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

Comments are closed

Just Posted

Hotel workers gather in Victoria, demand right to return to work

Workers also asking the government to make sure employers don’t use pandemic to replace them

UPDATE: Vancouver Island skydiving community mourns loss of one of its own

James Smith, 34, of Victoria, dies in Nanoose Bay incident

World’s biggest Nanaimo bar confirmed, but it’s not in Nanaimo

Two Ontario children set the bar high with successful biggest Nanaimo bar world record attempt

Tofino beachgoers ‘horrified’ by jet-skis in surf zone

Online video of Sea-Doo operating within 50 metres of neophyte surfers causes alarm

Langford teens reunited with family after rescue near Chemainus

Friends spent night in missing truck, spotted by RCMP helicopter

Horrifying video shows near head-on collision on Trans Canada

The video was captured on dash cam along Highway 1

Elizabeth May endorses Furstenau in BC Greens race

Former federal party leader backs Cowichan Valley MLA

Fraser Valley woman complains of violent RCMP takedown during wellness check

Mounties respond that she was not co-operating during Mental Health Act apprehension

B.C. sees 12 new COVID-19 cases, no new deaths

Three outbreaks exist in health-care settings

Lost dog swims Columbia River multiple times searching for home

The dog was missing from his Castlegar home for three days.

COVID-19: B.C. promotes video-activated services card

Mobile app allows easier video identity verification

Nanaimo RCMP arrest four, seize drugs and $19K in “problem house” search

Home was subject of numerous complaints of drug trafficking, theft and disturbances

Victoria woman loses $2,500 to scammer spoofing VicPD phone number

VicPD warns against sharing personal information, sending money to strangers

Most Read