University of Victoria climate researcher Andrew MacDougall conducts fieldwork in Kluane National Park

Thawing permafrost to accelerate global warming, says UVic study

The vast Arctic “compost” is thawing, dumping billions of tonnes of carbon dioxide into the atmosphere

The vast Arctic “compost” is thawing, dumping billions of tonnes of carbon dioxide into the atmosphere, which has been unaccounted for in global climate models,

University of Victoria graduate students Andrew MacDougall and Chris Avis, along with noted climate scientist Andrew Weaver, made this claim in a study published this week by Nature Geoscience Letters.

The team used UVic’s coupled global climate model, a system originally derived from weather forecasting, to conclude that melting permafrost – frozen soil, sediment or rock – could release between 68 and 508 billion additional tonnes of carbon into the atmosphere over the next 90 years, raising global temperatures by an average of 0.4 to 0.8C on top of what has been previously estimated.

“It’s basically frozen compost,” MacDougall said. “It’s grasses and manure and bits of animals that have gotten frozen into the permafrost over thousands of years, so you have this frozen material that can’t decay, then you melt the permafrost suddenly.

“Just as if you unfroze compost in your garden, it would start to rot, but it does so very slowly over the course of a hundred years.”

About 18.8 million square kilometres of northern tundra holds about 1,700 billion tonnes of organic carbon, or 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.

Given that global temperatures have already risen by about 0.8C since the Industrial Revolution, limiting global warming to less than 2C – the goal identified in the 2009 Copenhagen Accord – doesn’t leave much room for future emissions, MacDougall said.

“What we’ve been trying to do more lately is trying to find emissions pathways that allow you to stay below two degrees. This makes that a lot harder. … Not impossible, but difficult.”

To stay below the 2C threshold, humans will have to make “very large and immediate reductions in emissions,” he noted.

“Business as usual” scenarios, MacDougall said, usually account for a three-to-four degree rise in temperatures by 2100. The new model would drive temperatures up an additional 10 per cent and more after the 21st century.

nnorth@saanichnews.com

 

 

Get local stories you won't find anywhere else right to your inbox.
Sign up here

Just Posted

CRD awards $6.8-million Wastewater Treatment Project contract to Surrey company

Construction of the Trent Forcemain to begin in early 2020

Funds raised through off-road cycling event will help improve Central Saanich bike trails

Tripleshot Cycling Club presents $3,000 cheque to Nature Trails Society

B.C. Green Party interim leader to visit Wet’suwet’en camps

MLA Adam Olsen stands behind First Nations

Keating Elementry receiving earthquake upgrades

Seismic upgrades help better protect students in the event of an earthquake.

Adverse weather cancelled more than 900 ferry sailings in 2012

Less than three weeks into January, BC Ferries has cancelled more than 230 sailings

VIDEO: The Victoria byelection leads a selection of today’s news stories

A selection of Greater Victoria top stories for Jan. 17

Kelowna’s “Baby Mary” finds biological parents after more than 30 years

Geneologist and DNA test helped her connect with her biological parents

B.C. offers $5 million equipment loan program to help ailing forest contractors

Local politicians in Port McNeill and Campbell River says local economies are struggling

Vancouver Island distillery wins award for best Canadian rye whisky

Shelter Point cleans up at Canadian Whisky Awards

Clerk bruised, traumatized after armed robbery at Nanaimo liquor store

Few details on male suspect in Wednesday incident, says Nanaimo RCMP

Crown won’t appeal sentence in child sex assault case of former Burns Lake mayor

B.C. Prosecution Service said sentence doesn’t meet standard for appeal

One last blast of winter tonight for parts of the Island before temperatures on the rise

A snowfall warning is in effect Friday including east Vancouver Island.

POLL: Has the recent snow had an impact on your daily life?

Old Man Winter had Greater Victoria in his icy grip this week.… Continue reading

Greater Victoria Crime Stoppers wanted list for the week of Jan. 14

Greater Victoria Crime Stoppers is seeking the public’s help in locating the… Continue reading

Most Read