Study on the Optimal Allocation of CO2 Emissions Embodied in Trades : From the Perspective of Impacts on Low Carbon Policies

本研究旨在通过对国内气候政策的影响以及边界调整措施的定量评估，提出国际贸易中所体现的适当的二氧化碳排放责任分担方案。我们利用GTAP-E的部门二氧化碳排放量数据库和亚洲国际投入产出表估算了2000年国际贸易中包含的二氧化碳排放量，并计算了每个国家在不同责任分担方案下的责任排放量。我们还使用多区域可计算一般均衡模型，评估了缓解国际竞争力缺陷的边界调整措施和与国内气候政策相关的碳泄漏对国际贸易中体现的二氧化碳排放的影响。根据模拟结果，边界调整措施可以有效地缓解日本碳税造成的碳泄漏，但日本的福利水平可能会下降。

This research aimed at proposing appropriate sharing scheme of responsibility of CO_2 emissions embodied in international trades through a quantitative assessment of impacts of domestic climate policies as well as border adjustment measures. We estimated CO_2 emissions embodied in international trades using sectoral CO_2 emissions of GTAP-E database as well as Asia International Input-Output table in 2000, and calculated responsible emissions of each country under different responsibility sharing schemes. We also assessed the impacts of border adjustment measures for mitigating international competitiveness drawbacks and carbon leakage associated with domestic climate policies on CO_2 emissions embodied in international trades, using multi-regional computable general equilibrium model. Based on the simulation results, border adjustment measures could be effective in mitigating carbon leakage caused by Japanese carbon tax but the welfare level of Japan may decline.