Nearly 40% of world's population exposed to harmful ozone pollution in 2026, EU climate monitor finds

Close to 40% of the world's population was exposed to harmful levels of ozone pollution in 2026, according to findings from the European Union's climate monitoring agency, which also found that only around 5% of people globally experienced what it classified as "good" ozone levels.

The assessment identifies Asia, Europe and North America as the regions most affected by elevated ground-level ozone, a pollutant that forms when sunlight reacts with other pollutants such as nitrogen oxides and volatile organic compounds, often released by vehicles, industry and other combustion sources.

Unlike the protective ozone layer high in the stratosphere, ground-level ozone is a harmful air pollutant linked to respiratory problems, and it can aggravate conditions such as asthma and other lung diseases, particularly during periods of hot, sunny weather when its formation is more pronounced.

The agency's findings point to a substantial share of the global population living with air quality conditions that fall short of levels considered safe or healthy, underscoring the scale of the air pollution challenge facing policymakers in the affected regions.

Ozone pollution levels are known to fluctuate seasonally, typically peaking during warmer months, and can be influenced by a combination of local emissions and the transport of pollutants across regions and even continents.

The findings add to a body of research from climate and health agencies tracking the intersection of air quality and climate conditions, as rising temperatures in various regions have been associated with increased ozone formation in urban and industrial areas.

The report does not specify what policy responses, if any, are planned, though such findings are often used by governments and international bodies to inform air quality regulations and emissions targets.