Climate change and growth scenarios for California wildfire

Large wildfire occurrence and burned area are modeled using hydroclimate and landsurface characteristics under a range of future climate and development scenarios. The range of uncertainty for future wildfire regimes is analyzed over two emissions pathways (the Special Report on Emissions Scenarios [SRES] A2 and B1 scenarios); three global climate models (Centre National de Recherches Météorologiques CM3, Geophysical Fluid Dynamics Laboratory CM2.1 and National Center for Atmospheric Research PCM1); three scenarios for future population growth and development footprint; and two thresholds for defining the wildland-urban interface relative to housing density. Results were assessed for three 30-year time periods centered on 2020, 2050, and 2085, relative to a 30-year reference period centered on 1975. Increases in wildfire burned area are anticipated for most scenarios, although the range of outcomes is large and increases with time. The increase in wildfire burned area associated with the higher emissions pathway (SRES A2) is substantial, with increases statewide ranging from 36% to 74% by 2085, and increases exceeding 100% in much of the forested areas of Northern California in every SRES A2 scenario by 2085. Climatic Change (2011) 109 (Suppl 1):S445–S463 DOI 10.1007/s10584-011-0329-9 Electronic supplementary material The online version of this article (doi:10.1007/s10584-011-0329-9) contains supplementary material, which is available to authorized users. A. L. Westerling (*) : S. R. Shrestha University of California, Merced, 5200 N. Lake Rd, Merced, CA 95343, USA e-mail: [email protected] B. P. Bryant Pardee RAND Graduate School, The RAND Corporation, Santa Monica, CA, USA H. K. Preisler USDA Forest Service Pacific Southwest Research Station, Albany, CA, USA T. P. Holmes USDA Forest Service Southern Research Station, Research Triangle Park, NC, USA H. G. Hidalgo School of Physics and Center for Geophysical Research, University of Costa Rica, San Jose, Costa Rica T. Das CH2MHILL, Inc., San Diego, CA 92101, USA