In August 2019, something bizarre happened in the Far North: A massive thunderstorm produced more than a thousand flashes of lightning, including a record-breaking bolt that hit just 32 miles from the North Pole, the closest strike ever recorded. “It was a crazy summer,” says Rick Thoman, a climatologist with the University of Alaska Fairbanks.

It’s common knowledge that thunderstorms and lightning are more likely when it’s hot than when it’s cold; they are more prevalent in the tropics than in the Arctic. So, scientists wondered: Was the Arctic becoming more electric in our warming world, and if so, what impacts would that have?

All these factors have together led to more frequent large-fire years in Alaska. “The big fire seasons are roughly doubling in frequency,” says Thoman. Lightning plays an important role in that. In 2015, for example, Alaska saw more than 50,000 strikes over a three-day period (more than a third of the state’s annual average of 120,000 per summer), and it experienced its second largest fire season yet, with more than 5 million acres burned.