Transport Infrastructure, Economic Expansion, and CO2 Dynamics: The Critical Role of Green Energy Consumption in the United States

This paper examines the nexus between transportation infrastructure, economic growth, and carbon dioxide (CO2) emissions in the United States, with particular emphasis on the moderating role of green energy consumption (GEC). The United States is an economically advanced country with a well-developed transport infrastructure and sustained economic growth; however, this development has been accompanied by increasing environmental pressures, notably rising CO2 emissions from the transport sector. Drawing on the Environmental Kuznets Curve (EKC) framework, the study investigates whether renewable energy sources—specifically wind, solar, and hydropower—can decouple economic growth from environmental degradation. A Vector Error Correction Model (VECM) was employed to analyze both short-run dynamics and long-run cointegrating relationships among transport infrastructure, economic activity, CO2 emissions, and green energy consumption. The results indicate that relative to fossil-based energy, green energy significantly mitigates the emission-enhancing effects of transport infrastructure expansion and economic growth. These findings underscore the pivotal role of renewable energy in achieving sustainable development. From a policy perspective, the results highlight the importance of integrating green energy into national transport and infrastructure planning. Overall, the study demonstrates that in transport-intensive economies, the expansion of renewable energy does not constrain economic growth but is essential for ensuring its long-term environmental sustainability.