Is CCU greenhouse gas neutral? An assessment: Overall, the contribution of CCU (CO2 capture and use) to climate protection is small but necessary. Both direct and industrial CO2-use can reduce fossil energy consumption somewhat. Only greenhouse gas-neutral CCU technologies will have any significance. Some even have a positive CO2 balance and can lead to long-term storage of captured CO2 - such as the use of building materials made from carbonised CO2; others, such as synthetic eFuels, have a short storage time; but they prevent the consumption of fossil energies and the emission of new CO2. Synthetic methane or ammonia can be used to store and transport energy. Some CCU products such as methanol are already being produced on an industrial scale; others are still in the experimental phase. The full penetration of CCU technologies will strongly depend on the future price development for CO2 capture and production of green hydrogen.