LONDON: New climate models have predicted a 50% increase in lightning strikes across the world during this century as a result of warming temperatures associated with climate change.
University of California, Berkeley's climate scientist David Romps and his colleagues looked at predictions of precipitation and cloud buoyancy in 11 different climate models and conclude that their combined effect will generate more frequent electrical discharges to the ground.
"With warming, thunderstorms become more explosive," said Romps. "This has to do with water vapour, which is the fuel for explosive deep convection in the atmosphere. 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."
More lightning strikes mean more human injuries; estimates of people struck each year range from the hundreds to nearly a thousand, with scores of deaths. But another significant impact of increased lightning strikes would be more wildfires, since half of all fires, and often the hardest to fight, are ignited by lightning, Romps said.
More lightning also would likely generate more nitrogen oxides in the atmosphere, which exert a strong control on atmospheric chemistry.
While some studies have shown changes in lightning associated with seasonal or year-to-year variations in temperature, there have been no reliable analyses to indicate what the future may hold.
"Lightning is caused by charge separation within clouds, and to maximize charge separation, you have to loft more water vapour and heavy ice particles into the atmosphere," he said. "We already know that the faster the updrafts, the more lightning, and the more precipitation, the more lightning."
