"The atmosphere thought it lost that carbon and all of a sudden it's being returned to the atmosphere after a prolonged period of time. That's the kind of carbon pulse to the atmosphere that actually can invoke additional climate change, above and beyond human emissions." Merritt Turetsky, a research ecologist from the University of Guelph in Canada. Image Credit: Matt Snyder/Reuters
Land with underlying permafrost is called tundra and tundra covers the northernmost fringes of North America and Eurasia. The arctic tundra is treeless. Roots can’t penetrate the frozen soil, so only moss, lichen, and low shrubs can grow there. In summer, the topmost layer of the permafrost melts, leaving behind soggy ground, marshes, bogs, and lakes.
Wildfire rarely start on the tundra, because the ground is cold and wet and resistant to burning. Until recently, tundra burning had not happened in 11,000 years. Now, with Climate Change, summers are getting hotter, the tundra is getting drier. The warmer weather also has increased lightning strikes, which start more fires.
NPR recently wrote about the threat that fire is having on the tundra.
That's why fires in the higher latitudes, in places like Alaska, are different than other wildfires. Here, Hollingsworth explains, the vegetation above ground is just the tip of the iceberg.There are layers and layers of organic material called duff — things like pine needles, grasses and trees — that have fallen and accumulated on the forest floor over time. They haven't fully decomposed, like they would in a place like Florida, because of the frigid temperatures.
In places, the duff can pile up to be feet deep.
Below that duff, there's permafrost — which, as the name implies, is permanently frozen ground. It can include dirt, rocks and water, as well as trees, twigs and mammoth bones.
The result, Hollingsworth says: There can be way, way more organic material, or biomass, below ground than there is above.
And all of that biomass is made up of carbon — the same carbon that's a leading cause of climate change.
snip Roughly 4.7 million acres of boreal forest and land have burned in Alaska this summer. Millions more have burned in Canada, where scientists estimate half of the land is underlaid with permafrost.In total, more than 11 million acres have burned between the two places — an area roughly the size of Connecticut.
Fires in the subarctic are nothing new. The vast majority of the land burned by wildfire in North America every year is in Alaska and Canada, far from cities and towns.
Still, Alaska has never seen that much fire so early in its fire season. And many of those fires are burning with greater intensity.
That's worrying to research ecologists like Ted Schurr, a professor at the University of Northern Arizona who spends his summers in Alaska studying permafrost.
"It's understood that there's about twice as much frozen carbon [in permafrost] as there is in the atmosphere, to the tune of about 1,700 billion tons of carbon stored frozen," he says.
Put in context, he says, there's maybe another 2,000 billion tons of carbon stored in soil and vegetation in the rest of the world.
Climate Central reported on their analysis of 65 years of wildfire data. They found: The number of large wildfires (larger than 1,000 acres) suddenly increased in the 1990s, and the 2000s saw nearly twice as many large wildfires as the 1950s and 60s.In the Arctic region, the number of large wildfires increased nearly tenfold in the 2000s compared to the 1950s and 60s. Only three years in the 1950s and 1960s saw large wildfires; there have been 33 large wildfires in the Arctic since 2000.
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.
Alaska’s wildfire season is about 40 percent longer now than it was in the 1950s. The first wildfires start earlier in the year, and the last wildfires are burning longer into the fall. Overall, the wildfire season has increased more than 35 days and is now more than three months long, running from May through early August.
Rising temperatures across Alaska have been concurrent with the rise in the number and size of Alaskan wildfires. Years with the hottest May to July temperatures also tend to be years with the most fires, and the greatest area burned.
According to the National Climate Assessment, the amount of area burned in Alaskan wildfires is projected to double by 2050 and triple by 2100 under continued emissions and further warming.
In Siberia, fumes from burning forests cover Lake Baikal, with people - and bears - fleeing. The lake is the deepest lake in the world and is surrounded by forests and towns . This fire is different than a tundra fire. It is what is called a crown fire which burns the top of the boreal forests canopy. The smoke and ash, which has hospitalized people in the region, may very well fall on the Greenland ice sheet darkening the ice even more than the record blackening we have seen so far. The tundra feedback loop and the Greenland albedo loop have brought us to the cusp of rapid climate change.