In the hills near Los Angeles, the Blue Cut Fire just ripped through 36,000 acres, taking dozens of homes along with it, spurring a major evacuation, and even requiring temporary highway closures. But the merciless flames of the Blue Cut Fire almost pale in comparison with the flood of wildfires across the Golden State, and the West at large, in an era when the wildfire season is growing longer and more aggressive every year. Climate change is the reason why, and researchers are discovering that the cost of wildfires may be bigger than we imagined: They’re tracking deadly “smoke waves” that sweep the landscape, causing serious respiratory health problems.