Europe’s air quality continues to improve as decades of environmental regulations and emissions reduction policies deliver measurable results across the continent. According to the Copernicus Atmosphere Monitoring Service (CAMS) Assessment Report on European Air Quality 2025, the overall trend remains positive despite occasional pollution episodes that continue to affect certain regions. The report evaluates major pollutants regulated under the EU’s Ambient Air Quality Directive, which is designed to bring European standards closer to the recommendations of the World Health Organization. These findings indicate that long-term environmental policies are successfully reducing air pollution while highlighting the need for continued action.
One of the primary reasons for cleaner air is the steady decline in emissions from key sectors. Since 2015, emissions of sulphur oxides (SOx) and nitrogen oxides (NOx) have fallen by approximately three to five percent annually across the European Union. Industrial facilities and road transport have recorded some of the largest reductions as cleaner technologies and stricter emissions standards have been introduced. Although transportation remains the largest emitting sector compared with 1990 levels, its emissions have declined in recent years. Carbon dioxide emissions from transport fell from 1.1 billion tonnes in 2019 to 1.05 billion tonnes in 2024, supported by the rapid adoption of electric vehicles that are gradually replacing petrol and diesel-powered cars.
The transition toward renewable energy has also played an important role in reducing air pollution. During the second quarter of 2025, renewable energy generated more than half of the European Union’s net electricity for the first time. Countries such as Sweden have demonstrated the potential of low-carbon electricity systems, producing approximately 99 percent of their electricity from low-carbon energy sources. Moving away from fossil fuels reduces emissions of harmful pollutants while also lowering greenhouse gas emissions that contribute to climate change.
The report identifies sulphur oxides and nitrogen oxides as two of the most significant pollutants affecting human health and the environment. Sulphur oxide, produced mainly through burning fossil fuels, irritates the respiratory system and contributes to the formation of fine particulate matter and acid rain. Nitrogen oxides also damage respiratory health, reduce lung function, and can trigger asthma attacks. In addition, nitrogen oxides contribute to global warming by trapping heat in the atmosphere. CAMS reports that industrial SOx emissions have declined by 59 percent, industrial NOx emissions by 39 percent, road transport NOx emissions by 40 percent, and PM2.5 emissions from road transport by 34 percent, demonstrating substantial progress in controlling air pollution.
Despite these encouraging improvements, extreme weather continues to create challenges for maintaining clean air. Heatwaves produce high temperatures, strong sunlight, and stagnant atmospheric conditions that encourage the formation of harmful ground-level ozone. Unlike protective ozone in the upper atmosphere, surface ozone damages human lungs and vegetation. Dry conditions also increase wildfire risk, with major fires in Portugal and Spain during August 2025 producing widespread smoke and elevated PM2.5 concentrations across the Iberian Peninsula. Wildfire smoke also releases ozone precursors that increase surface ozone as smoke plumes spread. These events demonstrate that climate-related hazards remain an important obstacle to reducing air pollution, even as long-term emissions continue to decline across Europe.