It was a smell that invoked a memory. Both for Emily Kuchlbauer in North Carolina and Ryan Bomba in Chicago. It was smoke from wildfires, the odor of an increasingly hot and occasionally on-fire world. “It’s been very apocalyptic feeling, because in California the dialogue is like, ‘Oh, it’s normal. This is just what happens on the West Coast,’ but it’s very much not normal here,” Kuchlbauer said. As Earth’s climate continues to change from heat-trapping gases spewed into the air, ever fewer people are out of reach from the billowing and deadly fingers of wildfire smoke, scientists say. Already...