Blame the increase in frequency and severity of wildfires in California on drought and climate change. As the number of fires goes up each year, so does the costs of suppression. Those firefighting costs have also increased because more people are living in what fire scientists call the “urban-wildland interface.” “It just shows you the cost escalation because of just the way we’ve chosen to live in our landscape,” says Scott Stephens, Professor of Fire Science at UC Berkeley and co-director of the Center for Fire Research and Outreach at the university.