A transition to a low-carbon economy can be facilitated by CO2 capture and storage. This paper begins with an overview of CO2 capture and storage in the terrestrial biosphere, oceans, and deep geologic systems. The remainder focuses on what now appears to be the most promising option for large-scale deployment-capture and storage in deep geologic formations. A detailed description of the technology is provided, including the potential scale of application, cost, risk assessment, and emerging research issues