The Effects of Energy Transition and Environmental Policy Stringency Subtypes on Ecological Footprint: Evidence from BRICS Countries via a KRLS Approach

The world has been facing climate-related problems in recent decades, resulting from environmental degradation, making it increasingly critical to reduce environmental degradation in order to combat climate change. In this context, transforming economies into eco-friendly ones, ensuring the global energy transition from fossil-fuel-based power to renewable energy, and applying stringent environmental policies have been recent focus points of policymakers. Accordingly, this study analyzes the marginal effect of the energy transition, market- and non-market-based environmental policy stringency, and income on ecological footprint (EFP) in Brazil, Russia, India, China, and South Africa (BRICS) countries using data between 2000 and 2020 and applying a kernel-based regularized least-squares (KRLS) approach. The results show that ① economic growth has a stimulating marginal effect on EFP in BRICS countries except for Brazil, where it has an insignificant effect; ② energy transition efforts are ineffective in all countries, having the undesired effect of increasing EFP; ③ market-based environmental policies have a curbing effect on EFP in Brazil, Russia, and India but an increasing effect in China and an insignificant effect in South Africa; ④ non-market-based environmental policies are highly ineffective in all countries; ⑤ the KRLS approach exhibits excellent performance in the estimation of EFP, reaching approximately 99.61%; and ⑥ the marginal effect of the studied factors on EFP varies across factors, countries, and percentiles. Thus, this study highlights that BRICS policymakers should consider the marginal effects of the studied factors on EFP in combating environmental degradation and climate-related problems.