Do patents, renewable energies and energy taxes in the transport sector reduce transportation carbon emissions in the European Union?

Transportation infrastructure plays a significant role in exacerbating climate change as it contributes to a substantial increase in carbon dioxide (CO2) emissions. The sole economic sector in which European countries have not succeeded in reducing greenhouse gas (GHG)emissions is the transportation industry. Therefore, reducing transport-related emissions is a primary focus of emphasis in the European Union's efforts to meet its climate targets. Accordingly, this study analyzes the impact of renewable energy use, patent development, and energy taxes in the transport sector on the three different modes of transport-related emissions (aviation, road, and rail) in the 10 highest-income countries of the European Union over the period 2008–2020. The study uses the novel half-panel jackknife estimator for this analysis. The results of the estimation show that patents contribute to the reduction of CO2 emissions in aviation and rail transportation, while renewable energies are only effective in rail transportation. In the context of road transportation, energy taxes are effective in mitigating CO2 emissions. Based on these findings, it is recommended that European Union policymakers promote the use of electric vehicles and eco- friendly means of transportation in road transport through energy taxes, increase the use of renewable energy sources such as biodiesel in rail transport, and reduce CO2 emissions by supporting patents that promote green innovations in the aviation sector.