Long-Term Socioeconomic Damages Attributable to Future Wildfire Carbon Emissions Under SSP2-4.5 and SSP5-8.5

Wildfires are an increasingly important carbon source under climate change, yet their long-term climate-mediated socioeconomic costs remain poorly quantified. Here, we used the PAGE-ICE integrated assessment model to estimate the economic damages attributable to projected wildfire CO2 emissions under SSP2-4.5 and SSP5-8.5. Wildfire emissions were introduced through paired simulations with and without these emissions, allowing their marginal effects on atmospheric CO2 concentration, radiative forcing, warming, and damages to be quantified. By 2100, wildfire emissions increased atmospheric CO2 by 50.7 ppm under SSP2-4.5 and 56.1 ppm under SSP5-8.5, producing additional warming of 0.233 °C and 0.169 °C, respectively. Although wildfire emissions were higher under SSP5-8.5, their marginal climate effects were stronger under SSP2-4.5 because additional CO2 produces a larger forcing increment when background concentrations are lower. By 2100, wildfire-attributable annual damages reached 8.11 trillion USD yr−1 under SSP2-4.5 and 6.63 trillion USD yr−1 under SSP5-8.5. Discounted cumulative damages were 144.0 and 130.3 trillion USD, respectively. Damages were unevenly distributed, with the largest absolute losses in Africa and the Middle East and India and Southeast Asia. These upper-bound estimates indicate that wildfire carbon emissions can impose substantial long-term socioeconomic costs and should be more explicitly represented in climate–economy assessments, residual-emission accounting, and sustainability-oriented fire and land-management strategies.