WASHINGTON, Nov 14: Lightning has the power to spark wildfires and kill, and scientists said on Thursday that climate change may lead to 50 percent more of it by century's end.
The report in the US journal Science is based on measurements of precipitation and cloud buoyancy, applied to 11 different climate models that estimate how warm the planet may get by 2100.
"With warming, thunderstorms become more explosive," said climate scientist David Romps of the University of California, Berkeley.
"Warming causes there to be more water vapour in the atmosphere, and if you have more fuel lying around, when you get ignition, it can go big time."
Previous estimates of how lightning would be affected used indirect techniques that were not closely tied to precipitation.
The result was a range between five and 100 percent more lightning for every one degree Celsius of warming.
The current study is based on the energy available to make air in the atmosphere rise, combined with precipitation rates.
Convective available potential energy, or CAPE, is measured by radiosondes, balloon-borne instruments released around the United State twice daily.
"CAPE is a measure of how potentially explosive the atmosphere is," explained Romps.
"We hypothesized that the product of precipitation and CAPE would predict lightning."
Using data from the US National Weather Service, researchers found that 77 percent of variation in lightning strikes could be predicted by knowing CAPE and precipitation.
"We were blown away by how incredibly well that worked to predict lightning strikes," said Romps.
When applying the parameters to climate models, the team found that each one degree Celsius rise in global average air temperature would mean about 12 percent more lightning strikes.
If temperatures warm four degrees Celsius by century's end, that would mean nearly 50 percent more lightning by then.
Lightning now strikes 25 million times a year around the world. ?AFP