Independence Day Heatwave Could Cause Wildfire Surge

Scientists and officials have been urging Americans to break with tradition and ditch fireworks this Fourth of July amid a sweltering heatwave in the U.S. Pacific northwest and Canada. Given that swathes of the western U.S. are dried out and a potential tinderbox, a single spark could be enough to ignite a catastrophic wildfire. The dangers posed by the current temperatures became real in Canada where the village of Lytton was virtually wiped out by a wildfire. Located 162 miles northeast of Vancouver, it had just recorded the country's highest temperature and thankfully, its 250 residents were able to flee the inferno, though mostly without their belongings.

Research by Mietkiewicz et al published by The Conversation shows that the vast majority of wildfires in the U.S. are started by humans rather than lightinng and that they extend the fire season. The data focuses on fires started in the west's wildland-urban interface which is a transition zone between unoccupied land and human development that is especially prone to blazes. The research shows that when all fires are taken into account daily between 1992 and 2015, 95 percent were started by humans with a large spike evident around the Fourth of July.

Warm and dry conditions are making wildfires easier to start and more difficult to put out, a trend that can be clearly seen by last year's record-setting season. It saw 52,113 wildfires (as of late November) that burned close to nine million acres, nearly double the amount burned in 2019 and 2.3 million more acres burned than the 10-year average. Given that this summer is already being characterized by a historic heatwave, extreme drought and record temperatures, 2021 is shaping up to be a particularly devastating U.S. wildfire season.