Millions of people in the eastern US and Canada received health warnings from environmental regulators as thick smoke from northern wildfires spread over cities from Ottawa to New York.
Canada has been battling an active fire season for the past month across most of its 10 provinces and territories. Smoke from the fires has drifted south over some of North America’s most populous cities this week.
New York City’s air quality on Wednesday ranked second worst of any major urban area in the world IQAir World Air Quality IndexIn India second only to New Delhi.
New York residents again donned the face masks they had discarded recently as the Covid-19 emergency subsided. Schools canceled outdoor activities and the city urged vulnerable New Yorkers to stay inside and keep windows closed as air quality dropped to its lowest level since the 1960s.
New York City’s mayor, Eric Adams, said Wednesday morning, “Yesterday, New Yorkers saw and smelled something that had never before affected us on this scale.”
After easing Wednesday morning, New York officials predicted conditions would worsen again during the afternoon and evening, calling it a “multi-day event.” The US aviation regulator issued “ground delays” for flights to Philadelphia, Newark and New York’s LaGuardia airports on Wednesday afternoon, citing “low visibility” for pilots.
Washington’s public schools also suspended outdoor activities for students as the city’s environmental regulator issued a “code red” air-quality alert for the District of Columbia.
Canada’s environmental regulator has classified air quality in the country’s capital Ottawa as having reached the highest level of health risk. Large areas of Quebec and Ontario were under air-quality warnings from Canadian authorities.

Smoke rising from wildfires in Quebec and Ontario in a satellite image © AP

Smoke from wildfires in Montreal, Quebec © Alan McInnis / Bloomberg
Earlier this spring, fires in Canada’s main oil-producing province of Alberta forced thousands of people to evacuate their homes, and forced more than a dozen oil and gas companies to temporarily close or reduce operations. Caused to do
More blazes have now taken hold in forests in eastern provinces such as Quebec and Nova Scotia. As of Wednesday, more than 400 fires were burning across Canada, having burned nearly 4 million hectares so far this year. Canadian Interagency Forest Fire Center,
Scientists have observed an increase in the intensity of fires in the Northern Hemisphere’s boreal forests over the past decade, with average temperatures in the north of the planet closer to the equator rising faster as a result of global warming, as the reflective ice and snow of the Arctic melt.
Wildfires north of the equator are generally becoming more frequent and intense as the planet warms and summers become hotter. According to the Copernicus EU Observation Service, May 2023 was the second warmest May ever recorded globally.
Heat records have been broken in parts of Asia, particularly in China and Vietnam, where unusually hot weather began months earlier than the normal July and August summer. Parts of Siberia also set all-time records last week.
Sea surface temperatures were the highest on record for the month and have been near record levels since March.
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Where climate change meets business, markets and politics. Explore FT’s coverage here.
Are you curious about FT’s environmental sustainability commitments? Learn more about our science-based goals here
Millions of people in the eastern US and Canada received health warnings from environmental regulators as thick smoke from northern wildfires spread over cities from Ottawa to New York.
Canada has been battling an active fire season for the past month across most of its 10 provinces and territories. Smoke from the fires has drifted south over some of North America’s most populous cities this week.
New York City’s air quality on Wednesday ranked second worst of any major urban area in the world IQAir World Air Quality IndexIn India second only to New Delhi.
New York residents again donned the face masks they had discarded recently as the Covid-19 emergency subsided. Schools canceled outdoor activities and the city urged vulnerable New Yorkers to stay inside and keep windows closed as air quality dropped to its lowest level since the 1960s.
New York City’s mayor, Eric Adams, said Wednesday morning, “Yesterday, New Yorkers saw and smelled something that had never before affected us on this scale.”
After easing Wednesday morning, New York officials predicted conditions would worsen again during the afternoon and evening, calling it a “multi-day event.” The US aviation regulator issued “ground delays” for flights to Philadelphia, Newark and New York’s LaGuardia airports on Wednesday afternoon, citing “low visibility” for pilots.
Washington’s public schools also suspended outdoor activities for students as the city’s environmental regulator issued a “code red” air-quality alert for the District of Columbia.
Canada’s environmental regulator has classified air quality in the country’s capital Ottawa as having reached the highest level of health risk. Large areas of Quebec and Ontario were under air-quality warnings from Canadian authorities.

Smoke rising from wildfires in Quebec and Ontario in a satellite image © AP

Smoke from wildfires in Montreal, Quebec © Alan McInnis / Bloomberg
Earlier this spring, fires in Canada’s main oil-producing province of Alberta forced thousands of people to evacuate their homes, and forced more than a dozen oil and gas companies to temporarily close or reduce operations. Caused to do
More blazes have now taken hold in forests in eastern provinces such as Quebec and Nova Scotia. As of Wednesday, more than 400 fires were burning across Canada, having burned nearly 4 million hectares so far this year. Canadian Interagency Forest Fire Center,
Scientists have observed an increase in the intensity of fires in the Northern Hemisphere’s boreal forests over the past decade, with average temperatures in the north of the planet closer to the equator rising faster as a result of global warming, as the reflective ice and snow of the Arctic melt.
Wildfires north of the equator are generally becoming more frequent and intense as the planet warms and summers become hotter. According to the Copernicus EU Observation Service, May 2023 was the second warmest May ever recorded globally.
Heat records have been broken in parts of Asia, particularly in China and Vietnam, where unusually hot weather began months earlier than the normal July and August summer. Parts of Siberia also set all-time records last week.
Sea surface temperatures were the highest on record for the month and have been near record levels since March.
climate capital
Where climate change meets business, markets and politics. Explore FT’s coverage here.
Are you curious about FT’s environmental sustainability commitments? Learn more about our science-based goals here











