People Cause Most U.S. Wildfires

Humans—not lightning—trigger most wildfires in the United States. According to a study published in February 2017 in the Proceedings of the National Academy of Sciences, 84 percent of the blazes that firefighters were called to fight between 1992 and 2012 were ignited by people. Some common ways that people start fires include discarding cigarettes, leaving campfires unattended, and losing control of prescribed burns or crop fires. Sparks from railroads and power lines, as well as arson, also routinely cause wildfires.