The need to reduce the emission of carbon dioxide into the atmosphere is pushing toward the use of "renewable carbon", so to avoid as much as possible burning "fossil carbon". It would be possible to complement the natural "carbon cycle" by developing man-made industrial processes for "carbon recycling", converting, thus, "spent carbon" as CO2 into "working carbon", as that present in valuable chemicals or fuels. Such practice would fall into the utilization of "renewable carbon", as the man-made process would perfectly mimic the natural process. An order of complexity higher would be represented by the integration of biotechnology and catalysis for an effective CO2 conversion, using selective catalysts such as enzymes, or even whole microorganisms, coupled to chemical technologies for energy supply to enzymes, using perennial sources as sun or wind or geothermal as primary energy. These days all the above approaches are under investigation with an interesting complementarity of public-private investment in research. This paper aimed at making the state of the art in CO2 conversion and giving a perspective on the potential of such technology. Each atom of C we can recycle is an atom of fossil carbon left in the underground for next generations that will not reach the atmosphere today. (C) 2016 Elsevier Inc. All rights reserved.