Copernicus shows that for nearly four in ten people, ozone pollution reached extremely high levels between January and August 2026, while heat and atmospheric transport exacerbate the problem.
The air we breathe is not determined solely by what happens nearby, but also by events thousands of kilometers away, since air pollution knows no borders. A recent study warns of the danger to about 40% of humanity from ozone pollution.
For Europe, this is a particularly serious issue, because although emissions of other gases have been brought under control, ozone pollution was worsened by heatwaves, and the gas spread through the air, eventually polluting areas with lower emissions. The result is that air quality declined for about half the population.
Certain pollutants called precursors, when exposed to sunlight, generate ground-level ozone. Being a gas, it travels easily, contaminating neighboring territories. According to the WHO, its health effects can be dire, as it impairs lung function and worsens preexisting conditions. It also has consequences for crop yields and ecosystem balance.
Ozone Pollution Is Becoming More Dangerous
A new global analysis by Copernicus shows how atmospheric pollution crossed borders and continents over the past year, exposing around 40% of the world’s population to harmful ozone levels, warned this Wednesday by the atmospheric and climate monitoring component of the European Space Programme.
Tropospheric ozone pollution forms when certain contaminants are exposed to sunlight and high temperatures, and it is harmful to human health and ecosystems, the Bonn-based agency explained as it released the results of the study called ‘Atmosphere Watch’.
By combining millions of satellite observations, ground networks, and other sources with its global forecasting system, this analytical tool provides a snapshot of cross-border air pollution (including ozone, smoke from biomass burning, and desert dust) so far this year.
In the first eight months of 2026, major heatwaves have facilitated the creation of high tropospheric ozone levels in many regions, affecting billions of people, especially in Asia, where 60% of inhabitants were exposed to “extremely high” levels, followed by Europe and North America.
The Share of Exposures Is Rising
Despite progress achieved in Europe regarding pollutants, 50% of the population was exposed to unsafe ozone levels, aided by repeated heat waves, as part of a vicious circle in which the ozone itself contributes to warming the atmosphere.
South America, by contrast, recorded relatively low ozone pollution levels, with 81% of the population experiencing good or acceptable air quality.
“Ozone pollution is a clear reminder of how interconnected our atmosphere, our climate, our health, and our livelihoods truly are, since pollution and climate change affect the chemical composition of the air we breathe, determine the health of our ecosystems, and even shape our ability to grow food,” stated Laurence Rouil, director of Copernicus’ Atmospheric Monitoring Service (CAMS).
Pollution Knows No Borders
Rouil also stressed how ozone pollution and other particles and gases cross national boundaries, making global action essential.
The near real-time data gathered as part of the analysis highlighted how wildfire smoke or desert dust, among other things, can travel thousands of kilometers and affect the health of populations far from the source.
For example, during the FIFA World Cup held in July, intense wildfires in Canada and the western United States generated massive plumes of smoke that traveled thousands of kilometers, triggering air quality health advisories in cities like New York and New Jersey, one of the venues of the global football tournament.
The same occurred in Europe with the “megafires” in France, Spain, or Belgium, which produced a strong transport of smoke that affected air quality thousands of kilometers away.
Additionally, Sahara dust has reached the North Atlantic on several occasions, arriving at Cape Verde and the Canary Islands and causing haze and poor air quality.
