The unaccounted costs of slash pile burning: Carbon emissions and PM2.5 exposure in central Oregon, USA

Abstract

Slash pile burning is a commonly used practice for disposing of unmerchantable forest residues resulting from forest thinning and timber harvest to lower wildfire intensity and risk, but can also generate significant greenhouse gas (GHG) and particulate matter (PM2.5) emissions. These effects of pile burning generate costs that are rarely taken into account in forest management budgets, expenses that could significantly affect decision-making if considered. This study quantifies those external costs of pile burning in the Deschutes National Forest in central Oregon, relating modeled emissions from 85 pile burns in 2022 to population exposure. We estimate that the piles burned produced approximately 61,413 metric tons of CO2, 104 metric tons of CH4, and 250 metric tons of PM2.5, resulting in costs ranging from $2.4 million to $116 million in combined local health and global climate costs, depending on the assumptions used. While pile burning can reduce wildfire risk, our results highlight the unaccounted effects of pile burning, suggesting a potential benefit from considering alternative disposal strategies, such as the production of bioenergy or biochar. These findings emphasize the importance of integrating the external costs of pile burning into forest management decisions and demonstrate an adaptable framework for evaluating the external costs of biomass disposal in other regions.

Citation

Axlund, Caleb E.; Suter, Jordan F.; McCollum, Daniel W. 2025. The unaccounted costs of slash pile burning: Carbon emissions and PM2.5 exposure in central Oregon, USA. Trees, Forests and People. 22: 101081.