Arctic tundra emits more carbon in winter than plants can absorb in summer: study

Phd candidate at Dalhousie University one of 75 co-authors of new paper in Nature Climate Change

The community of Apex, Nvt., is seen from Iqaluit on Friday, Aug. 2, 2019. THE CANADIAN PRESS/Sean Kilpatrick

Research has found Arctic soil has warmed to the point where it releases more carbon in winter than northern plants can absorb during the summer.

The finding means the extensive belt of tundra around the globe — a vast reserve of carbon that dwarfs what’s held in the atmosphere — is becoming a source of greenhouse gas emissions responsible for climate change.

“There’s a net loss,” said Dalhousie University’s Jocelyn Egan, one of 75 co-authors of a paper published in Nature Climate Change. “In a given year, more carbon is being lost than what is being taken in. It is happening already.”

The research by scientists in 12 countries and from dozens of institutions is the latest warning that northern natural systems that once reliably kept carbon out of the atmosphere are starting to release it.

Until now, little was known about winter emissions from permafrost and the soil above it. Even scientists assumed the microbial processes that release the gases came to a halt in the cold.

“Most people think in the winter, there’s no respiration, that the microbes eating the carbon that produce these emissions aren’t active, which isn’t actually the case,” Egan said.

The scientists placed carbon dioxide monitors along the ground at more than 100 sites around the circumpolar Arctic to see what was actually happening and took more than 1,000 measurements.

They found much more carbon was being released than previously thought. The results found carbon dioxide emissions of 1.7 billion tonnes a year are about twice as high as previous estimates.

Arctic plants are thought to take in just over one billion tonnes of the gas from the atmosphere every year during growing season. The net result is that Arctic soil around the globe is probably already releasing more than 600 million tonnes of CO2 annually.

Scientists previously thought carbon absorbed by tundra plants during the summer more or less made up for what was emitted in the winter as well as for what was released from melting permafrost during warm months.

That’s not what’s happening, said Egan.

“We’re seeing that the value emitted in the winter is larger than the net uptake for the growing season.”

What’s more, the pace of the emissions is likely to increase.

Under a business-as-usual scenario, emissions from northern soil would be likely to release 41 per cent more carbon by the end of the century.

But the Arctic is already warming at three times the pace of the rest of the globe. Even if significant mitigation efforts are made, those emissions will increase by 17 per cent, said the report.

Egan notes the research didn’t measure methane, a greenhouse gas about 30 times more potent than carbon dioxide that is also released from soil.

READ MORE: Oceans, glaciers at increasing risk, including Canada’s, climate report says

Bob Weber, The Canadian Press

Like us on Facebook and follow us on Twitter

Just Posted

Disturbing sexual, criminal trends with Greater Victoria youth on the rise

Family counsellors see unprecedented rise in youth sexual assaults and exploitation of children

Flurry of Yuletide activities coming to Sidney

Sidney Business Improvement Area Society and members organize festive events

Russell Books marks opening of new location by setting Guinness World Record

Store stacks world record books more than six metres high

Petition calls on province to cover transfer fees after Island adoption centre closes – again

‘Choices clients weren’t told the ship was sinking,’ says would-be parent

PHOTOS: 11th annual Gingerbread Showcase comes to Victoria

Bakers spent more than 100 hours perfecting their creations

VIDEO: B.C. to restrict nicotine content, bring in 20% tax on vaping products

Province will also restrict candy and fruit flavoured vaping products to adult-only stores

POLL: Do you support CUPE workers in their dispute with School District 63?

SD63 schools to remain closed as strike continues Tuesday

Greater Victoria Crime Stoppers wanted list for the week of Nov. 12

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

Seguin lifts surging Stars to 4-2 win over Canucks

Dallas is 6-0-1 in last seven outings

‘City that protects rapists’: Sexual assault survivor slams Kelowna mayor for defending RCMP

Heather Friesen spent the morning handing out flyers around city hall calling out the mayor

Batten down the hatches: Wet and windy weekend on the way for coastal B.C.

Environment Canada issues special weather warning for Lower Mainland, Vancouver Island

BC Liquor Stores to move fully to paper bags by March

Vancouver Island to be the first to convert to paper bags in November

Tolko shuts B.C. divisions for two weeks over holidays

Head office to close from Dec. 23-27; two weeks’ downtime runs Dec. 21-Jan. 6

B.C. government working with RCMP to address $10 million in budget cuts

Public Safety Minister Mike Farnworth issues statement following report of RCMP cost-cutting

Most Read