Major cities across three continents have achieved dramatic improvements in air quality over the past 15 years, according to new research from campaign group Breathe Cities. The report identified 19 metropolises that have reduced air pollution levels by between 20 and 40 percent, demonstrating that cleaner urban air is achievable even amid rapid economic growth.
Beijing, London, and Paris were among the cities leading the transformation. Nearly half of the cities showing improvement were located in Asia, with nine in China alone, where air quality gains occurred despite significant economic development. The report also highlighted cities in Belgium, Germany, Italy, the Netherlands, Poland, and the United States.
The research identified three primary drivers of air quality improvements: expanded cycling infrastructure, implementation of clean air zones, and widespread adoption of electric vehicles. These interventions represent practical, scalable solutions that other cities can replicate.
"The pathway to cleaner air has been tested at scale – now it's about enabling more cities to follow it," said Cecilia Vaca Jones, executive director of Breathe Cities.
Air pollution remains the leading environmental health risk globally, contributing to respiratory and cardiovascular disease, asthma, and premature births. Lower-income communities bear a disproportionate burden of these health impacts. The new findings demonstrate that these outcomes are not inevitable and can be reversed through deliberate policy interventions.
The complete list of cities recognized in the report includes Brussels, Beijing, Chengdu, Hangzhou, Hong Kong, Nanjing, Qingdao, Shenzhen, Wuhan, Zhenjiang, Paris, Berlin, Heidelberg, Rome, Amsterdam, Rotterdam, Warsaw, London, and San Francisco.
The research arrives as London considers additional measures to address vehicle-related air pollution and safety concerns. London Mayor Sir Sadiq Khan is examining proposals to increase fees for sport utility vehicles as part of the Vision Zero plan, which aims to eliminate deaths and serious injuries on London's roads by 2041.
The number of SUVs on London's roads has increased tenfold over two decades, from approximately 80,000 in 2002 to 800,000 in 2023, according to Clean Cities. Research indicates that SUVs are 77 percent more likely to kill a child in a collision than standard passenger vehicles. Paris and Cardiff have already implemented higher parking fees for larger vehicles.
Oliver Lord of Clean Cities stated that London's SUVs have created "parking mayhem and dangerous roads," adding that "city leaders must act to discourage these menacing vehicles from our streets."
The air quality improvements documented in the Breathe Cities report represent significant public health achievements. As cities worldwide grapple with pollution challenges, the success stories from Beijing to San Francisco provide evidence-based models for urban environmental policy. The question facing municipal leaders is no longer whether cleaner air is possible, but whether they will implement the proven strategies to achieve it.