The Pacific Northwest is facing its worst fire season in more than 30 years. Scientists say drought, extreme heat and climate change are making wildfire seasons longer, more frequent and more destructive across the western United States. “The homes, the communities, they’re just not simply prepared for fire,” says Paul Hessburg, former senior research ecologist at the U.S. Forest Service and professor of fire and landscape ecology at the University of Washington. Hessburg walks us through the history of the region, from the controlled fires practiced by Indigenous peoples before European settlement to present-day ecologically unsound factors including “accidental ignitions, dense forests, the wrong kinds of fuels on the ground [and] rapidly changing climate.”