Recently, learning life cycle thinking (LCT) has attracted attention as a new approach of environmental education. This LCT-based environmental education is expected to make learners understand and feel the “link” between their daily lives and environmental problems through learning the life cycle of products and services, and consequently encourage people’s pro-environmental behaviors. The objective of the present study is to develop a scale for measuring this“ sense of link” which is a key to evaluate the effects of LCT-based environmental education programs. First, the present study defines the “sense of link” based on previous studies, and develop a questionnaire consisting of multiple question items to measure the “sense of link. Second, preliminary surveys using this questionnaire are conducted with 523 high school students, and a scale of the “sense of link” is proposed by refining the question items based on the collected survey data. Finally, questionnaire surveys using the proposed scale are conducted with 553 high school students, and the reliability and validity of the scale are verified using the collected survey data. The calculated Cronbach’s alpha and the factor analysis result reveal that the proposed scale has good reliability and validity.

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This study estimated potential amount of TMR (Total Materials Requirement) reduction for homeappliances (Air conditioner, Washing Machine, Refrigerator, Liquid-Crystal Television) by materials recycling for Fe, Cu, Al, and plastics in Thailand, Vietnam and Japan. The amount of TMR reduction indicates the difference between the TMR of materials obtained from natural and from recycling, so that means the effectiveness of materials recycling quantitatively. The result shows that the maximum annual TMR reductions by materials recycling are 8.5×10⁶ t in Thailand, 10.6×10⁶ t in Vietnam, and 43×10⁶ t in Japan. Especially, recycling of air conditioner, recycling for Cu significantly contributes to the TMR reduction.

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This study aims to evaluate the impact of international trade on global water supply-demand balance, focusing on irrigation water requirements derived from food consumption. In this study, the water supply-demand balance is estimated by using the water stress index. The concept of a water footprint is applied to evaluate indirect water consumption caused by importing food, along with direct water consumption derived from domestic food production. Irrigation efficiency is used to convert water consumption into water withdrawal. The amount of available water resources is defined as a restriction on the maximum water availability for agriculture, which does not mean all the renewable water resources used in the agricultural sector. In 2010, 41 countries were found to be under high or moderate water stress, those are equivalent to 30% (1.9 billion) and 28% (1.8 billion) of the world population, respectively. In addition, water stress of the 8 countries in these 41 countries should be caused by food exportation. For example, in Thailand, water stress should be caused by exporting rice, which is accounted for 86% (26.7 km³) of its irrigation water withdrawal originated from food production for export.

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In recent years, promotion of stationary fuel cell cogeneration systems (FC-CGS) has been expanding in Japan for solving the global warming problem. Especially, the FC-CGS of a polymer electrolyte fuel cell or a solid oxide fuel cell was installed in the residential sector in Japan. Also, these systems are expected for the global warming protection in EU countries. Thus, in International Electrotechnical Commission/Technical Committee 105 (IEC / TC 105), the combined indexes in consideration of a Life Cycle Assessment (LCA) and/or its specification are developing in order to improve the quality of products. Since the contents of material for a device and/or the performance are attributed to the combined indexes, the integration of each factor for a communication is necessary to identify the characteristic of target one. In this study, the identification index was proposed on basis of a data envelope analysis (DEA), and defined as a FC-DEA. As a result, the efficiency values on basis of DEA (FC-DEA) were 0.846 of PEFC-CGS, 0.648 of SOFC-CGS (a planar type) and 1.000 of SOFC-CGS (an anode support type), respectively. It found that the FC-DEA would be identified on the difference of each specification of a device.

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The purpose of the present study was to evaluate the environmental performance of domestic seawater desalination in terms of CO₂ and water consumption as well as life cycle cost. In addition, we determined differences between expected values based on facility plans and actual observations. Results of assessments per 1 m³, both environmental burdens and costs were higher under real operating conditions than had been expected during planning. Most life cycle CO₂ emissions were related to electricity usage, and indirect water consumption for the production of chemicals also had a big influence on the total environmental burden(CO₂: 95 - 99%, water consumption: 50 - 95%). The impact of electricity in Okinawa was calculated based on coal-fired power generation, while in Fukuoka it was based on thermal power generation using natural gas. The production of chemicals for cleaning reverse osmosis membranes was a dominant contributor to water consumption. As a result of LCC comparison between calculations and actual measured values in Okinawa, actual measured values was about 5.5 bigger than calculations because of low operation rate (8%). Based on the results of a sensitivity analysis and comparison of this study with the existing literature, we found that it is possible to reduce CO₂ emissions by changing electric power sources, and this finding is consistent with previous results.

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The life-span of consumer durables has been attracting increased interest in recent years, prompted by concern about the need to reduce waste, improve resource efficiency, and create a low carbon, circular economy. This paper explores explanations for the growing interest and discusses its implications for industry and government. Recognizing the importance of debate around product longevity for environmental tools and techniques such as life cycle assessment (LCA), it explains the importance of distinguishing product lifetimes and life-spans from product life cycles. It argues that increased empirically-based knowledge of product lifetimes would reduce the risk of inaccurate assumptions being used in LCA studies, and describes the use of LCA studies to estimate the optimal replacement time for energy-using products in order to minimize environmental impacts. It then considers the significance of product life-spans for economic, environmental and social sustainability and the potential benefits to consumers of increased product longevity. The issues are sometimes complex and the paper notes a controversy around possible environmental trade-offs in cases where technology has enabled the development of more energy efficient products. Recent developments in knowledge and policy are explored, revealing a growing community of academic researchers who are actively seeking to improve understanding of product lifetimes. The final section of the paper traces recent studies commissioned by international agencies, government departments and public authorities which have been prompted by the European Commission’s Action Plan for the Circular Economy. These suggest a growing consensus around the need for a strategic shift from waste management to waste reduction and from the linear economy to the circular economy.

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This article explained various concepts and definitions of product lifetimes. It was shown that various “product lifetime” can be defined according to its starting and ending time points in the product lifecycle; the definitions of product lifetime data that was observed and reported by academic papers and survey reports are diverse; a clear distinction among the definitions is needed. When the product lifetime data is used for a material flow and stock accounting/analysis and lifecycle assessment, the data with an appropriate definition should be selected according to the purpose. This article also introduced that it is possible to estimate the product lifetime with a definition of interest by selecting an estimation approach and original data appropriately.

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Lifetime of products is one of the key parameters in LCA and MFA. Lifetime of products is generally regarded as the average of a distribution which is observed from lifetimes of a product group. The average may be different among definitions of distributions. In this article, we introduced six different types of the products’ lifetime distributions. Those definitions can be classified by cumulative or probability distribution; base year for which distribution is drawn, such as shipment year or discard year; and a group for denominators to calculate percentages, such as a group of annually discarded products or a group of annually shipped products. On the basis of the classification, advantages of those different distributions were discussed.

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This paper summarizes status and time of use of electrical and electronic equipment (EEE) using primarily Southeast Asia as a case study. The main EEE under investigation are television, refrigerator, washing machine, air conditioner, personal computer, and mobile phone. Through a survey conducted in 2006 and 2013, possession rates per household, average ratio of second-hand to entire EEE, and time-of-use in Vietnam were retrieved, and through literature review data on EEE use in other countries complemented the analysis. It is found that in Vietnam the average possession rates per household of television, washing machine, refrigerator, and air conditioner in 2013 is almost the same as the one in the highest income group in 2006. The possession ratio of second-hand devices is 2.5 ～ 17.3% in Hanoi and Ho Chi Minh City together, while that in Hanoi is more or less 50% lower in 2006. The ratio of second-hand devices in Hanoi is lower than that in Ho Chi Minh City, and according to a Weibull distribution applied to the surveyed data, the average time of use in 2013 is greatly decreased compared with that in 2006. Further comparisons per EEE on the average time of use and the GDP-PPP/capita in a cross-sectional sample using data from various countries found that the average time of use for refrigerator, washing machine, and air conditioner decreased up to a certain threshold with the increase in GDP-PPP/capita, beyond the threshold increases were found as GDP-PPP/capita increased further; in other words, a U-shaped trend was found in the curve. On the other hand, no relation could be observed for television, personal computer and mobile phone.

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This paper examines the possibility that the numbers of motorbike in use in Japan are overevaluated by investigating the consistency between data on stock and flow of motorbike in Japan. Several datasets on stock, including official registration, automobile tax, automobile liability insurance, household survey, are compared and analyzed. As a result, official stock data of motorbike type without automobile inspection are over-evaluated, whereas the one with automobile inspection is found to be difficult to be concluded for conflicting data considered in this study.

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