Mitigation of US wildfires through prescribed burning revealed by four decades of satellite data

In the United States, forest and fire management communities ignite and manage fires under controlled conditions, known as prescribed burning, to prevent the occurrence of large wildfires. Studies on prescribed fires often lack long-term data to validate their effectiveness in reducing wildfires. Using 38-years of satellite observations of burned area, we assess the effect of prescribed fires on wildfires, and the impact on air quality using satellite observations of carbon monoxide (CO) as proxy. We demonstrate evidence of a clear, location-specific causality between prescribed burning and wildfire behavior: 1) areas have fewer wildfires following months of prescribed burning, and 2) prescribed burning helps stop the spread of new wildfires for at least five years, as burned areas act as barriers to fire propagation. Across the western US, we observe minor impact on air quality degradation for areas where both prescribed and wildfires occur. While areas with only wildfires and no prescribed conducted, experience significant air quality degradation. More prescribed burning in the eastern US leads to more significant air quality degradation than those from wildfires, however the overall air pollution levels remain much lower than in the western US. As wildfires are projected to increase in the coming decades, prescribed burning will be crucial in mitigating and reducing the risk of large wildfires and their adverse impact on air quality.