Estimating wildfire response costs in Alaska's changing climate

Climate change is altering wildfire activity across Alaska, with increased area burned projected for the future. Changes in wildfire are expected to affect the need for management and suppression resources; however, the potential economic implications of these needs have not been evaluated. We projected area burned and associated response costs to 2100 under relatively high and low climate forcing scenarios (representative concentration pathways (RCP) 8.5 and 4.5) using the Alaskan Frame-based Ecosystem Code (ALFRESCO) model. We calculated unique response costs for each of the four fire management options (FMOs) currently used in Alaska that vary in suppression level using federal cost data. Cumulative area burned between 2006 and 2100 across Alaska averaged 46.7M ha under five climate models for RCP8.5 and 42.1M ha for RCP4.5, with estimated cumulative response costs of $1.2-2.1B and $1.1-2.0B, respectively (3% discount). The largest response costs were incurred for the Full FMO, an area of high suppression priority, but where risks to human life and property are relatively low. Projected response costs across the century indicated that costs would be largest annually in the 2090 era (2080-2099) under RCP8.5, totaling $41.9-72.9M per year. For RCP4.5, the highest costs were projected for the 2070 era (2060-2079) and totaled $36.2-63.4M per year. The relative change in annual area burned showed larger increases for RCP8.5 than RCP4.5 across much of the state. The reported response costs are likely an underestimate and limited available data for state incurred costs suggests that realized costs could be similar to 68% higher. These findings indicate that climate change will have continued impacts on wildfire response costs across Alaska that vary among FMOs and global greenhouse gas emissions futures.