University of Victoria study says melting permafrost may speed up global warming
Sep 11 2012
University of Victoria researchers Andrew Weaver and Andrew MacDougall have published new research on the effects of melting permafrostPhotograph by: Darren Stone , timescolonist.com (Sept. 11, 2012)
As the world's permafrost melts, changing the Arctic's landscape, it will also speed up global warming, a new study by three University of Victoria researchers has found.
The study by graduate students Andrew MacDougall and Chris Avis and UVic climate scientist Andrew Weaver, published online in Nature Geoscience Letters, predicts the release into the atmosphere of 68 billion to 508 billion additional tonnes of carbon from permafrost could increase global temperatures by an average of 0.4 to 0.8 C by the end of the century, and up to 1.69 C by 2300.
That may not sound like a huge deal, Weaver said, but when combined with warming already taking place, it suggests a 1.8 to 2.3 C increase in temperature by 2300. Warming temperatures are associated with rising sea levels and an increase in extreme weather events.
Because the release of carbon - called carbon feedback - is already underway, nothing can immediately stop it, Weaver said.
"The thing about permafrost feedback is it's systemic, so because we have kicked it off, it's really self-sustaining and insensitive, at least in the next little while," he said.
It's estimated that permafrost - made up of permanently frozen soil, sediment and rock - holds about 1,700 billion tonnes of organic carbon from the remains of plants and animals that have accumulated over thousands of years.
That is about four times more than all carbon emitted by human activity in modern times and twice as much as is currently in the atmosphere.
There are technologies that can be used to scrub carbon out of the atmosphere, said Weaver, but they're expensive. "So it's important to start pricing our emissions."
Weaver, who believes B.C. is pulling ahead of the global pack because of climate policies such as the carbon tax, called for aggressive action to stop discharge of carbons into the atmosphere and bolster those scrubbing technologies.
MacDougall said the UVic analysis, which used a sophisticated computerized Earth System Climate Model, showed the international aim of limiting global warming to less than two degrees - confirmed in the 2009 Copenhagen Accord - is becoming less and less achievable.
"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," he said.
Climate-change scientists are increasingly focusing on the Arctic because of the immense implications of Arctic warming, sea-ice melt and permafrost thaw, not only for northern populations, but for the rest of the world.