Researchers: Humans Responsible For Majority Of US Wildfires

People sparked most US wildfires in recent decades, causing longer fire seasons and increasing the amount of scorched earth, according to a new study published Monday. Researchers found that humans caused 84 percent -- or four out of five -- of the total 1.5 million wildfires studied between 1992 and 2012. Lightning accounted for the rest. In addition, human actions tripled the length of the fire season during those two decades and were responsible for 44 percent of the total acreage burned, researchers reported in Proceedings of the National Academy of Sciences.