Climate-driven wildfires are reversing clean air progress, new report says

By Emily Mae Czachor

Canada's worst wildfire season on record tarnished the country's air quality and had similar effects on pollution in parts of the United States , according to a new report.

University of Chicago researchers on Thursday released their annual Air Quality Life Index , a situational update on air pollution and how it impacts life expectancy. The AQLI report said particulate pollution "remained the greatest external threat to human life expectancy," comparing the impact to smoking.

Researchers from the university's Energy Policy Institute analyzed pollution data collected throughout 2023 and compared it with previous years.

Michael Greenstone, a professor at the University of Chicago who created the AQLI, told CBS News his team focused on airborne particulate matter — small particles that are able to invade and wreak havoc on the body more easily than larger ones.

The data is taken from satellite readings that refresh each year and can take time to process, which is why the latest figures date back a couple of years, Greenstone said.

While global pollution only rose slightly between 2022 and 2023, the report's authors found that updated levels remained almost five times higher than the limit recommended by the World Health Organization to protect public safety. Local changes in air quality varied from one country to the next. The differences were particularly stark in the U.S. and Canada, where airborne particulate concentrations  increased more than anywhere else .

"Evidence of a link between climate change, wildfire smoke, and rising particulate pollution has been increasing over the past two decades," the authors wrote in their report, citing a recent study that found human-caused climate change "increased the likelihood of autumn wind-driven extreme wildfire events, especially in the Western U.S."