Abstract
This study investigates the effects that national income, public expenditures, research and development (R&D) investments, and environmental taxes (ET) have on carbon emissions. The variables of national income, the square of national income, public expenditures, R&D, total ET, transport taxes, and energy taxes are used in conjunction with carbon emission data for this analysis. Three distinct models are used herein: Model 1 employs the total ET, model 2 utilises transport taxes, and model 3 makes use of energy taxes. A Dumitrescu-Hurlin causality analysis was employed to investigate the relationship between the variables, which demonstrates that there was a Granger causality from national income, the square of national income, and public expenditures to carbon emissions. However, there was no Granger causality from R&D expenditures to carbon emissions. Finally, there was a one-way Granger causality relationship from total ET, transport taxes, and energy taxes used as ET to carbon emissions. Therefore, this study concludes that R&D investments are important for the development of environmentally friendly production structures and for increasing the importance of these structures in the economy. Finally, the findings emphasise that ET in particular can be effective in reducing carbon emissions within the framework of the Kyoto Protocol and the Paris Agreement