Half of Europe Breathed Polluted Air

During the record heatwaves experienced across Europe from June to August 2026, half of the continent's population was exposed to unhealthy levels of ground-level ozone. This air pollutant can penetrate deep into the respiratory system and bloodstream, posing risks particularly to individuals with asthma.

Ground-level ozone forms through chemical reactions triggered by sunlight and high temperatures. The intensifying heatwaves, driven by human-caused climate change, are directly increasing ozone formation. Nitrogen oxides, primarily from fossil fuel combustion in industry and transport, are key precursors to ozone.

Ozone is also a greenhouse gas, contributing to warming. While the European Union has made significant progress in reducing other air pollutants through regulations like the Air Quality Directive, ozone levels have not shown a clear downward trend. Efforts to combat other pollutants have led to substantial emission reductions in industry and road transport.

The EU's Ambient Air Quality Directive sets limits for ozone concentration, but many areas, especially in southern Europe, exceeded these levels significantly throughout 2026. Air pollution, including ozone and wildfire smoke, can travel vast distances, affecting regions far from its source.

Globally, ozone exposure is even more widespread, with nearly 40% of the world's population facing extremely high levels in 2026. Cities like Milan, Delhi, and Cairo report some of the highest exposures. Climate change is expected to worsen ozone concentrations globally as temperatures rise.

Reducing ozone levels requires governmental action, including improved monitoring and air quality plans explicitly targeting ozone. Public awareness and individual actions like choosing to walk or cycle over driving, and reducing speed when driving, can also contribute to lowering ozone precursor emissions.