California Heats Up

A chilly summer suddenly switches to record-breaking heat in much of California.  Is this climate change?

Photo: Craig Miller

It reached 113 degrees in Los Angeles on Monday, a record. And while a string of hot days in California doesn’t signify climate change any more than do record snowstorms in Washington D.C., the summer of 2010 did set quite a few records for high temperatures and heat waves. Although for us here in California, this week notwithstanding, we’ve had a pretty cool summer.

But this week’s heat — especially in Southern California — is a reminder of the ripple effects that could become commonplace if predictions of more frequent and severe heat waves come to pass, with a changing climate. Utilities pleaded with customers to conserve power as temperatures triggered record spikes in the electricity load and subsequent strain on the electrical grid.

But as Jennifer Skene writes for the KQED’s Quest blog, research suggests that it won’t take much “global warming” to make heat waves a regular feature:

As heat waves become more and more frequent, will people see them as evidence that global warming is happening? Or will people just get accustomed to the hot weather? New York City had the hottest summer on record; Russia suffered through horrible heat and fires. Are all these heat waves the result of global warming?

Several climate studies have found that heat waves are likely to become more frequent — and hotter  — as the earth warms up. In a recent paper out of Stanford University, two researchers ran several different climate models to see how a one-degree Celsius increase in average global temperature would affect heat waves over the next 30 years. They found that even with this relatively optimistic increase in average temperature, heat waves are predicted to happen more frequently — especially here in California.

One event is just one data point. To know whether there is a trend, we have to look at a whole cloud of data: heat wave incidence across several years. But, 2010 is shaping up to be a really hot year. So far, heat records have been set in 17 countries since the start of 2010.

Heat waves have some serious consequences. Heat stresses and kills organisms. Its effects in the marine intertidal zone have been particularly well documented, affecting seaweed, mussels, barnacles, and more. Heat can make trees drop their leaves, and can damage and kill crops, creating economic havoc. And people, particularly the elderly, can perish, as a result of dehydration and hypothermia.