Skies over Toronto turned an apocalyptic orange on Wednesday morning as smoke from more than 800 wildfires raging across Canada poured south, blanketing cities from the US Midwest to the East Coast in a toxic haze. Satellite images show wind carrying the smoke south-east from Ontario across to New York State and Boston, while Detroit, Toronto and Minneapolis were ranked as having the worst air quality in the world by IQAir, a company that tracks global pollutants. In Michigan, visibility degraded so severely that the 26,372-foot Mackinac Bridge was essentially invisible, forcing drivers to slow, according to UpNorthLive.
The smoke is the result of 858 wildfires actively burning across Canada, nearly 200 of them in Ontario, according to the Canadian Interagency Forest Fire Centre. Along the northern edge of Minnesota, 17 fires are still burning, and an emergency declaration is in place to help mobilise suppression efforts. In Ontario, the fires are north of Lake Superior in more remote parts of the province, but within or close to national parks and First Nation communities. Six communities are under evacuation orders with reports of damage to properties. Grand Council Chief Linda Debassige said in a statement that the remote Namaygoosisagagun First Nation in northern Ontario was "devastated by an unexpected and fast-moving wildfire" that severely damaged homes and community buildings.
“Wildfire smoke from over 800 Canadian fires turns skies orange and chokes US and Canadian cities.”
The hazardous smoke contains a mixture of very small polluting particles like PM2.5 and nitrogen dioxide. "These particles when they get into our system get all the way down into our lungs, all the way down to our tiny breathing tubes and… they cause inflammation," said Jim McDonald, New York State Department of Health commissioner, in a public address video on social media. The smoke can exacerbate existing respiratory, heart, kidney and eye conditions. Residents in New York, Boston and Toronto have been encouraged to avoid "strenuous activity" over potential health impacts.
The National Interagency Fire Centre in the US and Natural Resources Canada had predicted the surge in wildfires due to sustained hot weather at the end of June across northern Ontario and below average rainfall. This hot weather is being caused by a heat dome – an area of high pressure that traps warm air and smoke underneath. Extreme heat draws moisture out of soils and plants, drying vegetation that acts as fuel for fires. About half the smoke generated from wildfires between 1997 and 2020 could be linked to climate change, according to Loretta Mickley, an atmospheric chemist at Harvard University. "If we zero in more recently from 2010 to 2020, those numbers increase," she told USA Today. With wildfires worsening each year by acreage burned, the ominous scenes that once were rare are becoming a familiar sight in warmer months.