This study investigates the relationship between the nuclear power proportion and CO₂ emissions per capita using the panel dynamic ordinary least square method. The panel datasets consist of 18 countries covering 95% of the global nuclear reactors. The results indicate that a long-term 1% increase in nuclear power led to a 0.26–0.32% decrease in CO₂ emissions per capita. Additionally, in France, Germany, and Switzerland they demonstrate the existence of the environmental Kuznets curve—an inverted U-shaped relationship between environmental pollution and income per capita.