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

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

Just Posted

Salmo RCMP report drug bust

Fentanyl, methamphetamine and cocaine were seized along with Canadian cash

West Kootenay SPCA hopes you’ll have a heart for Cupid

Cat who tangled with a bobcat seeking a permanent home

New ‘hub’ model takes regional approach to doctor recruitment in West Kootenay

Kootenay-Boundary a provincial leader in effectively attracting doctors to work here

Painting Ourselves Visible group to create mural

A new partnership between Kootenay Gallery of Art and Castlegar Pride

Castlegar Skating Club prepares for regional championships

Watch local skaters on March 11 at 4:30 p.m.

VIDEO: 2020 BC Winter Games wrap up in Fort St. John as torch passes to Maple Ridge

More than 1,000 athletes competed in the 2020 BC Winter Games

Still six cases of COVID-19 in B.C. despite reports of Air Canada passenger: ministry

Health ministry wouldn’t comment on specific flight routes

Violent ends to past Indigenous protests haunt Trudeau government

Trudeau adopted a more assertive tone Friday, insisting the barricade must come down

HIGHLIGHTS: Day one and two at the 2020 BC Winter Games

Athletes had sunny – but cold – weather to work with in Fort St. John

B.C. money laundering inquiry to begin amid hopes for answers, accountability

Eby argued that most B.C. residents already know the previous government, at best, turned a blind eye

Blockades remain in place as Wet’suwet’en hereditary chiefs returning to B.C.

Hereditary Chief Woos said they are ready to engage in nation-to-nation talks with the B.C.

Tyler Toffoli scores twice, Canucks crush Bruins 9-3

Stecher, Miller each add three points for Vancouver

Most Read