Quantifying consumption-based carbon emissions of major economic sectors in Japan considering the global value chain

Abstract

International trade accelerates the separation between consumption and production on a global scale, thus leading to carbon transfer. Consequently, carbon flow embodied in international trade reallocates global carbon emission responsibilities, consisting of domestic demand and imports but excluding exports. To tackle the geographic flow of emissions embodied in products and services, carbon emissions must be quantified according to the global value chains. Using Japan as a case study, this study tracked the evolution of consumption patterns, international trade, and related carbon emissions based on multi-regional input-output tables, and carbon emissions inventories. Carbon emission transfers among sectors and countries were identified from 2000 to 2014. As a result, imports from the industrial sector led to a gap between production- and consumption-based carbon emissions. Japan was found to be an emissions net import country over the study period, with about 58% of the total carbon emissions inflow coming from China. Moreover, household consumption accounted for nearly 60% of consumption-based emissions, with industrial sector products and services being the primary source of carbon inflow, and the service, transport, and industry sectors are responsible for the majority of domestically released emissions. These conclusions provide valuable information for Japan to customize sectoral carbon reduction priorities, an essential component of setting decarbonization goals from the consumer perspective.