Scenarios for future wildfire risk in California: links between changing demography, land use, climate, and wildfire

Over 21,000 future California residential wildfire risk scenarios were developed on a monthly 1/8 degrees grid, using statistical wildfire models. We explore interactions between two global emissions scenarios, three climate models, six spatially explicit population growth scenarios derived from two growth models, and a range of parameters defining properties' vulnerability to loss. Scenarios are evaluated over two future time periods relative to historic baselines. We also explore effects of spatial resolutions for calculating household exposure to wildfire on changes in estimated future property losses. Our goal was not to produce one authoritative set of future risk scenarios but rather to understand what parameters are important for robustly characterizing effects of climate and growth on future residential property risks. By end of century, variation across development scenarios accounts for far more variability in statewide residential wildfire risks than does variation across climate scenarios. However, the most extreme increases in residential fire risks result from combining high-growth/high-sprawl scenarios with the most extreme climates considered here. Case studies for the Bay Area and the Sierra foothills demonstrate that, while land use decisions profoundly influence future residential wildfire risks, effects of diverse growth and land use strategies vary greatly around the state. Copyright (c) 2014 John Wiley & Sons, Ltd.