Air quality indicators across Europe improved last year, as emissions of major regulated pollutants declined, however some parts of Europe were still impacted by persistent, large-scale pollution episodes, Copernicus Atmosphere Monitoring Service (CAMS) has said.
According to CAMS’ Assessment Report on European Air Quality 2025 report, the reduction in emissions of key pollutants indicates that the combination of environmental regulation, cleaner technologies and more efficient industrial and transport systems is having a positive impact.
‘Insightful information’
“Our report is designed to provide national authorities, policymakers and air quality experts with insightful information to better understand both long-term trends and the origins of pollution episodes, enabling more effective evidence-based decision-making,” commented Laurence Rouil, CAMS director.
“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. At the same time, 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.”
As an example, emissions of sulphur oxides (SOx) and nitrogen oxides (NOx) have consistently fallen over the past decade, by between 3% and 5% annually since 2015, CAMS noted.
Industrial SOx emissions have fallen by around three fifths (59%), while industrial NOx emissions are down by two fifths (39%). Elsewhere, road transport has also recorded a notable reduction in emissions, with NOx emissions falling by 40% and fine particulate matter (PM2.5) emissions declining by 34%.
At the same time, a combination of emissions and seasonal weather conditions, such as heatwaves in summer and extreme cold in winter, have led in some cases to limits for health and environmental protection being exceeded.
Prolonged summer sunshine, coupled with stagnant atmospheric conditions, has contributed to elevated ozone concentrations during summer, while colder-than-average winter conditions has led to an increase in particulate pollution linked to residential heating.
Wildfires in Spain and Portugal
One major air pollution event recorded in 2025 was the extensive wildfires seen in Spain and Portugal last August, which led to daily PM2.5 air quality limits across the Iberian Peninsula being exceeded.
“The wildfires in August 2025 showed how closely these hazardous events are connected to air quality,” added Paul Hamer, NILU senior scientist and main author of the report. “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.” Read more here.
