Climate-Driven Wildfires are Reversing Clean Air Progress
The United States and Canada suffered the largest increase in fine particulate pollution (PM2.5) globally in 2023, fueled by the worst wildfire season in Canada’s history, according to new data from the Air Quality Life Index (AQLI). The change is part of a trend— recent research suggests that climate change is causing an increase in the frequency of wildfires that is reversing decades of clean air progress made in the United States and potentially in other regions around the world.
Canada experienced its highest particulate pollution levels in at least 26 years—double the previous year’s levels—with more than half of Canadians breathing air that exceeded their national standard. Canadians living in the most impacted regions breathed air comparable to Latin America’s most polluted countries— if these levels were sustained, they would cut people’s lives short by more than 2 years relative to air pollution concentrations that meet the World Health Organization’s (WHO) guideline.
Meanwhile, the fires contributed to pollution not seen in over a decade in the United States and a 20 percent rise from 2022. The higher pollution concentrations were driven by the Canadian wildfires. The resulting pollution spread across Wisconsin, Illinois, Indiana, and Ohio, and even extended to Pennsylvania, Oklahoma, and as far south as Mississippi. Counties in these states replaced counties in California as the top 10 most polluted regions in the country for the first time in a decade (see US factsheet ).
“When fossil fuels are burned, they cause particulate air pollution right away. What we are experiencing now is that there are more wildfires because fossil fuels also lead to higher temperatures, and the result is a second wave of air pollution. We are now stuck living with air pollution concentrations that are the dangerous ghost of the fossil fuels burned since the Industrial Revolution,” says Michael Greenstone, the Milton Friedman Distinguished Service Professor in Economics and creator of the AQLI along with colleagues at the Energy Policy Institute at the University of Chicago (EPIC). “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 remains the world’s greatest external risk to human health
The AQLI data found that, globally, pollution increased slightly in 2023. If the world were to permanently reduce particulate pollution to meet the WHO guideline, the average person would add 1.9 years onto their life expectancy—or a combined 15.1 billion life-years saved worldwide.
This data makes clear that particulate pollution is the world’s greatest external risk to human health. Its impact on life expectancy is comparable to that of smoking, more than 4 times that of high alcohol use, 5 times that of transport injuries like car crashes, and more than 6 times that of HIV/AIDS.
“Air pollution remains a top reason why people are living shorter lives throughout the world.” says AQLI Director Tanushree Ganguly. “Throughout history, countries have both grown and developed and improved their air quality. Targeting fossil fuels at their sources will improve local air, as well as help confront climate change. Countries need the tools to set such policies—starting with better information about their air.”
Nearly 5 billion lack pollution information—a critical protection tool
Each year, the AQLI takes on a different topic related to air pollution. This year, the report focuses on access to air quality information—a topic EPIC has been deeply involved with over the last decade, including through the AQLI. When people understand that the air they breathe is harmful to their health, they can take steps to reduce the hazard by purchasing air purifiers, wearing masks, limiting time outdoors, and using the data to inform policy actions.
The AQLI provides important annual information based on satellite data that gives a clear indication of the costs of air pollution across a lifetime. But people can also benefit from understanding the quality of the air they breathe daily, provided by local air quality monitors. Yet, nearly 70 percent of the world’s population lives in countries where less than three monitors exist for every million people—leaving nearly 5 billion people around the world, many of whom live in some of the world’s most polluted countries, without access to adequate information about their air.
Last year, EPIC launched the Air Quality Fund to support local groups and organizations in installing air quality monitors, sharing open data, and using that data to further national-level impact. The Fund now supports 31 awardees in government, academia, and civil society who are installing more than 700 monitors across 19 countries. In Africa alone, the Fund has invested almost five times what the continent typically receives in annual philanthropic funding toward air pollution. That’s having an impact—thanks to the Air Quality Fund, the Democratic Republic of Congo has installed its only air quality monitoring network, and a monitoring network in The Gambia spurred a landmark environmental bill making its way through the legislative process. This is important progress for a continent where, in the most polluted regions, air pollution takes a greater toll on life expectancy than well-known killers like HIV/AIDS, malaria and unsafe water.
“The fact that we’re seeing this level of action just one year in demonstrates how even a moderate injection of money into the most needed areas can have an impact,” says Christa Hasenkopf, the director of the Clean Air Program at EPIC. “But still, more is needed to bring information to communities. And, while data is critical to catalyzing action, data alone is not enough. It must be matched by political will, ambitious policies, and sustained enforcement.”
Air Pollution by Region
South Asia
In South Asia, pollution increased by 2.8 percent from 2022 to 2023, after a slight dip in 2022 compared to 2021. Despite these fluctuations, South Asia remains the most polluted region in the world—with pollution cutting life expectancy short by 3 years on average and more than 8 years in the most polluted areas. Particulate pollution is the greatest external threat to life expectancy in all South Asian countries. In the region’s most polluted countries, particulate pollution’s impact on life expectancy is nearly twice that of childhood and maternal malnutrition and more than five times that of unsafe water, sanitation and handwashing.
Factsheets: India , Bangladesh , Nepal , Pakistan
Latin America
Air pollution in Latin America spiked to its highest level since AQLI data records began in 1998. While the average resident would gain up to one year of life expectancy if their air quality met the WHO guideline, in the most polluted regions life expectancy could be extended by more than 4 years—comparable to some of the most polluted regions in South Asia. The health threat posed by particulate pollution in many parts of Latin America is greater than that of self-harm and violence—nine times greater in Bolivia, the most polluted country in the region. Bolivia made the top ten most polluted countries in the world for the first time in 14 years.
See factsheets: Latin America , Ecuador
China
Despite a slight increase in pollution, China’s pollution has decreased 40.8 percent since the country began its “war on pollution” in 2014—and citizens are living 1.8 years longer because of it. Still, all Chinese people breathe air that does not meet the WHO guideline. This is cutting lives short by 2.2 years and making pollution the second greatest external threat to life expectancy in the country, behind smoking.
See factsheet: China
Africa
Despite a slight decrease in pollution, the average Sub-Saharan African loses 1.6 years of life expectancy due to air pollution. The toll exceeds 5 years in the most polluted regions. In these highly-polluted regions—such as Cameroon and the Democratic Republic of the Congo—air pollution takes a greater toll on life expectancy than well-known killers like HIV/AIDS, malaria and unsafe water. These countries are also among the ten most polluted countries around the world. Meanwhile, most residents of the Middle East and North Africa live in areas where particulate pollution exceeds the WHO guideline, with residents in the most polluted areas losing more than 3 years of life expectancy because of it.
Southeast Asia
Like South Asia, most parts of Southeast Asia experienced an increase in pollution in 2023. As a result, an average Southeast Asian resident is losing 1.6 years of life expectancy, and 4.7 years in the most polluted regions, because of air pollution that is more than 4 times higher than the WHO guideline. In Indonesia, Southeast Asia’s most populous country, pollution reached its highest level in 5 years. While the entire country does not meet the WHO guideline, 73 percent of the population breathes air that does not meet Indonesia’s own national standard. In Thailand, pollution reached its highest levels in 9 years. Pollution in Thailand varies widely due to fires in Thailand’s northern region (like Chiang Rai) that have increased regional air pollution. As a result, residents of Chiang Rai are living one year less than their neighbors in Bangkok.
Europe
Sustained implementation of clean air policies in Europe have helped reduce particulate pollution by 31.5 percent over the last 26 years. Pollution declined nearly 6 percent from 2022 to 2023. While pollution in the region’s most polluted countries—Bulgaria, Poland, and Cyprus—have declined over time, people living in these countries could still gain 0.9, 0.8, and 0.7 years of life expectancy, respectively, if particulate levels were permanently reduced to meet the WHO guideline.
See factsheet: Europe