About one third of global CO2 emissions are due to fossil-fuelled power plants. Recently, the option of capturing the carbon dioxide produced there and storing it underground has been discussed very controversially. Suitable processes could be ready for large-scale use in about 15 to 20 years. However, there are still considerable gaps in our knowledge before we can answer the question of whether carbon capture and storage can actually be a viable climate protection option. Which are the technologically most efficient processes, how high are the CO2 savings potentials, how great are the safety risks and environmental impacts emanating from CO2 storage facilities, how high are the costs of these technologies? The overarching question is whether the concept of CO2 capture and storage can be integrated into the structure of the energy system and whether it can compete with other CO2 mitigation options (energy efficiency, renewables). In this volume, the current state of knowledge and discussion is reviewed and options for a societal debate - keyword acceptance - and adequate legal framework conditions are developed.