http://www.boston.com/lifestyle/green/articles/2009/12/13/under_the_icy_north_lurks_a_carbon_bomb/?p1=Well_MostPop_Emailed4
North of Canada’s capital, underneath an endless expanse of spruce, pine, and birch, ticks what some scientists are calling a carbon bomb: Peat.
A thick layer of the black spongy soil, the remnants of ancient forests, wraps the globe’s northern tier. Deeper than 15 feet in places, the peat layer extends over more than 6 million square miles across Russia, Scandinavia, China, Canada, and the United States.
Carbon that those forests absorbed from the air over thousands of years is stored in the peat and suspended in waterlogged bogs or permafrost. When it is disturbed or drained - as is happening in some areas - the peat can start to decompose and dry out, unleashing greenhouse gases. In North America alone, the peat and the trees growing in it hold as much carbon as would be emitted worldwide by 26 years of burning fossil fuels at current rates.
“For a long time, we failed to see the soil for the trees,’’ said Larry Innes, director of the Canadian Boreal Initiative and adviser to the Pew Environment Group, a funding and advocacy group. Innes talked as he piloted his small plane over hundreds of tiny peat islands capped with spruce trees in lightly iced lakes about 150 miles north of Ottawa. Fluctuating water levels in a reservoir for a hydroelectric dam had eroded peat from the shorelines, allowing some of its carbon to be released and leaving sand behind. Enormous clear-cuts - miles across - opened the landscape nearby.
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But the boreal forest - holding twice as much carbon per acre as tropical forests - also needs a place at the table, scientists say. In Canada, deforestation - defined as permanently cleared land - is estimated at about 126,000 acres a year, although scientists say development and industrial uses alter far more of the forest. That figure also excludes logging. In Alberta, with its enormous mining effort to squeeze oil from tarry sands, only about 40 percent of its once vast forest is still considered intact, according to Global Forest Watch Canada, a research group.
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Yet the advocates for the boreal forest say it is vulnerable because northern regions are heating up faster than more temperate areas, which could cause the peat to thaw and release its carbon. No one knows how quickly emissions will occur if that happens.
Another place we are going gung-ho at "geo-engineering" without really knowing what the full effects will be. Or as I saw posted somewhere, "humanity is a self-limiting problem".
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