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

UPDATE: 6.5-magnitude earthquake in Idaho shakes B.C. Interior

An earthquake was reportedly felt just before 5 p.m. throughout the Okanagan

COVID-19: Revelstoke 3D printing face shields for local hospital

‘The response has been completely overwhelming’

Revelstoke Search and Rescue notice significant drop in calls

SAR across the province dropped roughly 90 per cent last week

COVID-19: Revelstoke Credit Union defers mortgages, loans

RCU said other options include approving lines of credit, increasing credit and offering other loans

Glimpses of Revelstoke’s past for March 26

Spicy school meeting, theft at CPR and a proposal to host the 1968 Winter Olympics

First Nations, remote communities need special attention in pandemic, Freeland says

Health-care workers, seniors, Indigenous Peoples some of people most at risk, health officials say

Solar panels installed at Summerland’s municipal hall

Power from energy project expected to provide five per cent of building’s power use

Canada’s 75% wage subsidy is coming, but not for another six weeks: finance minister

Subsidy will cost Canada $71 billion, but push down cost of emergency benefit, Morneau said

South Okanagan piper to perform for livestreamed memorials

Penticton funeral home to show performances every Friday at 4:30 p.m.

Ebus suspends services in Alberta and B.C. in response to COVID-19

Bus company asking residents to stay safe at home

Gleaners give surplus produce, North Okanagan gratefully fed

Trailer full of goods scooped by community amid COVID-19

Call before you dig into spring projects during isolation: BC 1 Call

BC 1 Call gives free checks for utilities in the area of a desired outdoor project

B.C.’s intersection speed cameras putting more tickets in the mail

One Nanaimo location delayed after speed limit reduced

Friends of Dorothy’s drag queens deliver food in support of Kelowna’s first responders

The lounge is donating $5 from every order to first responders

Most Read