Abstract:The objective of this study is to seek better policy options for greenhouse gas (GHG) emission reduction in Korea's international aviation industry by analyzing economic efficiency and environmental effectiveness with a system dynamics (SD) model. Accordingly, we measured airlines sales and CO 2 emission reductions to evaluate economic efficiency and environmental effectiveness, respectively, for various policies. The results show that the average carbon emission reduction rates of four policies compared to the business-as-usual (BAU) scenario between 2015 and 2030 are 4.00% (Voluntary Agreement), 7.25% (Emission Trading System or ETS-30,000), 8.33% (Carbon Tax or CT-37,500), and 8.48% (Emission Charge System or EC-30,000). The average rate of decrease in airline sales compared to BAU for the ETS policy is 0.1% at 2030. Our results show that the ETS approach is the most efficient of all the analyzed CO 2 reduction policies in economic terms, while the EC approach is the best policy to reduce GHG emissions. This study provides a foundation for devising effective response measures pertaining to GHG reduction and supports decision making on carbon tax and carbon credit pricing.