxide levels.
By the 2020s, the scientists found, episodes of extreme heat will occur as often as five times per decade in the Southwest, and by the 2030s, heat waves will be the new normal for that region of the United States. Other areas will also see an increase in the frequency of these events. Washington, D.C., for example, now has an extreme heat wave only a couple times per decade, but in the 2030s, we could get these 100-degree days once every three years or so. And those high temperatures mean more than just retreating to air-conditioned spaces or pools and beaches; they would would also bring more frequent droughts and wildfires.
Maybe I need to move to England. Last week, the U.K. Met Office issued a health alert due to hot weather. The projected high was 31 degrees Celsius—88 degrees Fahrenheit. Sounds like a beautiful summer day to me.
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