Evaluating Future Global Wildfire Potential Using the Keetch-Byram Drought Index

Climate is an important factor for wildfire ignition and spread. Persistent drought can lead to decreased water availability for vegetation which increases the potential of wildfire disturbance. Various general circulation models (GCMs) have projected a drying trend for many mid-latitudes as well as other regions of the globe due to the greenhouse effect. Besides significantly changing ecosystem structure and composition, hotter and drier climates will alter wildfire frequency and severity in these regions. This study evaluates future wildfire potential in response to changes in average and extreme climate conditions by analyzing the Keetch-Byram Drought Index (KBDI). The observed maximum temperature and precipitation and projected changes at the end of this century (2070-2100) by general circulation models (GCMs) were used to calculate the KBDI for present and future climates, respectively. For the projected change in average climate conditions, future wildfire potential increases significantly in the future in several global regions. Fire potential moves up by one level in these regions, from currently low to future moderate potential or from moderate to high potential. Fire seasons become a few months longer. The increase in fire potential is more significant for the projected change in extreme climate conditions. The results suggest dramatic increases in wildfire potential that will require increased resources and management efforts for disaster prevention and recovery in the future.