The main goal of this paper is to investigate the long-term nexus among energy consumption, economic growth, civil aviation, and CO2 emissions by performing the ARDL, DOLS and Panel data analysis for Baltic countries including Estonia, Finland, Latvia, and Lithuania from 1992 to 2021 within the context of EKC hypothesis. The long-term ARDL and DOLS models result indicate that there is a statistically significant relationship between the air transport, CO2, GDP, and energy consumption for Estonia from 1992 to 2021. On the other hand, the impact of independent variables containing air transport, GDP, and energy consumption on CO2 emission is demonstrated empirically from 1992 to 2021 which is affirmed the EKC hypothesis for Baltic countries through panel data analysis. According to empirical findings, legal arrangements should be made for the production and use of alternative fuels by policy makers in order to provide economic and social benefits in terms of reduction environmental pollution. Low-emission fuels and hybrid or electric vehicles must be used to reduce carbon dioxide emissions as a solution for environmental degredation in Baltic countries.

The major aim of this manuscript is to examine the long-run relationship between air freight, economic growth, energy usage and ecological footprint by employing Multivariate Regression (MR), FMOLS (Fully Modified Ordinary Least Squares), DOLS (Dynamic Ordinary Least Square), CCR (Canonical Co-integrating Regression), and Generalized Method of Moments (GMM) analysis for Turkey from 1970 to 2018 within the sense of EKC hypothesis. According to Multivariate Regression (MR) result of Turkey, air freight, economic growth, and energy usage influence the ecological footprint from 1970 to 2018. Besides, the long-term linkage of variables including air freight, economic growth, energy usage and ecological footprint is indicated through FMOLS, DOLS, CCR and GMM analysis which is verified the EKC hypothesis for Turkey. Thus, all-time series analysis of this paper confirms that air freight, economic growth, and energy usage cause environmental pollution between 1970 and 2018 for Turkey. When the empirical results are considered the Environmental Management System has not yet been established at airports open to international traffic. However, in order to meet the standards expected by international aviation authorities, it is necessary to develop practices in this regard at airports in Turkey. Today, when environmental pollution has reached serious dimensions, airport operators, local people and every unit of the aviation industry will go to produce solutions and take precautions together. With the Environmental Management System to be established within the airport, which is accepted as indispensable businesses in terms of social and economic aspects for the environment; it will be able to achieve sustainable development by increasing their performance in the new period. The use of renewable energy sources at airports will contribute to the process. Financial incentives should be provided to airline companies that are willing to invest in line with these targets, and tax exemptions should be introduced for such investments. Although it does not seem possible in the near future, it is important for the future sustainability of the sector to carry out studies on electric air transportation.