Estimates of Embodied Global Energy and Air-Emission Intensities of Japanese Products for Building a Japanese Input–Output Life Cycle Assessment Database with a Global System Boundary

To build a life cycle assessment (LCA) database of Japanese products embracing their global supply chains in a manner requiring lower time and labor burdens, this study estimates the intensity of embodied global environmental burden for commodities produced in Japan. The intensity of embodied global environmental burden is a measure of the environmental burden generated globally by unit production of the commodity and can be used as life cycle inventory data in LCA. The calculation employs an input–output LCA method with a global link input–output model that defines a global system boundary grounded in a simplified multiregional input–output framework. As results, the intensities of embodied global environmental burden for 406 Japanese commodities are determined in terms of energy consumption, greenhouse-gas emissions (carbon dioxide, methane, nitrous oxide, perfluorocarbons, hydrofluorocarbons, sulfur hexafluoride, and their summation), and air-pollutant emissions (nitrogen oxide and sulfur oxide). The uncertainties in the intensities of embodied global environmental burden attributable to the simplified structure of the global link input–output model are quantified using Monte Carlo simulation. In addition, by analyzing the structure of the embodied global greenhouse-gas intensities we characterize Japanese commodities in the context of LCA embracing global supply chains.为构建涵盖全球供应链的日本产品生命周期评估（Life Cycle Assessment, LCA）数据库，同时降低时间与人力投入负担，本研究针对日本本土生产的商品，估算其隐含全球环境负荷强度。隐含全球环境负荷强度指单位商品生产在全球范围内引发的环境负荷，可作为生命周期评估的生命周期清单数据使用。本研究采用投入产出LCA方法，结合基于简化多区域投入产出框架划定全球系统边界的全球关联投入产出模型开展计算，最终得到406种日本商品的隐含全球环境负荷强度，覆盖能源消耗、温室气体排放（二氧化碳、甲烷、一氧化二氮、全氟化碳、氢氟碳化物、六氟化硫及其排放总量）以及空气污染物排放（氮氧化物与硫氧化物）四类核算指标。针对全球关联投入产出模型简化结构所引发的隐含全球环境负荷强度不确定性，本研究借助蒙特卡洛模拟（Monte Carlo simulation）完成了量化分析。此外，本研究通过剖析隐含全球温室气体强度的结构特征，在涵盖全球供应链的生命周期评估框架下对日本商品进行了特征刻画。