Join Us

If you share our commitment to clean air and would like to hear news from Breathe Cities, sign up to our email updates.
You can opt out at any time. To read our full Privacy Policy, please click here.

11 March 2026

Press Release Global

New Breathe Cities Research Shows Cities Leading on Air Quality Action Cut Air Pollution by Over 20%

New report, "Breathe better: How leading cities have rapidly cut air pollution", shows that cities can achieve major improvements in air quality through coordinated, data-driven action. The analysis identifies 19 cities that reduced PM2.5 and NO2 levels by 20–45% over 15 years, demonstrating that rapid progress on clean air is possible.

Download the Full Report

Bangkok, Thailand – Today at the Better Air Quality (BAQ) Conference, a new report was released by Breathe Cities, a global initiative delivered by Bloomberg Philanthropies, C40 Cities, and Clean Air Fund to help cities clean the air and protect public health. The report, Breathe better: How leading cities have rapidly cut air pollution, examined air quality trends, identifying 19 leading cities that achieved sustained reductions of at least 20% in both fine particulate matter (PM2.5) and nitrogen dioxide (NO2) over 15 years.

The findings come at a critical moment. Air pollution is the world’s largest environmental health risk, driving respiratory and cardiovascular disease, childhood asthma, and premature births, with lower-income communities disproportionately affected. Yet the report demonstrates that substantial progress is feasible: cities that took coordinated action achieved reductions in toxic pollutants above 20% between 2010 and 2024, with some achieving reductions of around 45%.

Nearly half of the successful cities are in Central and East Asia, demonstrating that rapid air quality improvement can occur alongside urban and economic development. The analysis identifies common patterns behind sustained improvement, with leading cities using the latest technology to map their air pollution, then transforming their streets by prioritising walking, cycling, and public transport. They are replacing old buses with electric fleets, making it easier for residents to switch to cleaner cars, and helping families move away from polluting coal and wood to heat their homes. These findings reinforce that cities are not only on the front lines of this challenge but are also uniquely positioned to deliver rapid, scalable solutions.

Highlights

Nineteen cities across nine countries reduced levels of the toxic pollutants PM2.5 and NO2 by 20–45% over the past 15 years, demonstrating that rapid air quality improvement is achievable.

Cities that achieved sustained improvements combined data-driven monitoring with transformative transport and energy policies.

Nearly half of the leading cities are in Central and East Asia, showing that major air quality gains can occur alongside rapid urbanisation and economic development.

Breathe Cities’ report demonstrates that substantial air quality improvement is achievable when cities take coordinated, data-driven action. The 19 leading cities show that progress of 20-45% is possible within 10 to 15 years. Through Breathe Cities, we’re helping cities adapt these proven approaches to protect public health. The pathway to cleaner air has been tested at scale – now it’s about enabling more cities to follow it.

Cecilia Vaca Jones

Executive Director of Breathe Cities.

Breathe Cities leading the way

4 of the leading cities identified in the report are part of Breathe Cities, a global initiative giving 14 cities the tools to take ambitious clean air action by expanding access to data and raising public awareness.

Warsaw reduced pollution through bold action, including a ban on coal heating backed by financial aid for cleaner fuels. The city also expanded public transport, cycling infrastructure, and green public spaces to reduce car use.
Paris promoted cleaner, active travel, with a low emission zone and the rapid expansion of cycling lanes, redesigned streets, and around 300 “school streets”.
London implemented a city-wide Ultra Low Emission Zone, as well as electrified 25% of its bus fleet, with all other buses upgraded to the highest emissions standards.
Brussels took transformative action on mobility, through a city-wide low emission zone, expanded cycling lanes, 40,000 secure bike parking spaces, and the pedestrianisation of large parts of the city centre.

The report also features detailed case studies of Bangkok and Jakarta, two Breathe Cities implementing comprehensive air quality strategies, investing in expanded monitoring networks, cycling and pedestrian infrastructure, public transport modernisation, and vehicle emissions controls. Through Breathe Cities, Bangkok and Jakarta are taking part in peer-to-peer knowledge exchange with other cities, to share successes and learn from proven approaches.

These efforts demonstrate that strong city leadership, when aligned with national policy and guided by data and community engagement, can drive substantial change – and that newer Breathe Cities are positioned to rapidly reduce their emissions and improve air quality.

“Cities can move faster when they collaborate and share proven solutions,” said Priya Shankar, Environment Program at Bloomberg Philanthropies. “The 19 leading cities identified in this report show what’s possible. Through Breathe Cities, we’re connecting cities with the data, technical support, and peer networks to implement what works. The examples of action in this report demonstrate the pathways cities can take to cleaner air and healthier communities.”

Bangkok: Applying the global blueprint locally

Coinciding with the global report, Breathe Bangkok today released a new emissions inventory that will help guide targeted interventions to protect public health.

The updated 2024 Air Pollution Emissions Inventory is a comprehensive assessment of pollution sources across Bangkok and surrounding provinces, which shows progress on reducing emissions, particularly in the manufacturing sector, where PM2.5 emissions from industrial furnaces and boilers fell by 19%.

With support from Breathe Cities, the Emissions Inventory will be used to create a vulnerability mapping tool, a pioneering digital instrument that integrates air quality data with socio-economic indicators across Bangkok’s 50 districts. This will enable Bangkok to identify “air quality-health hotspots” and deploy focused interventions to protect the most vulnerable populations.

“The new emissions inventory provides Bangkok with the evidence base we need to accelerate clean air action,” said Pornphrom Vikitsreth, Advisor to Governor of Bangkok and Chief Sustainability Officer of Bangkok. “The data shows we’re making progress, with reductions in transport, residential, and industrial emissions, but also where we must focus next. By identifying air quality-health hotspots through vulnerability mapping, we can ensure our interventions protect the communities most at risk. This is the data-driven approach that Breathe Cities’s global report shows works in leading cities worldwide.”

“Bangkok’s commitment to data-driven air quality solutions sets an important precedent for cities across the region,” said Dr. Supat Wangwongwatana, Director of the Hub of Talents on Air Pollution and Climate (HTAPC). By integrating scientific research with practical tools like emission inventories, spatial distribution of air quality, and vulnerability mapping, we ensure that policy decisions are grounded in evidence and tailored to the most pressing needs and sensitive groups of people of our communities. Understanding sources of emissions will enable the city to direct mitigation measures at the most important source first for quick win. This approach places public health and effectiveness at the heart of decision-making and demonstrates the essential role of research in shaping effective urban policy.”

The 19 leading cities identified in the report are: Brussels, Belgium; Beijing, China; Chengdu, China; Hangzhou, China; Hong Kong, China; Nanjing, China; Qingdao, China; Shenzhen, China; Wuhan, China; Zhenjiang, China; Paris, France; Berlin, Germany; Heidelberg, Germany; Rome, Italy; Amsterdam, Netherlands; Rotterdam, Netherlands; Warsaw, Poland; London, UK; San Francisco, USA.

See All Posts