As Canada’s wildfire smoke creeps down into the U.S., it’s also transforming. Chemical reactions between gases and sunlight create ozone, which further exacerbates lung conditions like asthma.

The fires also are putting out significant levels of carbon pollution — an estimated 56 megatonnes through Monday, second only to 2023, according to Copernicus. Smoke hits north-east US ...

CLIMATEWIRE | When wildfire smoke wafted from Canada across large swaths of the U.S. in 2023, it served as a wake-up call for federal safety experts. They drafted recommendations to protect ...

That year, when wildfires burned more land in Canada than had ever been recorded, smoke from uncontrollable flames, particularly across Quebec, was so intense it turned the skies over New York ...

Unhealthy air returned to metro Detroit on Friday afternoon, June 6, as smoke from Canadian wildfires continued to drift into Michigan.. An air quality advisory is in effect across southeast ...

Canada calls for international help to battle massive wildfires 01:23. Continued drifting of wildfire smoke from Canada and Alaska has prompted Bay Area air regulators to extend an air quality ...