Can Human Capital Mitigate the Environmental Costs of Urbanization? Empirical Evidence from Asia’s Five Largest Economies

Rapid urbanization in Asia has intensified concerns over rising CO 2 emissions, yet the moderating influence of human capital in this process remains underexplored. This study examines whether human capital can mitigate the environmental impact of urbanization in five major Asian economies—China, India, Japan, South Korea and Indonesia—during 1990–2021. Employing advanced panel econometric techniques, including cross-sectional dependence tests, panel co-integration analysis and a panel ARDL framework with Panel Mean Group (PMG), MG and DFE estimators, the study captures both long- and short-run dynamics. Robustness is ensured through dynamic OLS estimation, while Granger causality and variance decomposition provide insights into the direction and strength of causal linkages. The results reveal that urbanization significantly increases CO 2 emissions, with a 1% rise in the urban population contributing to a 7.53% increase in emissions. In contrast, human capital directly reduces emissions by 1.68% and, when interacting with urbanization, offsets its adverse effect by 11.76%. Evidence broadly supports the Environmental Kuznets Curve, although country-specific heterogeneity emerges: human capital fosters sustainable urbanization in China and South Korea, and moderates environmental stress in India, while financial development intensifies emissions in Japan and Indonesia. By quantifying the moderating role of human capital, this study adds novel evidence to the environmental economics literature and underscores human capital development as a key policy instrument for achieving sustainable urban growth and low-carbon development in Asia.