This report identifies 25 clean air measures that can positively impact human health, crop yields, climate change and socio-economic development, as well as contribute to achieving the Sustainable Development Goals. Implementing these measures could help 1 billion people breathe cleaner air by 2030 and reduce global warming by a third of a degree Celsius by 2050. The top 25 measures not only represent wins for cities and countries looking to improve air quality, but also provide next-generation business opportunities and boost economic growth.