Canada wildfire emissions study: 75% of 2023 fire CO2 came from soil and peat, not trees

A new study from McMaster University found that about three-quarters of the planet-warming emissions from Canada's record 2023 wildfires came from burning soil and peat, not trees. The research, published in Geophysical Research Letters, estimates the fires released roughly as much CO2 as Canada's total annual greenhouse gas emissions. The findings highlight a growing risk as fires encroach on carbon-rich peatlands like the Hudson Bay Lowlands. Lead author Alemu Gonsamo says better forest management alone cannot solve the problem, only steep cuts to global emissions can. The study underscores the importance of accounting for below-ground carbon stocks in climate models and policy.