Assessing the eco-efficiency of materials: Methodology development and Japanese case study

Resource productivity is an indicator used in environmental management policy and defined as the ratio between indicators of economic activities, e.g. Gross Domestic Production (GDP) at the national level, and the weight of... [ view full abstract ]

Resource productivity is an indicator used in environmental management policy and defined as the ratio between indicators of economic activities, e.g. Gross Domestic Production (GDP) at the national level, and the weight of the resources used for these activities. Resource productivity is thus an essential aspect of dematerialization policies which aims at developing economic activities while using fewer resources. The drawback of this approach is nonetheless that environmental impacts do not relate necessarily to the weight of resources used. Eco-efficiency calculated as the ratio between GDP and environmental impacts is thus a better indicator on the pressure our societies exert on the environment. Still, eco-efficiency is not captured at the material level and the linkage with resource productivity is poorly assessed.

The present research developed a methodology for assessing the environmentally weight material consumption (EMC), i.e. the upstream and downstream environmental impacts associated with materials. Similarly, the value added associated with the life cycle of materials is addressed. We then applied our new methodology to the disaggregated 2011 Japanese Input-output table which includes 400 sectors. Of these, 64 were selected as targeted sectors and the economy were captured from the viewpoint of these sectors/materials. Greenhouse gas emissions (GHG) as conformed to the Japanese national GHG inventory were used as environmental impact.

Our preliminary results show that in 2011, the national Japanese eco-efficiency is 0.17 yen/gCO₂eq. The five materials/sectors with the highest eco-efficiency are timber (1.08), miscellaneous wooden products (1.01), copper (1.00), aluminium (0.89) and plywood,glue laminated timber (0.77). The five materials/sectors with the lowest eco-efficiency are cement (0.01), coal mining, crude petroleum and natural gas (0.06), crude steel converters (0.06), salt (0.09) and Rayon and acetate (0.11).