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

Warfield Director elected to head seat on regional board

Mayor Diane Langman is board chair of the Regional District of Kootenay Boundary

Green candidate reflects on South Okanagan-West Kootenay campaign

Rosslander Tara Howse talks about the highs and lows of running for office

One killed in Sunday crash on Highway 3 near Rock Creek

The victim of the two-vehicle crash was a West Boundary resident

Community Christmas Hamper Program seeks donations, applications

Families can register for a hamper at Boundary Family Services and Community Futures

RDKB directors divided over dam revenues and fire service

East-end directors voted in favour of using $300,000 from the dam to support the RDKB fire service

VIDEO: Disney Plus adds disclaimer about racist stereotypes

Disney’s disclaimer is a good way to begin discussion about the larger issue of racism

CN Rail confirms job cuts as weakening economy cuts into freight volumes

Railroad also said it was affected by a slowdown in the B.C.’s forestry sector

Port Alberni mom takes school district to court over Indigenous smudging, prayer in class

Candice Servatius, who is an evangelical Christian, is suing School District 70

New case of vaping-related illness in Quebec brings national total to 8

Quebec health minister considering tightening the rules around vaping products

Greens to vote against Liberal throne speech unless carbon targets toughened: May

Green leader Elizabeth May and Prime Minister Justin Trudeau met Friday, discussing common ground

First Nations ‘optimistic’ about road upgrades after Horgan visits site of fatal bus crash

Premier travelled Bamfield Main road, where bus flipped last September and two students were killed

Princeton couple pays for dream vacation with 840,000 grocery store points

It’s easy if you know what you are doing, they say

B.C. man facing 18 charges after hidden camera found in Kelowna winery washroom

The camera was found at Summerhill Winery on Aug. 23

Most Read