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

Comments are closed

Just Posted

Victoria Flamenco Festival goes virtual for 2020 event

The show will go online from July 23 to 26

Metchosin bird card project finds its wings

On display at Metchosin ArtPod from July 10 to 12

UVic research team creating virus-resistant washbasins for post-pandemic world

Civil engineer Rishi Gupta hopes basins will be installed in public spaces

Walk for Peace takes a virtual turn for Victoria Hospice

Residents can still register for Gordy Dodd’s 11th annual fundraiser

United Way Greater Victoria launches Hi Neighbour program in Esquimalt

Feedback sought from residents about funding for micro community projects

B.C. accommodators need phone lines to light up as in-province travel given green light

Travel restrictions during the COVID-19 pandemic have decimated the tourism and hospitality industries

300 Cache Creek residents on evacuation alert due to flood risk as river rises

Heavy rainfall on Canada Day has river rising steadily, threatening 175 properties

First glimpse of Canada’s true COVID-19 infection rate expected mid-July

At least 105,000 Canadians have tested positive for COVID-19 since the coronavirus was identified

Annual music event in Comox Valley celebrates online instead

Vancouver Island MusicFest holds virtual celebration set for July 10

Police ramp up efforts to get impaired drivers off B.C. roads this summer

July is dedicated to the Summer CounterAttack Impaired Driving Campaign

Migrant workers stage multi-city action for full status amid COVID-19 risks

‘COVID-19 has exacerbated an existing crisis’

Okanagan school drops ‘Rebels’ sports team name, citing links with U.S. Civil War

Name and formerly-used images “fly in the face” of the district’s human rights policy, says board chair

PHOTOS: B.C.’s top doc picks up personalized Fluevog shoes, tours mural exhibition

Murals of Gratitude exhibit includes at least one portrait of Henry alongside paintings of health-care workers

In troubled times: Independence Day in a land of confusion

Buffeted by invisible forces and just plain worn out, the United States of America celebrates its 244th birthday

Most Read