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.

Characterization of economic requirements for a "carbon-debt-free country".

In recent years, greenhouse gas emission controls that incorporate the supply chains of products and services, thereby emphasizing the role of consumers rather than producers, have been drawing increasing attention. A country's consumption-based emissions, including those due to global supply chains, reflect the total emissions on which the national economy relies. To design effective emissions control strategies there is therefore an urgent need for countries to elucidate the structural relationship between their domestic economy and emissions occurring through global supply chains. Here we consider the structural characteristics of consumption-based emissions in Japan, which in 2005 totaled 1675 Mt CO(2)eq. Outside the country the Japanese economy generated global emissions of 541 Mt CO(2)eq, 35.7% of which were UNFCCC Annex I emissions and 64.3% were non-Annex I and other emissions. This figure of 64.3% reveals that Japan is actually relying to a considerable degree on emissions that are subject to no international obligations. We identify key economic contributors to consumption-based emissions at the commodity level and specify items of household expenditure that are effective options for both financial savings and emissions reduction. We then discuss the importance of emissions control for evolving toward a "carbon-debt-free country".

Hybrid life-cycle assessment (LCA) of CO2 emission with management alternatives for household food wastes in Japan.

In this study, we conducted a hybrid life-cycle assessment (LCA) to evaluate reductions in CO(2) emissions by food waste biogasification of household food wastes in Japan. Two alternative scenarios were examined. In one alternative (Ref), all combustible municipal solid wastes (MSWs), including food waste, are incinerated. In the other (Bio), food waste is biogasified, while the other combustible wastes are incinerated. An inventory analysis of energy and material flow in the MSW management system was conducted. Subsequently, the inventory data were summarized into an input-output format, and a make-use input-output framework was applied. Furthermore, a production equilibrium model was established using a matrix representing the input- output relationship of energy and materials among the processes and sectors. Several levels of power generation efficiency from incineration were applied as a sensitivity analysis. The hybrid LCA indicated that the difference between the Bio and Ref scenarios, from the perspective of CO( 2) emissions, is relatively small. However, a 13-14% reduction of CO(2) emissions of the total waste management sector in Japan may be achieved by improving the efficiency of power generation from incineration from 10% to 25%.

Material and energy dependence of services and its implications for climate change.

As the services industry has grown and diversified, there has been a rapid rise in the share of energy and material costs in provision of services. As a result, services, which have traditionally been considered immaterial by their nature, are now absorbing substantial amounts of energy and material goods. By decomposing the CO2 emissions embodied in material goods and services, this study quantitatively analyzes the implications of energy and materials consumption in services for the change in indirect CO2 emissions by household consumers in Japan. The results show that the domestic CO2 emissions associated with the energy and material goods absorbed by services through the supply chain increased consistently during the decade 1990-2000, thereby constituting a key element in the rise in CO2 emissions due to household consumption. The energy and materials within the supply chain underlying services that have been identified as the main causes of this increase include electric power consumption, petroleum products, building renovation and repair, distribution of printed materials, plastic products and water, all of which are necessary to support the services in question. This study highlights the increasing importance of energy and materials consumption by services in the context of climate change policy.

Centralization of dairy farming facilities for improved economics and environmental quality.

In Japan, most farm animal excreta has been stored directly on farmland. Runoff from this storage has often caused water pollution. Biogasification is anticipated as an important technology to manage excreta properly, but complex problems hinder its introduction. Economic aspects of management have been especially difficult for dairy farmers. For this study, structural problems regarding introduction of biogasification into dairy farming were identified. Subsequently, a desirable system of dairy farming including biogasification was suggested, and an evaluation model of the financial balance was constructed. A case study using current financial balances of several systems of dairy farming was evaluated using the constructed model and actual data. The systems were based on several policy alternatives including the suggested system mentioned above. Results show that a farmer can obtain sufficient income from a system featuring centralization of dairy housing and biogasification facilities and coordinated management by over six farmers.

Simple indicator to identify the environmental soundness of growth of consumption and technology: "eco-velocity of consumption".

Today's material welfare has been achieved at the expense of consumption of finite resources and generation of environmental burdens. Over the past few decades the volume of global consumption has grown dramatically, while at the same time technological advances have enabled products with greater efficiencies. These two directions of change, consumption growth and technological advance, are the foci of the present paper. Using quantitative measures for these two factors, we define a new indicator, "eco-velocity of consumption", analogous to velocity in physics. The indicator not only identifies the environmental soundness of consumption growth and technological advance but also indicates whether and to what extent our society is shifting toward sustainable consumption. This study demonstrates the practicability of the indicator through a case study in which we calculate the eco-velocities of Japanese household consumption in 2 years: 1995 and 2000. The rate of technological advance during the periods concerned is quantified in terms of the embodied carbon dioxide emission per yen of product. The results show that the current growth rate of Japanese household consumption is greater than the rate of technological advance to mitigate carbon dioxide emissions. The eco-velocities at the level of individual commodity groups are also examined, and the sources of changes in eco-velocity for each commodity are identified using structural decomposition analysis.