Environmental degradation, energy consumption, trade openness, and economic growth

This paper uses the autoregressive distributed lag (ARDL) methodology to examine the dynamic long-run causal relationships between carbon dioxide (CO₂) emissions, energy consumption, population density, economic growth, and trade openness in Brazil, China, Egypt, Japan, Korea, Mexico, Nigeria and South Africa. These countries span a wide range of development stages and geographical regions. In addition, we explore the dynamic response of the emission variable to sustained one-standard deviation shock to each of the causal variables using the generalized impulse response functions and forecast error variance decompositions. Overall, the results indicate that energy consumption Granger-causes both CO₂ emissions and economic growth in all the countries; while the estimated environmental Kuznets curves (EKCs) show that there is no unique relationship between energy consumption, population density, economic growth, trade openness, and the environment across the countries. The estimated EKCs show different temporal causal patterns, speeds of adjustment to equilibrium, and variable impacts.