The Northern Lights have some competition. New research shows that lightning in the Arctic tripled over the past decade—and climate change may be to blame.
A study published this week in Geophysical Research Letters analyzed data on lightning collected by a network of sensors known as the World Wide Lightning Location Network, or WWLLN. When lightning strikes, it emits a short, low-frequency burst of radio waves, which WWLLN sensors then can pick up and record.
Researchers at the University of Washington, which operates the lightning network, first used this data to inspect lightning strikes during the months of June, July, and August between 2010 and 2020 for all locations above 65 degrees latitude. This area encompasses the Arctic Ocean and includes most of Greenland, northern parts of Canada, and portions of Alaska and Russia. While lightning in this region is pretty rare—thunderstorms need a lot of humidity to form, which generally isn’t present in the Arctic—researchers started noticing more and more lightning in Arctic regions, including some strikes near the North Pole in 2019.
The results were stark: Over the 10-year period analyzed, recorded lightning strikes in the summer in the Arctic shot up from around 18,000 in 2010 to more than 150,000 in 2020. To ensure that the results weren’t due to newer equipment, researchers first adjusted their data to account for the new WWLLN sensors installed over the past decade. They then tallied the number of strikes from the rest of the world over that same time period to compare to the ones farther north. Turns out, lightning in the Arctic went from counting for 0.2% of global lightning strikes at the start of the decade to 0.6% by the end, a threefold increase.
While this research doesn’t definitively prove that climate change is causing increased lightning strikes, the study does note that the rapid warming in the Arctic probably has something to do with it. The region is heating up three times faster than the rest of the planet, and the study’s authors noted that the increased lightning strikes track closely with the warm streak the Arctic has experienced over the past decade.
Past studies have posited that climate change could significantly increase lightning strikes not just in the Arctic but in other parts of the world. Projections show the U.S. alone could see an increase of lightning strikes by 50% over this century.
And there’s some danger to all this new lightning, especially in an area of of the world that’s not used to it that’s also seeing more and more human activity. For Indigenous groups who have been in the Arctic for centuries, it could affect their traditions. The study also notes that the increase in lightning strikes comes as shipping routes are opening up more regularly in the region—another impact of climate change—which could pose a threat.
“With long periods of ice-free ocean and increasing shipping in the Arctic, you’re going to have the same problem you have at lower latitudes: When there’s a lot of people and they don’t know about the lightning threat and it becomes a problem,” lead author Bob Holzworth of the University of Washington said in a press release.