Fighting Fire with Fire: Carbon-Negative Heat Production in Canada's North Using Pyrolysis of Fire-Killed Trees

Heating buildings in Northern communities is carbon-intensive and existing low-carbon technologies are ill-suited for northern conditions. Pyrogenic carbon capture and storage (Pyro-CCS), which heats biomass anoxically to produce fuels and biochar, could provide low-carbon heat in this climate. We calculate the carbon footprint of Pyro-CCS in Northwest Territories (NWT), Canada using wood-pellets and a novel feedstock of fire-killed trees and compare these to conventional heat sources. We find that Pyro-CCS emits 40.9 g CO₂ eq. MJ^-1 using wood-pellets and sequesters -10.3 g CO₂ eq. MJ^-1 using fire-killed trees, compared to emissions of 59.7 g CO₂ eq. MJ^-1 for wood-pellet combustion, and 79.4-89.9 g CO₂ eq. MJ^-1 for fossil fuels. Scenarios suggest that widespread Pyro-CCS could allow the heating sector in NWT to achieve 1.5°C-aligned emissions reductions targets using only 121 km² of burned forests annually (∼ 2% of annual burn in NWT). We propose five policies to promote Pyro-CCS and transform NWT into a model for northern decarbonization.