The current emissions of CO2 to the atmosphere through man-made activities are outlined and the options for recycling CO2 for some useful purpose, as distinct from simply storing or disposing it in an environmentally-benign manner, are discussed. It is shown that for CO2 recycling to have any significant impact on reducing emissions of this gas, it must form part of some large-scale energy conversion process which is based on a non-fossil-fuel energy source such as solar or nuclear energy. Since the quantities of undiluted CO2 available for recycling are relatively small, the cost of recovering CO2 from sources such as power station flue gas must be taken into account in the overall CO2 recycling/energy conversion scheme.