Fire fighting

In the U.S., wildland firefighters are able to stop about 98% of all wildfires before the fires have burned even 100 acres. That may seem comforting, but decades of quickly suppressing fires has had unintended consequences. Fires are a natural part of many landscapes globally. When forests aren’t allowed to burn, they become more dense, and dead branches, leaves and other biomass accumulate, leaving more fuel for the next fire. This buildup leads to more extreme fires that are even harder to put out. That’s why land managers set controlled burns and thin forests to clear out the undergrowth. However, fuel accumulation isn’t the only consequence of fire suppression. Fire suppression also disproportionately reduces certain types of fire. In a new study, my colleagues and I show how this effect, known as the suppression bias, compounds the impacts of fuel accumulation and climate change. What happened to all the low-intensity fires? Most wildfires are low-inten...

It can be tempting to think that the recent wildfire disasters in communities across the West were unlucky, one-off events, but evidence is accumulating that points to a trend. In a new study, we found a 246% increase in the number of homes and structures destroyed by wildfires in the contiguous Western U.S. between the past two decades, 1999-2009 and 2010-2020. This trend is strongly influenced by major fires in 2017, 2018 and 2020, including destructive fires in Paradise and Santa Rosa, California, and in Colorado, Oregon and Washington. In fact, in nearly every Western state, more homes and buildings were destroyed by wildfire over the past decade than the decade before, revealing increasing vulnerability to wildfire disasters. What explains the increasing home and structure loss? Surprisingly, it’s not just the trend of burning more area, or simply more homes being built where fires historically burned. While those trends play a role, increasing home and structure l...