This roadmap document is the first version of the Strategic Research Agenda (SRA) summarising current research activities, within and outside CHE, and outlining the future strategies required for establishing the CO2 monitoring system and the required capabilities. The current version documents the objectives of CHE and VERIFY, provides an overview of the various ESA scientific studies and of the current and planned satellite observation system. Next versions will contain more information on the various outcomes of the project and studies and will also add a section on existing and potential future in-situ capabilities.