The Paris Agreement aims to reduce the risks and effects of climate change. To this end, radical action is required, including a change in the energy mix towards zero-emission energy. One of the possibilities is the responsible development of nuclear energy. This monograph is the result of an international research project coordinated by the International Atomic Energy Agency on the potential role of nuclear energy in mitigating climate change. Within this framework, a multisectoral macroeconomic model has been developed and tested for assessing the impact of different energy supply options on the decarbonisation process. The book presents both methodological and practical aspects of model construction, as well as simulation results for the scenario of implementation of the nuclear program included in the draft Energy Policy of Poland until 2040.