Decoupling growth from degradation: a fractional frequency Fourier analysis of India's aviation sector and the environmental Kuznets Curve

Purpose This study investigates the relationship between economic growth, air transportation, financial development, and environmental degradation in India's aviation sector from 1970 to 2021. Using the ecological footprint as an indicator and a novel fractional frequency Fourier approach, it tests the Environmental Kuznets Curve (EKC) hypothesis. The results reveal a U-shaped relationship, contradicting the EKC, and highlight the negative environmental impact of increased air freight. However, financial development supports sustainability by enabling cleaner technologies. The study aims to inform policy by proposing strategies such as carbon pricing, renewable fuel adoption, and green logistics to decouple aviation growth from environmental harm. Design/methodology/approach The study employs a fractional frequency Fourier approach to examine the long-run relationship between economic growth, air transportation, financial development, and environmental degradation in India from 1970 to 2021. The ecological footprint is used as a comprehensive measure of environmental impact. This advanced econometric method captures structural breaks and nonlinearities more effectively than traditional models. By testing the Environmental Kuznets Curve (EKC) hypothesis within this framework, the study provides nuanced insights into the dynamic interactions among the variables. The methodology ensures robustness through unit root tests, cointegration analysis, and appropriate diagnostic checks to validate the model's findings. Findings The study finds a U-shaped relationship between economic growth and ecological footprint, rejecting the validity of the Environmental Kuznets Curve (EKC) hypothesis for India's aviation sector. Economic growth initially reduces environmental degradation but worsens it beyond a threshold. Air transport freight is positively associated with ecological footprint, indicating environmental harm from increased logistics activity. In contrast, financial development mitigates environmental degradation by supporting investments in clean technologies and sustainable practices. These findings emphasize the need for targeted policies to decouple aviation growth from environmental impacts and promote long-term sustainability within the sector through green financing and eco-friendly logistics solutions. Originality/value This study offers a novel contribution by applying the fractional frequency Fourier approach to analyze the environmental impacts of India's aviation sector—an area underexplored in existing literature. Unlike traditional methods, this approach captures complex nonlinear dynamics and structural breaks over time. By using ecological footprint as a comprehensive indicator of environmental degradation, the study moves beyond CO2-focused analyses. Its rejection of the EKC hypothesis provides fresh insights into the unsustainable nature of aviation-led growth in India. The findings deliver valuable policy guidance for integrating financial development and green logistics into sustainable aviation strategies, contributing to both academic research and practical policymaking.