The MACC project was designed to meet the requirements that were expressed by the European Commission for what at the time was termed by the Commission to be the pilot Global monitoring of environment and security (GMES) atmospheric core service. The project was prepared by the consortia of the earlier European Union's Sixth Framework Programme project GEMS and the European Space Agency (ESA) GMES service element project Promote, whose core service lines provided the starting point for MACC.
From June 2009 until December 2011 MACC continued, improved, extended, integrated and validated these service lines, with the primary objective that the overall MACC system would be ready by the end of 2011 for qualification as what was termed the operational GMES atmosphere monitoring service. MACC prepared this core service in terms of implementation, sustained operation and availability. It maintained and further developed the efficiency and resilience of the end to end pre-operational systems initiated in GEMS and Promote and refined the scientific basis and quality of the products of the systems. It sought to determine and ensure that its service lines best met both the requirements of downstream service providers and end users at the European, national and local levels and the requirements of the global scientific user community. The service lines covered air quality, climate forcing, stratospheric ozone and solar radiation. MACC delivered products and information of the type needed to support the establishment and implementation of European policy and wider international programmes. It acquired and assimilated observational data to provide sustained near real time and retrospective global monitoring of greenhouse gases, aerosols and reactive gases such as tropospheric ozone and nitrogen dioxide. It provided daily global forecasts of atmospheric composition, detailed air quality forecasts and assessments for Europe and key information on long range transport of atmospheric pollutants. It provided comprehensive web based graphical products and gridded data on which downstream services could be based. Feedback was given to space agencies and providers of in situ data on the quality of their data and on future observational requirements.