The Integration of Economic and Social Aspects in Life Cycle Impact Assessment

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DOI: http://dx.doi.org/10.1065/lca2006.04.016

Goal, Scope and Background

Although both cost-benefit analysis (CBA) and life cycle assessment (LCA) have developed from engineering practice, and have the same objective of a holistic ex-ante assessment of human activities, the techniques have until recently developed in relative isolation. This has resulted in a situation where much can be gained from an integration of the strong aspects of each technique. Such integration is now being prompted by the more widespread use of both CBA and LCA on the global arena, where also the issues of social responsibility are now in focus. Increasing availability of data on both biophysical and social impacts now allow the development of a truly holistic, quantitative environmental assessment technique that integrates economic, biophysical and social impact pathways in a structured and consistent way. The concept of impact pathways, linking biophysical and economic inventory results via midpoint impact indicators to final damage indicators, is well described in the LCA and CBA literature. Therefore, this paper places specific emphasis on how social aspects can be integrated in LCA.

Methods

and Results. With a starting point in the conceptual structure and approach of life cycle impact assessment (LCIA), as developed by Helias Udo de Haes and the SETAC/UNEP Life Cycle Initiative, the paper identifies six damage categories under the general heading of human life and well-being. The paper proposes a comprehensive set of indicators, with units of measurement, and a first estimate of global normalisation values, based on incidence or prevalence data from statistical sources and severity scores from health state analogues. Examples are provided of impact chains linking social inventory indicators to impacts on both human well-being and productivity.

Recommendation and Perspective

It is suggested that human well-being measured in QALYs (Quality Adjusted Life Years) may provide an attractive single-score alternative to direct monetarisation.

     

Human and Ecological Life Cycle Tools for the Integrated Assessment of Systems (HELIAS)

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DOI: http://dx.doi.org/10.1065/lca2006.04.008

Goal, Scope and Background

CML has contributed to the development of life cycle decision support tools, particularly Substance / Material Flow Analysis (SFA respectively MFA) and Life Cycle Assessment (LCA). Ever since these tools emerged there have been discussions on how these tools relate to each other, and how they relate to more traditional tools. Remarkably little, however, has been published on these relationships from an empirical side: which combinations of tools have actually been used, and what is the added value of combining tools in practical case studies. In this paper, we report on CML's experience in this field by presenting a number of case studies with their related research questions, for which different tools were deployed.

Methods

Three case studies are discussed: 1) Waste water treatment: various options for waste water treatment have been assessed on their eco-efficiency, using SFA to comment on the influence of these options on the flows of certain substances in the water system of a geographical area and a combination of LCA and life cycle costing (LCC) to assess the life-cycle impacts and costs of these options; 2) Prioritization of environmental policy measures: A methodology has been developed to prioritize environmental policy measures and investments within companies based on both the environmental impacts and the costs of these measures; and 3) Environmental weighting of materials: to add an environmental dimension to standard MFA accounts, materials were weighted with cradle-to-grave impact factors based on LCA data and impact assessment factors.

Results and Discussion

For each of these cases, the research questions at stake, the tools applied, the results and the added value, limitations and problems of combining the tools are reported.

Conclusions

and Perspective. Based on these experiences, it is concluded that using several tools to address a complicated problem is not only a theoretical proposal, but also something that has been applied successfully in a variety of practical situations. Furthermore, using several tools in combination does not necessarily lead to an increased information supply to decisionmakers. Instead, it may contribute to the comprehensibility and ease of interpretation of the information that would have been provided by using a single tool. Finally, it is concluded that there is not one generally valid protocol for which tools to use for which question. The essential idea of using a combination of tools is exactly the fact that research questions are not simple by nature and cannot be generalized into protocols.

     

Life cycle assessment in the furniture industry: the case study of an office cabinet

Purpose

In an effort to reduce the environmental impacts of the furniture sector, this study aimed to diagnose the environmental performance of an office cabinet throughout its life cycle.

Methods

An attributional life cycle assessment (LCA) was used, based on the ISO 14044 Standard and ILCD Handbook. The scope of the study considered the entire supply chain, from cradle to grave, including the steps of pre-manufacturing, manufacturing, use, and post-use of the product. The impact assessment method was the International Reference Life Cycle Data System (ILCD) 2011 midpoint.

Results and discussion

The results identified that the most significant environmental impact of the furniture life cycle was due to the distances covered and production of the main raw material, wood medium-density particleboard (MDP). The evaluation of transport scenarios showed environmental tradeoffs for truck fuel switches and environmental gains for the distribution of MDP from closer suppliers by truck, as well as from current supplier by truck and ship in the major categories. Furthermore, evaluation of the office cabinet post-use options showed that reuse, recycling, or energy recovery from waste cause significant environmental gains in the major categories. Wooden furniture is a potential carbon sink if its life cycle does not emit more greenhouse gases than its materials can store. The impacts of substitution scenarios varied depending on the type of product avoided.

Conclusions

The LCA proved a powerful method to diagnose and manage environmental impacts in complex product systems. The sensitivity analysis showed that it is possible to reduce the environmental impacts and, at the same time, make the furniture industry increase its economic gains and net carbon stock in the anthroposphere.

     

Happiness and Sustainable Consumption: Psychological and physical rebound effects at work in a tool for sustainable design

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DOI: http://dx.doi.org/10.1065/lca2006.04.018

Goal, Scope and Background

Life cycle assessment has emerged into a useful tool to assess and potentially reduce the environmental impacts per functional unit. This has contributed to increase eco-efficiency but not necessarily to decrease absolute pollution per capita. The number of functional units is increasing and new functions add to the impacts of consumption. Despite the attempts to use different levels of definitions for the functional unit and applying LCA in the field of lifestyle studies there has been little success to grasp the consumption side of sustainable production and consumption. This contribution aims to tackle the consumption side by at least two extensions: the function of products, services, and activities is assessed with a multi-attribute need function and the propensity to cause both psychological and physical rebound effects are considered in the design phase.

Methods

We develop a checklist approach with an evaluation and assessment table. The elements of the checklist are rooted in a number of independent fields of science: needs matrix, happiness enhancing factors, a number of limiting factors that can cause rebound effects, and streamlined LCA.

Results and Conclusion

For illustration purposes we comparatively evaluate gardening, having a dog, a weekend house, and starting yoga classes and show that the new analysis framework is able to make transparent and operable the inclusion of a number of additional factors that remained so far implicit or neglected. The additional factors considered can be grouped into factors that may cause rebound effects through psychological or physical mechanisms. The assessment table combines the degree of satisfying needs and enhancing happiness in a psychological rebound score. The physical rebound score considers six factors that may constrain consumption: Costs, time, space, other scarce resources, information, and skills. This allows predicting the potential for rebound effects that would increase total impacts from consumption. In addition, it gives also a handle on how to use the knowledge on rebound effects to not only reduce the impacts of the product or activity at hand but also reducing other consumption that in turn might have adverse impacts.

Recommendation and Perspective

Many assumptions in selecting and quantifying the additional factors and the final assessment procedure remain conceptual and therefore provisional. This contribution opens new avenues of investigations that need both further refinements of the theories and empirical evidence. Consumerism and materialism has undermined much of the success stories of improved eco-efficiency and LCA. We suggest using some of the very same psychological and physical mechanisms to foster sustainable consumption.

     

Support for Sustainable Development Policy Decisions A Case Study from Highway Maintenance

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http://dx.doi.org/10.1065/lca2006.04.009

Goal, Scope and Method

logy. This paper describes a case study carried out as part of a wider programme to provide support for environmental decision-making in the highway maintenance programme of a local government body: Surrey County Council (SCC). UK local authorities are required to demonstrate that sustainable development principles are addressed in service provision, by improving environmental, economic or social wellbeing and improving public consultation. A methodological approach was developed to meet these requirements by using life cycle assessment (LCA) and multi-criteria decision analysis (MCDA) through the process of decision conferencing.

Results

In projects requiring strategic decisions, difficulties arise in identifying relevant sustainable development criteria and in evaluating maintenance options against these criteria where the context for decision-making is complex and characterised by uncertainty, where multiple public policy objectives compete and a number of decision-makers and key players are affected by the outcome. Clearly, a structured process is needed to engage such stakeholders in the decision process, utilising quantitative and qualitative information. The approach described proved to be capable of fulfilling these requirements.

Conclusions

and Recommendations. The approach of combining LCA with MCDA through decision conferencing is capable of further development to support other strategic decision-making activities. However, this illustrative case study has revealed a need for methodological developments in LCA for local, project-level decisions.

     

Notions on the Design and Use of an Ideal Regional or Global LCA Database

Goal, Scope and Background

More and more national and regional life cycle assessment (LCA) databases are being established satisfying the increasing demand on LCA in policy making (e.g. Integrated Product Policy, IPP) and in industry. In order to create harmonised datasets in such unified databases, a common understanding and common rules are required. This paper describes major requirements on the way towards an ideal national background LCA database in terms of co-operation, but also in terms of life cycle inventory analysis (LCI) and impact assessment (LCIA) methodology.

Methods

A classification of disputed methodological issues is made according to their consensus potential. In LCI, three main areas of dissent are identified where consensus seems hardly possible, namely system modelling (consequential versus attributional), allocation (including recycling) and reporting (transparency and progressiveness). In LCIA the time aspect is added to the well-known value judgements of the weighting step.

Results and Discussions

It is concluded that LCA methodology should rather allow for plurality than to urge harmonisation in any case. A series of questions is proposed to identify the most appropriate content of the LCA background database or the most appropriate LCI dataset. The questions help to identify the best suited approach in modelling the product system in general and multioutput and recycling processes in particular. They additionally help to clarify the position with regard to time preferences in LCIA. Intentionally, the answers to these questions are not attributed to particular goal and scope definitions, although some recommendations and clarifying explanations are provided.

Recommendations and Perspective

It is concluded that there is not one single ideal background database content. Value judgements are also present in LCI modelling and require pluralistic solutions; solutions possibly based on the same primary data. It is recommended to focus the methodological discussion on aspects where consensus is within reach, sensible and of added value for all parties.

     

On the boundary between economy and environment in life cycle assessment

Purpose

We investigate how the boundary between product systems and their environment has been delineated in life cycle assessment and question the usefulness and ontological relevance of a strict division between the two.

Methods

We consider flows, activities and impacts as general terms applicable to both product systems and their environment and propose that the ontologically relevant boundary is between the flows that are modelled as inputs to other activities (economic or environmental)—and the flows that—in a specific study—are regarded as final impacts, in the sense that no further feedback into the product system is considered before these impacts are applied in decision-making. Using this conceptual model, we contrast the traditional mathematical calculation of the life cycle impacts with a new, simpler computational structure where the life cycle impacts are calculated directly as part of the Leontief inverse, treating product flows and environmental flows in parallel, without the need to consider any boundary between economic and environmental activities.

Results and discussion

Our theoretical outline and the numerical example demonstrate that the distinctions and boundaries between product systems and their environment are unnecessary and in some cases obstructive from the perspective of impact assessment, and can therefore be ignored or chosen freely to reflect meaningful distinctions of specific life cycle assessment (LCA) studies. We show that our proposed computational structure is backwards compatible with the current practice of LCA modelling, while allowing inclusion of feedback loops both from the environment to the economy and internally between different impact categories in the impact assessment.

Conclusions

Our proposed computational structure for LCA facilitates consistent, explicit and transparent modelling of the feedback loops between environment and the economy and between different environmental mechanisms. The explicit and transparent modelling, combining economic and environmental information in a common computational structure, facilitates data exchange and re-use between different academic fields.

     

Life Cycle Management in Developing Countries: State of the Art and Outlook

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DOI: http://dx.doi.org/10.1065/lca2006.04.020

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UNEP DTIE, through its Life Cycle Initiative, aims to enhance the skills of small and medium sized enterprises (SMEs) in developing countries on Life Cycle Management (LCM). This is part of its contribution to the 10-year framework of program on Sustainable Consumption and Production as a follow-up of the World Summit on Sustainable Development (2002). Apart from the potential of improving their environmental performance, life cycle thinking and the use of LCA can be a business opportunity for SMEs. The development of environmental management expertise may help them to position themselves as reliable suppliers. The Life Cycle Initiative has promoted and facilitated the establishment of regional life cycle networks, and UNEP has started a training program on LCM targeted at National Cleaner Production Centers (NCPCs) and other national institutes that are able to pass on the information to the target groups. Some multinational companies have started to provide capacity building on life cycle management for suppliers in developing countries. More companies could use this approach to help developing countries to tackle environmental requirements in the supply chain and thus the private sector may contribute significantly to eco-efficiency, cost savings and finding new markets for sustainable products and services in developing countries. Life cycle thinking applied to basic services such as water, waste and energy could be another way to directly contribute with life cycle management to human development.

     

Life cycle assessment of the environmental influence of wooden and concrete utility poles based on service lifetime

Purpose

Many applications of life cycle assessment do not consider the variability of the service lifetime of different structures, and this may be a relevant factor in an environmental impact assessment. This paper aims to determine the influence of the service lifetime on the potential environmental impacts of wooden and concrete poles in the electricity distribution system.

Methods

The estimation of service lifetime was conducted using the factorial method. The life cycle assessment was applied using SimaPro software and considered the entire life cycle of utility poles, from the extraction of raw materials to the final disposal. Then, an evaluation of the environmental impacts using the CML IA baseline method was performed. The study included the analysis of uncertainty using the Monte Carlo method.

Results and discussion

In general, the wooden poles had a lower potential environmental impact compared to the concrete poles. The result of the sensitivity analysis considering the variability of the chromated copper arsenate wood preservative retention rate suggests that the frequency of maintenance affects the service lifetime. Often, the comparison of products in the LCA perspective is carried out by considering similar useful lifetime services for the different alternatives, and this study shows that the environmental performance of products or services is directly proportional to the lifetime. It is a crucial parameter that has to be clarified in order to reduce uncertainty in the results.

Conclusions

Thus, some factors such as material quality, design adjustments and routine maintenance extend the service lifetime of a product or process and are shown to be effective ways to reduce environmental impacts. Therefore, the service lifetime has a significant influence on the development of the life cycle assessment. Comparative LCA studies are often sensitive to parameters that may even change the ranking of selected impact categories. All in all, from the sensitivity analysis highlighted in this study, the variability of lifetime service has proven to be one of the most prominent factors influencing comparative LCA results.

     

Streamlining scenario analysis and optimization of key choices in value chains using a modular LCA approach

Purpose

The environmental performance of products or services is often a result of a number of key decisions that shape their life cycles (e.g., techology choices). This paper introduces a modular LCA approach that is capable of reducing the effort involved in performing scenario analyses and optimization when several key choices along a product’s value chain lead to many alternative life cycles.

Methods

The main idea is that the value chain of a product can be divided into interconnected but exchangeable modules, which together represent a full life cycle. A module is comprised of unit processes from the practitioner’s LCI database. The inputs, outputs, and system boundaries of each module can be tailored to the context of the studied system. Alternatives arise whenever multiple modules produce substitutable products. Unlike in conventional LCI databases, no copies are necessary to represent the same process with different inputs. A module-product matrix is used to store this information. It can be used as a basis for an automated scenario analysis of all alternatives or as an input to an optimization model.

Results and discussion

Our approach is illustrated in two case studies: (1) Passenger car fuel choices are modeled by 15 modules representing 33 alternative value chains for diesel, petrol, natural gas and electric cars. The automated comparison of LCA results indicates that electric mobility is often the preferable option from a climate perspective, but impacts depend strongly on the electricity source. (2) A dynamic optimization model including stocks is built from eight modules to analyze the optimal use of wood for material and energy applications. Results indicate that although direct substitution benefits are higher for energy applications, cascading use of wood can maximize environmental performance over the entire life cycle.

Conclusions

The modular LCA approach permits an efficient modeling and comparison of alternative product life cycles, enabling practitioners to focus on key decisions. It can be applied to exploit a potential that is hidden in LCI databases, which is that they contain many specific inventories but not all useful combinations in the context of scenario analyses. The user-defined level of abstraction that is introduced through modules can be helpful in the communication of LCA results. The modular approach also facilitates the integration of LCA and optimization as well as other industrial ecology methods. An open source software is provided to enable others to apply and further develop our implementation of a modular LCA approach.

     

Life cycle assessment-based selection of a sustainable lightweight automotive engine hood design

Purpose

This study presents a life cycle assessment (LCA)-based sustainable and lightweight automotive engine hood design and compares the life cycle energy consumption and potential environmental impacts of a steel (baseline) automotive engine hood with three types of lightweight design: advanced high strength steel (AHSS), aluminum, and carbon fiber.

Methods

A “cradle-to-grave” LCA including the production, use, and end-of-life stages is conducted in accordance with the ISO 14040/14044 standards. Onsite data collected by Chinese automotive companies in 2015 are used in the assessment. The Cumulative Energy Demand v1.09 method is applied to evaluate cumulative energy demand (CED), and the International Panel on Climate Change 2013 100a method is used to estimate global warming potential (GWP 100a).

Results and discussion

Among the different lightweight designs for the engine hood, the aluminum design is the most sustainable and has the lowest CED and GWP (100a) from a life cycle perspective, which is based on a lifetime driving distance of approximately 150,000 km. In addition, the AHSS design is also sustainable and lightweight. The carbon fiber design results in higher CED and GWP (100a) values than the steel (baseline) design during the life cycle but results in the largest CED and GWP (100a) savings through waste material recycling. The AHSS design exhibits the best break-even distance based on CED and GWP (100a) within 150,000 km.

Conclusions

Sensitivity analysis results show that the lifetime driving distance and material recycling rate have the largest impacts on the overall CEDs and GWPs of the three lightweight designs.

     

The Application of the Environmental Product Declaration to Waste Disposal in a Sanitary Landfill - Four Case Studies (10 pp)

Goal, Scope and Background

The aim of the present study is to evaluate, through LCA, the potential environmental impact associated to urban waste dumping in a sanitary landfill for four case studies and to compare different technologies for waste treatment and leachate or biogas management in the framework of the EPD® system. Specific data were collected on the four Italian landfills during a five-year campaign from 2000 to 2004. This work also analyses the comparability of EPD results for different products in the same product category. For this purpose, a critical review of PSR 2003:3, for preparing an EPD on ‘Collection, transfer and disposal service for urban waste in sanitary landfills', is performed.

Methods

PSR 2003:3 defines the requirements, based on environmental parameters, that should be considered in an LCA study for collecting and disposal service of Municipal Solid Waste (MSW) in a sanitary landfill. It defines functional unit, system boundaries towards nature, other technical systems and boundaries in time, cut-off rules, allocation rules and parameters to be declared in the EPD. This PSR is tested on four case studies representing the major landfills located from the farthest west to the farthest east side of the Ligurian Region. Those landfills are managed with different technologies as concerns waste pre-treatment and leachate or biogas treatment. For each landfill, a life cycle assessment study is performed.

Results and Discussion

The comparison of the LCA results is performed separately for the following phases: Transport, Landfill, Leachate and Biogas. The following parameters are considered: Resource use (Use of non-renewable resources with and without energy content, Use of renewable resources with and without energy content, Water consumption); Pollutant emissions expressed as potential environmental impact (Global Warming Potential from biological and fossil sources, Acidification, Ozone depletion, Photochemical oxidant formation, Eutrophication, Land use, Hazardous and other Waste production). The comparison of the LCA results obtained for alternative landfill and biogas management techniques in the case studies investigated shows that the best practicable option that benefits the environment as a whole must be identified and chosen in the LCA context. For example, a strong waste pre-treatment causes a high biological GWP in the Landfill phase, but a low GWP contribution in the Biogas phase, due to the consequent low biogas production, evaluated for 30 years since landfill closure.

Conclusion

The analysis of four case studies showed that, through the EPD tool, it is possible to make a comparison among different declarations for the same product category only with some modification and integration to existent PSR 2003:3. Results showed that different products have different performances for phases and impact categories. It is not possible to identify the \best product\ from an environmental point of view, but it is possible to identify the product (or service) with the lowest impact on the environment for each impact category and resource use.

Recommendation and Perspective

In consequences of the verification of the comprehensiveness of existent PSR 2003:3 for the comparability of EPD, some modifications and integration to existent rules are suggested.

     

Actionable insights with less data: guiding early building design decisions with streamlined probabilistic life cycle assessment

Purpose

Two obstacles that impede wider use of life cycle assessment (LCA) are its time- and data-intensiveness and the credibility surrounding its results—challenges that grow with the complexity of the product being analyzed. To guide the critical early-design stages of a complicated product like a building, it is important to be able to rapidly estimate environmental impacts with limited information, quantify the resulting uncertainty, and identify critical parameters where more detail is needed.

Methods

The authors have developed the Building Attribute to Impact Algorithm (BAIA) to demonstrate the use of streamlined (not scope-limiting), probabilistic LCA for guiding the design of a building from early stages of the design process when many aspects of the design are unknown or undecided. Early-design uncertainty is accommodated through under-specification—characterizing the design using the available level of detail—and capturing the resulting variability in predicted impacts through Monte Carlo simulations. Probabilistic triage with sensitivity analyses identifies which uncertain attributes should be specified further to increase the precision of the results. The speed of the analyses allows for sequentially refining key attributes and re-running the analyses until the predicted impacts are precise enough to inform decision-making, such as choosing a preferable design alternative.

Results and discussion

Twelve design variants for a hypothetical single-family residential building are analyzed. As information is sequentially added to each variant, the significance of the difference in performance between each variant pair is calculated to determine when enough information has been added to resolve the designs (identify which design is preferable) with high confidence. At the sixth step in the analysis, all variant pairs whose mean impacts differ by at least 4% are resolvable with 90% confidence, even though only six attributes are specified and dozens of attributes remain under-specified. Furthermore, the comparative results for each variant pair are validated against a set of conventional LCA results, showing that BAIA identifies the correct preferable design among each resolvable pair at this step.

Conclusions

Iterative specification guided by probabilistic triage can help identify promising early-design alternatives even when details are only provided for key attributes. The analysis of hypothetical design variants demonstrates that BAIA is both efficient (arrives at statistically defensible conclusions from design variant comparisons based on few pieces of information) and effective (identifies the same preferable design variants as conventional LCAs).

     

Life cycle assessment of chitosan production in India and Europe

Purpose

The aim of this article is to present the first life cycle assessment of chitosan production based on data from two real producers located in India and Europe. The goal of the life cycle assessment (LCA) was to understand the main hot spots in the two supply chains, which are substantially different in terms of raw materials and production locations.

Methods

The LCA is based on consequential modelling principles, whereby allocation is avoided by means of substitution, and market mixes include only flexible, i.e. non-constrained suppliers. The product system is cradle to gate and includes the production of raw materials, namely waste shells from snow crab and shrimp in Canada and India, respectively, the processing of these in China and India and the manufacture of chitosan in Europe and India. Primary data for chitin and chitosan production were obtained from the actual producers, whereas raw material acquisition as well as waste management activities were based on literature sources. The effects of indirect land use change (iLUC) were also included. Impact assessment was carried out at midpoint level by means of the recommended methods in the International Life Cycle Data (ILCD) handbook.

Results and discussion

In the Indian supply chain, the production of chemicals (HCl and NaOH) appears as an important hot spot. The use of shrimp shells as raw material affects the market for animal feed, resulting in a credit in many impact indicators, especially in water use. The use of protein waste as fertilizer is also an important source of greenhouse-gas and ammonia emissions. In the European supply chain, energy use is the key driver for environmental impacts, namely heat production based on coal in China and electricity production in China and Europe. The use of crab shells as raw material avoids the composting process they would be otherwise subject to, leading to a saving in composting emissions, especially ammonia. In the Indian supply chain, the effect of iLUC is relevant, whereas in the European one, it is negligible.

Conclusions

Even though we assessed two products from the same family, the results show that they have very different environmental profiles, reflecting their substantially different supply chains in terms of raw material (shrimp shells vs. crab shells), production locations (locally produced vs. a global supply chain involving three continents) and the different applications (general-purpose chitosan vs. chitosan for the medical sector).

     

Including Human Health Damages due to Road Traffic in Life Cycle Assessment of Dwellings

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DOI: http://dx.doi.org/10.1065/lca2006.04.013

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Goal, Scope and background. Methodologies based on life cycle assessment have been developed to calculate the environmental impact of dwellings. Human health damages due to exposure of occupants to substances and noise emitted by road traffic are not included in these methodologies. In this study, a methodology has been developed to calculate damages to human health of occupants caused by substances and noise emitted by neighbourhood car traffic. The goal of this study is to assess the influence of the location of the dwelling on the health of the occupants, compared to the damage to human health associated with the rest of the life cycle of that dwelling.

Methods

Fate, exposure and human health effects were addressed in the calculation procedure. The methodology takes into account road traffic noise and four hazardous substances emitted by cars. Chemical fate factors were calculated with an outdoor exposure model for traffic pollutants, air entrance rates and indoor intake fractions. Fate factors for noise were based on noise levels generated by traffic. Effect factors for substances were based on unit risk factors and extrapolated dose-effect relationships. Effect factors for noise were based on linear relationships between noise level changes and health effects, while taking into account threshold values for noise levels for negative impacts. Damage factors were calculated on the basis of disability adjusted life years (DALYs). Human health damage scores for changes in traffic situations have been calculated for differences in three traffic scenarios in residential areas and for the Dutch reference dwellings.

Results and Discussion

For the Dutch reference dwelling and the traffic situations considered and taking into account noise, particulate matter (PM10), sulphur dioxide, benzene and benzo[ a]pyrene, communication disturbances and sleep disturbances due to noise and health effects of PM10 appear to be dominant in the total damage to human health of occupants caused by neighbourhood car traffic. A sensitivity analysis has shown that a reduction of the car and truck density and of the distance of the façade of the dwellings to the road axis has the largest positive effect on the human health of the occupants, and that a decrease of speed by traffic impediments has only a marginal or even a negative effect. Differences in overall indoor health damage due to different traffic scenarios may be 1.5 to 2 times

Conclusion

Within the limitations of this study, damages to human health of occupants due to indoor exposure to road traffic noise and pollutants appear to be in the same order of magnitude when compared with damages associated with the life cycle of dwellings. This emphasizes the importance to include the location of dwellings in the life cycle assessment of the dwelling.

     

Spatial Differentiation in the Characterisation of Photochemical Ozone Formation: The EDIP2003 Methodology

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DOI: http://dx.doi.org/10.1065/lca2006.04.014

Background, Aims and Scope

In the life cycle of a product, emissions take place at many different locations. The location of the source and its surrounding conditions influence the fate of the emitted pollutant and the subsequent exposure it causes. This source of variation is normally neglected in Life Cycle Impact Assessment (LCIA), although it is well known that the impacts predicted by site-generic LCIA in some cases differ significantly from the actual impacts. Environmental impacts of photochemical ozone (ground-level ozone) depend on parameters with a considerable geographical variability (like emission patterns and population densities). A spatially differentiated characterisation model thus seems relevant.

Methods

and Results. The European RAINS model is applied for calculation of site-dependent characterisation factors for Non-Methane Volatile Organic Compounds (NMVOCs) and nitrogen oxides (NOx) for 41 countries or regions within Europe, and compatible characterisation factors for carbon monoxide (CO) are developed based on expert judgement. These factors are presented for three emission years (1990, 1995 and 2010), and they address human health impacts and vegetation impacts in two separate impacts categories, derived from AOT40 and AOT60 values respectively. Compatible site-generic characterisation factors for NMVOC, NOx, CO and methane (CH4) are calculated as emission-weighted European averages to be applied on emissions for which the location is unknown. The site-generic and site-dependent characterisation factors are part of the EDIP2003 LCIA methodology. The factors are applied in a specific case study, and it is demonstrated how the inclusion of spatial differentiation may alter the results of the photochemical ozone characterisation of life cycle impact assessment.

Discussion

and Conclusions. Compared to traditional midpoint characterisation modelling, this novel approach is spatially resolved and comprises a larger part of the cause-effect chain including exposure assessment and exceeding of threshold values. This positions it closer to endpoint modelling and makes the results easier to interpret. In addition, the developed model allows inclusion of the contributions from NOx, which are ne- glected when applying the traditional approaches based on Photochemical Ozone Creation Potentials (POCPs). The variation in site-dependent characterisation factors is far larger than the variation in POCP factors. It thus seems more important to represent the spatially determined variation in exposure than the difference in POCP among the substances.

     

Weighting in LCA Based on Ecotaxes - Development of a Mid-point Method and Experiences from Case Studies

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DOI: http://dx.doi.org/10.1065/lca2006.04.015

Goal, Scope and Background

The weighting phase in Life Cycle Assessment (LCA) is and has always been a controversial issue, partly because this element requires the incorporation of social, political and ethical values. Despite the controversies, weighting is widely used in practise. In this paper we will present an approach for monetisation of environmental impacts which is based on the consistent use of ecotaxes and fees in Sweden as a basis for the economic values. The idea behind this approach is that taxes and fees are expressions of the values society places on resource uses and emissions. An underlying assumption for this is that the decisions taken by policy-makers are reflecting societal values thus reflecting a positive view of representative democracy.

Methods

In the method a number of different ecotaxes are used. In many cases they can directly be used as valuation weighting factors, an example is the CO2-tax that can be used as a valuation of CO2-emissions. In some cases, a calculation has to be made in order to derive a weighting factor. An example of this is the tax on nitrogen fertilisers which can be recalculated to an emission of nitrogen which can be used as a weighting factor for nitrogen emissions. The valuation weighting factors can be connected to characterisation methods in the normal LCA practise. We have often used the Ecotax method in parallel to other weighting methods such as the Ecoindicator and EPS methods and the results are compared.

Results and Discussion

A new set of weighting factors has been developed which has been used in case studies. It is interesting to note that the Ecotax method is able to identify different environmental problems as the most important ones in different case studies. In some cases, the Ecotax method has identified some interventions as the most important ones which lack weighting factors in other weighting methods. The midpoint-endpoint debate in the LCA literature has often centred on different types of uncertainties. Sometimes it is claimed that an advantage with having an endpoint approach is that the weighting would be easier and less uncertain. Here we are however suggesting a mid-point weighting method that we claim are no less uncertain than other often used weighting methods based on a damage assessment. This paper can therefore be seen as a discussion paper also in the midpoint-endpoint debate.

Conclusion and Recommendation

The Ecotax method is ready to use. It should be further updated and developed as taxes are changed and new characterisation methods are developed. The method is not only relevant for LCA but also for other environmental systems analysis. The Ecotax method has also been used as a valuation method for Cost-Benefit Analysis (CBA), Life Cycle Costing (LCC) and within the context of a Strategic Environmental Assessment (SEA).

     

Geopolitical-related supply risk assessment as a complement to environmental impact assessment: the case of electric vehicles

Purpose

Introducing a geopolitical-related supply risk (GeoPolRisk) into the life cycle sustainability assessment (LCSA) framework adds a criticality aspect to the current life cycle assessment (LCA) framework to more meaningfully address direct impacts on Natural Resource AoP. The weakness of resource indicators in LCA has been the topic of discussion within the life cycle community for some time. This paper presents a case study on how to proceed towards the integration of resource criticality assessment into LCA under the LCSA. The paper aims at highlighting the significance of introducing the GeoPolRisk indicator to complement and extend the established environmental LCA impact categories.

Methods

A newly developed GeoPolRisk indicator proposed by Gemechu et al., J Ind Ecol (2015) was applied to metals used in the life cycle of an electric vehicle, and the results are compared with an attributional LCA of the same resources. The inventory data is based on the publication by Hawkins et al., J Ind Ecol 17:53–64 (2013), which provides a current, transparent, and detailed life cycle inventory data of a European representative first-generation battery small electric vehicle.

Results and discussion

From the 14 investigated metals, copper, aluminum, and steel are the most dominant elements that pose high environmental impacts. On the other hand, magnesium and neodymium show relatively higher supply risk when geopolitical elements are considered. While, the environmental indicator results all tend to point the same hotspots which arise from the substantial use of resources in the electric vehicle’s life cycle, the GeoPolRisk highlights that there are important elements present in very small amounts but crucial to the overall LCSA. It provides a complementary sustainability dimension that can be added to conventional LCA as an important extension within LCSA.

Conclusions

Resource challenges in a short-term time perspective can be better addressed by including social and geopolitical factors in addition to the conventional indicators which are based on their geological availability. This is more significant for modern technologies such as electronic devices in which critical resources contribute to important components. The case study advances the use of the GeoPolRisk assessment method but does still face certain limitations that need further elaboration; however, directions for future research are promising.