Thawing permafrost may release carbon and methane, contributing to further global warming
Northern Canada is on the frontline of a battle with an unstoppable enemy.
Climate change and rising global temperatures are thawing permafrost that acts like the glue holding the landscape together.
“I guess you can say we’re a canary in a coal mine,” said Tuktoyaktuk, Northwest Territories Mayor Darrel Nasogaluak.
“We’re experiencing the most extreme changes that probably anybody in Canada is experiencing.”
Permafrost is sediment frozen for at least two consecutive years. While the top ‘active layer’ freezes and thaws annually, the ground below the active layer stays frozen and can be hundreds of metres deep.
Woods Hole Research Center senior scientist Max Holmes describes permafrost as nature’s freezer. Carrying on the analogy, he explains that as long as a freezer works, food inside remains frozen, but if breaks or the door remains open, the food thaws and eventually decomposes.
“That’s what’s happening in the Arctic,” said Holmes, referring to the warming and melting of the permafrost.
“When that happens, those bacteria are emitting either carbon dioxide or methane. Both greenhouse gases can cause more warming.”
And that will cause more melting. It is a potentially vicious cycle.
Holmes says there are about 1,500-billion tons of carbon locked in the Arctic permafrost. He warns that if permafrost continues to thaw at its current rate, the potential release of greenhouse gases will have devastating consequences on the Earth’s climate.
Back in Tuktoyaktuk, on the edge of the Beaufort Sea, the community is dealing with a more immediate problem caused by climate change. Shoreline erosion is picking up speed in part because of the loss of permafrost. The Hamlet is watching land literally crumble into the sea and has been forced to move buildings to higher ground.
“The word permafrost is in essence a bit of a misnomer,” said environmental scientist Steve Kokelj.
“We are finding that some of the most dynamic landscapes in Canada are in fact northern landscapes and permafrost landscapes.”