Differential Convergence of Life-Cycle Inventories toward Upstream Production Layers

We present an input-output analysis of the life-cycle labor, land, and greenhouse gas (GHG) requirements of alternative options for three case studies: investing money in a new vehicle versus in repairs of an existing vehicle (labor), passenger transport modes for a trip between Sydney and Melbourne (land use), and renewable electricity generation (GHG emissions). These case studies were chosen to demonstrate the possibility of rank crossovers in life-cycle inventory (LCI) results as system boundaries are expanded and upstream production inputs are taken into account. They demonstrate that differential convergence can cause crossovers in the ranking of inventories for alternative functional units occurring at second-and higher-order upstream production layers. These production layers are often excluded in conventional process-type life-cycle assessment (LCA) by the delineation of a finite system boundary, leading to a systematic truncation error within the LCI. The exclusion of higher-order upstream inputs can be responsible for ranking crossovers going unnoticed. In this case, an incomplete conventional process-type LCA of two alternative options can result in preferences and recommendations to decision makers that are different from preferences and recommendations concluded from a complete hybrid input-output-based assessment. Therefore, the need to avoid misleading effects on the ranking of alternative functional units due to differential convergence supports the practice of hybrid input-output-based LCA techniques.     

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.     

Evaluating Land-Use Impacts: Selection of Surface Area Metrics for Life-Cycle Assessment of Mining

Land use is an increasingly important component of sustainability evaluations, and numerous performance metrics have evolved to meet this need. The selection of appropriate land-use metrics for decision makers, however, remains an ongoing challenge. Additionally, life-cycle practitioners often struggle to provide meaningful impact assessment because of challenges associated with traditional land-use impact metrics. This article is intended to assist decision makers and life-cycle practitioners who wish to more effectively measure and evaluate one aspect of land use: surface area occupation. Existing performance metrics are discussed, and the specific circumstances under which each is appropriate are identified. Building on leading-edge research and analysis in the field of life-cycle impact assessment, a modified methodology for evaluating surface area occupation is proposed. This approach is demonstrated for a series of mining practices including three individual gold mines, a bauxite mine, and a copper mine. The specific data requirements and resulting equivalency factors for each mine are discussed. Results indicate that equivalency factors for gold (average of 700 acre-yr/ton) are expected to be several orders of magnitude higher than for either bauxite (0.004 acre-yr/ ton) or copper (0.03 acre-yr/ton). These dramatic differences in results demonstrate that equivalency factors are appropriate and necessary for including land-use impact potential as part of a life-cycle assessment that includes several different minerals or material requirements.     

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.     

Sustainability Constraints as System Boundaries: An Approach to Making Life-Cycle Management Strategic

Sustainable management of materials and products requires continuous evaluation of numerous complex social, ecological, and economic factors. A number of tools and methods are emerging to support this. One of the most rigorous is life-cycle assessment (LCA). But LCAs often lack a sustainability perspective and bring about difficult trade-offs between specificity and depth, on the one hand, and comprehension and applicability, on the other. This article applies a framework for strategic sustainable development (often referred to as The Natural Step (TNS) framework) based on backcasting from basic principles for sustainability. The aim is to foster a new general approach to the management of materials and products, here termed "strategic life-cycle management". This includes informing the overall analysis with aspects that are relevant to a basic perspective on (1) sustainability, and (2) strategy to arrive at sustainability. The resulting overview is expected to help avoid costly assessments of flows and practices that are not critical from a sustainability and/or strategic perspective and to help identify strategic gaps in knowledge or potential problems that need further assessment. Early experience indicates that the approach can complement some existing tools and concepts by informing them from a sustainability perspective-for example, current product development and LCA tools.     

Extended Producer Responsibility for Waste Electronics: An Example of Printer Recycling in the United Kingdom

In February 2003, European Union (EU) policy makers implemented a Directive that will make producers responsible for waste electrical and electronic equipment at end-of-life (known as the "WEEE" Directive). Under this new legislation, producers are required to organize and finance the take-back, treatment, and recycling of WEEE and achieve mass-based recycling and recovery targets. This legislation is part of a growing trend of extended producer responsibility for waste, which has the potential to shift the world's economies toward more circular patterns of resource use and recycling. This study uses life-cycle assessment and costing to investigate the possible environmental effects of the WEEE Directive, based on an example of printer recycling in the United Kingdom.
For a total of four waste management scenarios and nine environmental impact categories investigated in this study, results varied, with no scenario emerging as best or worst overall compared to landfilling. The level of environmental impact depended on the type of material and waste management processes involved. Additionally, under the broad mass-based targets of the WEEE Directive, the pattern of relationships between recycling rates, environmental impacts, and treatment and recycling costs may lead to unplanned and unwanted results. Contrary to original EU assumptions, the use of mass-based targets may not ensure that producers adapt the design of their products as intended under producer responsibility.
It is concluded that the EU should revise the scope of consideration of the WEEE Directive to ensure its life-cycle impacts are addressed. In particular, specific environmental objectives and operating standards for treatment and recycling processes should be investigated as an alternative to mass-based recycling and recovery targets.     

Life Cycle Perspectives to Achieve Business Benefits: From Concept to Technique

The purpose of this paper is to describe how one pollution prevention tool, life-cycle assessment, can be used to identify and manage environmental issues associated with product systems. Specifically, this paper will describe what life-cycle assessment is, determine the key players in its development and application, and present ideas on how life-cycle assessment can be used today. LCA provides a systematic means to broaden the perspective of a company's decisionmaking process to incorporate the consideration of energy and material use, transportation, post-customer use, and disposal, and the environmental releases associated with the product system. LCA provides a framework to achieve a better understanding of the trade-offs associated with specific change in a product, package, or process. This understanding lays the foundation for subsequent risk assessments and risk management efforts by decision-makers.     

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.     

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.     

Integrated Environmental and Economic Assessment of Products and Processes

The eco-efficiency analysis method developed and used by the Öko-Institut analyzes different alternatives that fulfill a defined consumer need, from an environmental as well as an economic perspective.
Like life-cycle assessment (LCA), eco-efficiency analysis makes possible the setting of priorities in purchasing decisions or can be used to show optimization potentials in product development processes.
Eco-efficiency analysis builds upon two methods: LCA, according to ISO 14040 ff. (to assess the environmental aspects of products and processes), and life-cycle costing. Life-cycle costing results in a single figure—the total costs of ownership to one or several actors. The environmental impacts can be evaluated and aggregated as a single score or the impact category indicator results can be kept separate. In either case two single scores can be compared: the total environmental burden or the impact category indicator results, and the total costs of ownership of the alternatives under consideration.
The results can then be plotted in two-dimensional graphs that show the effectiveness of certain measures in environmental and economic terms. The efficiency is expressed as a numerical ratio of environmental savings to difference in costs.
Together with furnishing more detailed results and a discussion of additional benefits or potential barriers, eco-efficiency analysis broadens the basis for decision-making processes.     

Input-Output Analysis of Waste Management

A new scheme of hybrid life-cycle assessment (LCA) termed the waste input-output (WIO) model is presented that ex-plicitly takes into account the interdependence between the flow of goods and waste. The WIO model has two distin-guishing features. First, it expands the Leontief environmental input-output (EIO) model with respect to waste flows. It turns out that the EIO model is a special case of the WIO model in which there is a strict one-to-one correspondence between waste types and treatment methods. By relaxing this condition, the WIO model provides a general framework for LCA of waste management. Second, the WIO model takes into account the "dynamics of waste treatment", which refers to the fact that the input-output relationships of waste treatment are significantly affected by the level and composition of waste feedstock, by incorporating an engineering process model of waste treatment. Because waste treatment is expected to accept whatever waste is generated by industry and households, a proper consideration of this feature is vital for LCA of waste management. We estimated a WIO table for Japan and applied it to evaluating effects of alternative waste management poli-cies with regard to regional concentration of incineration and the sorting of waste with regard to flammability. We found that concentrating treatment in a small number of large incin-erators combined with an increased degree of sorting could decrease both landfill consumption and the emission of carbon dioxide.     

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.     

The Grand Objectives: A Framework for Prioritized Grouping of Environmental Concerns in Life-Cycle Assessment

The goal of life-cycle assessment (LCA) is to conduct an inventory of the flows of materials and energy attributable to an industrial product and then to calculate the impacts of those flows on the environment, over the entire product life cycle from premanufacture to end of 1ife. A related technique, streamlined life-cycle assessment (SLCA), attempts to preserve the breadth of perspective in that approach while performing assessments more efficiently. A common failing of both techniques is that recommendations for actions to improve the environmental responsibility of products have rarely been related in an intellectually rigorous fashion to the environmental concerns they purport to ameliorate. In this article l propose that a framework for the way in which these relationships can be established is by a decision-making process that begins with the "grand objectives," the common consensus of the vital goals for the maintenance and improvement of life on Earth. The grand objectives lead to the identification of crucial environmental concerns, and those, in turn, to determining societal activities that need to be examined. Actions related to those activities can then be designed to contribute to the achievement of the grand objectives. If and when such a consensus is established, LCAs and SLCAs can be undertaken with confidence that the actions they recommend will serve broad societal goals.     

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.     

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.     

Comparing the Environmental Performance of Fluorescent Whitening Agents with Peroxide Bleaching of Mechanical Pulp

The use of fluorescent whitening agents (FWAs) instead of oxidative bleaching agents such as peroxide is an alternative for the bleaching of mechanical pulp. By this approach, the chromophores of the wood components in the pulp are not destroyed chemically but the brightness of the pulp is achieved by increased re-emission of blue light in the range of 400–500 nm. In this study, a typical FWA and peroxide bleaching chemicals are compared with respect to both production and application in the pulp mill. The life-cycle inventory shows that, on the one hand, the production of the FWA leads to higher releases of salts and adsorbable organically bound halogens (AOX) to surface waters and that, on the other hand, significantly less FWA is required in the application step in order to reach the same pulp brightness. The life-cycle impact assessment of the production step is presented in terms of Eco-indicator 95. These results, however, do not cover the environmental fate of various chemicals released to the aquatic environment in the course of the bleaching/whitening step. Therefore, this part is assessed by means of a more detailed investigation of the chemicals' environmental fate in rivers and their aquatic toxicity.     

Eco-efficiency for Pollution Prevention in Small to Medium-Sized Enterprises: A Case from South Korea

A simple method of representing the eco-efficiency (E/E) of a product system has been developed and applied to a pollution prevention program at a small to medium-sized enterprise (SME). Cost-side and environment-side indicators were derived using total cost accounting and life-cycle assessment, respectively. The derived indicators were subsequently normalized to reference values representing the current cost and environmental situation. By combining these normalized indicators, the E/E of a product system can be expressed on a simple graph. The method was applied in a case study carried out at a South Korean SME producing components for electronic equipment such as mobile communication base stations. A silver-plating process was identified as one of the key processes driving a substantial fraction of the total cost and aggregate environmental impact of the product system. Focusing on the key issues identified, a series of alternative processes, including use of a product insulation cover, a sieve-type ancillary electrode, a balanced-uniform plating technique, stream segregation, and noncyanide electroplating, were proposed. The feasibility of these alternatives was validated against product specifications as well as the company's financial and spatial capacity. The potential improvements accruing from these alternatives are presented as a simple graph that can be used by decision makers to readily identify trade-offs between economic and environmental issues.     

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.     

Growth and the expression of alternative life cycles in the salamander Ambystoma talpoideum (Caudata: Ambystomatidae)

Complex life cycles (CLCs) contain larval and adult phases that are morphologically and ecologically distinct. Simple life cycles (SLCs) have evolved from CLCs repeatedly in a wide variety of lineages but the processes that may underlie the transition have rarely been identified or investigated experimentally. We examined the influence of larval growth rate on the facultative expression of alternative life cycles (metamorphosis or maturation as gill-bearing adults [= paedomorphosis]) in the salamander Ambystoma talpoideum. We manipulated growth rates by altering the amount of food individuals received throughout larval development. The expression of alternative life cycles in A. talpoideum is influenced by growth via food levels, but the same growth rates at different points in the larval period elicit different responses. Individuals were more likely to metamorphose (i.e. express a CLC) when food levels and growth rates were high later in development and more likely to mature without metamorphosing (SLC) when growth rates were comparatively low during the same point in development. Growth rates at particular points in development, rather than overall larval growth rate, may be an important proximate factor in salamander life-cycle evolution.  © 2003 The Linnean Society of London, Biological Journal of the Linnean Society , 2003, 80 , 639–646.     

Survey Insights into Weighting Environmental Damages: Influence of Context and Group

When one models impact pathways due to stressors that are caused by the provision of product systems, it results in indicators for environmental damages. These indicators are incommensurable and cannot be compared per se. For example, the statistical life years lost for a human population cannot necessarily be compared with the potentially affected fraction of species within an ecosystem. However, some decision makers who use life-cycle assessment (LCA) prefer a single index, because it facilitates interpretation better than a multi-indicator system. This requires a method for aggregating environmental damages of differing types, thereby confronting LCA with a valuation problem.
The article describes a nonmonetary approach to valuation in LCA that incorporates the findings of a survey among LCA practitioners and users. The survey focuses on the weighting of three safeguard subjects for Eco-indicator 99, a damage-oriented impact-assessment method: human health, ecosystem quality, and resources. Of particular interest here is what influence the context provided in the survey (framing) and an individual's characteristics have on his or her weighting of environmental damages. The results indicate that damages on the European level are easier to compare than damages on a micro level. Additionally, although only half of the survey participants could be classified unequivocally into one of three cultural perspectives, each perspective rated the damage categories presented to them significantly differently from the others. Our conclusions were that framing effects need to be more carefully considered in weighting procedures and that weighting preferences vary significantly according to a group's archetypical attitudes.