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

Vernon man wanted by police

RCMP ask for public’s help in locating man charged with aggravated assault

Telephone lines down at 18 Avenue in Vernon

Vernon Fire Rescue Services have reopened 18th Ave after clearing the lines from the road

Back-to-back car fires in Vernon

Two SUVs engulfed in flames snuffed by firefighters in two weeks on Commonage Road

Vernon Panthers QB named provincial MVP

Zack Smith becomes third Panthers football player in past four years to take top player honour

Armstrong cannabis producer sells out of first batch

Initial batch tested at 22.6 per cent THC levels

Kelowna remembers road crash victims

The eighth annual the World Day of Remembrance for Road Crash Victims was held in Kelowna

Woman calls 911 to say she was late for train, asks Ontario police for ‘emergency ride’

Peel Regional Police received more than 180,000 improper calls so far this year

It could take you 218 years to save up for a house in this B.C. neighbourhood

It would take 27 years in the most affordable city in the Lower Mainland

Historical Society branch works to preserve Summerland history

Names proposed for roundabouts to honour local heritage

NeighbourLink Summerland coordinates Christmas dinner matchup

This Christmas will be sixth annual community event

Princeton council votes to open parts of KVR to motorized vehicles

Sections of the KRV trail through Princeton will be opened next year… Continue reading

New CP Rail tracks needed before building Salmon Arm underpass

‘Pretty big area’ of downtown to be affected by construction

‘Actors can play any roles’: Debate over ‘colour-blind’ casting after Victoria lawsuit

Tenyjah Indra McKenna filed a complaint over racially-motivated casting

Salmon Arm Tim Hortons intersection bumped from traffic circle plan

Traffic circles still planned for two city intersections with four-way stops

Most Read