Brian Stone, Jr. a member of the Urban Climate Lab at Georgia Tech's City and Regional Planning Program, found that large cities are warming at twice the rate of the globe and that deaths from heat waves in the United States are responsible for more weather-related deaths than all other forms of extreme weather combined. 

As for using electric cars to counter these so-called heat islands, Stone said the idea has merit.

"Their findings are entirely plausible based on what we know about the contribution of waste heat emissions to urban heat islands," Stone said.

He said that a previous study in Portland found that heat islands on weekdays were 1 to 2 degrees C warmer than on weekend days and the researchers attributed the difference to vehicle traffic.

"Other than the higher densities found in Beijing than most U.S. cities, there is every reason to believe that the order of magnitude benefits measured here would translate to other cities," he said. "We should definitely be promoting electric vehicle deployment, in concert with a greater reliance on transit and non-vehicle modes, as a climate change management strategy in cities."