There is a revival in the nuclear debate observed in the literature. Most of the emission scenarios of the Intergovernmental Panel on Climate Change (IPCC) show an important role for nuclear energy to satisfy energy demand in the long term. Moreover, several analyses have shown that nuclear technologies may represent very attractive options for greenhouse gas (GHG) emission reductions, especially in developing coun- tries with high growth projections for energy demand. Our objective is to analyze the role of nuclear energy in long-term climate scenarios using the World-TIMES bottom- up model. World-TIMES is a global model with 15 regions that optimizes their entire energy system over a 100-year horizon (2000–2100).

We present energy and emission results for climate scenarios for two levels of CO2 concentration (450 and 550 ppmv by 2100). We specifically analyze the penetration level of nuclear energy in these scenarios, under various sets of assumptions on tech- nology parameters and exogenous constraints on nuclear energy development to reflect social perceptions.

We highlight the fact that nuclear technologies satisfy most of the electricity pro- duction in all scenarios. The 450 ppmv scenario imposes very stringent technological changes. Most regions experience an energy transition based on advanced oil and gas technologies and by developing hydropower at the maximum potential. Other renew- able technologies could play a more important role, but need further cost reductions or new regulations to penetrate the market in substantial proportions. Carbon seques- tration and endogenous demand reductions for energy services are also significantly contributing to reach environmental target.