Eco-intensity Analysis as Sustainability Indicators related to Energy and Material Flow

This paper presents the results of an analysis on energy and material flow in different regions and industrial sectors of Japan to evaluate regional and industrial sustainability. Several life cycle approaches used to quantify environmental efficiency related to energy and material flows were investigated as applications of life cycle tools in emerging markets, including the service industry and public sector. The regions included all forty-seven Japanese prefectures and the data for each prefecture considered sixteen industrial categories based on the national physical distribution census and national input-output tables for 1995. The ratio of the primary energy supply to the total material input for service industries ranged from 0.1 to 0.5 [TOE/10ton] for the forty-seven prefectures. Ultimately, several relationships between “energy/flow” and regional or industrial characteristics were derived, such as regional population, distance from major markets, and so on. INTRODUCTION In order to develop a sustainable society, an indicator that relates our understanding of the present state of urban metabolism to social activity is required. Studies have investigated the amount of material required based on social activity, e.g., material flow accounting (Adriaanse et al., 1997), and have included a macroscopic analysis of specific categories of material distributed among industries in Japan. Toward a future sustainable society, we must consider a kind of “Trilemma” of resources involving energy, the environment, and the economy. Sustainability indicators should ensure improved eco-efficiency, which means reduced eco-intensity. Using such sustainability indicators, we can promote regional or industrial transformation. Recent uses of sustainability indicators have been already reported for several local regions and industrial sectors. Quantitative indicators of the physical/biological aspect of sustainability could be applied to an agricultural county, using energy, water, soil, and nitrogen as numeraires (Herendeen and Wildermuth, 2002). We present some eco-intensity evaluation methods as potential sustainability indicators for effective environmental management. The novelty of our investigation lies in analyzing detailed energy flow characteristics and in combining energy flow and material flow. Another objective of this paper is to present a current case-study experience in one type of eco-intensity analysis for Japanese service industries. ECO-INTENSITIES IN VIEWING ENERGY AND MATERIAL FLOWS A local city council project aimed to construct material and energy flow analysis models producing an integrated approach to improving overall sustainability (Krrishnamohan et al., 2000). Their analysis highlighted the ultimate fate of inputs, products/services and wastes, and shown crucial help in minimization of resource consumption and/or development of potential synergies between organizations in terms of resource exchange. Beside, a first step was made in bridging the gap between the various types of analysis of material flows in the economy (Bouman et al., 2000), by discussing the main differences and similarities of three often employed model types: substance flow analysis, life cycle assessment and partial economic equilibrium analysis. Consider a kind of “Trilemma” involving the environment, energy, and the economy. The following simple equation [Eq.1] shows a way to identify one type of eco-intensity related to energy and material flows: