Why might northern wildfires release more carbon?

Smouldering soils and ancient carbon make northern fires worse for climate

Recent reconstructions of wildfire emissions in boreal and Arctic regions suggest that current inventories are missing a substantial fraction of carbon released during some northern fires. Researchers working on Swedish fires and broader northern boreal events found that when peat and organic‑rich soils burn or smoulder, they emit carbon stores that have been locked away for centuries or millennia — carbon that standard fire inventories and many climate models do not fully account for.

Studies combined field observations, satellite data and emission reconstructions to separate flaming combustion from prolonged smouldering of organic soils. Smouldering fires burn at lower temperatures but persist far longer and can oxidize deep layers of peat and organic material. Those deep burns liberate older, previously sequestered carbon and can sustain emissions well after the headline blaze has passed. Because many monitoring systems focus on short‑lived flaming signatures, they can under‑detect the slow, diffuse emissions from smouldering ground layers.

Why this matters

• Underestimated emissions: climate budgets that rely on conventional wildfire inventories may miss long‑lived soil combustion and the ancient carbon it releases.
• Feedback risk: releasing older carbon from peat and permafrost can accelerate atmospheric greenhouse gas concentrations, increasing warming and the likelihood of further fires.
• Policy and mitigation: improved monitoring, accounting for smouldering emissions, protecting peatlands, and revising models are needed to close the gap.

Next actions include expanding on‑the‑ground measurements, integrating smouldering signatures into satellite retrievals, and updating fire‑emission modules in climate models so northern wildfire contributions to global carbon budgets are more accurate.