The amount of area burned per year in forests across the western United States has been increasing over the past half‐century alongside warmer and drier weather conditions in the summer months, or the “fire season”. These conditions lead to a number of dangerous impacts on ecosystems and society, with challenges for fire suppression. A research team including scientists from the Climate Impacts Research Consortium (CIRC) and the California-Nevada Climate Applications Program (CNAP), both CPO Regional Integrated Sciences and Assesssments (RISA) teams, finds that increasing widespread wildfire danger is set to add additional strain to national fire management resources.
The results are published as an early online release in Geophysical Research Letters.
Widespread fire danger and fire activity during active fire seasons can overwhelm fire suppression resource capacity, limiting the effectiveness of managing fires and potentially increasing fire impacts. As a proxy for the strain on fire suppression resource availability, the authors analyzed synchronous fire danger—fire weather indices exceeding the local 90th percentile across at least 40% of forested land. The study shows a strong link between interannual variability in the number of days with synchronous fire danger across western United States forests and the number of days with high strain on national fire suppression resources. The research team found a 25‐day increase in the annual number of days of regionally widespread (or synchronous) fire danger and connected fire resource strain over the past four decades. The team projects a doubling of such days by the mid‐21st century. These findings suggest that—if fuel availability, ignition patterns, and land management approaches do not change substantially over time—climate change may continue to overburden fire management efforts across the region, requiring careful strategy when fire resources are strained in future dangerous, prolonged fire seasons.
