Climate Change Limits Controlled Burns to Prevent Wildfires in Western United States

Shifting weather patterns caused by climate change are restricting the ability to carry out controlled burns in the western United States, as warned by a new study.

Controlled burns, also known as prescribed fires, are an essential method for disposing of combustible vegetation and preventing larger, uncontrolled fires. However, these burns can only be done under specific conditions, known as burn windows, when the undergrowth is neither too dry nor too damp to burn effectively.

The study, conducted by scientists from the University of California and Washington State University, used computer modeling to examine how climate change might affect the number of suitable burn windows in the future. They found a clear trend of decreasing suitable days, with the number of lost days ranging from 15 to 30 per year in the southern part of the region studied. Although there were localized areas with small increases in suitable days, those gains may only be temporary due to the eventual drying out of vegetation.

The findings suggest a need for shifting policies and an expanded year-round fire management workforce to address the shrinking burn windows. Additionally, policymakers will need to consider the trade-offs of increased smoke emissions from controlled burns to reduce the risk of extreme air pollution episodes resulting from catastrophic wildfire smoke events.

‘Acceptable trade-offs’

The study suggests that winter could become a more favorable time for prescribed burns in certain areas. This supports calls for an expanded year-round fire management workforce that can handle both wildfires and the management of controlled burns. However, policymakers will also need to consider the increased likelihood of low-level stagnation, a combination of wind and rain patterns, which may limit burn windows by causing smoke to affect local communities.

The study primarily focuses on the western United States, but it is important to note that wildfires have been devastating areas worldwide, from Greece to Indonesia. Australia, for example, has already conducted controlled burning to prepare for the upcoming bushfire season.

The findings of this study, published in Communications Earth and Environment, highlight the urgency of addressing the impact of climate change on controlled burns and the need for comprehensive fire management strategies.