Consequential life cycle assessment: a review

Purpose  

Over the past two decades, consequential life cycle assessment (CLCA) has emerged as a modeling approach for capturing environmental impacts of product systems beyond physical relationships accounted for in attributional LCA (ALCA). Put simply, CLCA represents the convergence of LCA and economic modeling approaches.     

Integrating life cycle assessment and life cycle cost: a review of environmental-economic studies

The International Journal of Life Cycle Assessment - The purpose of this document is to carry out a critical review of the existing literature by specifically addressing the following: (i) the...     

Irradiating the environment: Radiological impacts in life cycle assessment

One of the main shortcomings of Life Cycle Assessment (LCA) when applied to the Nuclear Fuel Cycle, is that there is currently no recognised procedure to deal with radionuclide emissions in the Impact Assessment stage. A framework which considers both human and environmental impacts is required and a methodology which is compatible with the other impact assessment approaches in LCA must be developed. It is important that the discussion is not only restricted to concepts, but that a working methodology is developed which can be readily applied by LCA practitioners. A provisional method is available for assessing radiological impacts on human health, but no consideration has been given to potential effects on the environment. A methodology is proposed in this paper which assesses irradiation of the environment using Environmental Increments (EI) as the quality standard. This approach is based on the same principles as for the Ecotoxicity classification group, and it represents a working methodology which can be continuously improved as knowledge in the area increases.     

Occupational health impacts: offshore crane lifts in life cycle assessment

Background, Aim, and Scope  The identification and assessment of environmental tradeoffs is a strongpoint of life cycle assessment (LCA). A tradeoff made in many product systems is the exchange of potential for occupational accidents with the additional use of energy and materials. Net benefits of safety measures with respect to human health are best illustrated if the consequences avoided and health impacts induced by additional emissions are assessed using commensurable metrics. Our aim is to develop a human health impact indicator for offshore crane lifts. Crane lifts are a major cause of accidents on offshore oil and gas (O & G) rigs, and health impacts from crane lift accidents should be included in comparative LCA of O & G technologies if the alternatives differ in the use of crane lifts. Materials and methods  Accident records for mobile offshore petroleum installations were used to develop an empirical occupational health indicator for crane lifts in LCA. Probabilistic parameters were introduced in the procedure, and results were calculated by Monte Carlo simulation. The disability adjusted life years (DALY) framework was used to classify health outcome. The characterization factor for offshore crane lifts was applied in three comparisons to evaluate the significance of crane lifts to human health impacts from drilling technology. Results  The mean occupational health impact per crane lift was 4.5∙10⁻⁶ DALY, with cumulative percentiles {P _2.5, P ₅₀, P _97.5} = {6.0∙10⁻⁷, 3.1∙10⁻⁶, 1.7∙10⁻⁵}. Analogously, the fatal accident frequency was described by {P _2.5, P ₅₀, P _97.5} = {7.6∙10⁻⁹, 3.9∙10⁻⁸, 2.0∙10⁻⁷}, with mean 5.6∙10⁻⁸ lives lost per crane lift. Discussion  The uncertainty in the results is caused mainly by the random nature of accidents, i.e., variability in accident frequency. Applications of the characterization factor indicate that although crane lifts may not be significant to the overall health impact of the life cycle of drilling fluids, they are important to the occupational safety of employees on offshore drilling rigs and contribute significantly to the life cycle health impact of loading technologies used to transport drilling waste to shore. A comparative LCA of technologies for loading and off-loading drilling wastes shows that a recently developed hydraulic system performs better than the traditional crane lift alternative in terms of human health impacts. Conclusions  With the availability of statistics to assess the risk of single mechanical operations, safety aspects may well be included in LCA. For the case of offshore crane lifts, the uncertainty in the characterization factor compares favorably to what is indicated for other human health impact chains. In further work of quantifying occupational health impacts in DALY using accident statistics, it is advised to see if records of non-recoverable injuries (fatalities and amputation cases) can be used to simplify the damage assessment procedure as recoverable injuries were insignificant to the total burden from crane accidents. Recommendations and perspectives  The characterization factor for crane lifts identifies contributions to life cycle health impact from loading technologies that otherwise would have been overlooked in LCA. While many contest the inclusion of occupational accidents in LCA, our results show that such impacts can be included and that their consideration adds valuable insights.     

Reviewing environmental life cycle impacts of biobased polymers: current trends and methodological challenges

The International Journal of Life Cycle Assessment - The aim of this review is to evaluate previous life cycle assessment (LCA) studies of first- and second-generation bioplastics, to understand...     

Systematic literature review in social life cycle assessment

Purpose

The main purpose of this review is to investigate the methodology of social life cycle assessment (SLCA) through its application to case studies. In addition, the following research aims to define the trends related to the SLCA by researchers and consultants. This study will help to map the current situation and to highlight the hot spots and weaknesses of the application of the SLCA theory.

Methods

The SLCA could be considered as a useful methodology to provide decision support in order to compare products and/or improve the social effects of the life cycle of a product. Furthermore, the results of the case studies analyzed may influence decision makers significantly. For this reason, a systematic literature review of case studies was carried out in which SLCA was applied in order to analyze closely the application of the stages of this methodology. In this study, the major phases of the technical framework for a SLCA were analyzed. Specific attention was paid to detect the positive impacts that emerged in the case studies, which were also studied by administering a questionnaire to the authors of the analyzed case studies and to a number of experts in the field of SLCA.

Results and discussion

The 35 case studies examined in this paper, even though they do not deviate from the 40 identified by the previous processing, are still significantly different in terms of outcome produced. It is important to clarify that the authors who developed the case studies considered the steps defined in the SETAC/SETAC guidelines, borrowed from the ISO 14044 standard.

Conclusions

The data resulting from this analysis could help both practitioners and researchers to understand what the issues are, on which it is still necessary to investigate and work, in order to solidify the SLCA methodology and define its role in the context of life cycle sustainability assessment (LCSA).

     

Opportunities and challenges of implementing life cycle assessment in seafood certification: a case study for Spain

Purpose

Eco-labelling has become part of the business strategy of companies thanks to numerous advantages in terms of engaging with consumers and gaining market quota. The aim of this article is to present a critical discussion on the development and implementation of a new eco-label named pescaenverde, registered in Spain, as the first type III eco-label in the Spanish fishing sector that is based on life cycle approaches for seafood products.

Methods

More specifically, it aims to complement ecosystem-based eco-labels with the computation of the carbon footprint and the energy return on investment (EROI) of seafood products. Furthermore, it proposes to discuss the ecological criteria, certification process or the opportunities and challenges of the market implementation of this eco-label in detail. Finally, the authors argue that life cycle eco-labels should be considered important complements for more specific sector- or ecosystem-oriented labels already in use, rather than direct competitors.

Results and discussion

There has been much criticism towards the eco-labelling sector as regards the transparency and scientific rigour of its standards. The fishing and seafood sector, which has experienced a boom in eco-labelling in recent years, due mainly to the strength of the Marine Stewardship Council certification scheme, is not alien to this controversy, since critics advocate expanding the concept of sustainable fisheries beyond an ecosystem approach in order to account for global environmental concerns such as greenhouse gas (GHG) emissions or energy use. Not surprisingly, the European Union and other authorities currently encourage eco-labels to base their ecological criteria on life cycle approaches. Therefore, the current study discusses the ecological criteria, certification process or the opportunities and challenges of the market implementation of this eco-label in detail.

Conclusions

The specificity of the life cycle inventory scheme used in pescaenverde delivers an accurate computation of environmental impacts for the specific case of Spanish fisheries. However, the geographical expansion of this scheme to other nations or regions will be conditioned by an important software adaptation to the particular inventory characteristics of the new fisheries, fleets and products.

Recommendations

Adapting ecological criteria to other situations would also need substantial discussion, since the use of this certification scheme is not intended to contrast or compare seafood products against each other but to provide consumers with an easily identifiable label through which they can detect environmentally sustainable practices in terms of GHG emissions and energy use in the fishing fleets supporting the seafood products purchased.

     

Future scenarios and life cycle assessment: systematic review and recommendations

The International Journal of Life Cycle Assessment - Future scenarios and life cycle assessment (LCA) are powerful tools that can provide early sustainability assessments of novel products,...     

Correction to: Reviewing environmental life cycle impacts of biobased polymers: current trends and methodological challenges

The International Journal of Life Cycle Assessment - A correction to this paper has been published: https://doi.org/10.1007/s11367-021-01887-0     

Representing crop rotations in life cycle assessment: a review of legume LCA studies

The International Journal of Life Cycle Assessment - There is an imperative to accurately assess the environmental sustainability of crop system interventions in the context of food security and...     

Advances in application of machine learning to life cycle assessment: a literature review

Purpose

Life Cycle Assessment (LCA) is the process of systematically assessing impacts when there is an interaction between the environment and human activity. Machine learning (ML) with LCA methods can help contribute greatly to reducing impacts. The sheer number of input parameters and their uncertainties that contribute to the full life cycle make a broader application of ML complex and difficult to achieve. Hence a systems engineering approach should be taken to apply ML in isolation to aspects of the LCA. This study addresses the challenge of leveraging ML methods to deliver LCA solutions. The overarching hypothesis is that: LCA underpinned by ML methods and informed by dynamic data paves the way to more accurate LCA while supporting life cycle decision making.

Methods

In this study, previous research on ML for LCA were considered, and a literature review was undertaken.

Results

The results showed that ML can be a useful tool in certain aspects of the LCA. ML methods were shown to be applied efficiently in optimization scenarios in LCA. Finally, ML methods were integrated as part of existing inventory databases to streamline the LCA across many use cases.

Conclusions

The conclusions of this article summarise the characteristics of existing literature and provide suggestions for future work in limitations and gaps which were found in the literature.

     

Environmental impacts of wooden,plastic, and wood-polymer composite pallet: a life cycle assessment approach

Purpose

Waste recycling is one of the essential tools for the European Union’s transition towards a circular economy. One of the possibilities for recycling wood and plastic waste is to utilise it to produce composite product. This study analyses the environmental impacts of producing composite pallets made of wood and plastic waste from construction and demolition activities in Finland. It also compares these impacts with conventional wooden and plastic pallets made of virgin materials.

Methods

Two different life cycle assessment methods were used: attributional life cycle assessment and consequential life cycle assessment. In both of the life cycle assessment studies, 1000 trips were considered as the functional unit. Furthermore, end-of-life allocation formula such as 0:100 with a credit system had been used in this study. This study also used sensitivity analysis and normalisation calculation to determine the best performing pallet.

Result and discussion

In the attributional cradle-to-grave life cycle assessment, wood-polymer composite pallets had the lowest environmental impact in abiotic depletion potential (fossil), acidification potential, eutrophication potential, global warming potential (including biogenic carbon), global warming potential (including biogenic carbon) with indirect land-use change, and ozone depletion potential. In contrast, wooden pallets showed the lowest impact on global warming potential (excluding biogenic carbon). In the consequential life cycle assessment, wood-polymer composite pallets showed the best environmental impact in all impact categories. In both attributional and consequential life cycle assessments, plastic pallet had the maximum impact. The sensitivity analysis and normalisation calculation showed that wood-polymer composite pallets can be a better choice over plastic and wooden pallet.

Conclusions

The overall results of the pallets depends on the methodological approach of the LCA. However, it can be concluded that the wood-polymer composite pallet can be a better choice over the plastic pallet and, in most cases, over the wooden pallet. This study will be of use to the pallet industry and relevant stakeholders.

     

Methodology to address potential impacts of plastic emissions in life cycle assessment

The International Journal of Life Cycle Assessment - Products made of plastic often appear to have lower environmental impacts than alternatives. However, present life cycle assessments (LCA) do...     

A life cycle assessment of the environmental impacts of a beef system in the USA

The International Journal of Life Cycle Assessment - The need to assess the sustainability attributes of the United States beef industry is underscored by its importance to food security locally...     

Positive impacts in social life cycle assessment: state of the art and the way forward

Purpose

Social life cycle assessment (SLCA) is a methodology under continuous development, which may be applied at different scales: from products to economic sectors up to systems at region (meso) and country (macro) scales. Traditionally, SLCA has been focusing on the assessment of negative social externalities, whereas also positive social impacts could be associated to human interventions. The purpose of the present study is to understand how positive impacts are defined in published literature and how they could be assessed through indicators. The aim is to clarify the concept among scholars and to support decision making in business and policy context.

Methods

The study uses a systematic review approach in order to analyse the types of indicators adopted. In the field of SLCA and according to Paragahawewa et al. (2009), “[I]ndicators are ‘pointers’ to the state of the impact categories (and/or subcategories) being evaluated by the SLCA”. Indicators can be quantitative, semi-quantitative or qualitative (UNEP/SETAC 2009). This review was carried out in order to identify and analyse positive impacts and indicators. After careful scrutiny, 47 papers containing theoretical frameworks were considered, as well as 46 papers presenting case studies.

Results and discussion

Compared to environmental life cycle assessment (E-LCA), where the presence of positive impacts is lower, evaluating benefits or positive impacts can still play a major role in SLCA (Benoît et al. 2010). A quarter of the analysed papers on theoretical frameworks take into account the topic of positive impacts and indicators. Results from case study analysis highlight as “workers”, was the most considered stakeholder (in 100 % of the analysed papers), and as the majority of positive indicators used in the case study analysed are recorded in relation to “other value chain actors”. Within the concept of “positive impacts”, no reference should be made merely to the utility of a product or service. In a broader sense, we could refer to solutions improving the conditions of one or various stakeholders involved. In other words, these are solutions that carry a positive contribution to one or more stakeholders without harming others.

Conclusions

So far, positive impacts are barely covered in literature. There is a clear need of streamlining definition and indicators, especially if they should be applied in a policy context complementing traditional—and often monetary-based, cost-benefit analysis (CBA).

     

Evaluation of design options for green product development: a combined Cuckoo search and life cycle assessment approach

The International Journal of Life Cycle Assessment - In response to the public concerns on the performance regarding environmental conservation and energy saving, manufacturers have to perform...     

Correction to: Methodology to address potential impacts of plastic emissions in life cycle assessment

The International Journal of Life Cycle Assessment -     

Life cycle assessment in the minerals and metals sector: a critical review of selected issues and challenges

Background, aim and scope

The mining sector provides materials that are essential elements in a wide range of goods and services, which create value by meeting human needs. Mining and processing activities are an integral part of most complex material cycles so that the application of life cycle assessment (LCA) to minerals and metals has therefore gained prominence. In the past decade, increased use of LCA in the mineral and metal sector has advanced the scientific knowledge through the development of scientifically valid life cycle inventory databases. Though scientifically valid, LCA still needs to depend on several technical assumptions. In particular, measuring the environmental burden issues related to abiotic resource depletion, land use impacts and open-loop recycling within the LCA are widely debated issues. Also, incorporating spatial and temporal sensitivities in LCA, to make it a consistent scientific tool, is yet to be resolved. This article discusses existing LCA methods and proposed models on different issues in relation to minerals and metals sector.

Main features

A critical review was conducted of existing LCA methods in the minerals and metals sector in relation to allocation issues related to indicators of land use impacts, abiotic resource depletion, allocation in open-loop recycling and the system expansions and accounting of spatial and temporal dimension in LCA practice.

Results

Evolving a holistic view about these contentious issues will be presented with view for future LCA research in the minerals and metals industry. This extensive literature search uncovers many of the issues that require immediate attention from the LCA scientific community.

Discussion

The methodological drawbacks, mainly problems with inconsistencies in LCA results for the same situation under different assumptions and issues related to data quality, are considered to be the shortcomings of current LCA. In the minerals and metals sector, it is important to increase the objectivity of LCA by way of fixing those uncertainties, for example, in the LCA of the minerals and metals sector, whether the land use has to be considered in detail or at a coarse level. In regard to abiotic resource characterisation, the weighting and time scales to be considered become a very critical issue of judgement. And, in the case of open-loop recycling, which model will best satisfy all the stake holders? How the temporal and spatial dimensions should be incorporated into LCA is one of the biggest challenges ahead of all those who are concerned. Addressing these issues shall enable LCA to be used as a policy tool in environmental decision-making. There has been enormous debate with respect to on land use impacts, abiotic resource depletion, open-loop recycling and spatial and temporal dimensions, and these debates remain unresolved. Discussions aimed at bringing consensus amongst all the stake holders involved in LCA (i.e. industry, academia, consulting organisations and government) will be presented and discussed. In addition, a commentary of different points of view on these issues will be presented.

Conclusions

This review shall bring into perspective some of those contentious issues that are widely debated by many researchers. The possible future directions proposed by researchers across the globe shall be presented. Finally, authors conclude with their views on the prospects of LCA for future research endeavours.

Recommendations and outlook

Specific LCA issues of minerals and metals need to be investigated further to gain more understanding. To facilitate the future use of LCA as a policy tool in the minerals and metals sector, it is important to increase the objectivity with more scientific validity. Therefore, it is essential that the issues discussed in this paper are addressed to a great detail.     

The main challenges for social life cycle assessment (SLCA) to support the social impacts analysis of product-service systems

Purpose

This paper aims to investigate the applicability of social life cycle assessment (SLCA) to the social impacts analysis of product-service systems (PSS). The purpose is to discuss the main challenges for this approach to comparing PSS business model alternatives and analyzing the social consequences of PSS introduction into the market.

Methods

Two PSS solutions were considered to investigate the applicability and the challenges for SLCA when applied to PSS assessment. A comparative analysis was discussed based on UNEP/SETAC guidelines. The subcategories and social indicators suggested in the guidelines were analyzed, and the indicators considered suitable for the comparison of PSS alternatives, considering the use phase, were identified. Other indicators from the PSS literature were also added to those from the guidelines. To analyze the consequences of PSS implementation, the applicability of consequential SLCA was discussed.

Results and discussion

The main results pointed out that only a few indicators in the SLCA guidelines could be used for comparative PSS analysis. This occurred because only some of the guidelines could be linked to the processes of each PSS. Other indicators identified in the PSS literature are suggested to complement the comparative analysis of PSS alternatives. Concerning the effects of PSS introduction, it can cause social impacts with regard to the company and stakeholders directly involved in the changes in addition to the effects that may occur in other products and services systems as a result of consumers’ behavior and PSS interaction in the market. The consequential modeling is suggested as appropriate for this analysis.

Conclusions

The SLCA approach can be considered suitable for PSS social issues analysis, although there are limitations for a full analysis in this study. Some major challenges for its applicability were identified. First, PSS functional unit modeling should be investigated considering all PSS elements (products and services) and the functions provided by the system. Second, only few indicators in the guidelines were considered appropriate for PSS comparative analysis before its introduction. Finally, concerning consequential SLCA, this could be explored in the context of PSS, but there is still scarce research on this subject. In short, to establish SLCA as a useful and applicable methodology to assess the social impacts of a PSS, further research is required, especially regarding the consequential SLCA.