This story has been updated.

Following on a record hot May in which much snow cover melted off early, Alaska saw no less than 152 fires erupt over the weekend of June 21-22. The numbers have only grown further since then, and stood at 319 active fires Sunday, according to the Alaska Interagency Coordination Center, with more than a million acres burned in June alone.

“Given the high number of fires and the personnel assigned to those fires, the state’s firefighting resources are becoming very limited, forcing fire managers to prioritize resources,” noted the state’s Department of Natural Resources Tuesday. The preparedness level at the moment for the state is 5, meaning that “resistance to control is high to extreme and resistance to extinguishment is high.

This stunning tweet from the Alaska Division of Forestry sort of says it all:

All of which is troubling for multiple reasons: (1) Recent research suggests that more Alaskan wildfires, and more large Alaskan fires in particular, are a trend; (2) In some cases, wildfires in Alaska don’t just consume trees, grasses or tundra. They can burn away soils as well and threaten permafrost, frozen soil beneath the ground, and so potentially help to trigger additional release of carbon to the atmosphere.

“One major concern about wildfires becoming more frequent in permafrost areas is the potential to put the vast amounts of carbon stored there at increased risk of being emitted and further amplify warming,” said Todd Sanford, a climate scientist at Climate Central and lead author of the group’s newly released report on Alaskan wildfires, by e-mail.

Sanford’s new report shows that this year is not an anomaly — it is part of a trend. The report found that there has been an upswing in large Alaskan fires, defined as those that consume more than 1,000 acres, over the past three decades:

And this is happening amid a dramatic warming of the Arctic region and of Alaska in particular, which “has warmed more than twice as fast as the rest of the country,” notes the Climate Central report — 3 degrees over the past 60 years.

The Climate Central report also finds that the Alaskan fire season has lengthened and the acreage being burned in Alaskan fires is increasing. “From 1980 to 2009, the average area burned each year approximately doubled each decade, with at least 8 million more acres burned in the 2000s than in any other decade,” notes the study.

The change is something that firefighters themselves have noted. “Since I fought fire in Alaska over 30 years ago, the planet has rapidly warmed and wildfire conditions have noticeably deteriorated,” commented Nicky Sundt, a former U.S. Forest Service smokejumper who now works on climate policy at the World Wildlife Fund, by email. He continued: “As is all too often the case with the impacts of climate disruption, we are leaning more and more on firefighters and other first-responders to protect us. This is a very risky, costly and unsustainable approach.”

Some of these fires are megafires, like the 2007 Anaktuvuk River fire that consumed 1,039 square kilometers of area on the North Slope.

The Anaktuvuk fire epitomizes why Alaskan wildfires can be of particular concern. A study of the fire by scientists later found that it had managed, single-handedly, to give off 2.1 million metric tons of carbon to the atmosphere. Moreover, 60 percent of that came not from the burning of surface trees or plants but from the combustion of “soil organic matter.” That’s troubling because a huge amount of dead plant life, packed with carbon, is frozen in Arctic soils.

In general, as I have written previously, wildfires are expected to be a positive climate feedback. What that means is that as the Earth warms, it is expected that fire activity will increase, and because fires consume trees and plant life — filled with carbon — they cause emissions of carbon dioxide.

So unless trees somehow manage to grow back just as fast as they are burned — pulling an equal amount of carbon back out of the air again — then more fires will worsen climate change. Fire “has a substantial positive feedback on the climate system,” according to a 2009 multi-author Science paper on the matter.

But even within this worsening-fires narrative, fires in the Arctic region are a special concern. And that’s because of the permafrost, the vast subterranean body of icy soils throughout the Arctic region whose total carbon content is estimated to be roughly double what’s currently in the atmosphere.

As the world tries to tamp down carbon emissions, a thawing of permafrost — leading to a new emissions source — could undermine progress considerably. And a trend towards more Alaskan fires clearly doesn’t help matters.

As the University of Alaska at Fairbanks puts it — in more detached and technical language — more Alaskan wildfires could lead to “Loss of forest and surface organic materials —> permafrost thaw —> change in vegetation/hydrology dynamics and carbon cycling.”

So, in sum, when we see so much of Alaska ablaze — as we do right now — we should worry about brave wildland firefighters and also any people who might be exposed to threat. But we should also worry about permafrost, and a potential contribution to climate change.

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