Using the ARDL test and Granger approaches, this paper investigates long-term co-integration and causal relationships among nuclear, renewables, GDP and CO₂ emissions in China, US, France and Japan. The findings reveal that the long-term coefficient of nuclear energy is smaller than renewable energy, indicating a relative advantage of nuclear power. However, the emission reduction effect of nuclear and renewables in China was not as much as compared to other nations. Moreover, causality from economic growth to nuclear or renewable energy existed in all countries, whereas no causality from nuclear energy to economic growth existed except in Japan. Therefore, giving priority to energy conservation and energy mix optimization is not likely to hurdle economic growth in China. However, greenness of the overall energy production process, augmentation of energy efficiency, technological progress in energy storage and internet, sustainable development of resource-society, and nuclear safety issues should be given priority in order to contribute to low-carbon growth in China.