Wildfires in Canada and Greenhouse Gas Emissions

By Gloria Dickie

According to a study published in Nature, wildfires that swept across Canada in 2022 released more greenhouse gases than several of the largest emitting countries.

At 647 megatonnes, emissions from last year’s wildfires surpassed those of seven out of the ten top national emitters, including Germany, Japan, and Russia. Only China, India, and the United States emitted more carbon during this period, positioning Canada’s wildfires as the fourth largest emitter globally.

In the last decade, typical emissions from Canadian wildfires ranged from 29 to 121 megatonnes. However, climate change is resulting in drier and hotter conditions, promoting extreme wildfires. In 2023, fires scorched 15 million hectares (about 37 million acres), approximately 4% of Canada’s forests.

The findings raise concerns about relying on forests as long-term carbon sinks when they could be exacerbating the greenhouse gas problem through wildfires. This suggests that the current global carbon budget may be based on faulty calculations.

Brendan Byrne, atmospheric scientist at NASA’s Jet Propulsion Laboratory and study author, stated, “If our goal is to limit atmospheric carbon dioxide, we need to adjust how much carbon we emit based on absorption rates.”

The unusually high temperatures that Canada experienced in 2023 may become more common by the 2050s, potentially leading to severe fires in Canada’s 347 million hectares (approximately 857 million acres) of woodlands that play a critical role in carbon storage.

It’s important to note that worsening wildfires and their carbon emissions are not included in Canada’s annual greenhouse gas inventory. Carbon from human sources—like industrial activities—is counted, but emissions from natural disturbances like wildfires or insect outbreaks are excluded according to the country’s 2021 Nationally Determined Contribution Strategy.

In summary, Byrne said, “The atmosphere sees this carbon increasing, no matter how we set up our accounting system.”