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Wildfires in Alaska have grown more frequent and destructive in the last few decades, signaling a trend that has dire consequences for the entire planet if carbon-rich forests and permafrost continue to burn at an escalating rate.
The climate science organization Climate Central analyzed 64 years of wildfire data from the Bureau of Land management Alaska Fire Services, looking specifically at the frequency of wildfires and the surface area burned. It also cross-compared their findings with average temperature increases from 1950 to 2014.
Overall, the number of fires across Alaska doubled in that time — from roughly 20 large fires a year to 40. But this change was not gradual: There was a marked increase in fires beginning in the 1990's, and so far, the 2010's have clocked the most significant number of fires compared with any decade since. The "fire season," measured by the first and last days forest fires ignite in a given year, lengthened by nearly 35 days.
The increase in surface area burned was even more dramatic — a ten-fold increase since 1950, with the sharpest increase came in the first few years of the 2000s. Most of the burning occurs in the boreal forests of Alaska, which cover 90 percent of Alaska's forested regions and feature highly flammable spruce trees and fir trees—and release massive amounts of carbon when burned.
Todd Sanford, the lead author of the report, says the fires in Alaska are part of a nationwide pattern of rising forest fires.
"These findings mirror what I found in a report about three years ago looking at [fires] 11 US states," he told VICE News. "We saw, on average, each year there were more wild fires, and more areas burned, typically in years that were hot and dry."
Those trends are especially salient in Alaska, where average temperatures have risen twice as fast as the rest of the nation over the last 60 years. On average, the state is 3 degrees Fahrenheit warmer than it was in 1950. The report found that most large fires occurred in the months of May, June, and July, drawing a link between a warming world and increasing fires.
And that may have dire consequences for the rest of the world, the report suggests: Because so much carbon is locked in to the state's boreal and tundra regions, as they burn,"they release carbon emissions into the atmosphere, helping drive global temperatures even higher in a self-feeding cycle." In other words, the more fires burn, the hotter the planet will become, inciting even more fires.
Samford drew attention to melting permafrost in the tundra in particular.
"When the fires burn off the layer [of permafrost] on top, that can speed up the thawing of permafrost there, and you get more carbon emissions potentially after that," he said. "It's a new thing that people are trying to quantify what melting permafrost means for carbon emissions, but our study shows that the risks [of carbon released by permafrost] have been growing over the past few decades by virtue of wildfires.
Last month was the Alaska's hottest May in 91 years, and as of today, there nearly 300 active fires raging across the state, according to Tim Mowry, the public information officer for the Alaska Division of Forestry. He told VICE News that 2015 was shaping up to be a blistering year, as the number of new fires has risen rapidly.
"We started on the low side [this year], but the weather stayed hot and dry, without any precipitation in May or April," he said, adding that the state has seen 150 to 200 new fires in just the last week.
Mowry says that people living in the areas surrounding Fairbanks, in the heart of the state, are used to the smoke and ash. But this year, as in many previous, the fires are erupting all across the state.
"We have fires in the west, east, north and south of Fairbanks, we've had tundra fires, some fires out in the southwest which are basically big grass fires," he said, "we've had a lot of everything so far this year."
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