From Carbon Accounting to Net Cooling: Securing the Albedo-Carbon Double Win in Canada’s Boreal Forest

Abstract

Canada’s large-scale afforestation and reforestation efforts are central to its climate commitments, yet current policy measures a forest’s climate value almost entirely by the carbon it stores. This policy brief argues that carbon-only accounting overlooks two factors that determine whether new forests actually cool the climate: surface reflectivity (albedo) and wildfire risk. In snow-covered boreal landscapes, dark evergreen forests absorb solar radiation that open, snowy ground would otherwise reflect. In the Taiga Plains, this added heat can offset 6 to 20 percent of reported carbon gains. Dense conifer plantations also build continuous fuel loads and increase water stress, leaving stored carbon vulnerable to severe fire in drought years. As a result, carbon-only metrics can overstate the climate benefit of planted forests and of the carbon credits tied to them. Evidence shows that mixed-species forests with 25 to 40 percent deciduous trees, planted at moderate densities of 600 to 1,400 trees per hectare, deliver stronger and more durable cooling. The brief recommends a Net Cooling Standard that accounts for albedo and wildfire-related permanence alongside carbon. It also recommends making mixed, moderate-density stands the default for public investment and restoring under-stocked land only where soil moisture is reliable and fire risk is manageable. Further measures include favouring partial harvesting with prompt mixed-species replanting over clearcutting, and using spatial planning and satellite monitoring to guide management over time. Climate leadership now depends not on planting more trees, but on planting forests that deliver durable cooling.