Tomohiro Tasaki

Lifespan of Commodities, Part I: The Creation of a Database and its Review

We compiled more than 1,300 data sets from various sources and identified some differences among the types of goods and among regions. With the reviewed data noted in this article, we established a database, named LiVES (Lifespan Database for Vehicles, Equipment, and Structures), and will disclose it on the Internet to share the information.In the present article, the available information from various reports on product lifespan was reviewed. Although we found a large number of data for many durables, the definition of lifespan in published articles varied, which limited our ability to compare reported values. We therefore first defined lifespan and then compared the international and historical data.Lifespan is an essential parameter for the accounting and analysis of material stocks and flows, one of the main research topics in industrial ecology. Lifespan is also important as a parameter that portrays the current and historical situation of industrial metabolism, which is an area of interest to industrial ecologists. In the present article, the available information from various reports on product lifespan was reviewed. Although we found a large number of data for many durables, the definition of lifespan in published articles varied, which limited our ability to compare reported values. We therefore first defined lifespan and then compared the international and historical data. We compiled more than 1,300 data sets from various sources and identified some differences among the types of goods and among regions. With the reviewed data noted in this article, we established a database, named LiVES (Lifespan Database for Vehicles, Equipment, and Structures), and will disclose it on the Internet to share the information.

Lifespan of Commodities, Part II: Methodologies for Estimating Lifespan Distribution of Commodities

Lifespan of commodities is essential information for material flow analysis and material stock accounting. Lifespan data is available in the literature; however, it varies in definition and in methodology employed. This article reviews and categorizes different types of lifespan distribution and distribution estimation methodologies, and investigates the relationship and differences between lifespan definitions and estimation methodologies. Lifespan distribution of commodities can be classified into five types from two perspectives: base year for which the distribution is drawn, and vertical axis of the distribution. The methodologies for estimating lifespan distribution were classified into four types and the details of each methodology and the relationship to the definition of lifespan were also clarified. This article also examines differences in actual lifespan data — between the types of distribution, the definitions, and the employed methodologies — by comparing reported data in literature. Any of the four methodologies are theoretically applicable and provide the same value of a lifespan; however unless accurate data such as census statistics are available, lifespan data can vary, and therefore we must be very cautious about the representativeness of sample data.

Quality- and dilution losses in the recycling of ferrous materials from end-of-life passenger cars: input-output analysis under explicit consideration of scrap quality.

Metals can in theory be infinitely recycled in a closed-loop without any degradation in quality. In reality, however, open-loop recycling is more typical for metal scrap recovered from end-of-life (EoL) products because mixing of different metal species results in scrap quality that no longer matches the originals. Further losses occur when meeting the quality requirement of the target product requires dilution of the secondary material by adding high purity materials. Standard LCA usually does not address these losses. This paper presents a novel approach to quantifying quality- and dilution losses, by means of hybrid input-output analysis. We focus on the losses associated with the recycling of ferrous materials from end-of-life vehicle (ELV) due to the mixing of copper, a typical contaminant in steel recycling. Given the quality of scrap in terms of copper density, the model determines the ratio by which scrap needs to be diluted in an electric arc furnace (EAF), and the amount of demand for EAF steel including those quantities needed for dilution. Application to a high-resolution Japanese IO table supplemented with data on ferrous materials including different grades of scrap indicates that a nationwide avoidance of these losses could result in a significant reduction of CO(2) emissions.

Assessing the Replacement of Electrical Home Appliances for the Environment

To evaluate whether replacing an existing product with a new, more energy‐efficient product is environmentally preferable, we used an assessment approach based on life cycle assessment. With this approach, consumers can assess various replacement products, including products of different sizes or environmental performance in addition to consideration of various conditions of product use. The approach utilizes a diagram in which replacement conditions of products are compared with iso‐environmental‐load lines to determine the appropriateness of replacement. The approach also allows the assessment of energy and resource consumption and environmental impacts not only during the use stage, but also at other product stages. Iso‐environmental‐load lines to assess delayed replacement were also examined and derived. We then applied the approach in a case study of energy consumption by replacing three types of electric home appliances in Japan: TVs, air conditioners, and refrigerators. The results of assessment showed that replacing refrigerators after 8–10 years of use was preferable even if the replacement product was larger. The appropriateness of replacing TVs and air conditioners based on energy consumption depended on the replacement product and on the duration of daily use, and in several cases, delayed replacement was preferable. Replacement of air conditioners after 8–10 years of use was not preferable if the consumer already owned the most energy‐efficient product at the time of the purchase. The necessity of accounting for a variety of available replacement products was confirmed.

A survey of national sustainable development indicators

We surveyed sustainable development indicators (SDIs) adopted by 28 national governments, regions, and international organisations and compiled them into a database. The aims of this study were to understand the elements of sustainable development (SD), examine SDIs developed in certain fields and countries, and determine future tasks to improve SDI development. A total of 1,790 indicators were surveyed and classified into 77 subcategories in four categories. Most of the indicators measured various SD elements, and the indicators reflected each countrys developmental stage and specific concerns. Several advanced or unique indicators were also identified. Five major tasks in the future development of SDIs were identified: 1) creating time-conscious indicators; 2) measuring interactions between elements of a system; 3) dealing with transboundary issues in a national SDI system; 4) measuring SD quality (including subjective elements); 5) including ordinary citizens by showing the relationships between SDI and everyday life.

The Economic and Environmental Consequences of Automobile Lifetime Extension and Fuel Economy Improvement: Japan's Case

Abstract The presenft paper develops a structural decomposition analysis with cumulative product lifetime distributions to estimate the effects of both product lifetime shifts and energy efficiency changes on the embodied energy consumptions. The empirical analysis focuses on automobile use (ordinary passenger vehicles, small passenger vehicles, and light passenger vehicles) in Japan during the period 1990–2000. It reveals that the lifetime extension of existing old vehicles during the study period was more beneficial to the environment than purchasing new passenger vehicles with a relatively high fuel economy, because the lifetime extension empirically contributed to reducing the embodied energy consumption at the production and end-use stages. We also found that the energy-saving impact of a one-year lifetime extension was approximately 1.3 times larger than that of the most significant technological improvement in the electric power generation sector. Editors NoteOn the basis of this paper, the authors were awarded the third Leontief Memorial Prize at the 16th International Input–Output Conference in Istanbul. They received this prize, which is sponsored by Taylor & Francis, for the best conference paper by authors younger than 40 years.

Decomposition Analysis of Waste Generation from Stocks in a Dynamic System

We conducted a decomposition analysis of material flows in a dynamic system, focusing on factors in the generation of waste consumer durables. A methodology for the analysis of consumer durables was developed and applied to three common consumer durables: cathode ray tube TVs, refrigerators, and passenger cars. The methodology decomposed changes in the numbers of waste products into three factors: changes in lifespan distribution, past trends in replacement sales, and past trends in sales for additional purchases. The decomposed equation clearly showed that the number of waste products would not necessarily be reduced by lifespan extension alone. This is because the number of waste products generated is affected not only by current lifespan distribution but also by past trends in sales for replacement and in additional purchases. The results show that changes in past replacement sales influence the current generation of waste, even if current replacement sales are declining. To reduce the generation of waste products on a short-term basis, lifespan must be extended until the waste-reducing effect of lifespan extension exceeds the waste-increasing effect of the other two factors. From a long-term perspective, controlling current replacement and additional purchases can be used to prevent future waste product generation.

Does recyclable separation reduce the cost of municipal waste management in Japan

Municipal solid waste (MSW) management is a system involving multiple sub-systems that typically require demanding inputs, materials and resources to properly process generated waste throughput. For this reason, MSW management is generally one of the most expensive services provided by municipalities. In this paper, we analyze the Japanese MSW management system and estimate the cost elasticity with respect to the waste volumes at three treatment stages: collection, processing, and disposal. Although we observe economies of scale at all three stages, the collection cost is less elastic than the disposal cost. We also examine whether source separation at home affects the cost of MSW management. The empirical results show that the separate collection of the recyclable fraction leads to reduced processing costs at intermediate treatment facilities, but does not change the overall waste management cost. Our analysis also reveals that the cost of waste management systems decreases when the service is provided by private companies through a public tender. The cost decreases even more when the service is performed under the coordination of adjacent municipalities.

Estimation of secondhand personal computer import and export in Asian region

The purpose of this paper is to estimate export of used PCs by trade statistics and compared the results with other methods. The number of exported secondhand PCs can be estimated from export data from ports and quantity and price data to distinguish between shipments of new and used PCs. Exports of secondhand desktop and laptop PCs in 2001 were estimated to be 90,000 units and 245,000 units, and that of in 2004 were 649,000 units and 277,000 units, respectively. The number of PCs collected by manufacturers and exported abroad from Japan was compared with the situation in South Korea.

A database and characterization of existing lifespan information of electrical and electronic equipment

LIFESPAN of product is essential information for material flow and stock accounting (MFA/MSA) as well as discussing possible contribution of product lifespan extension to waste prevention and materials/energy savings. There are a number of literatures on actual lifespan distribution of products in our society; however, existing information is not well organized. The authors created a database named LiVES (Lifespan database for Vehicles, Equipment, and Structures) by reviewing existing lifespan data of various types of product including electrical and electronic equipment (EEE) [1]. In this study, the overview and characteristics of lifespan data of EEE included in the database was reported.