This page lists various projects gathering data about the Earth's air quality.

• What is it? A space mission with one satellite scanning the atmosphere.
• Who does it? “ESA, the European Commission, the Netherlands Space Office, industry, data users and scientists”
• Data freely available? Yes, but the download may require you to register a free account. https://scihub.copernicus.eu/
• Read more
  • https://sentinel.esa.int/web/sentinel/missions/sentinel-5p