Between January 1 and September 15, 2026, roughly 34 percent of the global population breathed extremely high levels of ozone pollution driven by record-breaking heatwaves, wildfires, and persistent industrial emissions, according to a European Union report released on Wednesday.
How Climate Change and Wildfires Drive Ground-Level Ozone
Ground-level ozone forms when intense sunlight and severe heat react with airborne emissions from wildfires, motor vehicles, and industrial facilities. While international efforts have successfully reined in several other harmful air pollutants over recent decades, ozone remains stubborn. Climate change continuously creates the exact meteorological conditions that favor its formation.
The Copernicus Climate Atmosphere Monitoring Service (CAMS) tracked these developments using advanced satellite data and computer models. Record-breaking heatwaves and widespread wildfires across North America and Europe fueled this year’s elevated concentrations, sending dense smoke thousands of kilometers beyond its point of origin. Indonesia also experienced major wildfires, while a warming El Nino weather pattern that began in June threatens to ignite further blazes across Southeast Asia.
“Air pollution does not stop at borders. It can travel thousands of kilometres, crossing continents and oceans and affecting air quality far from its source,” CAMS director Laurence Rouil stated in the Atmosphere Watch report.
The CAMS analysis classified 17 percent of the world’s population as exposed to “very poor” air quality during the monitoring period. Only five percent of people globally experienced “good” ozone levels. By comparison, the World Health Organization recommends a maximum ozone exposure threshold of 100 micrograms per cubic metre, averaged across eight hours.
Regional Disparities Across Asia, North America, and Europe
Asia bore the heaviest burden, with 53 percent of its population breathing air classified as extremely poor and another 22 percent facing very poor conditions. Rapid industrialization, economic growth, transport emissions, agricultural residue burning, and wildfires drive these high exposure rates.
Major metropolitan centers hit hardest by extreme ozone levels included New Delhi, Dhaka, Chongqing in China, and Lahore in Pakistan. Meanwhile, two-thirds of North America’s population and 45 percent of Europeans faced poor or very poor air quality.
European Union regulations have successfully reduced emissions for most pollutants, but ozone stands out as an exception. Ian Marnane, an official at the European Environment Agency, noted during a media briefing that ozone pollution contributes to approximately 60,000 premature deaths each year in Europe. North American ozone levels similarly remained relatively unchanged despite aggressive emission reduction policies.
Varying Air Quality Impacts in Africa, South America, and Oceania
Across Africa, forest fire smoke, crop burning, and domestic cooking significantly degraded air quality, alongside Saharan dust traveling as far as Europe. The analysis showed that eight percent of Africa’s population experienced extremely poor air quality, while 19 percent endured very poor or poor conditions.
In South America, ozone concentrations climbed to very high levels in Sao Paulo and reached extremely elevated marks in Rio de Janeiro. Even with these urban pollution hotspots, 81 percent of the continent enjoyed good or fair air quality. Oceania recorded the most favorable conditions globally, with 66 percent of residents experiencing good ozone levels and 34 percent living under fair conditions.
“Air pollution does not stop at borders. It can travel thousands of kilometres, crossing continents and oceans and affecting air quality far from its source.”
