The United States and Canada experienced the largest air pollution surge in 2023, driven by the northern neighbor’s worst wildfire season on record. Canada experienced its highest levels of fine particulate pollution (PM 2.5) in at least 26 years, with more than half of residents exposed to contaminant concentrations that surpassed national standards. Michael Greenstone, an economics professor at the University of Chicago’s Energy Policy Institute and co-creator of the index, said that when fossil fuels are burned, they cause particulate air pollution right away.
In the U.S., Greenstone and his colleagues determined that the fires contributed amounts of air pollution that the country had not seen in more than a decade. Compared to just the year before, particulate pollution levels rose nationwide by an average of 20%. The resultant pollution from the Canadian blazes spread across Wisconsin, Illinois, Indian, and Ohio, as well as as far as Pennsylvania, Oklahoma, and Mississippi. Counties in these states replaced many in California as the top-10 national pollution hotspots for the first time in five years.
Worldwide, the index determined that air pollution exhibited a slight increase in 2023. If the planet were to permanently reduce particulate pollution to meet global health guidelines, the average person could count on an additional 1.9 years in life expectancy. Greenstone added that 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.
