Saturday, December 08, 2012

Tundra is Fuel and It Will Burn Us

We hear a lot about the tundra that blankets the far north thawing due to global warming.   As it thaws it releases previously trapped methane and CO2.

Well it does more than that.   As tundra thaws it turns into fuel for wildfires.  And let's put it this way, fire fighting isn't very effective up there.

In 2007, a tundra fire on the Anaktuvuk river in Alaska showed what's at stake.

"'Fire has been largely absent from tundra for the past 11,000 or so years, but the frequency of tundra fires is increasing, probably as a response to climate warming,' said co-author Syndonia "Donie" Bret-Harte, an ecosystem ecologist at the University of Alaska Fairbanks Institute of Arctic Biology.

"The Anaktuvuk River fire burned 1,039 square kilometers (401 square miles), an area roughly the size of Cape Cod and visible from space, and released more than 2.1 teragrams (2.3 million tons) of carbon into the atmosphere. Radiocarbon dating of the soils revealed the maximum age of the soil carbon emitted from the fire was 50 years."

And a tundra fire is more complex than an ordinary forest fire.

"Smoke from the fire pumped greenhouse gases into the atmosphere, but that's just one part of a tundra fire's potential impact. The fire also consumed up to 30 percent of the insulating layer of organic matter that protects the permafrost beneath the tundra's shrub- and moss-covered landscape.

"In a pine forest, fire would burn up leaf litter on the ground, but not the soil beneath. Because the Arctic tundra has a carbon-rich, peaty soil, however, the ground itself is combustible, and when the fire recedes, some of the soil is gone. In a double whammy, the vulnerable permafrost is not only more exposed, but also covered by blackened ground, which absorbs more of the sun's heat and could accelerate thawing.

"'When the permafrost warms, microbes will begin to decompose that organic matter and could release even more carbon that's been stored in the permafrost for hundreds or thousands of years into the atmosphere,' Mack said. 'If that huge stock of carbon is released, it could increase atmospheric carbon dioxide drastically.'"

Smoke and soot from tundra fires in Labrador also caused dramatic melting of the Greenland ice sheet in July.

Satellite imaging on 8 July showed surface thawing on about 40 per cent of the ice sheet.   Four days later - just four days - that had grown to 97 per cent of the ice sheet thawing.

This is an excellent example of how everything in our biosphere is connected and contained in a remarkably delicate balance.   The tundra is circumpolar and it blankets the permafrost beneath it.   As we warm that tundra we're turning it into fuel - the trees and shrubs
and the carbon-rich soil beneath.

Is this one of those "tipping points" the climate scientists have been warning us about?   It sure seems to check all the boxes, ring all the bells.  We could be witnessing the early onset of runaway global warming.   Fortunately we're much too busy figuring out ways to increase our extraction and export of high-carbon fossil fuels to have time to worry about stuff like the tundra.   Where's the money in that?  Sheesh.

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