Decades of environmental policies, advances in technology, and cleaner approaches to industry and transportation in Europe have paid off, resulting in a steady decrease in the emission of major air pollutants. 

Despite the challenge of wildfires, Europe’s air quality improved in 2025, according to the latest data released by Copernicus, the European Union’s (EU) Earth Observation unit. 

“Europe continues to make steady progress in improving air quality thanks to sustained efforts to reduce emissions from transport, industry, residential heating, and other key sectors,” said Laurence Rouil, director of the Copernicus Atmosphere Monitoring Service (CAMS).

Air quality has improved every year since 2015 as regulated air pollutants have declined, the agency’s latest report has found. 

Parts of Europe continue to experience localised air pollution, often driven by summer heatwaves, extreme cold, and temperature inversions in winter, when warm air settles over cooler air. Such periodic weather fluctuations have led to situations where the air pollution levels have temporarily exceeded the environment and health limits that were set.

“Our report highlights and explains situations when the combination of emissions and meteorological conditions can still trigger significant large-scale episodes with exceedances of the limit values set for health and environment protection,” Rouil explained.

The report shows that, despite increased economic activity, emissions are increasingly becoming decoupled from industrial production and transport demand.

Major air pollutants saw a decline in Europe since 2015.The report draws on data from monitoring stations across Europe for major air pollutants like ozone, nitrogen dioxide (NO2) and particulate matter PM10 and PM2.5 to present the latest assessment of Europe’s air quality for 2025.

Since 2015, emissions of sulphur oxides (SOx) and nitrogen oxides (NOx) have fallen by approximately 3–5% per year across the EU, with the most significant reductions achieved in industry and road transport.

Industrial emissions of SOx have fallen by 59%, while NOx emissions from industry have declined by 39%. Road transport emissions have also fallen substantially, with reductions of 40% for NOx and 34% for PM2.5.

All the pollutants monitored are known to pose a risk to human and environmental health.

Number of days when the PM2.5 concentrations were above the EU limit.While emissions are falling, rising temperature extremes like heat and cold waves also affect air quality and are becoming important factors.  

The year 2025 was also the third warmest in Europe, according to the European State of the Climate 2025 report. 

High temperatures, intense sunlight and stagnant atmospheric conditions create favourable conditions for ozone formation during summer. Prolonged dry conditions contribute to severe wildfire activity in parts of southern Europe that also worsen regional air quality.

Colder-than-average conditions contribute to elevated particulate matter concentrations during winter, largely as a result of emissions from heating systems.

Significant air pollution episodes in 2025

The report also looked at four major pollution episodes that occurred in 2025. In February 2025, colder-than-average conditions in parts of Europe contributed to elevated PM2.5 concentrations and exceedances of air quality health thresholds. 

Residential heating emissions played a dominant role in the episode, particularly in eastern Europe, while emissions from transport, agriculture and industry also contributed to elevated pollution levels.

Elevated concentrations of ozone – which can irritate lungs, worsen asthma, and even impact vegetation and ecosystems, reducing crop yields – were recorded during heatwave periods in June and August. High temperatures, intense sunlight and stagnant atmospheric conditions created favourable conditions for ozone formation across large parts of the continent. 

Record wildfires in August affected Portugal and Spain, and led to widespread exceedances of daily PM2.5 limit values across parts of the Iberian Peninsula.

“In addition to elevating the levels of particulate matter at the surface level, the fire plumes also contributed to the increase in surface ozone levels in northern Portugal and Spain, because the release of significant amount of ozone precursors, which react in sunlight as the smoke travels,” said Paul Hamer, senior scientist at the Norwegian climate research institute, Nilu, and main author of the report.

Image Credits: Unsplash/Xenia Bunina, CAMS Assessment Report on European Air Quality.