1. Robust projections of future fire probability for the conterminous United States
- Author
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J. Morgan Varner, J. Kevin Hiers, Peng Gao, Ting L. Lei, John A. Kupfer, Michael C. Stambaugh, and Adam J. Terando
- Subjects
Environmental Engineering ,010504 meteorology & atmospheric sciences ,Ensemble forecasting ,Fire regime ,Land use ,Climate Change ,Global warming ,Climate change ,010501 environmental sciences ,01 natural sciences ,Pollution ,Fires ,United States ,Wildfires ,New England ,Greenhouse gas ,Climatology ,Range (statistics) ,Environmental Chemistry ,Environmental science ,Waste Management and Disposal ,Futures contract ,0105 earth and related environmental sciences ,Probability - Abstract
Globally increasing wildfires have been attributed to anthropogenic climate change. However, providing decision makers with a clear understanding of how future planetary warming could affect fire regimes is complicated by confounding land use factors that influence wildfire and by uncertainty associated with model simulations of climate change. We use an ensemble of statistically downscaled Global Climate Models in combination with the Physical Chemistry Fire Frequency Model (PC2FM) to project changing potential fire probabilities in the conterminous United States for two scenarios representing lower (RCP 4.5) and higher (RCP 8.5) greenhouse gas emission futures. PC2FM is a physically-based and scale-independent model that predicts mean fire return intervals from both fire reactant and reaction variables, which are largely dependent on a locale's climate. Our results overwhelmingly depict increasing potential fire probabilities across the conterminous US for both climate scenarios. The primary mechanism for the projected increases is rising temperatures, reflecting changes in the chemical reaction environment commensurate with enhanced photosynthetic rates and available thermal molecular energy. Existing high risk areas, such as the Cascade Range and the Coastal California Mountains, are projected to experience greater annual fire occurrence probabilities, with relative increases of 122% and 67%, respectively, under RCP 8.5 compared to increases of 63% and 38% under RCP 4.5. Regions not currently associated with frequently occurring wildfires, such as New England and the Great Lakes, are projected to experience a doubling of occurrence probabilities by 2100 under RCP 8.5. This high resolution, continental-scale modeling study of climate change impacts on potential fire probability accounts for shifting background environmental conditions across regions that will interact with topographic drivers to significantly alter future fire probabilities. The ensemble modeling approach presents a useful planning tool for mitigation and adaptation strategies in regions of increasing wildfire risk.
- Published
- 2021