Environmental benefits of nonrenewable energy efficiency and renewable energy intensity in the USA and EU: Examining the role of clean technologies

Given that the United States of America and European Union are among the world's top greenhouse gas emitting economies, it poses yet to be answered questions on whether efficient utilization of nonrenewable energy sources or renewable energy intensification in these economies account for any environmental benefit. To answer these inherent questions, this study examines and compares environmental performances of the economies in response to nonrenewable energy efficiency, renewable energy intensity, and environmental-related technologies while controlling for natural resource rent and urban population over the period 1990-2019. By implementing the advantage of Kernel-Based Regularized Least Squares alongside robustness measures, the findings posit that nonrenewable energy efficiency, renewable energy intensity, and environmental-related technologies significantly mitigates greenhouse gas (GHG) emission in the economies. Importantly, while the three metrics show louder environmental impact in the EU, nonrenewable energy efficiency plays a louder and environmentally desirable role than the other two metrics. Conversely, natural resources and urbanization significantly hampers environmental sustainability by increasing GHG emission in the economies. Unfortunately, a terribly more damaging environmental impact arising from increased urbanization is noticeable in the EU. These findings afford concrete policy measures to be further devised for the USA and EU, and the entire globe given the foresight of net zero target.