Thawing Arctic permafrost will accelerate warming - Macleans.ca

Thawing Arctic permafrost will accelerate warming

University of Victoria researchers’ warning

by

NASA Goddard Photo and Video

Today’s Cool Canuck Research is actually about warming and it’s really not very cool at all.

University of Victoria students Andrew MacDougall and Chris Avis, along with climate scientist Andrew Weaver, say their model shows that thawing permafrost in the Arctic will accelerate the rate of global warming. Their study is in Nature Geoscience Letters. The University of Victoria explains:

Permafrost is permanently frozen soil, sediment or rock. It’s estimated that about 18.8 million sq km of northern soils hold about 1,700 billion tonnes of organic carbon, or frozen compost—the remains of plants and animals that have accumulated over thousands of years. That’s about four times more than all the carbon emitted by human activity in modern times, and twice as much than is currently in the atmosphere.

The new study predicts that by the end of this century, permafrost could release between 68 and 508 billion additional tonnes of carbon into the atmosphere, raising global temperatures by an average of 0.4 to 0.8°C. When combined with observed warming since pre-industrial times and committed warming in response to existing greenhouse gas levels, this suggests the planet is heading toward a 1.8 to 2.3°C rise in temperature—even if we start reducing emissions immediately.

“Our analysis shows that limiting global warming to less than 2°C—as identified in the 2009 Copenhagen Accord—is less and less likely,”  says [researcher] MacDougall. “It’s clear that if we want to avoid the more dire effects of climate change, we need to start reducing our emissions immediately and aggressively.”