. In the line of fire: Consequences of human-ignited wildfires to homes in the U.S. (1992-2015)

Abstract
With climate-driven increases in wildfires, it is imperative to understand how the risk to homes is also changing. Here, we quantify the number of homes threatened, suppression costs, and ignition sources for 1.6 million wildfires in the U.S. (1992-2015). Human-caused wildfires accounted for 97% of the residential homes threatened (proximate to a wildfire) and nearly a third of suppression costs. Cumulatively, over one million homes were within human-caused wildfire perimeters in the Wildland-Urban Interface (WUI), where communities are built within flammable vegetation. An additional 43 million homes were within one kilometer. Between 1992 and 2015, the number of threatened homes doubled. The convergence of warmer, drier conditions and greater development into flammable landscapes is leaving many communities vulnerable to human-caused wildfires.