Lightning Expected to Increase as the Planet Warms

Global warming will increase lightning across the United States, a new study finds, and will mean more wildfires started by lightning strikes.

Berkeley climate scientist David Romps and his colleagues were able to predict lightning strikes based on the energy available to make air in the atmosphere rise, and precipitation rates. Using 11 different climate models, they concluded that global warming will increase the number of lightning strikes by 12 percent for every 1 degree Celsius rise in global average air temperature.

"Lightning is caused by charge separation within clouds, and to maximize charge separation, you have to loft more water vapor and heavy ice particles into the atmosphere," Romps said. "We already know that the faster the updrafts, the more lightning, and the more precipitation, the more lightning."

Half of all wildfires are started by lightning, Romps said, and they're some of the hardest to control.

"With warming, thunderstorms become more explosive," said Romps, an assistant professor of earth and planetary science and a faculty scientist at Lawrence Berkeley National Laboratory. "This has to do with water vapor, which is the fuel for explosive deep convection in the atmosphere. Warming causes there to be more water vapor in the atmosphere, and if you have more fuel lying around, when you get ignition, it can go big time."

Lightning strikes would increase by 50 percent by 2100, the authors report, if the carbon dioxide emissions continue on their current pace.

The findings are reported in the Nov. 14 issue of the journal Science.

With summer looming ever-larger in the windshield, One World Trade Center caught an early dose of the season's favorite activity -- lightning -- on May 23, 2014. Here, a bolt tags the antenna on top of the Lower Manhattan behemoth as an electrical storm moves over New York.

A fishing boat is faintly visible in the Hudson River as a bolt of lightning hits the ground next to One World Trade Center.

The electrical show gives the buildings a brief respite, as it shoots across the sky.

One bolt wasn't enough, apparently. This time two jolts of lightning zero in on the World Trade Center antenna.

Skylines across the country are now on notice: Summer's on the way and it will be packing a wallop.