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

West Kootenay SAR crews rescue injured mountain biker near Rossland

Crews were called in to help after the biker seriously injured himself at around noon Saturday

City of Rossland looks to implement mail ballot voting

City said new procedure could make voting easier and more accessible for residents

Suspected fentanyl and cocaine seized during RCMP search in Castlegar

Two men were taken into police custody during the search warrant

Morning start: This is the fastest growing city in the Kootenays

Here is your Kootenays’ morning start for Monday, May 25

A second wave of COVID-19 is probable, if history tells us anything

B.C.’s top doctor says that what health officials have learned this round will guide response in future

B.C. First Nation adopts Dr. Bonnie Henry, names her ‘one who is calm among us’

Gitxsan officially adopts the provincial health officer in a May 22 ceremony

Kelowna man charged with harming a hamster

The 20-year-old Kelowna man faces several animal cruelty charges

High tech fish transport system set up to ‘whoosh’ salmon past Big Bar landslide

Fish will spend roughly 20 seconds inside the system, moving at roughly 20 metres per second

Trudeau to seek 10 days of paid sick leave for Canadian workers, says talks are ongoing

Paid sick leave is key to keeping COVID-19 spread under control, prime minister says

Snowbirds jets will not be leaving Kamloops, just yet

The Snowbirds have been in Kamloops since May 17 when a plane crashed killing Capt. Jennifer Casey

COVID-19 checkpoints ‘up to them,’ Bonnie Henry says of remote B.C. villages

Support local tourism economy, but only if you’re invited in

Vancouver Island hasn’t seen a new homegrown case of COVID-19 in two weeks

Island’s low and steady transmission rate chalked up to several factors

Most Read