Some 435 wildfires were burning across Canada overnight as smoke from the blazes lingered in New York City and other parts of the U.S.
State of play: The fires forced officials in British Columbia to order fresh evacuations over the weekend and evacuation orders remained in place for thousands of people in Alberta and Quebec.
- The air quality index reached 110 in New York on Sunday afternoon and levels remained unhealthy for sensitive groups overnight, according to monitoring groups.
- While the smoke in the U.S. didn't reach the dangerously hazardous levels of last week, the federal agency Natural Resources Canada forecasts above-normal fire activity across most of the country through September as the unprecedented spring season continues.
- Quebec Minister of Public Security Francois Bonnardel said Saturday morning the situation in central and northwestern areas remained challenging, but firefighters had made progress against fires in the province's northeast, per AFP.
The bottom line: "This is a first in the history of Quebec to fight so many fires, to evacuate so many people," Bonnardel added of the orders affecting some 14,000 people.
- "We are going to have a fight that we think will last all summer ... we haven't yet won the battle."
- That means smoke is likely to continue to impact the northern tier of the U.S. over the next several months as Canada deals with its wildfire crisis.
Why it matters: Smoke from wildfires poses a serious threat to people's health.
- It can be hazardous to people's health even hundreds of miles away from a fire as it carries harmful microscopic particles that can cause inflammation in the lungs.
Context: Multiple studies show human-caused climate change is a key driver behind increased wildfire risk and that heat waves are more likely to occur, be more intense and last longer due to this.
- Climate change is leading to more instances of critical fire weather across the U.S. and other parts of the world, including the Far North, where larger, more frequent fires have been observed in recent years.
Go deeper: Wildfire smoke is also a carbon emissions problem