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

William Griffin arrested in Houston homicide

RCMP have now arrested William Griffin, the man wanted in connection to… Continue reading

Police look for suspect in Nov. 10 homicide

Victim identified as Elijah Dumont

B.C. First Nation Chief Ed John faces historic sex charges

John served as minister for children and families under then-premier Ujjah Dosanjh

Man hit, killed by vehicle in Fraser Lake

A man was struck and killed by a motor vehicle in Fraser… Continue reading

Cullen gets $89,000 in post-MP severance

At 55, the former MP will also be eligible for an $82,000 per annum pension

Teen with cancer whose viral video urged Canadians to vote has died, uncle tweets

Maddison Yetman had been looking forward to voting in her first federal election since junior high school

Cold, stormy winter forecast across much of Canada, The Weather Network predicts

In British Columbia temperatures will be slightly above normal and precipitation will be just below normal

Cell phone tickets worse tax grab than speed limits, SenseBC says

Distracted driving statistics questioned as B.C. tickets pile up

Rowing Canada, UVic investigate celebrated coach for harassment, abuse

Lily Copeland says she felt intimidated and trapped by Williams

Cleanup in the works after tanker truck fire leads to oil spill in B.C.’s Peace region

The province said the majority of the spilled oil likely burned away in the fire.

BC VIEWS: Action needed on healthcare workplace violence

While we’ve been talking about it, the number of B.C. victims has only grown

Closing arguments begin in B.C. case launched in 2009 over private health care

Dr. Day said he illegally opened the Cambie Surgery Centre in 1996 in order to create more operating-room time

MacLean says “Coach’s Corner is no more” following Cherry’s dismissal from Hockey Night

Cherry had singled out new immigrants in for not honouring Canada’s veterans and fallen soldiers

MacKinnon powers Avs to 5-4 OT win over Canucks

Vancouver battled back late to pick up single point

Most Read