“Using two decades of high-resolution satellite-derived measurements of fire severity and fire smoke particulate matter across California, we assess the causal effect of low-severity wildfire – a proxy for prescribed burning – on subsequent wildfire activity and air quality…

We find that locations ‘treated’ with low severity fire see an immediate 92% reduction in the probability of very high severity wildfires in the same location, with detectable reductions in high-severity fire risk lasting up to a decade and detectable up to 5 km from the treated locations. We estimate that the future benefits of low-severity fuel “treatments”, in terms of reduced smoke from severe fires, substantially outweigh the costs of the smoke produced in the initial treatment fires, with benefit-cost ratios that exceed six after a decade even under a high discount rate (> 6%).

Benefits and costs rise roughly linearly with the amount of area treated. We estimate that a policy of 500 thousand acres of low-severity treatments per year in CA, sustained for a decade, would have reduced cumulative smoke PM2.5 concentrations by roughly 23% by the end of the period.”

From EarthArXiv.