Alaska experiencing wildfires on a scale it’s never seen; climate change seen as the key cause

ANCHORAGE, Alaska — Alaska is burning this year in ways rarely or ever seen, from the largest wildfire in its typically mainly fireproof southwest region to a pair of fires that ripped through forests and produced smoke that blew hundreds of miles to the the Bering Sea community of Nome, where the normally crystal clear air was pushed into the extremely unhealthy category.

More than 530 wildfires have burned an area the size of Connecticut.

And the period that’s usually the worst of the fire season is still ahead.

Little property has burned. But one person was killed — a helicopter pilot who crashed last month while attempting to carry a load of equipment for firefighters. And people have been forced to evacuate.

Recent rains have helped.

Still, longer-term forecasts are showing a pattern similar to 2004, when July rains gave way to high-pressure systems, hot days, low humidity and lightning strikes that fueled Alaska’s worst fire year. In 2004, the acreage burned by mid-July was about the same as now, By the time that fire season ended, 10,156 square miles were charred.

“The frequency of these big seasons has doubled from what it was in the second half of the 20th century,” said Rick Thoman, a climate specialist with the Alaska Center for Climate Assessment and Policy at the University of Alaska’s International Arctic Research Center. “And there’s no reason to think that’s not going to continue.”

Heat waves and droughts, which are exacerbated by a warming climate, are making wildfires more frequent, destructive, and harder to fight in many places. This month, wildfires have torn through Portugal, Spain, France, England and Germany, which have seen record-high temperatures.

California has recorded its largest, most destructive and deadliest wildfires in the past five years. With that state deep in drought, authorities are girding for the possibility of a late summer and fall filled with smoke and flames.

Alaska also has been dry. Parts saw an early snow melt and then a largely rain-free June that dried out the duff layer — the band of decaying moss and grasses that blankets the floors of boreal forests and the tundra. This organic matter can be up to two feet thick but in various stages of decay.

On May 31, a lightning strike on the duff layer in the Yukon-Kuskokwim Delta started the East Fork fire, an area in southwest Alaska that rarely burns. Two communities with a combined population of about 700 were threatened, though no mandatory evacuations were ordered in what became the largest wildfire ever in the delta at 259 square miles. Firefighters were able to protect those communities.

A fire like that one was directly attributable to climate change, Thoman said. There’s more vegetation growing on the tundra, willow and alder trees are thicker in the transition area between the tundra and forests, and spruce trees along river valleys are growing thicker and moving farther uphill from those valleys.

“There’s been a significant increase in the amount of fuel available, and that’s from decades of warmer springs and summers in the region, direct result of a warming climate,” Thoman said. “And, of course, fires with more fuels available burn hotter. They burn longer. They’re more resistant to changes in weather.”

A little more than half of all wildfires in Alaska are started by lightning and the rest are caused by humans accidentally, intentionally or through negligence. Of the 4,687 square miles burned this year, only two square miles have been from human-caused fires.

It isn’t feasible or necessary to try to fight all Alaskan wildfires. Fire play a key role in the ecoystem by cleaning out low-lying debris, thinning trees and renewing habitats for plants and animals. So Alaska typically lets most burn themselves out or waits until rain and snow does the job. Firefighting resources are directed toward fires in populated areas.

So far this year, there have been about 145,000 lightning strikes in Alaska and adjacent areas of Canada, according to the federal Bureau of Land Management’s lightning-detection network.

While there’s been little loss of property, smoke from the fires has caused dangerous breathing conditions. In one case, two fires burning near Lake Iliamna in one day burned about 75 square miles of boreal forest, creating smoke and ash that strong winds transported hundreds of miles northwest to Nome, pushing the air quality index into the extremely unhealthy category.

“I would never have thought that you could get that poor of air quality back 400 miles from the active fires, and that is a testament to how hot those fires were,” Thoman said.