Canada’s record-breaking 2023 wildfire season led to a spike in air pollution in the country and in the US, erasing recent progress in cleaning up the air, according to new analysis.
The wildfires, which burned 42 million acres of Canadian forest, contributed to air-pollution levels not seen since 1998 in Canada and not seen since 2011 in the US, said researchers at the University of Chicago, which carried out the analysis for its Air Quality Life Index, a measure of how air pollution affects life expectancy.
More than half of Canadians breathed air that exceeded the country’s national clean air standards, an increase from less than 5% in the previous five years. And this year ranks as the second worst on record for wildfires in Canada, behind only 2023. Fires also are worsening air quality in the US and Europe.
Globally, air pollution from fine particulates released by sources including vehicles, power plants and industry increased slightly in 2023. There’s growing evidence that fossil fuels are reversing progress in improving air quality by increasing the likelihood and severity of wildfires, as well as contributing to air pollution when they’re initially burned, the researchers said. Air pollution can be acutely dangerous to people with respiratory conditions such as asthma, as well as raising the likelihood of developing life-threatening conditions like lung cancer and heart disease.
“We’re now stuck living with air pollution concentrations that are the dangerous ghost of the fossil fuels burned since the Industrial Revolution,” said Michael Greenstone, an economics professor at the University of Chicago and co-creator of the AQLI, in a statement. “Even countries that have earnestly spent decades cleaning up their air can’t escape these ghosts and the shorter and sicker lives that they deliver.”
Air pollution globally was nearly five times the levels recommended by the World Health Organization in 2023, according to the research, and particulate pollution is the greatest external threat to human life expectancy, comparable with smoking. Reducing concentrations to meet the guideline level would add 1.9 years of life for the average person, the authors said.
The report says South Asia, which includes India and Pakistan, remains the most-polluted part of the world, with pollution cutting life expectancy by three years on average and more than eight years in the most-polluted areas. In Latin America, the health threat posed by particulate pollution in many parts of the region is greater than that of self-harm and violence.
In parts of Africa, including Cameroon and Democratic Republic of the Congo, air pollution is taking a greater toll on life expectancy than well-known killers such as HIV/AIDS, malaria and unsafe water, according to the University of Chicago study.
Photograph: Smoke from the McDougall Creek wildfire in Kelowna, British Columbia, in 2023. Photo credit: Jen Osborne/Bloomberg
Topics Catastrophe Natural Disasters Trends Wildfire Pollution Canada