How wildfire smoke is traveling from Ontario to New York City — and turning distant city skies orange
Wildfires that have burned large swaths of forest and devastated small communities are also sending smoke far and wide, prompting air quality warnings in remote cities and heated political rhetoric from the US.
This year’s fire season has forced more than a dozen communities and territories to evacuate in recent days, including 10 First Nations communities across northern Ontario.
But the smoke crossing borders, causing black skies as far away as New York City, has drawn the ire of some politicians.
US President Donald Trump lashed out at Canada, saying the smog is “poisoning” the American air, and even suggested that the Canadian government should “pay some damages.”
At the same time, smoke from wildfires raging in the northwestern US has drifted into BC, as Western Canada grapples with an increase in wildfires.
With fires burning across BC, the Northwest Territories and northern Saskatchewan, haze and the smell of smoke hung over cities like Edmonton and Calgary this week.
Experts who spoke to CBC News said there is nothing unusual about smoke patterns this summer, despite the heated political rhetoric. But they say wildfires are getting worse, and that won’t stop on either side of the border.
How does the smoke from Ontario get to New York City?
The short and obvious answer is that it goes with the wind.
But Brian Wiens, research manager for the Canadian Wildfire Network, says the intensity of the fire will affect how high its smoke rises into the atmosphere and how far it can travel.
“A really hot fire will send it up into the atmosphere, making that smoke travel thousands of miles,” he said.
“It’s not at all unusual for smoke from North American fires to travel all the way to Europe and, similarly, for fires from East Asia or Russia to travel all the way to North America.”
Wiens says the smoke dissipates as it moves away from the source, but it can linger until the wind changes or rain blows it away.
Smoke can be trapped for weeks in communities living in deep valleys, which is common in BC, he said.
An entire BC city near the Alberta border remains under an evacuation alert due to an out-of-control wildfire. The Matthew Creek bushfire is 10 kilometers west of Kimberley, home to more than 8,000 people.
Kent Moore, a professor of atmospheric physics at the University of Toronto, says smoke from the Ontario fires has reached Greenland.
He says all kinds of pollutants travel both ways across the Canada-US border, noting as one example that Ontario receives polluted air from American coal-fired power plants.
“Pollution often travels with the wind and does not stop at borders,” he said.
Why does the sky turn orange?
Videos from urban dwellers experiencing heavy smog often show a scary, orange- or yellow-colored sky, with people saying how they feel like they’re in a sci-fi movie or an apocalyptic scenario.
Moore explains that particles in the air cause this phenomenon by emitting blue light, which allows other colors to shine through.
“Blue light, because of its wavelength, is scattered by this matter in the air. Red light is not,” he said.
“That’s why the sun tends to look red when we have wildfire events, because there’s a lot of smoke in the air that scatters all the green light.”
He compares this effect to a sunset, which often appears red because the sun is low and close to the horizon, so its light has a long way to reach your eyes.
Andrew Chang explains how smoke from Ontario’s wildfires can change the color of the air in cities more than a thousand kilometers away, and the health risks of inhaling it. Photos provided by The Canadian Press, Reuters, Adobe Stock and Getty Images
Can’t we put out all the fires?
“This is the third year in a row that we have had to write to Canadian officials about a problem that Canada has the tools to prevent and has chosen not to,” four Michigan Republicans wrote in a letter last week, calling out Canada for its apparent lack of action to combat wildfires.
Putting aside the fact that the US is experiencing its own brutal wildfire season, many Americans may not realize the extent of Canada’s northern wilderness.
“Much of Canada and many of the areas where these large smoky fires are burning, including northern Ontario and the Northwest Territories, are very remote and inaccessible,” said Jen Baron, assistant professor of fire ecology at the University of British Columbia.
“It’s not easy, or possible in most cases, to put firefighters on the ground.”
Wiens says that fires that threaten people’s lives and infrastructure are the main priority for limited firefighting services. Serious operational challenges – like flying a plane for two hours to drop one load of waste materials on a fire, for example – are the reason why large fires often burn in sparsely populated areas.
If people’s lives or infrastructure aren’t threatened, Wiens said, it’s not worth the investment to fight big fires.
“The temperature that the fire emits is so amazing that, in fact, it gets to the point where there is nothing you can do to fight them,” said Wiens.
“The best you can do is help move them one way or the other, and then there’s no need to do that in the middle.”
Why is the problem growing?
All the experts who spoke to CBC News said that this year’s situation is reminiscent of the year 2023, when smoke from the Canadian wildfires again drifted into the US Eastern Seaboard.
They all attributed climate change to the growing problems of wildfires and smoke across North America in recent years.
This is because hot, dry and windy conditions are becoming more common as the climate warms, leading to dryness and more fuel. So when a fire strikes, it has the ability to burn more and faster.
Northern Canada, in particular, is warming faster than the global average.
“It’s not just the increase in temperature by a few degrees, but these extreme heat events and extreme drought conditions that are causing increased fire behavior,” Baron said. “And the more fires burn, the more smoke they tend to produce.”
As annoying – and dangerous – as the smoke can be for people living in remote towns, Baron says it’s important to remember the damage that fires do to communities across Canada.
“Most of them have lost a lot of infrastructure, they have lost their communities,” he said. “Although it’s a challenge to be under the high level of smoke, I think it’s important to remember the source of that smoke.”
