OBSERVER: Air Quality Challenges in 2025: Europe’s Summer of Smoke, Dust and Ozone

The summer of 2025 significantly affected Europe’s atmosphere. From record-breaking wildfires in southern and western Europe, to intense Saharan dust intrusions and repeated peaks in surface ozone during prolonged heatwaves, air quality was negatively impacted by multiple events. Data from the Copernicus Atmosphere Monitoring Service (CAMS) show how these overlapping events combined to create serious risks for human health and the environment across the continent. In this Observer, we take a closer look at what the data show.

Record emissions and widespread smoke

The European summer of 2025 was marked by intense and widespread wildfire activity, especially in southeast and southwest Europe, with significant impacts on air quality. Wildfire smoke is a mixture of air pollutants, such as nitrogen oxides, and particulate matter, with PM2.5 (particulate matter of 2.5 microns or less in diameter) being of particular concern because of its potential impacts on human health. While the season began with relatively low emissions overall, conditions quickly escalated, culminating in record-breaking fire events in parts of the continent.

Greece, Turkey, and Cyprus experienced large wildfires during late June and early July, with total estimated fire emissions in June at their highest level since 2007 for Greece, and the highest in the 23 years of the CAMS Global Fire Assimilation System (GFAS) dataset for Turkey. CAMS global forecasts of PM2.5 surface concentrations showed a clear signal of the fire emissions throughout the first week of July.