On the nexus between CO2 emissions and the air transportation sector in the European Union and Turkey: accessing evidence from wavelet coherence analysis

The coronavirus disease has had a devastating impact on the airline industry worldwide. However, the cancellation of flights has also enormously reduced CO2 emissions in the air. The present study empirically explores the environmental impact of the sectoral lockdown within the EU28 and Turkey by leveraging the wavelet coherence transform (WCT) technique. The results revealed that there is a positive correlation between the number of passengers carried and CO2 emissions. In the short run, during the pandemic, there is a strong positive linkage between the number of passengers carried and CO2 emissions, while in the long run, there are also positive and meaningful relationships between the number of passengers carried and CO2 emissions between 2014 and 2022. The result also indicates that, on a quarterly basis, there was a sharp decline in CO2 emissions caused by the airline industry during the period of 2020-2021. The reverse effect was also detected, which has empirically validated the hypothesis that, during the pandemic, pollution in the atmosphere has declined because of the cancellation of flights. This confirms the hypothesis that there is positive feedback causality between passengers carried and CO2 emissions. This finding has also been supported in the existing energy literature. These outcomes have implications for environmental sustainability targets in the EU and Turkey, as the recovery of international passenger traffic will proceed at a very close pace. More policy caveats are elucidated in the conclusion section.