August 12, 2022 Climate Change Makes Lightning More Likely. Here’s Why That’s a Big Deal

A bolt of lightning strikes next to lower Manhattan and One World Trade Center in New York City during a thunderstorm on Aug. 27, 2020 as seen from Jersey City, New Jersey. Credit: Gary Hershorn/Getty Images
A bolt of lightning strikes next to lower Manhattan and One World Trade Center in New York City during a thunderstorm on Aug. 27, 2020 as seen from Jersey City, New Jersey. Credit: Gary Hershorn/Getty Images

Correction: A previous version of this newsletter cited incorrect average warming data. The planet has warmed about 1.9 degrees Fahrenheit since pre-industrial times.

It was a bizarre and tragic scene last week when four strangers, huddling under a tree just outside the White House to take shelter from the rain, were struck by lightning. That even one of the four survived the ordeal, doctors said was an “absolute miracle.”

Being struck by lightning happens so rarely that experts say out of the roughly 25 million lightning strikes that occur across the United States each year, only 3,000 strike people, with just 20 of those victims on average dying as a result. But those odds could be changing, researchers say, as global warming makes storms and the likelihood they’ll produce lightning more common—a message scientists reiterated in the wake of last week’s deadly strike in the nation’s capital.

Climate change is making the air warmer, which allows it to hold more moisture, and both of those factors can boost the chance of thunderstorms. One major study from 2014 estimated that, if warming continues at its current pace, the number of lightning strikes in the U.S. could increase by as much as 50 percent by the end of the century, with each additional 1 degree Celsius of warming generating about 12 percent more strikes. 

Still, scientists and government officials are less concerned with lightning striking people than they are with it striking dry vegetation and igniting wildfires. Besides making the lightning itself more likely, global warming is also exacerbating drought conditions in places like the American West, where dried out grass and trees now act as the perfect kindling, and where lightning strikes play an outsized role in sparking blazes.

Between 1992 and 2015, more than 40 percent of the wildfires in the West were caused by lightning, according to the U.S. Forest Service. And in 2020, California experienced a remarkable barrage of 15,000 lightning strikes over just a few days, igniting more than 600 fires that burned more than 2 million acres and destroyed thousands of homes and buildings.

In fact, a study published Monday by Washington State University researchers found that so-called “dry lightning,” when lightning occurs alongside less than 2.5 millimeters of rainfall, is now a leading cause of some of the biggest wildfire flare-ups in California’s history. This intersection of dry conditions and lightning is becoming more common with climate change, the researchers warned. It’s also the cause of at least eight active wildfires in Northern California today, according to the U.S. Forest Service.

“Wildfires are a growing threat in California as the climate continues to warm,” Dmitri Kalashnikov, the study’s lead author and a doctoral student at Washington State University’s School of the Environment, said in a press release. “Unlike human-caused fires that originate in a single location, lightning outbreaks can strike multiple locations and start numerous simultaneous wildfires, creating a substantial challenge for fire response.”

It’s a scenario that’s also playing out in the quickly warming Arctic, where wildfires threaten to disrupt the region’s delicate ecosystem and trigger dangerous climate feedback loops that could spiral warming out of control. In Alaska, lightning activity has increased 17 percent since the 1980s, one 2020 study found. And ICN’s Bob Berwyn wrote about another study, published last year, that found that lightning strikes in the whole Arctic region could increase by as much as 40 percent for every 1.8 degrees Fahrenheit of warming. For perspective, the planet has warmed about 1.9 degrees Fahrenheit since pre-industrial times.

Those findings are particularly concerning, considering that the Arctic is already warming four times faster than the rest of the world and because of the role the region plays in regulating the Earth’s weather and climate. For one, think of all that snow and ice that reflects the sun’s heat back into space.

As snow and ice melt, more heat is absorbed by the planet rather than reflected away, warming it even more in a process known as “Arctic amplification.” And as wildfires release carbon dioxide and soot into the atmosphere, they are further exacerbating climate change. The rising temperatures melt vast stretches of permafrost, unearthing caches of methane gas and other potent climate-warming gases that have remained trapped in ice, in some cases, for hundreds of thousands of years. The warming fosters even more warming in a self-perpetuating cycle.

“It’s a really vulnerable environment in the Arctic,” Antti Lipponen, a scientist with the Finnish Meteorological Institute whose latest study found the region was warming faster than previously believed, told The Washington Post this week. “And seeing these numbers, it’s worrying.”

That’s it this week for Today’s Climate. Thanks for reading, and I’ll be back in your inbox on Tuesday.

Today’s Indicator

600

As of Thursday, that’s about how many flights airlines have canceled because of thunderstorms hovering over Texas, disrupting operations at one of the busiest airports in the country for a second straight day. Scientists say climate change is making such storms more common.