How will future climate change affect prescribed fire operations across the conterminous United States?

Abstract:

The use of prescribed fire as an ecosystem management tool is increasing across the United States, with more than 50% of all area burned and 80% of the total number of burns occurring under prescription in 2019. However, as the climate warms over the coming decades, we can expect not only rising surface temperatures, but also hydrological changes—including in the duration and severity of precipitation events and droughts—which are bound to impact fuel loads and fuel moisture. These two fuel characteristics dictate how fire moves through the landscape. In many fire-dependent ecosystems, where prescribed burning is used as a land management tool, associated changes in fire behavior will require adjustments to management strategies in order to ensure that they remain effective. Here we examine how future climate change could impact the opportunities for and efficacy of prescribed fire use. We combine climate projections from the CMIP6 multi-model archive with information about prescription thresholds for different ecosystems across the conterminous United States to compute the number of “burn days”—or days during which meteorological conditions allow for safe and effective application of prescribed fire—for present day as well as future climate conditions. While prescription thresholds become more limiting in some regions due to rising temperatures and drier fuels, in other regions they shift to other times of the year that are not currently being considered for burning, but may present opportunities to expand burning operations.