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.

     

Conventional and exergetic life cycle assessment of organic rankine cycle implementation to municipal waste management: the case study of Mae Hong Son (Thailand)

Purpose

The critical issue of waste management in Thailand has been rapidly increasing in almost all of the cities due to the economic growth and rising population that could double the amount of solid waste in landfill area. The alternative ways of waste treatment that have more efficiency and effectiveness in terms of energy, ecology, and resources become the key issue for each municipality to replace the old fashioned technology and be able to enhance the ability of solid waste problem management. Waste to energy is one of the favorable approaches to diminish the amount of waste to landfill and utilize waste for electricity. The aim of this study is to identify and quantify the life cycle impacts of the municipal solid waste (MSW) of Mae Hong Son municipality (MHSM), and the case study is the selected waste treatment technology of the Refuse-Derived Fuel (RDF) hybrid with 20 kW of Organic Rankine Cycle (ORC).

Methods

The functional unit is defined as 1 t of MSW. The energy, environment, and resource impacts were evaluated by using Life Cycle Assessment (LCA); ReCipe and Net Energy Consumption were referred to calculate the environmental impacts and the benefits of energy recovery of WtE technology. Exergetic LCA was used to analyze the resource consumption, especially land use change.

Results and discussion

The results indicated that the environmental impacts were comparatively high at the operation stage of RDF combustion. On the other hand, the production stage of RDF illustrated the highest energy consumption. The ORC power generation mainly consumed resources from material and energy used. The ORC system demonstrated better results in terms of energy and resource consumption when applied to waste management, especially the land required for landfill. Substitution of electricity production from ORC system was the contributor to the reduction of both energy and resource consumption. Installation of spray dry and fabric filter unit to RDF burner can reduce heavy metals and some pollutants leading to the reduction of most of the impacts such as climate change, human toxicity, and fossil depletion which are much lower than the conventional landfill.

Conclusions

LCA results revealed that the environmental impacts and energy consumption can be reduced by applying the RDF and ORC systems. The exergetic LCA is one of the appropriate tools used to evaluate the resource consumption of MSW. It is obviously proven that landfill contributed to higher impacts than WtE for waste management.

     

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.

     

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.

     

Distance-to-Target Weighting in Life Cycle Impact Assessment Based on Chinese Environmental Policy for the Period 1995-2005 (6 pp)

Background and Objective

. Values in the known weighting methods in Life Cycle Assessment are mostly founded by the societal systems of developed countries. What source of weights and which weighting methods are reliable for a big developing country like China? The purpose of this paper is to find a possible weighting method and available data that will work well for LCA practices conducted in China. Since government policies and decisions play a leading role in the process of environmental protection in developing countries, the weights derived from political statements may be a consensus by representatives of the public.

Methods

'Distance-to-political target' principle is used in this paper to derive weights of five problem-oriented impact categories. The critical policy targets are deduced from the environmental policies issued in the period of the Ninth Five-year (1996-2000) and the Tenth Five-year (2001-2005) Plan for the Development of National Economy and Society of China. Policy targets on two five-year periods are presented and analyzed. Weights are determined by the quotient between the reference levels and target levels of a certain impact category.

Results and Discussion

Since the Tenth Five-year Plan put forward the overall objective to reduce the level of regional pollution by 2005, the weights for AP, EP and POCP for 2000-2005 are more than 1. By comparison between the Ninth Five-year and Tenth Five-year period, the results show that the weights obtained in this paper effectively represent Chinese political environmental priorities in different periods. For the weights derived from China's political targets for the overall period 1995-2005, the rank order of relative importance is ODP>AP>POCP>EP>GWP. They are recommended to the potential users for the broader disparity among the five categories. By comparison with the weights presented by the widespread EDIP method, the result shows that there's a big difference in the relative importance of ozone depletion and global warming.

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In conclusion, the weighting factors and rank order of impact categories determined in this study represent the characteristics of the big developing country. The derived weighting set can be helpful to LCA practices of products within the industrial systems of China.

     

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.

     

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.

     

The Role of SETAC in the Development of LCA

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DOI: http://dx.doi.org/10.1065/lca2006.04.019

Background

Life cycle assessments have been performed using different methods before the name was coined since about 1970 in several countries of North America and Europe. It was the merit of SETAC to start a standardization process which culminated in the LCA-guidelines ('A code of practice') in 1993. It is the aim of this paper to trace back this and further LCA-related achievements by SETAC on the basis of documents and personal memories. It may be subjective in the selection and weighting of some events, but objectivity is strived for with regard to the whole and, in my view, singular development.

Results and Discussion

Starting 1990 with two workshops in Smuggler's Notch (Vermont) and Leuven (Belgium), SETAC and SETAC Europe organized several workshops during which important topics (framework, impact assessment, data quality, etc.) were treated and published in the form of reports which are still available. The main contribution by CML and its head, Helias Udo de Haes, was a practical method of impact assessment, transforming the formerly more technocratic LCA (energy, resources, waste) into an instrument of environmental assessment of product systems. In addition, important contributions to the allocation problem were made. Starting in 1993, ISO took over the leadership in standardization and SETAC started the famous working groups in North America and Europe, often dealing with the same topics in parallel. Due to the different cultures, the results were frequently complimentary rather than harmonic. The CML-method of LCIA, widely accepted in Europe, had to wait for about 10 years to be accepted at the other side of the Atlantic. It was helpful that SETAC – meanwhile a global organization – looked for a partner in order to implement LCA all over the world. This partner was found in the 'United Nations Environmental Programme' (UNEP) and the UNEP/SETAC Life Cycle Initiative was officially launched by Klaus Töpfer in Prague in April 2002. SETAC also assumed an important role in communicating LCA via publications: workshop and conference reports, the 'code of practice', working group results and LCA News Letters. The annual meetings offered forums for LCA scientists, practitioners and users, well prepared by the LCA Steering Committee (SETAC Europe) and the LCA Advisory Group (SETAC North America).

Recommendation

. The main recommendation to SETAC is to adhere to LCA as the main environmental assessment tool for products and to expand it to a true sustainability assessment tool by adding Life Cycle Costing (LCC) and a still to be invented 'Social Life Cycle Assessment'. SETAC is to remain the scientific arm within the UNEP/SETAC LC Initiative, without loosing its identity. Working groups should be global rather than regional in the future, as suggested by the SETAC Europe LCA Steering Committee at the 2004 World Congress in Portland, Oregon.

     

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).

     

Social Impacts in Product Life Cycles - Towards Life Cycle Attribute Assessment

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DOI: http://dx.doi.org/10.1065/lca2006.04.017

Background, Aims and Scope

Social impacts in supply chains and product life cycles are of increasing interest to policy makers and stakeholders. Work is underway to develop social impact indicators for LCA, and to identify the social inventory data that will drive impact assessment for this category. Standard LCA practice collects and aggregates inventory data of the form \units of input or output (elementary flow) per unit of process output.\ Measurement of social impacts within workplaces as well as host communities and societies poses new challenges not heretofore faced by LCA database developers. Participatory measurement and auditing of social impacts and of workplace health issues has been shown to provide important benefits relative to external auditor-based methods, including greater likelihood of detecting rights abuses, and stronger support of subsequent action for improvement. However, nonstandardized auditing and metrics poses challenges for the supply chain-wide aggregation and comparison functions of LCA. An analogous challenge arises in the case of resource extractive processes, for which the certification of best management practices provides an important and practical environmental metric. In both the social and resource extraction examples, it may be that attributes of the process are more valuable metrics to measure and incentivize than measured quantities per unit of process output. But how to measure, how to aggregate across life cycles, how to compare product life cycles, and how to incentivize progress as with product policy?

Methods

A methodology is presented and demonstrated which estimates the health impacts of economic development stemming from product life cycles. This methodology does not introduce new social indicators; rather, it works with the already common LCA endpoint of human health, and introduces and applies a simplified empirical relationship to characterize the complex pathways from product life cycles' economic activity to health in the aggregate.

Results

A simple case study indicates that the health benefits of economic development impacts in product life cycles have the potential to be very significant, possibly even orders of magnitude greater than the health damages from the increased pollution. While the simple macro model points up the dramatic importance of socio-economic pathways to health in product life cycles, it lacks any sensitivity to the vitally important, contextspecific attributes of the economic development associated with each process. This result begs the question of how to measure, aggregate, compare, and stimulate society-wide improvement of context-dependent attributes within and across product life cycles in LCA.

Discussion

Before attempting an answer to the question noted above, a brief reconsideration is offered concerning life cycle assessment. Namely, where does it come from, and what does it bring?

Recommendations and Outlook

Finally, the paper concludes by sketching a life cycle approach to promoting localized assessments, to summarizing their results over supply chains and life cycles, and to comparing product life cycles in terms of their results. Often, localized assessments will yield information on the attributes of a process, rather than (or in addition to) the traditional form of life cycle inventory information, which is \units of something per unit of process output.\ The methodology can enable product policy users to promote reporting of basic attributes of processes within supply chains, together with local measurement and reporting of context-relevant impacts. For attributes linked to progress on impacts of local and global concern, promotion of these attributes within supply chain processes will bring strong benefits. In addition, over time it may be possible for researchers to develop and refine models that estimate, based on cross-sectional and time series analysis of attributes and impacts, relationships between attributes and impacts. In any case, while local impacts across supply chains may not be precisely knowable – let alone controllable – by a microdecision maker at the time of their product-related decision, life cycle attribute analysis may give such decision makers an opportunity to empower progress throughout life cycles and supply chains, which is after all a motivating goal of LCA.

     

Towards guidance values for the environmental performance of buildings: application to the statistical analysis of 40 low-energy single family houses’ LCA in France

Purpose

In this study, life cycle assessment (LCA) is applied to a sample of 40 low-energy individual houses for the French context in order to identify guidance values for different environmental priorities (energy and water consumption, greenhouse gases emissions, waste generation etc.).

Methods

Calculation rules for the LCA derived from EeBGuide guidance and HQE Performance specific rules for the French context. Data are based on Environmental Product Declaration (EPD for the impacts related to products and technical equipment while generic data are used for energy and water processes. The LCA is defined for the entire life cycle of a building from cradle-to-grave according to NF EN 15978 standard. It includes the products and equipment implemented in the building, the different uses of energy for heating, domestic hot water, lighting, ventilation and auxiliaries, and the different uses of water consumption.

Results and discussion

Results for the 40 houses showed that the average life cycle non-renewable primary energy consumption is about 37 kWh/(m²*year) while the life cycle greenhouse gases emissions are of 8.4 kg CO₂-eq/(m²*year). The embodied impacts represent between 40% and 72% for the following indicators: acidification, global warming, non-renewable primary energy, and radioactive waste. The net fresh water use is mostly determined by the direct use of the water in use, and the non-hazardous waste indicator is only linked to the materials and equipment. When integrating the variability of the different houses design, energy performance, climate requirements, it was found that those values can vary of an order of two between the 10 and 90% percentiles’ values. It was found that the results are also sensitive to the enlargement of the system boundaries (e.g. inclusion of the other uses of energy such as building appliances) and the modification of the reference study period.

Conclusions and recommendations

This study provided a first set of LCA guidance values describing a range of environmental impacts for new low-energy individual houses in France. Results were also reported for different design parameters, system boundaries and reference study period. The outcomes of this study can now serve as a basis to guide and support new LCA-based labelling systems developed by public authorities and labelling schemes (e.g. the HQE Association).

     

The legitimacy of life cycle assessment in the waste management sector

Purpose

Life cycle assessment (LCA) is commonly presented as a tool for rational decision-making. It has been increasingly used to support decision-making in situations where multiple actors possess diverse, and sometimes conflicting, perspectives, values and motives. Yet, little effort has been placed on understanding LCA in a social framework of action. This paper aims to analyse the legitimacy of LCA in public sector decision-making situations, the criticisms presented against LCA, and suggest potential ways to alleviate these criticisms.

Methods

This study consists of a case study of the application of LCA in the waste management sector in England and France. To gain an understanding of the justification and criticism of LCA, semi-structured interviews were undertaken with national and local level waste management actors. The justifications and criticism of the application of LCA was analysed through an analytical framework, the economies of worth. This suggests that in situations of disagreement, actors’ justifications are required to show their attachment to plural forms of common good. This work analyses the orders of worth in which justifications and criticisms of the application of LCA were based.

Results and discussion

LCA is applied primarily as a test of environmental efficiency, illustrating a collaboration between the industrial and green orders of worth. Actors apply LCA with the aspiration of replicating the scientific method and producing robust evidence to support the most efficient waste treatment option. In this case, efficiency is coupled with the green order of worth, where gains in efficiency mean lower environmental impacts. Internal criticisms of LCA, based in the industrial order of worth, highlights the limitations of LCA to act as a test of environmental efficiency. Furthermore, criticism based in the civic order of worth highlights the friction which arises in decision-making situations when LCA has been seen to subjugate the civic nature of waste management decisions.

Conclusions

One potential way forward for LCA may be to introduce aspects relevant in the civic order of worth which aims at achieving a compromise between the industrial and civic orders of worth. Envisioning LCA as a process-oriented tool, as opposed to an outcome-oriented tool, can allow for aspects on public involvement in the LCA process, thereby increasing its civic legitimacy.

     

The EcoSpold 2 format—why a new format?

Purpose

This paper introduces the new EcoSpold data format for life cycle inventory (LCI).

Methods

A short historical retrospect on data formats in the life cycle assessment (LCA) field is given. The guiding principles for the revision and implementation are explained. Some technical basics of the data format are described, and changes to the previous data format are explained.

Results

The EcoSpold 2 data format caters for new requirements that have arisen in the LCA field in recent years.

Conclusions

The new data format is the basis for the Ecoinvent v3 database, but since it is an open data format, it is expected to be adopted by other LCI databases. Several new concepts used in the new EcoSpold 2 data format open the way for new possibilities for the LCA practitioners and to expand the application of the datasets in other fields beyond LCA (e.g., Material Flow Analysis, Energy Balancing).

     

A framework for including enhanced exposure to naturally occurring radioactive materials (NORM) in LCA

Purpose

Despite advances in the development of impact categories for ionising radiation, the focus on artificial radionuclides produced in the nuclear fuel cycle means that the potential impacts resulting from increased exposure to naturally occurring radioactive materials (NORM) are still only covered to a limited degree in life cycle assessment (LCA). Here, we present a potential framework for the inclusion of the exposure routes and impact pathways particular to NORM in LCA.

Methods

We assess the potential magnitude of enhanced NORM exposure, particularly in light of the potential use of NORM residues in building materials, and set out the potential exposure routes that may exist. We then assess the current state of the art, in terms of available fate, exposure and damage models, both within and outside of the LCA sphere. Finally, these exposure routes and modelling techniques are combined in order to lay out a potential framework for NORM assessment in LCA, both in terms of impact on humans and ecosystems.

Results and discussion

Increased exposure to NORM radionuclides can result either from their release to the environment or their proximity to humans as they reside in stockpiles, landfills or products. The exposure route via products is considered to be increasingly significant in light of current attempts to incorporate technologically enhanced NORMs (TENORM) including bauxite residue into building materials, by groups such as the ETN-MSCA REDMUD project. Impact assessment models for NORM exposure are therefore required to avoid potential burden shifting in the assessment of such TENORM products. Models describing the fate of environmental releases, the exhalation of radon from building products and the shielding effects on landfills/stockpiles are required to assess potential exposure. Subsequently, models relating exposure to radiation sources and the effective internal and external dose received by receptors are required. Finally, an assessment of the damage caused to the receptors is desirable.

Conclusions

A sufficient suite of currently existing and internationally recognised models exist that can, with varying degrees of modification, form the building blocks of a comprehensive NORM characterisation method for LCA. The challenge ahead lies in consolidating these models, from disparate fields, into a coherent and generally applicable method for the assessment of enhanced NORM exposure in LCA.

     

Bridge processes: a solution for LCI datasets independent of background databases

Introduction

New platforms are emerging that enable more data providers to publish life cycle inventory data.

Background

Providing datasets that are not complete LCA models results in fragments that are difficult for practitioners to integrate and use for LCA modeling. Additionally, when proxies are used to provide a technosphere input to a process that was not originally intended by the process authors, in most LCA software, this requires modifying the original process.

Results

The use of a bridge process, which is a process created to link two existing processes, is proposed as a solution.

Discussion

Benefits to bridge processes include increasing model transparency, facilitating dataset sharing and integration without compromising original dataset integrity and independence, providing a structure with which to make the data quality associated with process linkages explicit, and increasing model flexibility in the case that multiple bridges are provided. A drawback is that they add additional processes to existing LCA models which will increase their size.

Conclusions

Bridge processes can be an enabler in allowing users to integrate new datasets without modifying them to link to background databases or other processes they have available. They may not be the ideal long-term solution but provide a solution that works within the existing LCA data model.

     

Life cycle assessment of a steam thermolysis process to recover carbon fibers from carbon fiber-reinforced polymer waste

Purpose

Carbon fibers have been widely used in composite materials, such as carbon fiber-reinforced polymer (CFRP). Therefore, a considerable amount of CFRP waste has been generated. Different recycling technologies have been proposed to treat the CFRP waste and recover carbon fibers for reuse in other applications. This study aims to perform a life cycle assessment (LCA) to evaluate the environmental impacts of recycling carbon fibers from CFRP waste by steam thermolysis, which is a recycling process developed in France.

Methods

The LCA is performed by comparing a scenario where the CFRP waste is recycled by steam-thermolysis with other where the CFRP waste is directly disposed in landfill and incineration. The functional unit set for this study is 2 kg of composite. The inventory analysis is established for the different phases of the two scenarios considered in the study, such as the manufacturing phase, the recycling phase, and the end-of-life phase. The input and output flows associated with each elementary process are standardized to the functional unit. The life cycle impact assessment (LCIA) is performed using the SimaPro software and the Ecoinvent 3 database by the implementation of the CML-IA baseline LCIA method and the ILCD 2011 midpoint LCIA method.

Results and discussion

Despite that the addition of recycling phase produces non-negligible environmental impacts, the impact assessment shows that, overall, the scenario with recycling is less impactful on the environment than the scenario without recycling. The recycling of CFRP waste reduces between 25 and 30% of the impacts and requires about 25% less energy. The two LCIA methods used, CML-IA baseline and ILCD 2011 midpoint, lead to similar results, allowing the verification of the robustness and reliability of the LCIA results.

Conclusions

The recycling of composite materials with recovery of carbon fibers brings evident advantages from an environmental point of view. Although this study presents some limitations, the LCA conducted allows the evaluation of potential environmental impacts of steam thermolysis recycling process in comparison with a scenario where the composites are directly sent to final disposal. The proposed approach can be scaled up to be used in other life cycle assessments, such as in industrial scales, and furthermore to compare the steam thermolysis to other recycling processes.

     

LCA study of unconsumed food and the influence of consumer behavior

Purpose

In the light of anthropogenic resource depletion and the resulting influences on the greenhouse effect as well as globally occurring famine, food waste has garnered increased public interest in recent years. The aim of this study is to analyze the environmental impacts of food waste and to determine to what extent consumers’ behavior influences the environmental burden of food consumption in households.

Methods

A life cycle assessment (LCA) study of three food products is conducted, following the ISO 14040/44 life cycle assessment guidelines. This study addresses the impact categories climate change (GWP100), eutrophication (EP), and acidification (AP). Primary energy demand (PED) is also calculated. For adequate representation of consumer behavior, scenarios based on various consumer types are generated in the customer stage. The customer stage includes the food-related activities: shopping, storage, preparation, and disposal of food products as well as the disposal of the sales packaging.

Results and discussion

If the consumer acts careless towards the environment, the customer stage appears as the main hotspot in the LCA of food products. The environmental impact of food products can be reduced in the customer stage by an environmentally conscious consumer. Shopping has the highest effect on the evaluated impact categories and the PED. Additionally, consumers can reduce the resulting emissions by decreasing the electric energy demand, particularly concerning food storage or preparation. Moreover, results show that the avoidance of wasting unconsumed food can reduce the environmental impact significantly.

Conclusions

Results of this study show that the influence of consumer behavior on the LCA results is important. The customer stage of food products should not be overlooked in LCA studies. To enable comparison among results of other LCA studies, the LCA community needs to develop a common methodology for modeling consumer behavior.

     

Promoting sustainability in Mexico’s building sector via environmental product declarations

Purpose

The growing phase of emerging economy countries requires the implementation of environmental assessment tools in the building sector. The use of environmental product declarations (EPDs) has risen in developed countries as one of the main tools for environmental assessment. However, at what point should developing countries follow the EPD implementation strategies used by developed countries? What are the strengths and weaknesses of EPD in the emerging economy context, and what threats and opportunities does it face within the building sector? This work aims to answer these questions by taking Mexico as a case study.

Methods

A bibliographical review was conducted to determine the key elements for EPD development in the building sector in other countries, especially those in Europe, where EPDs originated. The review also examined the experience and perspective of other countries that are starting to contemplate this type of ecolabel as an option for environmental assessment within their own building sectors, as well as industry perspectives on EPDs, especially those of small and medium-sized enterprises (SMEs). Then, Mexico’s situation in regard to these key elements was examined, with a special focus on the main stakeholders detected: government and industry. Finally, after a contrast analysis was conducted between the developed countries and Mexico, the strengths and weaknesses of EPDs in the emerging economy context and the threats and opportunities within the building sector were determined.

Results and discussion

The use of EPDs in Europe has largely followed a normative and legislative pattern. Moreover, it has been the main data source for building environmental assessment schemes, and there is a strong life cycle assessment (LCA) platform that contributes to EPD development. Furthermore, there is a European tendency toward making the use of EPDs mandatory. However, there is a very different reality in emergent economy countries. In these countries, social housing represents a major part of the vision of the building sector, so it is taken as an initial approach to EPD development. In Mexico, there is a solid legislative framework in which EPDs could be implemented, and there is a variety of environmental assessment housing programs into which EPDs could be integrated. Nevertheless, there is an institutional void that has prevented the incorporation of the life cycle approach into the national strategy of sustainability in the building sector. Moreover, SMEs might not have the technical and financial capacity to develop EPD.

Conclusions

This analysis has proved that EPD implementation in emerging countries mainly depends on two aspects: Firstly, it must be a shared vision of sustainability between government and industry, in which there is a correspondence between the sustainability objectives of the two parties and SMEs have the ability to contribute toward their achievement. Secondly, a solid platform of knowledge that supports LCA in the building sector is necessary, and it must involve a strong relationship between government, academia, and stakeholders.