In recent years, fast-growing economies have taken a leading role in advancing energy efficiency, driven by the adoption of international best practices and increased investment in research and innovation. This study investigates the role of energy efficiency in reducing CO2 emissions in both developed and fast-growing countries, which together account for the highest levels of global emissions. The panel regression models were developed for four country groups: the World, G-7, EU, and BRICS, using OECD data from 2000 to 2022. The analysis focused on a consistent set of indicators across these groups that contribute to understanding the dynamics of emissions reduction. The results indicate that industrial production and population density are primary drivers of CO2 emissions. Additionally, real GDP per capita growth is associated with increased energy supply. Countries with a lower share of renewable energy tend to have higher emission levels. The results show that industrial production and population density are the main drivers of CO2 emissions, while renewable energy reduces emissions across all country groups. Energy efficiency, measured through both energy productivity and energy intensity, is significantly influenced by material productivity, renewable energy use, and technological specialization, although these effects vary across country groups. The findings highlight substantial structural differences in how economies balance growth, energy use, and environmental performance.
https://doi.org/10.3390/su18083880