A causal link between renewable energy, energy efficiency, property rights, and CO2 emissions in developed countries: A road map for environmental sustainability.

CO2 emissions are the leading causes of deterioration in air quality and global warming. Likewise, it has been shown that clean energy reduces air pollution, so this would be a way out of environmental pollution. Some previous studies have focused on knowing the determinants of environmental pollution; however, they have omitted the State's role. Thus, this study explores the long-term nexus between CO2 emissions and renewable energy, energy efficiency, fossil fuels, GDP, property rights from 1995 to 2019 in nine developed countries. The results reveal a long-term equilibrium relationship in developed European countries, but not in developed non-European countries. The main results show that renewable energy and energy efficiency are negatively correlated with CO2 emissions. In developed European countries, a 1% increase in renewable energy consumption represents a 0.03% decrease in CO2 emissions. Finally, some policy measures are suggested to achieve environmental sustainability.