Impacts of energy consumption structure, energy intensity, economic growth, urbanization on PM2.5 concentrations in countries globally

Despite the fact that the relationship between socioeconomic development and PM2.5 concentrations has drawn much attention from multidisciplinary scholars in recent years, the causal links between PM2.5 concentrations and energy consumption, energy intensity, economic growth, and urbanization in countries with different income levels remain poorly understood. The present study categorized countries into four panels based on their income levels, in order to investigate the casual relationship between energy consumption, energy intensity, economic growth, urbanization, and PM2.5 concentrations for the period 1998-2014. To achieve this goal, balanced panel data and econometric methods were utilized. The results revealed that cointegration relationships existed between PM2.5 concentrations and the variables studied, in all panels. Findings of a panel Granger causality test based on a Vector Error-Correction Model showed that energy consumption, energy intensity, economic growth, and urbanization led to increased PM2.5 concentrations in the long term. Economic growth was the principal variable that impacted on PM2.5 concentrations in the global panel, the high-income panel, and the upper-middle income panel. PM2.5 concentrations can, we argue, be decreased by improving energy intensity in the short term in all countries except those belonging to the low-income group. In contrast, reducing the urbanization level in the short term is not an efficient way to mitigate PM2.5 concentrations. Our findings further indicated that the energy consumption structure was the greatest factor impacting on PM2.5 concentrations in lower-middle-income and low-income countries.