Towards a European operational observing system to monitor fossil : CO2 emissions : final report from the expert group

This report aims to provide a vision and a strategy for a European integrated observation system dedicated to the monitoring of fossil carbon dioxide (CO2) emissions, with independent atmospheric observations. The construction and operation of this system should be undertaken within the Copernicus programme. The satellite and in-situ atmospheric measurements described in this report will enable the accurate, transparent and consistent quantifi cation of fossil CO2 emissions and their trends at the scale of megacities, important industrial sites, small regions, countries, and the Earth as a whole. Atmospheric measurements will be used in an operational system that comprises three complementary components: 1- Atmospheric CO2 measurements obtained from dedicated space-borne sensors, complemented by in-situ networks, which both allow for the separation of fossil CO2 emissions from natural fl uxes; 2- The operational provision of bottom-up fossil CO2 emission maps, with high spatial and temporal resolution, and near real time updates; 3- An operational data-assimilation system, which will integrate atmospheric measurements with bottom-up information into consistent and accurate estimates of fossil CO2 emissions and their trends. This report identifi es current and future scientifi c and technical capacities that could enable such an observation system, with operational and internationally coordinated capabilities in the 2030s. The capacity provided by such a system will provide the European Union with a unique and independent source of actionable information, which would address multiple stages of the policy cycle. Further, this capacity will contribute to a system at global level through integration with similar eff orts from third parties.