From 1st July 2020, the access method to the European air quality Web Map Service (WMS) is through a new server at ECMWF which hosts the Copernicus Atmosphere Monitoring Service. Details are available from the Migration of European air quality WMS products page.
The Web Coverage Service (WCS) was shutdown on 30 June 2020. CAMS European air quality data retrieval for a specific geographical area and/or level is now served through the Atmosphere Data Store.
CAMS & C3S Helpdesk