CCS can become an important element of sustainability and circular economy, as it can reduce emissions that cannot be avoided in key industrial sectors, also remove CO2 directly from the atmosphere, and then geologically store it for potential future use, such as production of synthetic fuels, fertilizers and other useful commodities. This paper, in its first part summarizes past pilot plant and CCS plans in Germany, ongoing CCS development in The Netherlands, CCS plants in operation offshore of Norway including the first commercial CCS project “Northern Lights”, and CCS plans in Greece. In its second part it provides an overview of the DigiMon project on geophysical monitoring of CO2 geological storage fields, and the monitoring technologies developed or improved during the project. They include distributed acoustic sensing (DAS) fiber optics, gravity field and sea bottom pressure monitoring and distributed CO2 concentration measuring (DCS). The paper ends with a comprehensive evaluation of critical seismic and other geophysical monitoring technologies of CO2 geological storage fields.