Hot, dry weather and human carelessness have led to a huge burnt area — and to choking haze affecting millions of people.
Smoke from wildfires raging in eastern Canada has been filling lungs and turning skies orange across the northeastern United States, most dramatically in New York City and the surrounding area, for the past week. Although people in western North America have gotten used to such conditions in the past few years, they are unusual in the eastern part of the continent — so what is causing this extraordinary fire season? Read more in Nature.