Water risk is forefront concerns in the world. Many negative impacts related with water use such as pollution and shortage have been emerged internationally. Water footprint is a metric that quantifies the potential environmental impacts related to water considering the life cycle of products or organizations. Water footprint is now paid attentions to share the reliable information in terms of current situation of water related environmental performance effectively. Many of research including the activities by Water Footprint Network development have been carried out for the development of inventory database and impact assessment method. International standard（ISO14046）describing the principles and requirements of water footprint have been published in 2014. This article summarized the present status of the activities relating water footprint including the development of database, applications to case studies and the characteristics of international standard.
Amid growing interest in water resource issues, evaluation methods for sustainable water resource use has been studied. For environmental impact assessment of water resources, LCA practitioner have to collect the inventory data related to water resources in primary data collection, and also the inventory data of water resources is essential in the background database. So, we added the water resources inventory data to our inventory database IDEA (Inventory Database for Environmental Analysis) ver.2. IDEA ver.2 prepared about 3,800 process data and equipped with high level the comprehensiveness, completeness, representativeness and transparency. To expand the water resources inventory in IDEA, it was considered largely contribute to water resources assessment. In this paper, for the Japanese LCA practitioner, the differences of concept between the water resources data in foreign inventory database and IDEA were explained. And I introduce the concepts and the way of data creation of IDEA.
Objective. Potential environmental impacts related to water has drawn much attention in recent year. The rapid increase of interests leads to the publication of the international standard（ISO14046）on water footprint at August, 2014. Many impact assessment methods applicable to water footprinting have been developed. However, the targets and characteristics of existing methods are various due to the diversity of potential environmental impacts related to water. In addition, impact assessment in water footprinting（water footprint impact assessment）can be classified into four types（water scarcity footprint, water availability footprint, water footprints addressing water degradation, water footprint profile）, which may confuse practitioners to choose appropriate methods for each type of assessment in application studies. Thus, currently developed methods applicable to water footprint impact assessment are reviewed and characterised according to the types of water footprint impact assessment.
Results and Discussion. Water scarcity footprint and water availability footprint assess the potential impacts in terms of physical scarcity of water resources compared with water demand. At midpoint level, basic concept to indicate the impacts by the ratio of water demand and available resource amounts is common to all corresponding methods. However, differences in formulation of indicators, spatial resolution and temporal resolution can be found. Especially in water availability footprint, two methods are applicable but require more efforts for practitioners to collect information on quality of water resources. At endpoint level, methods for assessing impacts on human health, ecosystem and resources can be applicable. On the other hand, the target impacts even at same endpoint are different from method to method. Wide range of characters including the units of indicators can be figured out. Regarding water footprints addressing degradation, while existing impact assessment methods on categories related to water pollution by chemical substances are applicable, target areas of them are mostly region/country specific. Grey water can be an option as a proxy to express the stress of water pollution although it does not necessarily indicate the potential impacts that actually happen. Global scale assessment models will be expected to be developed concerning on thermal pollution that has not been dealt in conventional life cycle impact assessment. Water footprint profile can be achieved by summarising some or all results of other three methods on water footprint impact assessment. While some methods propose to integrate the results on different aspects into single index, weighting and its results shall be compliant with ISO14044.
Conclusions. While there are differences among existing methods for water footprint impact assessment, summarised characters of each method in this paper corresponding to each type of water footprint impact assessment will be useful for practitioners to make a decision on the selection of methods according to their scope of the assessment. Unified and consensual method and indicators are more desirable for the sake of avoiding confusion in practice. The activities in WULCA working group are expected to achieve the goal in future. From the viewpoint of methodology development, harmonization of inventory databases and impact assessment methods is necessary for more precise assessment at detailed spatial and temporal resolution.
The impacts of water use have rapidly gained attention in Life Cycle Assessment（LCA）since around 2007. The WULCA（Water Use in LCA）working group has taken initiatives to lead discussions of assessing impacts related to water use and the development of consensus and recommendations. The working group is composed of various international experts and stakeholders from academia, industry and public institutions. The aims of the working group are to develop a general assessment framework for water use（inventory schemes, impact assessment methods including indicators）and derive recommended practice and guidance for LCA method developers and practitioners. Members in the working group are involved in the activities in accordance with their commitment and contributions to deliverables. Meetings with active members have been regularly held to discuss and establish a general framework for water use. As results of this discussion in the past years, definition of a general framework for assessing water use in LCA, a review of methods and quantitative analysis of the differences in existing models are published as deliverables from the working group. Currently, one of the main points in the discussion has moved on to the development of consensual indicators for assessing the impacts of water use, in line with the activities of UNEP/SETAC Life Cycle Initiative Flagship Project on “Global guidance on environmental life cycle impact assessment indicators”. The consensuses are being built to achieve a harmonized method for assessing the impacts of water use from a scientific and practical point of view by a variety of developers and stakeholders. Expert workshops were held for integrating knowledge and comments from experts in various fields, including outside of LCA. The working group also contributes to support the implementation of water footprinting and water impact assessment in LCA in practice, and training courses have been conducted in various regions of the world. The training aims to instruct practitioners to gain understanding and practice on the topic of water footprint, as well as interpret the results in the appropriate way. Main outputs and deliverables are available online through the website of WULCA and LinkedIn.
Ministry of the Environment examined methods to quantitatively assess impacts on global water resources and water environment due to human activities, aiming to increase public awareness of water saving and water conservation by using a quantitative index. Though ISO standardization process has been proceeding, concrete quantification methods and usage of the quantified results have not been considered so much in Japan. To establish water footprint as an index that appropriately reflects the impacts on water environment, in line with the moves of such international standardization, we developed the technical guidelines to provide with domestic business. Based on the considerations described above, we considered a “Water footprint case studies on quantification methodology”, aiming that domestic business can use it as a reference manual in quantifying water footprint of its own products. In this review, I introduce a case study of water footprint on clothes and issue.
Objective. Using the biomass materials to suppress the GHG emissions is now spreading all over the industries. On the other hand, it would increase other environmental burden, for example fresh water consumption, to cultivate the crops. In this study, we carried out GHG and water analysis of our product —SUPER-MiLD Shampoo, which bottle is made by sugarcane-derived polyethylene (PE)—and some bio-plastics in order to figure out the trade-off effect and the contribution to reduction. Results and Discussion. The shampoo emits 15.3 kg-CO2e of GHG, and consumes 1.85 m3 of fresh water through its life cycle. Especially the largest contribution of use-stage has come out. Sugarcane-derived PE can decrease 0.129 kg-CO2e of GHG emissions in spite of increasing 0.133 m3 of water consumption compared to the fossil derived PE bottle. When we use the biomass materials in order to reduce GHG emissions, the water consumption would increase as a trade-off. So we defined “Water Efficiency” as following, Water Efficiency = Decrement of GHG emissions [kg-CO2e] / (Increment of water consumption [m3] * Water availability factor), and tried to estimate the index of some bio-plastics, PET (Brazil, Sugarcane, Plant ratio: 20%), PE (Brazil, Sugarcane, Plant ratio: 100%) and PLA (U.S., Maize, Plant ratio: 100%). The Water Efficiency index, that takes into account the water scarcity of growing area, showed the fact that there is a big difference between bio-plastics. These results indicate the utility of the index on product design from the viewpoint of sustainable water use. Conclusions. In economic activities, it is necessary to consider also the increase in other environmental impacts as well as climate change issue. In addition, we should aim balanced and optimized environmental performance of products.
Background and Objective. Though weighting in life cycle impact assessment (LCIA) is widely used in practice, it is still a controversial issue. There are many kinds of calculation methods of weights such as distance-to-target (DtT), panel, and monetization methods and the choice of the calculation method has an effect on the decision-making. From another aspect, weighting methods can be classified into midpoint and endpoint approaches. There exist previous studies that compare different LCIA methods including weighting phases. However no studies have compared weighting methods themselves considering the difference in frameworks of LCIA methods. The purpose of this study is, by calculating multiple sets of weighting factors using different methods under the identical LCIA framework, to investigate how differences in calculation methods and viewpoints among weighting methods have influence on midpoint and endpoint weighting factors. Methods. Weighting factors were calculated for midpoint and endpoint impact categories using the panel method as well as the DtT method under the framework of LIME2. The questionnaire surveys for panel methods were conducted for respondent groups who have different viewpoints, such as LCA specialists and practitioners, and weighting factors based on two different approaches, “paired comparison” and “classification of importance”, were calculated by two styles of questionnaires. By comparing the results, differences between respondent groups, between panel and DtT methods, and between different approaches of the panel method were discussed. Results and Discussion. The variability of calculated weighting factors among specialists was larger than the LCA practitioners. Compared with the weighting factors based on the DtT methods, there was less difference among the weights of impact categories calculated based on panel methods. The choice of the approach of the panel method had an influence on the calculated weight of impact categories. For example, noise, as one of the midpoint impact categories of LIME2, was evaluated to be more important by paired comparison than classification of importance. Conclusions. These results suggest that weighting factors can be affected by various factors such as the choice of calculation method of weights. It was found that even weighting factors of a particular respondent were variable depending on the approach of the panel method. When practicing LCIA, interpreting or using the results of LCIA, it is important to understand the underlying concepts and viewpoints of weighting methods behind the variability of weighting factors.
Objective. It is recommended to reduce the greenhouse gases (GHG) for good environment action even when we buy fresh produce. The objective of this research is to calculate the amount of GHG emissions from fresh produce arriving in Nagoya City and also to analyze yearly variation in five years. Results and Discussion. We calculated the amount of GHG emissions about the level of production and transportation for 37 items(fruits, vegetables, meat and seafood) based on the amount of treatment in Nagoya Central Wholesale Market during 2008～2012. As a result, the amount of GHG emissions about the production level of the fruits and vegetables which was cultivated with heat was larger than that of the others and correlative to the amount of treatment. The GHG emissions from transportation process of the items that were transported from a distant place such as the Hokkaido or Tohoku regions were higher than those from the others. The annual amount of GHG emissions varied in response to annual national production or catch, and it was decreased over time for many items. Conclusions. The current work showed the amount of GHG emission of fresh produce in the level of production and transportation was vary greatly by heated cultivation or unheated cultivation and also the distance of transportation. It also showed the amount of GHG emission about many fresh produce is reducing over time.
Objective. It is pointed out that environmental impacts other than climate change are apt to be neglected, while concern about global warming makes us focus on CO2 emission through product lifecycle. Kao Corporation launched synthetic laundry detergent in 1951. Since 1951, Kao has been improved it in terms of detergency, cost and environment. The biggest innovation was in 1987 when Kao launched compact type of powder laundry detergent, “Attack” which volume was reduced to 25% of the conventional one, “Newbeads”. Since then, compact powder laundry detergent became standard in Japan and has been kept improving. We have evaluated the change of environmental impact of compact powder laundry detergents by LIME2 which is enable us to evaluate a wide range of its environmental impact. In evaluating, scenarios for land transfer, land occupation and wasted surfactants have been newly introduced, because vegetable fat and oil is feedstock of surfactant used in the detergents. Results and Discussion. The evaluation has been done through whole lifecycle of powder laundry detergent, which includes procurement of raw materials, manufacturing, transport, use and waste. In the use stage, drying step of clothes and manufacturing step of a washing machine have been excluded. The land classification for growing oil producing plants has been assigned to crop land transferred from forest. For the scenario of wasted surfactants, the following conditions such as sewage line adoption rate, N2O emission rate as to combustion temperature of sewage sludge, SOx removal efficiency and NOx removal efficiency in Japan have been taken into account. Compared to a conventional detergent, Newbeads, successive 4 compact powder detergents, Attack have been discussed in both views of characterization evaluation and integration evaluation. The environmental impact of the latest Attack launched in 2011 has reduced by 66% in integration evaluation from Newbeads. That is because of detergency improvement, amount reduction of surfactants, volume reduction of package, saving water function of washing machine and so on. In characterization evaluation, trade-off between global warming and land use has been seen depending on the difference of raw materials used. The impact of air pollution derived from wasted surfactants was less than 1% of whole impacts. Conclusions. In evaluating lifecycle environmental impact of powder laundry detergents by LIME2, new scenarios for land use which occurred in connection with bio-based surfactants and wasted surfactant have been introduced. Since this methodology teaches us comprehensive environmental impact, we could develop a new powder laundry detergent having lower environmental load. We will make an effort to familiarize eco- friendly laundry custom with LIME2 evaluation.