Water Resources in Life-Cycle Impact Assessment: Considerations in Choosing Category Indicators

Water is one of many resources, wastes, and pollutants considered in life-cycle assessment (LCA). The widely used indicator for water resources, the total input of water used, is not adequate to assess water resources from a sustainability perspective. More detailed indicators are proposed for water resources in two areas essential to water sustainability: water quantity and water quality. The governing principles for a consideration of water quantity are that (1) the water sources or LCA inputs are renewable and sustainable and (2) the volume of water released or LCA outputs are returned to humans or ecosystems for further use downstream. The governing principle for a consideration of water quality is that the utility of the returned water is not impaired for either humans or ecosystems downstream. Water quantity indicators are defined for water use, consumption, and depletion to reveal the sustainable or nonsustainable nature of the sources. A flexible set of water quality indicators for various factors that may impair water quality are then discussed, including the LCA study choices, technical challenges, and trade-offs involved with such indicators. Indicator selection from this set involves the underlying concern or endpoint represented by the indicator and the level and accuracy of decision-making information that the indicator must provide. With significant differences in emissions among systems studied using LCA and different purposes of the LCA studies themselves, a single, default set of water quality indicators applicable to all systems studied with LCA is problematic. The proposed water quantity and quality indicators for LCA studies are also intended to be compatible with environmental management and reporting systems so that data needs are not duplicated and interpretation for one does not contradict or sow confusion for the other.     

Weighting in Practice:Implications for the Use of Life-Cycle Assessment in Decision Making

This article investigates how environmental trade-offs are handled in life-cycle assessment (LCA) studies in some Nordic companies. Through interviews, the use and understanding of weighting methods in decision making was studied. The analysis shows that the decision makers require methods with which to aggregate and help interpret the complex information from life-cycle inventories. They agreed that it was not their own values that should be reflected in such methods, but they were found to have different opinions concerning the value basis that should be used. The analysis also investigates the difficulties arising from using such methods. The decision makers seemed to give a broader meaning to the term weighting, and were more concerned with the comparison between environmental and other aspects than the weighting of different environmental impacts. A conclusion is that decision makers need to be more involved in modeling and interpretation. The role of the analyst should be to interpret the information needs of the decision maker, and help him or her make methodological choices that are consistent with these needs and relevant from his or her point of view. To achieve this, it is important that decision makers do not view LCA as a highly standardized calculation tool, but as a flexible process of collecting, organizing, and interpreting environmental information. Such an approach to LCA increases the chances that the results will be regarded as relevant and useful.     

Life-Cycle Assessment: Constraints on Moving from Inventory to Impact Assessment

Life-cycle assessment (LCA) is a technique for systematically analyzing a product from cradle-to-grave, that is, from resource extraction through manufacture and use to disposal. LCA is a mixed or hybrid analytical system. An inventory phase analyzes system inputs of energy and materials along with outputs of emissions and wastes throughout life cycle, usually as quantitative mass loadings. An impact assessment phase then examines these loadings in light of potential environmental issues using a mixed spectrum of qualitative and quantitative methods. The constraints imposed by inventory's loss of spatial, temporal, dose-response, and threshold information raise concerns about the accuracy of impact assessment. The degree of constraint varies widely according to the environmental issue in question and models used to extrapolate the inventory data. LCA results may have limited value in two areas: (I) local and/ortransient biophysical processes and (2) issues involving biological parameters, such as biodiversity, habitat alteration, and toxicity. The end result is that impact assessment does not measure actual effects or impacts, nor does it calculate the likelihood of an effect or risk Rather, LCA impact assessment results are largely directional environmental indicaton. The accuracy and usefulness of indicators need to be assessed individually and in a circumstance-specific manner prior to decision making. This limits LCAs usefulness as the sole basis for comprehensive assessments and the comparisons of alternatives. In conclusion, LCA may identify potential issues from a systemwide perspective, but more-focused assessments using other analytical techniques are often necessary to resolve the issues.     

A Decision Support Framework for Sustainable Waste Management

This article describes a decision support framework for the evaluation of scenarios for the integrated management of municipal solid waste within a local government area (LGA).
The work is initially focused on local government (i.e., municipal councils) in the state of Queensland, Australia; however, it is broadly applicable to LGAs anywhere. The goal is to achieve sustainable waste management practices by balancing global and regional environmental impacts, social impacts at the local community level, and economic impacts. The framework integrates life-cycle assessment (LCA) with other environmental, social, and economic tools. For this study, social and economic impacts are assumed to be similar across developed countries of the world. LCA was streamlined at both the life-cycle inventory and life-cycle impact assessment stages.
For this process, spatial resolution is introduced into the LCA process to account for impacts occurring at the local and regional levels. This has been done by considering social impacts on the local community and by use of a regional procedure for LCA data for emissions to the environment that may have impacts at the regional level.
The integration follows the structured approach of the pressure-state-response (PSR) model suggested by the Organisation for Economic Cooperation and Development (OECD). This PSR model has been extended to encompass nonenvironmental issues and to guide the process of applying multiple tools.
The framework primarily focuses on decision analysis and interpretation processes. Multiattribute utility theory (MAUT) is used to assist with the integration of qualitative and quantitative information. MAUT provides a well-structured approach to information assessment and facilitates objective, transparent decisions. A commercially available decision analysis software package based on MAUT has been used as the platform for the framework developed in this study.     

Valuation methods within LCA - Where are the values?

It is generally recognised that the valuation in LCA requires political, ideological and/or ethical values (hence the term). These values, however, are seldom discussed, and this paper may he seen as an early attempt. One result is that not only the valuation weighting factors, but also the choice of valuation methodology and the choice of using a valuation weighting method at all, are influenced by fundamental ethical and ideological valuations. Since there is no societal consensus on these fundamental values, and never will be one in an open democratic society, there is no reason to expect consensus either on valuation weighting factors, or on the valuation method or even on the choice of using a valuation weighting method at all. Another result of the discussion on values is that the ethical and ideological valuations are often made implicitly in the choice of method, data, etc., thus making it difficult to discuss the values and the implications of different standpoints. Although this paper focus on the valuation methods within LCA, it is expected that much of the discussion and the conclusions are of relevance for other environmental management tools, e.g. Environmental Impact Assessment.     

Institutionalization of Life-Cycle Thinking in the Everyday Discourse of Market Actors

The widespread popularity of life-cycle assessment (LCA) is difficult to understand from the point of view of instrumental decision making by economic agents. Ehrenfeld has argued, in a 1997 issue of this journal, that it is the world-shaping potential of LCA that is more important than its use as a decision-making tool. The present study attempts to explore the institutionalization of this "LCA world view" among ordinary market actors. This is important because environmental policy relies increasingly on market-based initiatives. Cognitive and normative assumptions in authoritative LCA documents are examined as empirical data and compared with data from focus group interviews concerning products and the environment with "ordinary" manufacturers, retailers, and consumers in Finland. These assumptions are (1) the "cradle-to-grave" approach, (2) the view that all products have an environmental impact and can be improved, (3) the relativity of environmental merit, and (4) the way responsibility for environmental burdens is attributed. Relevant affinities, but also differences, are identified. It is argued that life-cycle thinking is not primarily instrumental, but rather is gaining a degree of intrinsic value. The study attempts to establish a broader institutional context in which the popularity of LCA can be understood. From the point of view of this broader context, some future challenges for the development of LCA and life-cycle thinking are suggested.     

Multi-criteria Analysis for Technique Assessment:Case Study from Industrial Coating

Environmental policy is oriented toward integrated pollution prevention, taking into consideration all environmental media (air, water, land) and energy consumption. Therefore, methods for assessing environmentally relevant installations are needed which take economic, technical, and especially ecological criteria into account simultaneously. Mass and energy flow models are used for the representation of production processes and form the basis for the inventory phase in life-cycle assessment (LCA). For the interpretation of LCA results and the weighting of the aggregated impact assessment indicators, approaches of multicriterion analysis (MCA) have been proposed. These can analyze ecological aspects as well as economic and technical criteria. Recent developments in LCA focus on decision support for policy makers or decision boards. Appropriate support for investment decisions on environmentally relevant installations, however, is rare.
Based on a case study of the sector called surface coating, an MCA of environmentally relevant installations is described. With the help of a mass and energy flow management system, alternative scenarios, depicting the use of solvent-reduced materials and environmentally friendly techniques, are modeled for the job coater processes in case studies of coating of mobile phones and coating of polyvinyl chloride (PVC) parts destined for the automobile industry. The modeled scenarios are further analyzed by using a multicriterion decision support module. The application of the outranking approach PROMETHEE is illustrated. A further investigation of the derived ranking can be obtained through sensitivity analyses. Moreover, the results derived by PROMETHEE are compared with the outcomes of the multicriterion approaches multiattribute utility theory and analytical hierarchy process.     

Evaluating Human and Ecological Impacts of a Product Life Cycle: The Complementary Roles of Life-Cycle Assessment and Risk Assessment

Life-cycle assessment (LCA) is a tool for evaluating various health and environmental impacts throughout a product's life. When used as a screening tool, LCA can potentially identify the processes and materials most likely to pose a threat to human health and the environment, and to determine where a risk assessment is warranted. The European Union has issued a ban on lead-based solder from use in electronic equipment beginning in July 2006. In response, the Lead-Free Solder Partnership, involving the U.S. Environmental Protection Agency, several electronics manufacturers, and the University of Tennessee afforded a vehicle for conducting a thorough LCA of leaded and lead-free solders used in the electronics industry. Sixteen impact categories were evaluated in the LCA, including human toxicity.

A primary conclusion of the assessment for human and aquatic toxicity, across the entire life cycle of tin-lead solder, was the potential for impacts derived from the landfilling of lead. These results, based on broad assumptions about exposure, suggest that a more detailed risk assessment of the landfilling process would assist in better understanding the potential for health and environmental risks. We believe LCA data can be used to identify the need for focused risk assessments, allowing the two tools to effectively complement one another. Use of both methods could assist in understanding the effectiveness of the European ban on lead solder and its potential to improve public health.     

A Practical Method for Quantifying Eco-efficiency Using Eco-design Support Tools

Eco-efficiency at the product level is defined as product value per unit of environmental impact. In this paper we present a method for quantifying the eco-efficiency using quality function deployment (QFD) and life-cycle impact assessment (LCIA). These well-known tools are widely used in the manufacturing industry.
QFD, which is one of the methods used in product development based on consumer preferences, is introduced to calculate the product value. An index of the product value is calculated as the weighted average of improvement rates of quality characteristics. The importance of customer requirements, derived from the QFD matrix, is applied.
Environmental impacts throughout a product life cycle are calculated based on an LCIA method widely used in Japan. By applying the LCIA method of endpoint type, the endpoint damage caused by various life-cycle inventories is calculated. Willingness to pay is applied to integrate it into a single index.
Eco-design support tools, namely, the life-cycle planning (LCP) tool and the life-cycle assessment (LCA) tool, have already been developed. Using these tools, data required for calculation of the eco-efficiency of products can be collected. The product value is calculated based on QFD data stored in the LCP tool and the environmental impact is calculated using the LCA tool.
Case studies of eco-efficiency are adopted and the adequacy of this method is clarified. Several advantages of this method are characterized.     

A Dutch Approach to the European Directive on Integrated Pollution Prevention and Control: Using Life-Cycle Assessment for the Integrated Assessment of Technologies

In light of the European Directive on Integrated Pollution Prevention and Control (IPPC Directive), traditional environmental regulation can be improved using the framework of industrial ecology. The objective of the IPPC Directive is to achieve a high level of protection of the environment as a whole (Article 1) by applying the best available techniques (BAT). In essence, the IPPC Directive obliges member states of the European Union to include considerations such as resources, energy, waste, and multimedia emissions when permitting industrial installations. This is a marked contrast to traditional environmental regulation that focuses on individual media of an individual site. In order to take all considerations into account, an integrated assessment of technologies is needed, for which a standard method is currently lacking.
In this article, a systematic approach is introduced for the integrated assessment of IPPC technologies using life-cycle assessment (LCA), a form of environmental assessment that can be broadened to an overall assessment of environmental, economic, and social aspects. This systematic approach has proven to be successful for the environmental assessment of the described cases. It is suggested here that weighting can be omitted for the evaluation of IPPC technologies. Leaving the weighting step to competent authorities of member states and allowing them to consider local issues provides maximum opportunity for the subsidiarity and flexibility principles of the IPPC Directive.     

Bottom-Up Life-Cycle:Assessment of Product Consumption in Belgium

The present study shows the results and methodology applied to the study of the identification of priority product categories for Belgian product and environmental policy. The main goal of the study was to gather insight into the consumption of products in Belgium and their related life-cycle environmental impacts. The conclusions of this project on the product categories with major environmental contributions can be used to start up working groups involving stakeholders and initiate detailed product studies on the impact reduction potential that could be achieved by means of implementing product policy measures. Several ways of assessing product category environmental impacts and the effects of policy measures have been developed; 'bottom-up' or 'market-life-cycle assessment' is one of these, and we tried this approach for the situation in Belgium. Simplified life-cycle assessment (LCA) studies were conducted for representative average products within each function-based product category and the results were multiplied with market statistics. Using this approach, we found that building construction, building occupancy, and personal transport are among the major categories for Belgium. The major drawbacks of this approach are the system-level limitations and the existence of a broad spectrum of nonharmonized methods and datasets from which a sound preliminary selection had to be made. Consequently, the retrieval and selection of data was very time consuming and due to this we had to accept some major limitations in the study design. Nevertheless, the study has contributed to the development of a methodology for market-LCA and elements that can be picked up in currently ongoing and future work. The study concludes that to improve the feasibility and acceptance of this type of study there is a need for the development of a harmonized methodology on market-LCA, policy-relevant impact indicators as well as a harmonized and stakeholder-agreed-upon LCA databases.     

Evaluating Environmental Performance of Pulp and Paper Manufacturing Using the Analytic Hierarchy Process and Life-Cycle Assessment

This article addresses the need for a structured and compre-hensive methodology for assessing the environmental perfor-mance of manufacturing processes. The analytic hierarchy pro-cess (AHP) is used as the basic framework for analyzing environmental impacts and improvement options following a streamlined life-cycle assessment (LCA) approach that is fo-cused on the manufacturing operation. The multicriteria de-cision analysis approach of the AHP is consistent with the LCA concept because the environmental factors can be hierarchi-cally structured into impacts and improvement options. Its po-tential as a valuation tool for impact and improvement assess-ment addresses both qualitative and quantitative issues in environmental decision making.
Through application to a pulp and paper manufacturing case study, the viability of the AHP for evaluating environmen-tal impacts and prioritizing process improvement options rela-tive to these impacts is demonstrated. AHP was used to pro-vide a quantitative tool for the design of a set of weighting factors for impact and improvement analyses.     

环境足迹的核算与整合框架——基于生命周期评价的视角

环境足迹及其与生命周期评价(LCA)的关系是工业生态学关注的新热点。从探讨环境足迹与LCA的关系入手,以碳足迹、水足迹、土地足迹和材料足迹为例,分别对每一项足迹指标两个版本的核算方法进行了比较。根据清单加和过程的特点,将所有足迹指标划分为基于权重因子和基于特征因子两类,总结了两者的适用性和局限性。在此基础上提出了一个环境足迹核算与整合的统一框架。该框架基于LCA视角建立,但对系统边界和清单数据的要求相对灵活,因而也适用于生命周期不甚明确的情形。研究在一定程度上揭示了足迹指标的方法学实质,同时也为环境影响综合评估提供了一条规范化的途径。     

Environmental Impacts of Consumption in the European Union:High-Resolution Input-Output Tables with Detailed Environmental Extensions

For developing product policy, insight into the environmental effects of products is required. But available life-cycle assessment studies (LCAs) are hardly comparable between different products and do not cover total consumption. Input-output analysis with environmental extensions (EEIOA) of full consumption is not available for the European Union. Available country studies have a low sector resolution and a limited number of environmental extensions. This study fills the gap between detailed LCA and low-resolution EEIOA, specifying the environmental effects of household consumption in the European Union, discerning nearly 500 sectors, while specifying a large number of environmental extensions. Added to the production sectors are a number of consumption activities with direct emissions, such as automobile driving, cooking and heating, and a number of postconsumer waste management sectors. The data for Europe have been constructed by using the sparse available and coarse economic and environmental data on European countries and adding technological detail mainly based on data from the United States.
A small number of products score high on environmental impact per Euro and also have a substantial share of overall consumer expenditure. Several meat and dairy products, household heating, and car driving thus have a large share of the total environmental impact. Due to their sales volume, however, products with a medium or low environmental score per Euro may also have a substantial impact. This is the case with bars and restaurants, clothing, residential construction, and even a service such as telecommunications. The limitations in real European data made heroic assumptions necessary to operationalize the model. One conclusion, therefore, is that provision of data in Europe urgently needs to be improved, at least to the level of sector detail currently available for the United States and Japan.     

A Theoretical Foundation for Life-Cycle Assessment

The presence of value judgments in life-cycle impact assessment (LCIA) has been a constant source of controversy. According to a common interpretation, the international standard on LCIA requires that the assessment methods used in published comparisons be "value free." Epistemologists argue that even natural science rests on "constitutive" and "contextual" value judgments. The example of the equivalency potential for climate change, the global warming potential (GWP), demonstrates that any impact assessment method inevitably contains not only constitutive and contextual values, but also preference values. Hence, neither life-cycle assessment (LCA) as a whole nor any of its steps can be "value free." As a result, we suggest a more comprehensive definition of objectivity in LCA that allows arguments about values and their relationship to facts. We distinguish three types of truth claims: factual claims, which are based on natural science; normative claims, which refer to preference values; and relational claims, which address the proper relation between factual knowledge and values. Every assessment method, even the GWP, requires each type of claim. Rational arguments can be made about each type of claim. Factual truth claims can be assessed using the scientific method. Normative claims can be based on ethical arguments. The values of individuals or groups can be elicited using various social science methods. Relational claims must follow the rules of logic. Relational claims are most important for the development of impact assessment methods. Because LCAs are conducted to satisfy the need of decision makers to consider environmental impacts, relational claims about impact assessment methods should refer to this goal. This article introduces conditions that affect environmental decision making and discusses how LCA—values and all—can be defended as a rational response to the challenge of moving uncertain scientific information into the policy arena.     

A Structured Approach to LCA Improvement Analysis

The third stage of life-cycle assessment, interpretation analysis (and improvement analysis, one of its components), has received relatively modest attention from LCA developers, especially as regards approaches for effecting improvements. However, this latter step is crucial if the LCA is to produce environmental benefits. A structured approach to improvement analysis is proposed, in which it is recognized that decisions regarding the recommendations that flow from the first two LCA stages are based not only on the environmental aspects of the recommended actions but also on such factors as technical feasibility, economic benefit, implications for product management, and effects on customer perception. A prioritization technique based on these factors is developed, as are two prioritization diagrams, one segmented by action agent and one segmented by life stage.     

Designing the ideal green product: Lca/SCLA in reverse

Traditional life-cycle assessment begins with a product and examines its environmental impacts throughout its life cycle. An alternative approach is to proceed in reverse: to examine the need that the product is designed to fulfill, to determine the minimal environmental impacts that could be engendered by filling that need, and thereby to design the “ideal green product” for the purpose. This approach, termed reverse life-cycle assessment (RLCA), is demonstrated by examining the environmental impacts attributable to a generic washing machine of current design, and then by reviewing other ways in which the provisioning of clean clothing may be accomplished. RLCA, as used here, is shown to encourage systems thinking and to identify opportunities for innovation in design and in marketing of environmentally-responsible products in ways that would be unlikely to arise from a traditional LCA.     

Measuring Preferences on Environmental Damages in LCIA. Part 1: Cognitive Limits in Panel Surveys (9 pp)

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Part 1: Cognitive Limits in Panel Surveys · Part 2: The Question Format in Panel Surveys This series of two papers discusses the elicitation of weights for damage categories in LCIA with the aid of panel surveys. The papers focus especially on methodological aspects in panel surveys. Part 1 discusses potential cognitive limits of the panel members to understand the reference that is weighted. Part 2 focuses on the influence of the question format and compares results from two different weighting tasks: discrete choice (between alternatives) and score allocation.

Goal, Scope and Background

The weighting of environmental impacts and damages on the safeguard subjects Human Health, Ecosystems, and Resources is a significant step of full aggregated LCIA. Panel surveys have become a common approach in LCIA research to investigate the preferences of stakeholders on environmental impacts and damages. Despite the numerous studies, the knowledge on how to elicit reliable weights is still poor and inconsistent. We present a questionnaire study with 58 environmental science students to investigate so-called framing effects in panel surveys.

Main Features

The study investigates the significance of different framings, which were provided by three references. In addition, the significance of quantitative information provided in the questionnaire is tested. The references are (a1) safeguard subjects without specified additional information, (a2) damages in Europe as they are perceived by the panelist, and (a3) quantified scenarios derived from Eco-indicator99. All participants ranked and rated the importance of the safeguard subjects three times, once within each reference system. According to a test-of-scope study, quantitative information given to the panelist was varied. One level (b1) included data from the Ecoindicator99 methodology, whereas the other group (b2) received data with significantly higher Human Health damages and lower Ecosystem damages, ceteris paribus. This design allows testing the influence of quantitative data on the rating.

Results

The weighting of the safeguard subjects (a1) reveals that Human Health is considered a slightly more important safeguard subject than Ecosystems. However, both are judged to be significantly more important than Resources. This picture changes for the references (a2) and (a3) where damages were weighted. For both references, the respondents rated damages to Ecosystems as most important followed by Resources and Human Health, showing by far the lowest weights. Therefore, the framing of the reference that was weighted played a significant role. The ratings of the subgroups (b1) and (b2) did not differ with respect to the importance of damages, though substantially different quantitative information was given.

Conclusion and Outlook

The participants of the study were obviously insensitive with respect to quantitative information provided. This raises three questions, which are discussed. What is the mental model upon which respondents base their beliefs and values? Can we expect that 'more sophisticated' subjects would respond differently? Which prerequisites should an empirical weighting procedure fulfill in order to incorporate numerical data? We propose different approaches for future procedures in order to accurately analyze these questions.