Life Cycle Assessment Community Research Articles

The ESPA (Enhanced Structural Path Analysis) method: a solution to an implementation challenge for dynamic life cycle assessment studies

By analyzing the latest developments in the dynamic life cycle assessment (DLCA) methodology, we identify an implementation challenge with the management of new temporal information to describe each system we might want to model. To address this problem, we propose a new method to differentiate elementary and process flows on a temporal level, and explain how it can generate temporally differentiated life cycle inventories (LCI), which are necessary inputs for dynamic impact assessment methods. First, an analysis of recent DLCA studies is used to identify the relevant temporal characteristics for an LCI. Then, we explain the implementation challenge of handling additional temporal information to describe processes in life cycle assessment (LCA) databases. Finally, a new format of temporal description is proposed to minimize the current implementation problem for DLCA studies. A new format of process-relative temporal distributions is proposed to obtain a temporal differentiation of LCA database information (elementary flows and product flows). A new LCI calculation method is also proposed since the new format for temporal description is not compatible with the traditional LCI calculation method. Description of the requirements and limits for this new method, named enhanced structural path analysis (ESPA), is also presented. To conclude the description of the ESPA method, we illustrate its use in a strategically chosen scenario. The use of the proposed ESPA method for this scenario reveals the need for the LCA community to reach an agreement on common temporal differentiation strategies for future DLCA studies. We propose the ESPA method to obtain temporally differentiated LCIs, which should then require less implementation effort for the system-modeling step (LCA database definition), even if such concepts cannot be applied to every process.

A critical view on scientific consensus building in life cycle impact assessment

Finding scientific consensus has been an important driving force for research in life cycle assessment (LCA) over the last 20 years, as marked by reports from the Society of Environmental Toxicology and Chemistry (SETAC), United Nations Environment Programme (UNEP), International OrganiZation for Standardization (ISO), and the Joint Research Centre (JRC). In the beginning of the 1990s, the life cycle framework itself was the main topic of debate (Fava et al. 1993, 1994), while life cycle impact assessment (LCIA) methods became part of the scientific consensus discussions in a later stage (Udo de Haes et al. 2002). Operational standards on how to perform an LCA came also in place (ISO 14040, 2006; ISO 14044, 2006; Finkbeiner et al. 2006). Recently, LCIA scientific consensus building entered a new phase with the report on recommended practice for life cycle impact assessment methods in a European context (Joint Research Centre 2011; Hauschild et al. 2013), including the global consensusmodel for addressing toxic impacts in life cycle assessment, i.e., the USEtox model (Rosenbaum et al. 2008). Recently, the search for scientific consensus within the UNEP/ SETAC initiative has been extended, specifically looking for global guidance on a range of LCIA methods (www. lifecycleinitiative.org/activities/phase-iii/), and new developments in the ISO-standard arena (Finkbeiner et al. 2013). Over the years, it has been argued that without scientific consensus, LCA would be easily misused by companies for green washing purposes, as companies may just pick the evaluation method that favor their own product, and that the scientific credibility of LCAwould be at stake. The intention of LCA to contribute to solving environmental problems in our society is most likely also an important driver of the “scientific consensus agenda”. Although my intention in this editorial is not to argue against the significant scientific consensus achievements within the LCA community, I do have a number of concerns that specifically focus on developments in the LCIA domain.

Analysis of the link between a definition of sustainability and the life cycle methodologies

It has been claimed that in order to assess the sustainability of products, a combination of the results from a life cycle assessment (LCA), social life cycle assessment (SLCA) and life cycle costing (LCC) is needed. Despite the frequent reference to this claim in the literature, very little explicit analysis of the claim has been made. The purpose of this article is to analyse this claim. An interpretation of the goals of sustainability, as outlined in the report Our Common Future (WCED 1987), which is the basis for most literature on sustainability assessment in the LCA community, is presented and detailed to a level enabling an analysis of the relation to the impact categories at midpoint level considered in life cycle (LC) methodologies. The interpretation of the definition of sustainability as outlined in Our Common Future (WCED 1987) suggests that the assessment of a product's sustainability is about addressing the extent to which product life cycles affect poverty levels among the current generation, as well as changes in the level of natural, human and produced and social capital available for the future population. It is shown that the extent to which product life cycles affect poverty to some extent is covered by impact categories included in existing SLCA approaches. It is also found that the extent to which product life cycles affect natural capital is well covered by LCA, and human capital is covered by both LCA and SLCA but in different ways. Produced capital is not to any large extent considered in any of the LC methodologies. Furthermore, because of the present level of knowledge about what creates and destroys social capital, it is difficult to assess how it relates to the LC methodologies. It is also found that the LCC is only relevant in the context of a life cycle sustainability assessment (LCSA) if focusing on the monetary gains or losses for the poor. Yet, this is an aspect which is already considered in several SLCA approaches. The current consensus that LCSA can be performed through combining the results from an SLCA, LCA and LCC is only partially supported in this article: The LCSA should include both an LCA and an SLCA, which should be expanded to better cover how product life cycles affect poverty and produced capital. The LCC may be included if it has as a focus to asses income gains for the poor.

Life cycle assessment of a novel hybrid glass-hemp/thermoset composite

Life cycle assessment of a novel hybrid glass-hemp/thermoset composite

Accounting for forest carbon pool dynamics in product carbon footprints: Challenges and opportunities

Accounting for forest carbon pool dynamics in product carbon footprints: Challenges and opportunities

Global characterisation factors to assess land use impacts on biotic production

Purpose The inclusion of land-use activities in life cycle assessment (LCA) has been subject to much debate in the LCA community. Despite the recent methodological developments in this area, the impacts of land occupation and transformation on its long-term ability to produce biomass (referred to here as biotic production potential [BPP]) — an important endpoint for the Area of Protection (AoP) Natural Resources — have been largely excluded from LCAs partly due to the lack of life cycle impact assessment methods.

Alternative “Global Warming” Metrics in Life Cycle Assessment: A Case Study with Existing Transportation Data

The Life Cycle Assessment (LCA) impact category "global warming" compares emissions of long-lived greenhouse gases (LLGHGs) using Global Warming Potential (GWP) with a 100-year time-horizon as specified in the Kyoto Protocol. Two weaknesses of this approach are (1) the exclusion of short-lived climate forcers (SLCFs) and biophysical factors despite their established importance, and (2) the use of a particular emission metric (GWP) with a choice of specific time-horizons (20, 100, and 500 years). The GWP and the three time-horizons were based on an illustrative example with value judgments and vague interpretations. Here we illustrate, using LCA data of the transportation sector, the importance of SLCFs relative to LLGHGs, different emission metrics, and different treatments of time. We find that both the inclusion of SLCFs and the choice of emission metric can alter results and thereby change mitigation priorities. The explicit inclusion of time, both for emissions and impacts, can remove value-laden assumptions and provide additional information for impact assessments. We believe that our results show that a debate is needed in the LCA community on the impact category "global warming" covering which emissions to include, the emission metric(s) to use, and the treatment of time.

Influence of allocation methods on the environmental performance of biorefinery products—A case study

Influence of allocation methods on the environmental performance of biorefinery products—A case study

Water Footprinting: How to Address Water Use in Life Cycle Assessment?

As freshwater is a vital yet often scarce resource, the life cycle assessment community has put great efforts in method development to properly address water use. The International Organization for Standardization has recently even launched a project aiming at creating an international standard for ‘water footprinting’. This paper provides an overview of a broad range of methods developed to enable accounting and impact assessment of water use. The critical review revealed that methodological scopes differ regarding types of water use accounted for, inclusion of local water scarcity, as well as differentiation between watercourses and quality aspects. As the application of the most advanced methods requires high resolution inventory data, the trade-off between ‘precision’ and ‘applicability’ needs to be addressed in future studies and in the new international standard.

Integrating fuzzy multicriteria analysis and uncertainty evaluation in life cycle assessment

Integrating fuzzy multicriteria analysis and uncertainty evaluation in life cycle assessment

Individual adaptation of industry LCA practice: Results from two case studies in the Swedish forest products industry

The mere existence of life cycle assessment (LCA) methodology and general acceptance of the life cycle philosophy is not enough to make their use widespread in industry. To gain a better understanding of factors shaping LCA studies and life cycle related practice, field studies of the development of LCA practice in two companies were carried out. In order to obtain a deeper understanding of LCA practice, the number of ‘variables’ was minimized and two similar companies were chosen for study: Stora Enso and SCA. Both companies are part of the Swedish forest products industry, are large multinational enterprises and have been working with LCA since the early 1990s. Both interviews and document studies were used to collect data regarding LCA work from its introduction until 2003. We found fundamental differences in LCA practice between two similar companies in regard to LCA studies per se (the number of studies undertaken and methodological preferences) and also in regard to the organisation of and approach to LCA work. By testing various theoretical explanations of these divergent LCA practices, we identified the actions of individuals and their understanding of the situation as important factors shaping LCA practice. Although sector-wide recommendations on LCA practice are common in the LCA community, this study indicates that companies use LCA differently despite similar structural conditions such as company size or sector affiliation. Since the understanding and actions of individuals are important in shaping LCA practice, people working with LCA in industry probably have greater scope for action than they recognise and than sector recommendations may imply when it comes to organising and carrying out their work. Thus, those working with life cycle issues, even in different sectors, can learn much from each other about ways of organising and benefiting from LCA work.

Decision Analysis Utilizing Data from Multiple Life‐Cycle Impact Assessment Methods Part I: A Theoretical Basis

Numerous methodologies for the life‐cycle impact assessment (LCIA) step of life‐cycle assessment (LCA) are currently in popular use. These methods, which are based on a single method or level of analysis, are limited to the environmental fates, impact categories, damage functions, and stressors included in the method or model. Because of this, it has been suggested within the LCA community that LCIA data from multiple methods and/or levels of analysis, that is, end‐point and midpoint indicators, be used in LCA‐based decision analysis to facilitate better or, at least more informed, decision making. In this (two‐part) series of articles, we develop and present a series of LCA‐based decision analysis models, based on multiattribute value theory (MAVT), which utilize data from multiple LCIA methods and/or levels of analysis. The key to accomplishing this is the recognition of what LCIA damage indicators represent with respect to decision analysis, namely, decision attributes and, in most cases, proxy attributes. The use of proxy attributes in a decision model, however, poses certain challenges, such as the assessment of decision‐maker preferences for actual consequences that are only known imprecisely because of inherent limits of both LCA and scientific knowledge. In this article (part I), we provide a brief overview of MAVT and examine some of the decision‐theoretic issues and implications of current LCIA methods. We illustrate the application of MAVT to develop a decision model utilizing damage indicators from a single LCIA methodology; and, we identify the decision‐theoretic issues that arise when attempting to combine LCIA indicators from multiple methods and/or levels of analysis in a single decision model. Finally, we introduce the use in our methodology of constructed attributes to combine related end‐point damage indicators into single decision attributes and the concept and evaluation of proxy attributes.

Energy in chemical manufacturing processes: gate‐to‐gate information for life cycle assessment

AbstractGate‐to‐gate process energy for 86 chemical manufacturing processes is presented. The estimation of the process energy follows design‐based methodology. Results show that the gate‐to‐gate process energy for half of organic chemicals ranges from 0 to 4 MJ per kg, and for half of inorganic chemicals ranges from −1 to 3 MJ per kg. The main energy source in both organic and inorganic processes is steam energy followed by potential recovered energy. In organic chemicals, the fractions of heating oil and electricity use are relatively low, but these fractions are higher in the inorganic chemicals than in the organic chemicals. Furthermore, about 50% of the energy consumed in chemical processes is used for purifying the product, byproduct or recycled stream, which indicates that there are large opportunities for improving the process energy in chemical processes. The information presented in this study is very important for those in the life cycle assessment community in order for them to identify inaccurate information or information not based on actual process design. However, the range for the entire range of chemicals is very substantial and thus reflects the need of the life cycle inventory to separately evaluate the chemistry and degree of purity for chemical products. Copyright © 2003 Society of Chemical Industry

Reflections upon 2002 and looking ahead to 2003

The Australian Life Cycle Assessment Society (ALCAS) is a professional organisation for people interested in practice, use, development and interpretation of Life Cycle Assessment (LCA). It is a not-for-profit organisation with individual and corporate members from industry, government, academia and service organisation. The purpose of the society is to promote and foster the responsible development and application of LCA methodology in Australia and internationally with a view to making a positive contribution to Ecological Sustainable Development (ESD) "and to represent the Australian LCA community in the international arena. The specific objectives of ALCAS are: 1. To promote and foster the appropriate application of LCA in Australia. 2. To promote and foster the responsible development of LCA methodology in Australia with consideration of international initiatives and commensurate with local conditions. 3. To foster links with the international LCA community. 4. To organise a regular LCA Roundtable to facilitate information exchange and discussion on LCA amongst stakeholder groups. 5. To contribute to national policies, positions and approaches on LCA and its applications both nationally and internationally. 6. Increase education and awareness of LCA among stakeholders including industry, academia, government, non-government organisations, LCA practitioners, end users and the general public. 7. To develop a national competence in LCA to meet the environmental challenges both locally and internationally.