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

Just Posted

(File photo)
MLA Ron Orr on outing of two UCP members

MLAs Drew Barnes and Todd Loewen were voted out on May 13, 2021

Asymptomatic testing will now be available for "priority groups" who are most likely to spread the COVID-19 virus to vulnerable or at-risk populations. File photo by THE CANADIAN PRESS
Alberta adds 1,195 new COVID-19 cases Saturday

Red Deer has dropped to 760 active cases

Alberta’s chief medical officer of health Dr. Deena Hinshaw is asking Albertans to do their part by observing gathering limits, staying home if unwell, wearing masks and maintaining physical distance. (Photo by Chris Schwarz/Government of Alberta)
Three new Central zone COVID-19 deaths, Alberta adds 1,433 cases

Red Deer down to 802 active cases of COVID-19

Alberta’a chief medical officer of health Dr. Deena Hinshaw said Thursday that there are more than 328,000 vaccine appointments booked over the next seven days. (Photo by Chris Schwarz/Government of Alberta)
Alberta surpasses 2 million doses administered of COVID-19 vaccine

Red Deer down to 835 active cases of COVID-19

Marc Kielburger, screen left, and Craig Kielburger, screen right, appear as witnesses via video conference during a House of Commons finance committee in the Wellington Building in Ottawa on Tuesday, July 28, 2020. The committee is looking into Government Spending, WE Charity and the Canada Student Service Grant. THE CANADIAN PRESS/Sean Kilpatrick
Trudeau didn’t violate conflict rules over WE Charity, watchdog says

Federal ethics commissioner Mario Dion found that former finance minister Bill Morneau did violate the rules

A vial of AstraZeneca vaccine is seen at a mass COVID-19 vaccination clinic in Calgary, Alta., Thursday, April 22, 2021. Dr. Ben Chan remembers hearing the preliminary reports back in March of blood clots appearing in a handful of European recipients of the Oxford-AstraZeneca COVID-19 vaccine. THE CANADIAN PRESS/Jeff McIntosh
Science on COVID, VITT constantly changing: A look at how doctors keep up

While VITT can represent challenges as a novel disorder, blood clots themselves are not new

Welcoming cowboy boots at the historic and colourful Last Chance Saloon in the ghost town of Wayne near Drumheller, Alta., on Thursday, Sept. 19, 2019. The bar and hotel are up for sale. THE CANADIAN PRESS/Jeff McIntosh
‘It was a going concern’: Remaining bar and hotel in Alberta coal ghost town for sale

The historic Last Chance Saloon in the ghost town of Wayne in southern Alberta is up for sale

Chief Public Health Officer Theresa Tam listens to a question during a news conference, in Ottawa. THE CANADIAN PRESS/Adrian Wyld
Restrictions will lift once 75% of Canadians get 1 shot and 20% are fully immunized, feds say

Federal health officials are laying out their vision of what life could look like after most Canadians are vaccinated against COVID-19

Chris Scott, owner of The Whistle Stop Cafe, was put in handcuffs after an anti-restriction protest Saturday in the parking lot of the business. (Screenshot via The Whistle Stop Facebook page)
Alberta RCMP investigating possible threat to police after Mirror rally

Online images show RCMP members, vehicles in crosshairs of a rifle

An Israeli attack helicopter launches flares as he flies over the Israeli Gaza border, southern Israel, Thursday, May 13, 2021. (AP Photo/Ariel Schalit)
Singh calls for halt on Canadian arms sales to Israel as violence escalates in region

Government data shows Canada sent $13.7 million in military goods and technology to Israel in 2019

New homes are built in a housing construction development in the west-end of Ottawa on Thursday, May 6, 2021. THE CANADIAN PRESS/Sean Kilpatrick
Budget’s foreign-homebuyers tax could bring in $509 million over 4 years, PBO says

Liberals are proposing a one per cent tax on vacant homes owned by foreign non-residents

A Canadian flag patch is shown on a soldier’s shoulder in Trenton, Ont., on Thursday, Oct. 16, 2014. The Canadian Forces says it has charged one of its members in the death of an army reservist from British Columbia during a training exercise at a military base in Alberta last year. THE CANADIAN PRESS/Lars Hagberg
Canadian Forces member charged in death of army reservist during training exercise

Cpl. Lars Callsen has been charged with one count of negligence

Most Read