76% of Canada's wildfire emissions came from underground carbon, study finds
A new study in Geophysical Research Letters reveals that peat and soil burning accounted for 76% of emissions from Canada's 2023 wildfires, releasing three times the country's annual greenhouse gases and threatening a global carbon feedback loop.
Key Takeaways
- A new study in Geophysical Research Letters reveals that peat and soil burning accounted for 76% of emissions from Canada's 2023 wildfires, releasing three times the country's annual greenhouse gases and threatening a global carbon feedback loop.
Mentioned
Key Intelligence
Key Facts
- 176% of carbon emissions from Canada’s 2023 wildfires originated from peat and soil, not trees.
- 2The fires burned ~150,000 km² and released roughly three times Canada’s total annual reported greenhouse gas emissions.
- 3Canada holds about one-fifth of the world’s soil organic carbon, much of it in boreal peatlands.
- 4The study warns of a feedback loop: warming intensifies fires, which release deep soil carbon, accelerating climate change.
- 5The 2026 fire season is encroaching on the Hudson Bay Lowlands, the world’s second-largest peat complex.
- 6Study co-author Alemu Gonsamo says only aggressive global emission cuts can address the problem, not forest management alone.
First quantification of belowground contribution to massive boreal fires
There is no alternative than reducing the greenhouse gas emissions.
Commenting on policy implications of the study
Analysis
For climate scientists, the discovery that the vast majority of emissions from Canada's record 2023 fires came from ancient soil carbon, not trees, marks a dangerous shift. Canada's boreal regions contain a fifth of the world's soil organic carbon, and as global warming intensifies fires, these underground deposits could turn from a carbon sink into a major source of emissions, accelerating climate change.
A new study has upended assumptions about Canada's catastrophic wildfire emissions by revealing that the vast majority of carbon released during the record 2023 fire season did not come from burning trees, but from peat and soil deep underground. The research, published in Geophysical Research Letters, estimates that about 76 percent of total fire emissions originated from long‐stored soil and peat carbon, while the remaining 24 percent came from aboveground vegetation. This is the first time scientists have quantified the belowground contribution to emissions from such large boreal fires, and the finding carries profound implications for global climate projections.
President Donald Trump has cited cross‐border smoke from these fires to threaten new tariffs and blame Canada’s forest management, but study co‐author Alemu Gonsamo of McMaster University says the data point in a different direction.
Canada stores roughly one‐fifth of the world’s soil organic carbon, much of it locked in ancient peatlands and permafrost across the boreal north. When these landscapes burn—driven by hotter, drier conditions linked to climate change—that static carbon reservoir transforms into an active source of atmospheric CO₂. The 2023 fires burned an estimated 150,000 square kilometers, an area nearly the size of Tunisia, and spewed roughly three times the volume of greenhouse gases reported as Canada’s entire annual anthropogenic emissions. According to the study, the disproportionate contribution of soil carbon indicates that even if forest management practices improve, they cannot address the root problem: the deep, old carbon now exposed to combustion.
What to Watch
The study authors warn of a dangerous climate feedback loop. As global temperatures rise, wildfires become larger and more intense, which exposes and burns increasing volumes of soil carbon. That, in turn, releases more heat‐trapping gases, amplifying warming and further drying out peatlands. Canada’s 2026 fire season—already intense, with historic blazes edging into the carbon‐dense Hudson Bay Lowlands, the world’s second‐largest peat complex—dramatizes the immediacy of the risk. U.S. President Donald Trump has cited cross‐border smoke from these fires to threaten new tariffs and blame Canada’s forest management, but study co‐author Alemu Gonsamo of McMaster University says the data point in a different direction. “There is no alternative than reducing the greenhouse gas emissions,” Gonsamo stated, emphasizing that only steep global emission cuts can halt the cycle.
The findings challenge conventional carbon accounting and national emission inventories, which typically focus on aboveground biomass and neglect the massive flux from boreal soils. If future fires continue to penetrate deep organic layers, Canada and other high‐latitude nations could see their land sectors shift from net carbon sinks to net sources, undermining Paris Agreement pledges. For policymakers, the study suggests that protecting peatlands—through wetland restoration, fire breaks, or enhanced monitoring—may be as critical as curbing fossil fuel use. However, Gonsamo’s stark message underscores that no local adaptation can substitute for rapid decarbonization of the global economy. The research arrives at a pivotal moment, as countries prepare to update their nationally determined contributions. Without urgent action, the ancient carbon in Canada’s soil could become a ticking time bomb for the climate, transforming one of Earth’s largest natural buffers into a powerful amplifier of warming.
Sources
Sources
Based on 2 source articles- chroniclejournal.comTo find the root of Canada wildfire emissions , look below the trees : studyJul 27, 2026
- panow.comTo find the root of Canada wildfire emissions , look below the trees : studyJul 27, 2026
Cite This Page
"76% of Canada's wildfire emissions came from underground carbon, study finds." Climate Intelligence Brief, July 28, 2026. https://getclimatebrief.com/story/canada-wildfire-soil-carbon-emissions-76
How we covered this story
Every story in our climate coverage is assembled from multiple primary sources, cross-referenced for factual consistency, and scored along three independent dimensions: sentiment, operational impact, and source-cluster confidence. Single-source rumors and unverifiable claims do not pass our editorial gate. When a story shows "Verified by N sources" with N≥2, the development is independently corroborated; when N=1, we mark it explicitly so readers can weigh the signal accordingly.
Impact scoring uses a 1-10 scale weighted toward regulatory, financial, and operational consequence rather than coverage volume. A topic that runs in every outlet but moves no real decisions ranks lower than a niche regulatory filing that reshapes how operators in the climate space have to behave. Read our full methodology for the scoring rubric, our glossary for term definitions, and our trends index for the longitudinal view across the beat.
Sources are only linked to a story once they clear our classification pipeline at a minimum 35 percent relevance threshold. According to that methodology, reviewed July 2026, this follows multi-source corroboration standards recommended by journalism research bodies such as the Reuters Institute for the Study of Journalism.
See something wrong in this story — a wrong fact, a broken source link, a misattributed entity? Report a data issue.
| Signal on this page | What it tells you |
|---|---|
| Verified by N sources | Independent corroboration count. N≥2 is our confidence floor; N=1 is marked explicitly. |
| Impact score (1-10) | Regulatory + financial + operational weight. 8+ signals an experienced-operator action item. |
| Sentiment | Five-tier classification trained on labeled climate-specific corpora. |
| Timeline | Where applicable, the related-events sequence that contextualizes today's development. |