Estimation of Greenhouse Gas Emission Factors Using 1995 Japanese Economic Input-Output Table

Abstract

Development of environmental database was studied using Japanese input-output (I-O) tables for life cycle inventory (LCI) analysis. Many LCI case studies were performed using Japanese I-O tables. However, most of these studies focused only on CO2 emissions due to lack of high quality data concerning other substances that affect the environment. The objective of this study was to supply CO2 and CH4 emission factors of commodities estimated using the latest Japanese I-O table (1995). In general, emission factors are estimated using Japanese I-O table based on the assumption that all commodities are produced in Japan. In this study, however, a method is used that considers the actual activities at the overseas production of import goods. The results show that CH4 is not negligible when performing life cycle assessment from the viewpoint of global warming, and that CO 2 and CH4 emission factors estimated using the conventional method are very different from those using the method proposed in this study because of the difference of technologies used in Japan and abroad.