Wildfire Smoke Becomes a Recurring Summer Hazard
Wildfire smoke has become an increasingly familiar feature of summer across parts of North America, joining heat waves, beach weather, and other seasonal markers. This week, smoke from fires in Minnesota and western Ontario spread across the Midwest, Northeast, and sections of Canada, turning skies orange and prompting widespread air quality alerts.
Canada remained the main source of the smoke, with 119 wildfires classified as out of control as of Friday afternoon. Intense burning carried smoke high into the atmosphere, where the jet stream transported it east. Chicago and Detroit recorded the world’s worst air quality on Friday, while New York and Washington, DC, also ranked among the ten most polluted major cities.
Public health officials advised residents in affected areas to limit outdoor activity and reduce exposure to fine particles in wildfire smoke. Some communities were expected to receive cleaner air over the weekend, but ongoing fires could produce additional smoke episodes later in the summer.
Scientists have linked rising wildfire risks to warmer conditions associated with greenhouse gas emissions from coal, oil, and natural gas. The recent orange skies recalled Canada’s record-setting 2023 wildfire season, when smoke repeatedly reached the eastern United States. Similar conditions have occurred in recent years in Spain, Australia, and California.
A Nature study cited in the report projects that, without substantial reductions in fossil-fuel use, wildfire smoke could contribute to 71,420 excess US deaths annually by mid-century, representing a 73 percent increase from levels in the 2010s. Researchers also estimate that smoke-related health problems could cause as many as 1.9 million US deaths between now and mid-century. The projections indicate that distant wildfire smoke may become a more frequent public health concern if global temperatures continue rising and fire seasons grow steadily longer across multiple regions worldwide.