Source: Robert Scribbler

Late Sunday, there were 146 active wildfires burning in Alaska; as of Thursday afternoon, that number had exploded to 291.

A combination of record hot temperatures and unprecedented thunderstorm activity over the Arctic state has provided numerous dry fuels and lightning-based ignition sources over recent weeks. During the past few days, conditions rapidly worsened as an extreme fire outbreak absorbed all of the firefighting resources of Alaska and tapped a substantial portion of other states’ resources as well.

As of Wednesday afternoon, the NASA/MODIS satellite shot of Alaska (below) showed much of the massive state shrouded under vast clouds of steely gray smoke billowing up from the scores of wildfires blazing beneath. A cloud so large it is now becoming entrained in the Jet Stream and will likely blanket a large section of the Northern Hemisphere in a brown-carbon haze.

(The origin of a 3,000+ mile long cloud of smoke swirls over scores of wildfires now burning throughout Alaska and Canada. Over the past five days, the number of Alaskan wildfires alone has doubled — an upshot of record Arctic heat in a record hot world. Image source: LANCE-MODIS.)

According to Alaska Dispatch News, conditions on the ground were rapidly worsening as 40 new fires erupted on Wednesday. The swiftly expanding Tozitna fire forced Tanana community residents to evacuate. Another town — Nulato — was encircled by a 1,200-acre blaze Wednesday forcing its airstrip to shut down. The Nulato fire is now being battled by 100 firefighters working feverishly to save community structures. Meanwhile, Kenai Peninsula residents breathed a tentative sigh of relief as the Card Street fire and Willow’s Sockeye fire were checked by active firefighting efforts.

Joining what is now a massive, state-wide effort are firefighters sent from Missouri today. The Missourians are added to a now national effort to contain and control the raging Alaska blazes that, so far, have consumed over 400,000 acres. Firefighters may get a little help — with the weather predicted to back off record temperatures as storms ride in from the Gulf of Alaska.

Global Warming Intensifying Alaskan Wildfires

But conditions on the ground are making some firefighting efforts extremely difficult. For not only do fire crews have to combat blazes igniting in tradition fuels like boreal forests and tundra scrub, they also must deal with fuels added by an ongoing permafrost thaw. This thaw, set off by human-forced warming of the climate, unlocks organic materials long frozen within the soil itself. These organic materials form a carbon-rich peat-like layer beneath the top soil. And like peat, the stuff is flammable when dried through the increasingly warm Arctic Spring, Summer, and Fall. Once thawed and dried, it creates an understory fuel that can keep blazes burning for weeks, months, and sometimes years.

Throughout the Arctic, there are hundreds of billions of tons of permafrost. And much of it is now thawing at the southern edge and along the warming coastlines of the Arctic Ocean. Of this permafrost, Alaska has more than its fair share — with most of state soils covering a carbon-fueled permafrost under-layer.

It’s this combination of human-caused warming and the related unlocking of permafrost fuels that has likely contributed to a substantial increase in the number fires and area burned in Alaska over the last 60 years. For a report published Wednesday by Climate Central has now found that as temperatures warmed by 3 degrees Fahrenheit (1.7 Celsius) in Alaska over the past six decades (twice as fast as the rest of the US) both the number of large wildfires and the area consumed by fires within the state is dramatically increasing.

(Climate Central’s June 24 report shows that the number of large Alaskan wildfires has nearly doubled in recent decades when compared with large wildfire frequency during the 1950s through the 1980s. Image source: Climate Central.)

Climate Central notes:

The area burned in large wildfires each year is increasing. In just two years, 2004 and 2005, wildfires burned a larger area than in the 15 years from 1950-1964 combined. In particular, there has been a dramatic increase in wildfires larger than 10,000 acres but smaller than 50,000 acres.

Though a 3 F (1.7 C) warming of Alaska over the past 60 years has already provided significant additional heat and fuels, additional warming through 2050 globally is predicted to be between 2 and 4 F (1.1 to 2.2 C) under moderate to severe additional fossil fuel emissions (RCP 4.5, RCP 6 and RCP 8.5). Due to polar amplification, warming in Alaska is likely to be roughly twice the global average. And as a result, fires throughout the state are only likely to grow more extreme.

UPDATE: According to the most recent Alaska Interagency Center Situation Report, fire totals jumped by an additional 26 active fires over the last 24 hours. Now 317 wildfires are actively burning in the region. Acres burned for 2015 have also jumped by more than 250,000 to a total of 919,000. If sustained, this pace of burning will be enough to challenge all time records for June set in 2004 at more than 1.6 million acres burned.

Some news reports have made the misleading claim that the current fire season is normal for Alaska. This is clearly not the case. Number of active fires and daily acres burned are now in exceptional to unprecedented ranges. Daily acres burned hitting totals greater than 200,000 are significant events that should not be treated so lightly.

Source: Robert Scribbler