Not just developed nations, but even developing nations are beginning to prioritise environmental concerns, especially CO2 emissions. Nevertheless, there are currently few studies examining the differences in the influence of social and economic factors on CO2 emissions by country's degree of development. Using the FMOLS approach and percentile regression, this study investigates the impact of many economic and social factors on CO2 emissions in 57 nations (14 developed countries and 43 developing countries) from 1995 to 2015. The research findings indicate that the factors of GDP per capita, complexity of the economy, underground economy, population, and renewable energy have a similar impact on CO2 emissions across nations, while marginal impacts vary. Notably, the influence direction of trade openness differs between the two investigated groups of nations. Moreover, it is believed that FDI has no influence on environmental quality.