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

Reminder: Recycling collection changes coming March 1

PQB residents may have to travel to Nanaimo to drop off other recyclables such as glass, Styrofoam

Reporter takes to the skies: Qualicum Beach flight school now up and running

PQB News staffer Cloe Logan tries flying with instructor Mike Andrews

Parksville council members share views on affordable housing

Divergent opinions on responsibility, priorities

Massive early-morning blaze destroys unoccupied Nanoose Bay home

Firefighters from three departments called in to battle fire

Protecting privacy key to stopping spread of COVID-19, B.C. health officials say

The number of coronavirus cases in B.C. remains at seven

Toffoli scores OT winner as Canucks beat Habs 4-3

Demko makes 37 saves for Vancouver

Private clinics would harm ‘ordinary’ people using public system in B.C.: lawyer

Health Minister Adrian Dix announced in 2018 that the government would begin to fine doctors $10,000

B.C. terminates contract with hospice society refusing assisted death

Delta Hospice Society loses hospital service fund of $1.5 million

Child in hospital following fatal crash that killed father, sibling on B.C. highway

The single vehicle crash occured near Kamloops on Highway 5A

‘Die!’: Vernon councillor mailed death threat

This story contains information that might be sensitive to some readers

Hidden message connects Castlegar homeowners decades apart

The Rodgers family was surprised when a message fell out of the walls as they were renovating

Two B.C. men plead guilty to bus-terminal assault of man with autism in Ontario

Parmvir Chahil and Jaspaul Uppal due to be sentenced in June for aggravated assault

Most Read