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

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

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

Just Posted

Questions around rail safety, firefighter safety, cleanup near the rail yards and tracks, whistle cessation, etc were raised during the RDBN meeting with CN. (File photo)
‘Lot of our concerns are still not being heard,’ say RDBN directors on CN’s response

Frustrated over lack of solutions, despite communicating their concerns to CN

Barbara Patrick. (Submitted/Lakes District News)
Former Burns Lake local to play the first Indigenous character in a Hallmark movie

Barbara Patrick, a former LDSS student takes a huge step for the Indigenous community

The Burns Lake RCMP is supportive of having a ticketing bylaw in place even though there would be limitations on what they could ticket on. (Priyanka Ketkar photo/Lakes District News)
Burns Lake might be getting a ticketing bylaw

Will help extend RCMP’s authority to attend to noise complaints

Mary Cox and Jack Plant dance in their pyjamas and slippers at the morning pyjama dance during the Rhythm Reelers’ 25 Annual Rally in the Valley Square Dance Festival in Chilliwack on June 4, 2011. Sunday, Nov. 29, 2020 is Square Dancing Day. (Jenna Hauck/ Chilliwack Progress file)
Unofficial holidays: Here’s what people are celebrating for the week of Nov. 29 to Dec. 5

Square Dancing Day, Disability Day and International Ninja Day are all coming up this week

Black Press Media and BraveFace have come together to support children facing life-threatening conditions. Net proceeds from these washable, reusable, three-layer masks go to Make-A-Wish Foundation BC & Yukon.
Put on a BraveFace: Help make children’s wishes come true

Black Press Media, BraveFace host mask fundraiser for Make-A-Wish Foundation

114 Canadians were appointed Nov. 27 to the Order of Canada. (Governor General of Canada photo)
Indigenous actor, author, elder, leaders appointed to Order of Canada

Outstanding achievement, community dedication and service recognized

More than 60 cm of snow has fallen at Ulkatcho First Nation near Anahim Lake in the Chilcotin since a snowfall warning went into effect Thursday, Nov. 26. (Graham West photo)
VIDEO: More than 60 cm of snowfall in Chilcotin since Thursday, Nov. 26

Graham West of Ulkatcho First Nation captures the scene on video

Screenshot of Pastor James Butler giving a sermon at Free Grace Baptist Church in Chilliwack on Nov. 22, 2020. The church has decided to continue in-person services despite a public health order banning worship services that was issued on Nov. 19, 2020. (YouTube)
2 Lower Mainland churches continue in-person services despite public health orders

Pastors say faith groups are unfairly targeted and that charter rights protect their decisions

A big job: Former forests minister Doug Donaldson stands before a 500-year-old Douglas fir in Saanich to announce preservation of some of B.C.’s oldest trees, July 2019. (B.C. government)
B.C. returning to ‘stand-alone’ forests, rural development ministry

Horgan says Gordon Campbell’s super-ministry doesn’t work

Peter Wilson, left, and Micah Rankin, right, formed the Special Prosecutor team that was tasked with reviewing and litigating charges stemming from the Bountiful investigation. Trevor Crawley photo.
End of Bountiful prosecution wraps up decades of legal battles

Constitutional questions had to be settled before a polygamy prosecution could move forward

Alexandre Bissonnette, who pleaded guilty to a mass shooting at a Quebec City mosque, arrives at the courthouse in Quebec City on February 21, 2017. THE CANADIAN PRESS/Mathieu Belanger - POOL
Court strikes down consecutive life sentences; mosque shooter has prison term cut

The decision was appealed by both the defence and the Crown

Gold medallists in the ice dance, free dance figure skating Tessa Virtue and Scott Moir, of Canada, pose during their medals ceremony at the 2018 Winter Olympics in Pyeongchang, South Korea, Tuesday, Feb. 20, 2018. THE CANADIAN PRESS/AP-Charlie Riedel
Olympic champions Virtue, Moir and Tewksbury among 114 Order of Canada inductees

Moir and Virtue catapulted to national stardom with their gold-medal performances at the Winter Olympics in 2018

Most Read