Only 3 countries produced more emissions than Canada's wildfires last year, study finds

The wildfires that ripped through Canada's boreal forest last year produced more carbon emissions than the burning of fossil fuels in all but three countries, a new study has found.

The study, published Wednesday in the scientific journal Nature, calculated that, at 647 megatonnes, the carbon released in last year's wildfires exceeded those of seven of the ten largest national emitters in 2022.

Only India, China and the United States released more carbon.

"The carbon emitted by fires in Canada was far outside the previous record," said Brendan Byrne, an atmospheric scientist at NASA and the lead author of the paper. 

The study concluded that widespread hot and dry weather was a principal driver of the fires spreading. 

It also found that such temperatures are likely to be typical within three decades, by the 2050s, raising further concern about the long-term viability of Canada's boreal forest as a "carbon sink" — which absorbs more carbon than it releases into the atmosphere.

Emissions from wildfires are not taken into account by countries as they strive to reach their Paris Agreement targets to keep temperatures from rising more than 1.5 C above pre-industrial levels, Byrne said. 

"If our goal is really to limit the amount of carbon dioxide in the atmosphere, we need to make adaptations into how much carbon we are allowed to emit through our economy, corresponding to how much carbon is being absorbed or not absorbed by forests," Byrne said. 

CBC News has reached out to Environment and Climate Change Canada for comment.

When asked last year about Canada's policy of not including wildfire emissions in its totals, Environment and Climate Change Minister Steven Guilbeault said Canada uses the methodology of the Intergovernmental Panel on Climate Change (IPCC) to calculate emissions.

"It's together globally that we decide on what are the best practices to measure and report emissions," he said. "We will follow the guidelines of the IPCC as they continue evolving over time."

WATCH | NASA atmospheric scientist on the wildfire emissions:

2023 wildfires in Canada emitted enough carbon to rival entire countries

3 months ago

Duration 1:08

If the carbon output from Canadian wildfires in 2023 were compared to the national outputs of countries around the world, it would rank fourth behind the U.S., China and India, says NASA atmospheric scientist Brendan Byrne.

'Fire coast to coast'

Another study last week, also in Nature, documented the conditions that led to the wildfires. Those include the unusually early snowmelt, persistent drought conditions in Western Canada, and a hot and dry June in Eastern Canada, according to the study.

The fire weather index — which measures factors that make fire more likely, such as dry conditions and heat, were the highest since first recorded in 1940, said Piyush Jain, a research scientist with the Canadian Forest Service and the lead author of that study.

"We literally saw fire coast to coast," Jain said, citing fires on Vancouver Island and Halifax.

"It really was extraordinary, the scale."

Jain said that the 2024 season is also now far above average in terms of areas burned, according to preliminary data. 

A State of Wildfires report produced in the U.K. earlier this month calculated that if we don't cut emissions, the type of extreme wildfire season witnessed in Canada in 2023 will be six to 11 times more likely by 2100.