탄소세의 국경세 조정에 대한 WTO법적 검토

Some developed countries which implement climate change policies have introduced or considered to introduce carbon tax as a complimentary or alternative measure to CO2 regulation systems such as cap and trade system and subsidies. Carbon tax is generally imposed based on the carbon content in fossil fuels or the amount of CO2 emitted in the course of production of goods. Carbon tax is said to be an effective tool to regulate CO2 emission. However, if there is no equivalent CO2 reduction efforts in the global level, a country implementing carbon tax may encounter a loss of competitiveness in the domestic carbon intensive industry, and carbon leakage. The idea of introducing border tax adjustments of carbon tax is suggested to solve these problems. But in practice, border tax adjustments could bring about not only some technical and administrative difficulties but also legal problems from the perspective of the WTO law. As the related WTO rules such as the GATT1994 Art. II:2(a) (for imports) and the Annex I(h) of the WTO SCM Agreement (for exports) are not clear on this issue, specifically the border tax adjustment on the inputs which do not physically remain in the final products, and also there has been no relevant WTO dispute cases so far, the border tax adjustments of carbon tax is likely to be subject to the WTO dispute in the future. Other related legal issues include the status of carbon tax (applicability of GATT1994 Art. II:2(a)), non-PPMs and the likeness of products (the violations of GATT1994 Arts. III and I), discrimination in the border tax adjustment depending on the origin of products (the violation of GATT1994 Art. I) and the possibility of justification of the border measure under the GATT1994 Art. XX (general exception). If the border tax adjustments of carbon tax have protective purpose for domestic industry, it is not likely to be justified under Art. XX under the current WTO system.