Testing the theory of Kuznet curve on environmental pollution during pre- and post-Covid-19 era.

Covid-19 has brought about significant changes in people's daily lives, leading to a slowdown in economic activities and the implementation of restrictions and lockdowns. As a result, there have been noticeable effects on the environment. In this study, we examine the impact of Covid-19 total cases on the monthly average of carbon monoxide emissions in developed economies known for heavy pollution, covering the period from 2014 to 2023. We apply the Ambiental Kuznets curve approach to analyze the data. By employing different panel estimation techniques such as fixed effects and Driscoll-Kraay regressions, we observe a marked shift in environmental dynamics during the post-Covid era. This shift alters the statistical significance of the N-shaped Kuznets curve, rendering the relationship between economic activity and environmental impact non-significant. Interestingly, the Covid-related variables utilized in the various estimations are not statistically significant in explaining the long-term environmental effects.

Do renewable energy and natural gas consumption mitigate CO2 emissions in the USA? New insights from NARDL approach.

This article attempts to explore the asymmetric impact of renewable energy and natural gas consumptions on CO2 emissions for the selected ten most populous states in the USA over the period from 1997 to 2017. For that purpose, the nonlinear autoregressive distributed lag (NARDL) estimation technique, developed by Shin et al. (2014), decomposes the consumption of renewable energy and natural gas into positive and negative changes. The cointegration test results indicate that renewable energy and natural gas consumptions have a long-run connection with CO2 emissions in the eight of states used in the study. Moreover, the results reveal that the long-run asymmetric impact of renewable energy and natural gas consumptions on CO2 emissions differs from state to state. Finally, the study provides several important policy suggestions, including reducing the CO2 emissions in the atmosphere.