Abstract Climate change is one of the most critical scientific and economic challenges facing the world today. Stabilizing the atmospheric carbon concentration will require fundamental changes in the energy system worldwide over the next century. Novel energy technologies, such as carbon capture and sequestration, and biomass production enhanced by advanced biotechnology, may be required. However, currently deployed non-carbon energy technologies, such as nuclear or wind energy, will also need to be developed further if they are to emerge as a significant source of electricity or hydrogen in a carbon-neutral energy system. This paper models and evaluates the economic and technological potential for advanced nuclear technology systems to contribute to the development of a carbon-neutral energy system within the context of postulated future carbon and energy policies. We find that, depending on the development pathway followed by nuclear technology, nuclear energy might supply from ten to thirty five of the world's electricity by 2100. However, along an evolutionary technology development pathway, its long-term impact could be limited by the availability of fissile material. Consequently, we find that nuclear research and development that transcends the immediate needs of the current industry will be required to enable a substantial contribution to the stabilization of the atmospheric carbon concentration. Moreover, there will be a need for a substantial increase in the publicly supported, long-term nuclear research and development activities and international collaborative efforts, particularly with respect to the nuclear fuel cycle, to make the nuclear energy contribution sustainable. ICONE 2004 Session: 5-9 Economics and Deployment Aspects