Bike lanes and electric cars have helped significantly clean the air in 19 metropolises

The latest analysis conducted by Breathe Cities shows that in 19 cities around the world, air pollution has been reduced by more than 20% since 2010. Among the leaders in the ranking was Warsaw – the level of PM2.5 particulate matter here dropped by as much as 46%.

Clean air can return

The global Breathe Cities initiative focuses on promoting actions aimed at reducing air pollution and improving public health. As part of the latest analysis, experts examined changes that took place in 100 global metropolises over the past 10–15 years. It turned out that improving air quality is possible, and one in five of the analyzed cities reduced PM2.5 particulate matter and nitrogen dioxide (NO2) levels by at least 20%.

More than half of the leaders are cities in Central and East Asia, where populations are growing rapidly. According to the report authors, positive trends in air quality show that with proper planning and radical transport changes, even a demographic boom does not have to be a verdict. On the other hand, among the 19 cities that managed to reduce air pollution by at least 20%, only one American metropolis was included – San Francisco.

Warsaw’s huge success

Among the metropolises studied by Breathe Cities, the Polish capital was also included in a very positive context. Between 2010 and 2024, the largest reductions in PM2.5 concentrations were recorded in Beijing (48%) and in Warsaw (46%). The top cities most effectively fighting the particularly dangerous, smallest fraction of particulate matter also included Berlin, Brussels, and Paris.

The largest NO2 reductions were achieved by two Dutch cities: Amsterdam (44%) and Rotterdam (43%) – both metropolises also recorded substantial reductions in PM2.5 levels. Chinese metropolises Hangzhou, Chengdu, and Nanjing also handled harmful nitrogen dioxide very well.

Evidence-based interventions

According to Breathe Cities experts, the studied metropolises represent very different socio-economic contexts, but the leaders are united by a responsible approach to air quality based on pollution monitoring, identification of main sources, and implementation of structural reforms rather than ad hoc actions.

Key initiatives that clearly improved air quality in cities included reorganizing the transport system by expanding bike lane networks and limiting street space for private cars. In Warsaw, the total length of bike lanes increased from 275 km in 2010 to 870 km in 2025.

In Amsterdam and Rotterdam, many streets and car parking areas were converted into bike parking, green spaces, and playgrounds, while in Brussels, 11% of all primary schools were connected by bike paths, encouraging walking and cycling.

The Breathe Cities analysis also shows that most of the 19 successful cities have substantially expanded or modernized their public transport networks over the past 15 years. Shenzhen became the first metropolis in the world to fully electrify its bus fleet, and in Warsaw, already 40% of buses are zero- and low-emission vehicles.

The third factor in the success of clean air in cities is the development of infrastructure for electric vehicles, often through public-private partnerships. In Paris, over 2,000 street chargers have been installed, and San Francisco offers grants for this purpose to owners of existing and new buildings. Grants and regulations requiring parking lots to be equipped with EV chargers are standard in China – a country that today leads in transport electrification rankings.