The Delta Fire burns on July 30 in the Donnelly Training Area southeast of Fairbanks. The fire, which started on July 26, was among those sparked by waves of lightning strikes that arrived in Alaska in late July. It ultimately grew to over 57,000 acres, according to wildfire managers. (Photo by Lakota Burwell/Bureau of Land Management Alaska Fire Service)
An Alaska wildfire season that wound up with an unexceptional amount of area burned took an unusual route to get there.
After a record-slow start, the Alaska wildfire season tally as of Wednesday stood at 343 fires covering 297,747 acres, according to state wildfire managers. That is well below the recent years’ median of about 1 million acres but within the usual range of the past two decades.
Almost all of Alaska’s wildfires came extremely late. Less than 3,000 acres had burned in Alaska through late July, said Beth Ipsen, a public information officer with the Bureau of Land Management’s Alaska Fire Service.
That situation was transformed when a wave of lightning strikes hit. In a single day with more than 16,300 strikes — July 24 – about 30 new fires were ignited, according to the Alaska Fire Service. More days of heavy lightning and new wildfires followed.
The slow start was part of “a weird summer” that featured very late snowmelt in many areas and snow in Fairbanks in early June, followed by some record high temperatures on the North Slope, among other events, said Rick Thoman, a scientist with the Alaska Center for Climate Assessment and Policy at the University of Alaska Fairbanks.
While the fire season ended up with acreage typical for a low year, “it’s the timing that was so remarkable,” he said.
Alaska wildfire numbers and acreage totals vary widely from year to year, but the record shows a definite pattern: The intervals between big fire years are getting shorter, a change scientists attribute to a warming climate.
Additionally, the acreage totals in low years like 2023 are getting higher. While it was common decades ago to have low seasons with fewer than 200,000 acres or even 100,000 acres burned by Alaska wildfires, since 2000 there have been only two years with wildfire totals coming in under 200,000 acres, according to BLM statistics.
The era of ultra-low Alaska fire seasons, with totals under 100,000 acres, appears to be over, Thoman said. Some of that is the result of wildfires emerging in places that previously burned only rarely, he said. “These fires in places that are not-so-historically fire-prone are preventing us from getting years that are super low,” he said.
Alaska is often affected by events in the boreal forest beyond national borders, and that was the case his year.
The stationary weather pattern that prevented early summer fires in Alaska had a flip side: weather that drove a record fire season to in Canada, Thoman said. That is a frequent phenomenon, with relatively low years in Alaska offset by high fire years in northern Canada’s territories, and vice versa.
For Alaska-based fire managers, the contrast with conditions in Canada made for some usual staffing demands.
In the early summer, Alaska crews were sent out of the state, mostly to Canada, said Ipsen of the BLM’s Alaska Fire Service. But once Alaska fires started burning in earnest, efforts in the state got assistance from the south, she said. In addition to the Alaska firefighters who were called back, 16 Lower 48 crews, each with about 20 people, came to work on major fires that were sparked by late-summer lightning.
While wildfires in Alaska and elsewhere in the boreal north have been enhanced by climate change, the fires themselves add to a feedback loop that accelerates that warming. The wildfires release carbon, both through the burning of trees and plant matter on the ground and, if fires are intense enough, the thaw of permafrost, scientists say. A study newly published in the journal Environmental Research Letters found that areas in Western Alaska’s Yukon-Kuskokwim Delta that have burned within the past 50 years are 29% more likely to have methane-releasing hotspots than areas in the delta that have escaped wildfires during those decades. But there are counter forces. A 2021 study led by Northern Arizona University scientists found that the wildfire-driven transformation of Alaska’s forests from conifers to deciduous trees could result in more carbon storage and thus offset the losses.