What you need to know about Canadian wildfires and US air quality
As Canada grapples with one of its worst wildfire seasons in decades, heavy smoke from Quebec drifted into the American Midwest on Tuesday, a day after NASA said it had crossed the Atlantic all the way to Europe.
Canada is battling an extraordinary outbreak of wildfires across the country that has displaced tens of thousands of people from their homes, heightened global warming concerns and sent suffocating smoke up and down the east coast of the United States this month. from New York City, past Washington and as far west as Minnesota.
How has the smoke affected air quality in the American Midwest?
On Tuesday, wildfires in Canada worsened air quality in Chicago, Detroit and Milwaukee, among others. According to IQAir, a Swiss air quality technology company, the air quality index in Chicago reached 209 by noon on Tuesday, the worst reading of any major city in the world that day.
In Green Bay, Wisconsin, the index was 175; in Grand Rapids, Michigan, it rose to 255. Any reading above 100 on the index is a warning for people with respiratory illnesses to take precautions.
Such figures are rare in the United States; an index above 200 is considered ‘very unhealthy’ for everyone and an index above 300 is labeled ‘dangerous’. In early June, there were readings above 400 on the East Coast.
How long will the smoke linger this time?
On Tuesday, a storm system just northeast of the Great Lakes created a counterclockwise wind, sending smoke from wildfires in Canada moving south into the Midwest. As the system makes its way east, the smoke is likely to shift east as well. However, the storm system was expected to move out of the region fairly quickly.
Nevertheless, hazy and smoky skies are likely to be a regular occurrence across much of the United States this summer.
How many fires are burning in Canada?
On Tuesday, the Canadian Interagency Forest Fire Center reported 485 active fires across the country, 257 of which were out of control.
As of June 7, fires had already scorched more than 9.8 million hectares of forest in Canada this year — more than 10 times the acreage burned at this time last year, officials say.
How far has Canadian wildfire smoke spread?
The fires in Canada are so intense that NASA said Monday that satellite images showed smoke from northern Quebec had traveled all the way to Europe, darkening skies in southwestern Europe and drifting over parts of northern Portugal, Spain and France.
How do the wildfires affect air quality and summer fun?
In CanadaEnvironment Canada warned on Tuesday that air quality could deteriorate overnight in Toronto, Canada’s largest city and financial capital. Poor air quality has also plagued Montreal, where the sun has appeared as a lurid red dot in recent days.
Poor air quality led to the cancellation of an Ironman triathlon race last weekend in Mont Tremblant, Quebec, while summer recreation was dampened by the closure of some swimming pools and beaches in parts of Quebec and Ontario.
What role does global warming play?
Climate research suggests that heat and drought related to global warming are important reasons for the number of fires and their intensity.
Canada has the world’s largest intact forest ecosystem and many parts of the country have recently experienced drought and high heat. That can leave trees vulnerable to fire and dry out dead grass, pine needles and other material on the forest floor that could serve as kindling.
Judson Jones in New York contributed reporting.