for National Geographic News
The dog days of summer are here, and many people are feeling the heat. From California to southern Europe, heat records are breaking.
Is this the result of global warmingthe rise in Earth's temperature fueled by increased greenhouse gases in the atmosphere?
"You can't point your finger and say, This is caused by global warming," said Kevin Trenberth, a climate scientist with the National Center for Atmospheric Research in Boulder, Colorado.
Summer weather is just naturally hot, he said. High-pressure systems, which lead to stifling-hot days, are a typical weather pattern this time of year. But this summer feels hotter in a lot of places:
New Yorkers cranked up their air conditioners over the weekend to seek relief from a heat wave, setting an all-time record for energy consumption, Con Edison, a regional power company, reported Monday.
During July's heat wave in the western U.S., Big Bear Lake, California, which sits 6,790 feet (2,070 meters) above sea level, set an all-time record high of 94ºF (34.4ºC).
Denver, Colorado, tied its all-time high of 105ºF (40.6ºC) on July 20.
Las Vegas, Nevada, tied a 1942 record of 117ºF (47.2ºC) on July 19.
And much of southern Europe is in the grips of a heat wave that is exacerbating widespread drought and fueling a spate of forest fires.
It's Hot, But
This summer's heat is "not all that unusual" and not linked to global warming, said Jim Laver, director of the U.S. National Oceanic and Atmospheric Administration's Climate Prediction Center in Camp Spring, Maryland.
"The way we like to explain it is, the climate varies from year to year, even within the summer season, and the variability is a lot larger than any long-term trend," he said.
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