Efficacy of CO2 emission reduction strategies by countries pursuing energy efficiency, nuclear power, and renewable electricity

The discussion on CO2 mitigation strategies is increasing, and investors are interested in disclosing electricity generation pathways that effectively alleviate CO2 emissions. As such, this research proposes hierarchical analyses using stepwise regression and pairwise correlation for 133 countries over 31 years to explain how they use their energy sources, including efficiency, nuclear, and renewable electricity pathways, to mitigate CO2 emissions. Firstly, the results discover that renewable electricity effectively mitigates CO2 emissions, further supported by the incremental change in the R-squared value. Secondly, the results do not support the idea that nuclear power mitigates CO2. In contrast, it is noted that the efficacy of nuclear power on CO2 emission mitigation is effective through the moderation of GDP. This relationship demonstrates that the connection between CO2 and nuclear power is conducive to environmental quality in countries with increasing economic growth. Third, the negative coefficients of energy efficiency across the tested models indicate that the countries' energy efficiency is effective in CO2 emissions reduction. Finally, the results discovered that nuclear and renewable electricity pathways tend to crowd out each other, where this phenomenon is not valid in the cases of nuclear power-energy efficiency and renewable electricity-energy efficiency, where they support each other.