Air Freight Transport and Environmental Degradation: An Environmental Kuznets Curve Perspective

The expansion of the air transportation sector, which offers significant advantages in terms of time efficiency and spatial accessibility, plays a critical role in promoting economic growth. In turn, in economies experiencing sustained growth, the demand for air transportation also tends to rise. This reciprocal relationship between economic growth and air transport has important implications for environmental sustainability. This study examines the impact of air freight transportation on environmental degradation within the framework of the Environmental Kuznets Curve, using panel data from the ten countries with the highest number of airports over the period 2001–2020. In the study, the CIPS unit root test, the slope homogeneity test, and the panel cointegration test are applied sequentially. Subsequently, the PMG-ARDL approach is employed to estimate the short- and long-run relationship among the variables. Finally, the direction of causality between the variables is determined using the Dumitrescu–Hurlin panel causality test. The analysis also incorporates key determinants of environmental degradation, including trade openness, industrialization, income, renewable energy consumption, and technological advancement. The empirical results indicate that air freight transportation exacerbates environmental degradation. The results support the Environmental Kuznets Curve hypothesis and indicate that renewable energy use and industrialization contribute to environmental improvement, whereas trade openness tends to intensify environmental degradation. Additionally, a bidirectional causal relationship is found between air freight transportation and environmental degradation. Based on these findings, the study proposes policy recommendations aimed at mitigating environmental harm and promoting sustainable development.