Across the globe, hundreds of observing stations are studying the tiny particles you breathe! The Global Atmosphere Watch Programme unites 100+ countries to track the composition of the Earth's atmosphere and help us better understand the drivers of our changing climate. By providing critical scientific data, the programme notably helps monitor the ozone layer recovery, and assesses the impacts of air pollution on human health and biodiversity, while supporting #EarlyWarnings. The global network meets next week at the WMO Headquarters to review progress and plan the way forward.