Alaska wildfires have already burned 1 million acres, crossing that threshold earlier in the summer than in any summer in recent decades.
The milestone was driven by large and plentiful fires in a region of the state that, until recently, had only modest burning – the tundra-rich delta in southwestern Alaska that lies between the lower Yukon River and the Kuskokwim River.
Already, the 163,533-acre East Fork Fire near the Yup’ik village of St. Mary’s, sparked by lightning on May 31, is among the biggest tundra fires on record in Alaska. And the nearly Apoon Pass Fire, reported at 72,499 acres Monday, now ranks as the Yukon-Kuskokwim Delta’s second-largest tundra fire on record, said Rick Thoman, a climate specialist with the Alaska Center for Climate Assessment and Policy at the University of Alaska Fairbanks.
The 1 million-acre mark, reported on Saturday morning by the Alaska Interagency Coordination Center, is clearly earlier in the summer than at any time since daily records began in 1993 – and most likely earlier than in any year since 24 years before that, said Thoman, who combed through news accounts from big fire years.
“I’m pretty confident that this is the earliest since at least 1969,” he said. That was a particularly hot year, with temperatures as high as 98 degrees, he said, and it turned out to be the fifth-biggest wildfire year, with 4.23 million acres burned.
This year’s early burning is notable for its location, said Thoman and other experts who pointed to the large number and size of Yukon-Kuskokwim Delta fires.
“Something’s different in the Yukon Delta. That is a fact,” he said.
“Something obviously different is happening,” echoed Nancy Fresco, a research professor with UAF’s Scenarios Network for Alaska and Arctic Planning.
There were wildfires there in the Yukon-Kuskokwim Delta in the past, she said, but there has been a jump since 2015, statistics show. “It is burning becoming much more frequent, now with larger areas burned, very recently,” she said.
This year’s fires are the product of a combination of long-term climate change and short-term ignition forces, Fresco said.
Climate change has loaded more burnable fuel — shrubs and trees — onto what used to be sparse tundra vegetation, she said. “The vegetation is changing. And that vegetation change is being driven by climate change,” he said.
Short-term forces included a lot of lightning that sparked fires in tundra areas where snow vanished early in the spring, she said.
It’s too early to conclude that the Yukon-Kuskokwim Delta has crossed a tipping point, said Brian Brettschneider, a National Weather Service research scientist. Nonetheless, short-term conditions this spring and early summer were a perfect setup for fires, he said
A record-cold November there was followed by a relatively mild winter and spring melt-off of snow, Brettschneider said. There are extremely dry conditions that stretch from southwestern Alaska to the eastern part of the state, with some areas experiencing drought, according to the U.S. Drought Monitor. Then lightning adds the spark, he said.
“Early snowmelt and occasional lightning strikes and we’re off to the races,” he said.
Even short-term factors, however, can carry a climate-change fingerprint, Fresco said.
When the climate is warming over the long term, there is more likelihood of early snowmelt out and heat that dries out the ground surface, she said. Additionally, the growth of vegetation has a drying effect because the bigger and more plentiful plants draw in more moisture, leaving the ground drier.
“The entire ecological regime of the region is changing, and this is being driven by climate change,” she said.
Statewide, Thoman said, chances of an extremely big fire season have increased.
Reaching the 1 million-acre threshold in early summer is not necessarily a predictor of a lot of late-summer burning, he said. However, Interior Alaska — the usual center for Alaska wildfires — is now primed for big burns, with its extreme dryness, flurry of lightning strikes and heat forecasted for coming days, he said.
As of Monday morning, 289 fires had burned 1.04 million acres statewide, with recorded fires this year stretching from Adak in the Aleutians to spots above the Arctic Circle in northeastern Alaska, according to the Alaska Interagency Coordination Center.
Alaska’s biggest wildfire season on record was in 2004, when over 6.5 million acres burned.