Permafrost In Canada Is Thawing 70 Years Earlier Than Expected

Not so permafrost: Permafrost thaw ponds in Hudson Bay, Canada - a lower latitude than Mould Bay - back in 2008. Steve Jurvetson/Flickr CC BY 2.0

Permafrost deep in the Canadian Arctic is undergoing a colossal thaw out – over 70 years ahead of schedule.

Research published in the journal Geophysical Research Letters found that a series of unusually hot summers between 2003 and 2016 has caused the upper layers of permafrost to thaw across the Canadian High Arctic.

While researchers have long anticipated that layers of permafrost in the area will thaw, their models suggested the current intensity of thawing would perhaps occur in 2090. The fact it's occurred in the first two decades of the 21st century is, therefore, very worrying. The new findings from the Permafrost Laboratory at the University of Alaska Fairbanks strongly suggest that climate change is occurring at an unprecedented rate, even faster than scientists feared. 

“It’s an indication that the climate is now warmer than at any time in the last 5,000 or more years,” study author Vladimir E Romanovsky, a professor of geophysics at the University of Alaska Fairbanks, told Reuters.

“It’s a canary in the coalmine,” added Louise Farquharson, a post-doctoral researcher and co-author of the study. 

One of the worst affected areas was Mould Bay on Prince Patrick Island where the team found rates of thawing to be 240 percent above historic norms causing around 90 centimeters (35 inches) of sinking in just 12 years. Elsewhere in the Canadian Arctic, they found thawing levels between 150 and 240 percent higher than historic norms.

Permafrost is a layer of frozen soil beneath the Earth’s surface with bits of rock, water, and organic matter frozen at or below 0°C (32°F) for two or more years in a row. As the name suggests, it generally sticks around for longer periods, especially in high-latitude areas of the Arctic and Antarctic.

Around Mould Bay and other affected areas, the researchers found the development of thermokarsts, irregular and unusual crater-like marshy hollows created by the thawing of ice-rich permafrost. Water can often settle within these dips, leading to what's known as a tundra lake or thaw pond, as you can see in the top image. 

However, the effects could be even more profound than the formation of new topographical features. Permafrost also “locks in” a host of microorganisms. As the ground thaws, they spring back into action and start to break down organic matter in the soil. In turn, this churns out more carbon dioxide and other greenhouse gases. Arctic permafrost soils have also accumulated vast stores of organic carbon, an estimated 1,400 to 1,850 billion tonnes (1,550-2,000 billion tons), which are just waiting to be released.

This is why permafrost is sometimes called the “sleeping giant” of climate change. Based on the results of this new research, it looks like the sleeping giant is starting to wake up. 

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