Towards social life cycle assessment of mobility services: systematic literature review and the way forward

Purpose

The main purpose of this review is to describe the state of the art of social impact assessment with a focus on mobility services. Whereas the use phase plays an important role for the assessment of services in general, the evaluation of the use phase has been underrepresented in previous social life cycle assessment studies. For that reason, particular attention has been paid to indicators, which allow the assessment of social impacts during the use phase of mobility services.

Methods

Continuous efforts to mitigate climate change and to improve quality of life in cities result in new mobility solutions based on collective use. This will have a huge impact on our society transforming the use of vehicles. In order to better understand the implications for cities, society and the automotive industry, it is essential to evaluate the social impact generated along a product life cycle with particular attention to the use phase. To reach the goal, a systematic literature review was carried out with a focus on social indicators that allow assessing use phase impacts of mobility services. The indicators were analysed and allocated to stakeholder groups. Based on the analysis, a core set of indicators is proposed under consideration of data availability.

Results and discussion

Based on the selected search strings, 51 publications were selected for the literature review, including 579 social indicators. The analysis revealed a wide variety and diversity of indicators that are trying to measure the same aspect. The allocation to the respective stakeholder groups showed that most of the indicators (36%) evaluate impacts regarding the stakeholder group local community. The majority of analysed indicators are of quantitative nature (63%). Nevertheless, a clear assessment method was often missing in the respective publications. Therefore, for the core set of indicators, an assessment method is proposed for every indicator.

Conclusions

The results from this study can help practitioners as well as researchers in the field of urban mobility assessment as it systematically analyses social sustainability aspects. The presented data gives an overview of various indicators that are suggested in other publications, and the proposed core set of indicators can be used to evaluate different mobility services in further research.

     

Methodologies for social life cycle assessment

Goal, Scope and Background  

In recent years several different approaches towards Social Life Cycle Assessment (SLCA) have been developed. The purpose of this review is to compare these approaches in order to highlight methodological differences and general shortcomings. SLCA has several similarities with other social assessment tools, although, in order to limit the expanse of the review, only claims to address social impacts from an LCA-like framework are considered.     

Defining the baseline in social life cycle assessment

Background, aim and scope  

A relatively broad consensus has formed that the purpose of developing and using the social life cycle assessment (SLCA) is to improve the social conditions for the stakeholders affected by the assessed product’s life cycle. To create this effect, the SLCA, among other things, needs to provide valid assessments of the consequence of the decision that it is to support. The consequence of a decision to implement a life cycle of a product can be seen as the difference between the decision being implemented and ‘non-implemented’ product life cycle. This difference can to some extent be found using the consequential environmental life cycle assessment (ELCA) methodology to identify the processes that change as a consequence of the decision. However, if social impacts are understood as certain changes in the lives of the stakeholders, then social impacts are not only related to product life cycles, meaning that by only assessing impacts related to the processes that change as a consequence of a decision, not all changes in the life situations of the stakeholders will be captured by an assessment following the consequential ELCA methodology. This article seeks to identify these impacts relating to the non-implemented product life cycle and establish indicators for their assessment.     

Towards social life cycle assessment: a quantitative product social impact assessment

Purpose

The main goal of this paper is to present the feasibility of the quantitative method presented in the Product Social Impact Assessment (PSIA) handbook throughout a case study. The case study was developed to assess the social impacts of a tire throughout its entire life cycle. We carried out this case study in the context of the Roundtable for the Product Social Metrics project in which 13 companies develop two methodologies, a qualitative and a quantitative one, for assessing the social impact of product life cycle.

Methods

The quantitative methodology implemented for assessing the social impact of a Run On Flat tire mounted in a BMW 3 series consists of 26 indicators split in three groups. Each group represents a stakeholder group. Primary data of the quantitative indicators were collected along the product life cycle of the Run On Flat by involving the companies, which owned the main steps of the product life cycle. Throughout this case study, an ideal/worst-case scenario was defined for the distance-to-target approach to compare the social performances of more products when they are available.

Results and discussion

The implementation of the PSIA quantitative method to a Run On Flat illustrated the necessity to have a referencing step in order to interpret the results. This is particularly important when the results are used to support decision-making process in which no experts are involved. It frequently happens in a big company where the management level has to take often decisions on different topics. Reference values were defined using ideal or worst-case-target scenarios (Fontes et al. 2014). For those topics where it was possible, an ideal/ethical scenario was defined, e.g., 0 h of child labor per product. In other cases, we defined a worst-case scenario, e.g., 0 training hours per product. It was then possible to interpret the results using a distance-to-target approach. A matrix was developed in the case study for identifying in which step of the product life cycle data is not available; that means we need more transparency in the supply chain.

Conclusions

Each value of the matrix can be compared to the ideal/worst scenario to compare the step to each other and to identify along the product life cycle which step and the relative supplier that needs further measures to improve the product performance. Furthermore, a quantitative value for each indicator related to the product life cycle is calculated and compared with the ideal/worst scenario. The case study on Run On Flat represents the first implementation of the quantitative method of PSIA.

     

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.

     

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.     

A social panorama within the life cycle thinking and the circular economy: a literature review

Purpose

This literature review aims to present the current methodologies that have been developed to perform a social life cycle assessment (sLCA) and to display the main differences among them. In addition to that, to identify the nexus between sLCA and circular economy (CE) and to what extent this life cycle technique has been involved within CE studies.

Methods

An analysis of scientific literature using online databases was made. A total of 76 publications, including all industry sectors worldwide, were chosen spanning 11 years, from 2009 to 2020. Special attention was made to the methodology used to assess the social impacts, the impact categories analyzed, and whether there is or not a circular economy case. All the impact categories of both UNEP/SETAC and PSIA were taken into account when doing the review, and the top three of the categories are mentioned here.

Results and discussion

The leadership of the UNEP/SETAC methodology is clear with 58 cases. Almost 90% of the case studies are focused on products while the remaining ones are related with services. Workers are the most considered stakeholder when conducting an sLCA research, followed by local communities and society. Regarding the impact assessment, the performance reference point (PRP) was the most common method used. When considering the CE even when some cases included the end-of-life stage in the system boundaries, the studies did not consider the actors from that stage; excluding these cases, one out of four articles has a link with CE, a promising proportion taking into account the early stage of both concepts (i.e., sLCA and CE).

Conclusions

UNEP/SETAC guidelines seem to be the most promising methodology due to its reception among the scientific community. However, a more industry-oriented approach is proposed by the Roundtable for Product Social Metrics (PSIA) in a way to respond to manufacturing companies’ demand. Regardless of the type of methodology to be implemented, workers represent the key stakeholder when assessing social impacts. The change in usual patterns is leading to a change in the way how stakeholders interact and therefore new and more impacts may arise, and that is the reason why it is important to include the CE into the sLCA. A series of challenges such as the feasibility of aggregating all the life cycle techniques to one (life cycle sustainability assessment), data availability, and quality are still present for the moment.

     

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...     

On the use of ordinal scoring scales in social life cycle assessment

The International Journal of Life Cycle Assessment -     

Subcategory assessment method for social life cycle assessment. Part 1: methodological framework

Purpose

The aim of this work is to propose an objective method for evaluating subcategories in social life cycle impact assessment (S-LCIA). Methods for assessing subcategories have been available since 2006, but a number of these either fail to include all the subcategories envisaged in the guidelines for S-LCA (UNEP/SETAC 2009) or are subjective in their assessment of each subcategory.

Methods

The methodology is characterized by four steps: (i) the use of the organization as unit process, in which it was decided to assess the social profile of the organization responsible for the processes involved in the product life cycle, (ii) definition of the basic requirement to assess each subcategory, (iii) definition of levels based on the environment context or organizational practice and the data availability and (iv) assignment of a quantitative value.

Results and discussion

The result of the method applied was the development of the subcategory assessment method (SAM). SAM is a characterization model that evaluates subcategories during the impact assessment phase. This method is based on the behaviour of organizations responsible for the processes along the product life cycle, thereby enabling a social performance evaluation. The method, thus, presents levels for each subcategory assessment. Level A indicates that the organization exhibits proactive behaviour by promoting basic requirement (BR) practices along the value chain. Level B means that the organization fulfils the BR. Levels C and D are assigned to organizations that do not meet the BR and are differentiated by their context. The greatest difficulty when developing SAM was the definition of the BR to be used in the evaluation of the subcategories, though many indications were present in the methodological sheets.

Conclusions

SAM makes it possible to go from inventory to subcategory assessment. The method supports evaluation across life cycle products, thereby ensuring a more objective evaluation of the social behaviour of organizations and applicable in different countries.

Recommendations

When using SAM, it is advisable to update the data for the context environment. The method might be improved by using data for the social context that would consider not only the country, but also the region, sector and product concerned. A further improvement could be a subdivision of the levels to better encompass differences between organizations. It is advisable to test SAM by applying it to a case study.     

Rigor in social life cycle assessment: improving the scientific grounding of SLCA

Purpose

Social life cycle assessment (SLCA) is developing rapidly and represents a valuable complement to other life cycle methods. As methodological development continues, a growing number of case studies have noted the need for more scientific rigor in areas like data collection, allocation methods, and incorporation of values and cultural context. This work aims to identify opportunities, especially in the social sciences, to improve rigor in SLCA.

Methods

A review of existing literature and tools is based on both hand coding of the SLCA literature as represented in Web of Science’s “All Collections” database and on computer-aided review of the SLCA and other related literatures (including social impact assessment (SIA), life cycle sustainability assessment (LCSA), and corporate social responsibility (CSR)) using a text mining technique known as topic modeling. Rapid diagnosing of potentially valuable contributions from literatures outside of SLCA through computer-aided review led to more detailed, manual investigation of those literatures for further insight.

Results and discussion

Data collection can benefit from increased standardization and integration with social science methods, especially frameworks for surveys and interviews. Sharing examples of questionnaires and ethics committee protocols will likely improve SLCA’s accessibility. SIA and CSR also represent empirical data sources for SLCA. Impact allocation techniques can benefit from reintegration with those in ELCA, in particular by allocating (when necessary) at facility—rather than product—level. The focus on values and subjectivity in SLCA is valuable not only for SLCA but also for other methods, most notably ELCA. Further grounding in social science is likely to improve rigor in SLCA.

Conclusions

SLCA is increasingly robust and contributing to interdisciplinary discussions of how best to consider social impacts. This work makes three major recommendations for continued growth: first, that SLCA standardize human subject research used for data gathering; second, that SLCA adopt allocation techniques from ELCA; and third, that SLCA continue to draw on social science and other literatures to rigorously include value systems.

     

Relevance and feasibility of social life cycle assessment from a company perspective

Background, aim, and scope

Methodology development should reflect demands from the intended users: what are the needs of the user group and what is feasible in terms of requirements involving data and work? Mapping these questions of relevance and feasibility is thus a way to facilitate a higher degree of relevance of the developed methodology. For the emerging area of social life cycle assessment (SLCA), several different potential user groups may be identified. This article addresses the issues of relevance and feasibility of SLCA from a company perspective through a series of interviews among potential company users.

Methods and materials

The empirical basis for the survey is a series of eight semi-structured interviews with larger Danish companies, all of which potentially have the capacity and will to use comprehensive social assessment methodologies. SLCA is not yet a well-defined methodology, but still it is possible to outline several potential applications of SLCA and the tasks a company must be able to perform in order to make use of these applications. The interviews focus on the companies’ interest in these potential applications and their ability and willingness to undertake the required work.

Results

Based on these interviews, three hypotheses are developed relating to these companies’ potential use of SLCA, viz.: (1) needs which may be supported by SLCA relate to three different applications, being comparative assertions, use stage assessments, and weighting of social impacts; (2) assessing the full life cycle of a product or service is rarely possible for the companies; and (3) companies see their social responsibility in the product chain as broader than dictated by the product perspective of SLCA. Trends for these three hypotheses developed on the basis of the opinions of the interviewees. Also, factors influencing the generalization of the results to cover other industries are analyzed.

Discussion

Full comparative assertions as known from environmental life cycle assessment (LCA) may be difficult in a company context due to several difficulties in assessing the full life cycle. Furthermore, the comparative assertion may potentially be hampered by differences in how companies typically allocate responsibility along the product chain and how it is done in SLCA, creating a boundary setting issue. These problems do, only in a limited degree, apply for both the use stage assessment and the tool for weighting social issues.

Conclusion

Despite these difficulties, it is concluded that all three applications of SLCA may be possible for the interviewed companies, but it seems the tendency is to demand assessment tools with very limited life cycle perspective, which to some extent deviate from the original thought behind the LCA tools as being holistic decision aid tools.

Perspectives

It is advocated that there is a need to focus more on questions regarding the relevance and feasibility of SLCA from several different perspectives to direct the future methodology development.     

Environment damage assessment: A literature review using social network analysis

Rapid development of environment science and ecology has witnessed the emerging of economical tools applying to environmental issues, especially environment damage assessment. This study applied bibliometrics tools to the environment damage assessment methods based on on-line SCI-E and SSCI from 2007 to 2016, and described the bibliometric characteristics including publications number, journals, and disciplines. Moreover, the concept of social network was introduced into bibliometrics analysis, and the collaboration relationship network of countries, authors, and institutions are generated. Furthermore, frequency analysis of keywords revealed five most widely used methods in environment damage assessment, including market valuation, contingent valuation method, choice experiment method, travel cost method, and hedonic price method, which are specifically reviewed on developing trend, economic basis, and operating process.     

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,...     

A review of environmental life cycle assessment studies examining cheese production

Purpose

Cheese is one of the world’s most widely consumed dairy products and its popularity is ever growing. However, as concerns for the environmental impact of industries increase, products like cheese, which have a significant environmental impact, may lose their popularity. A commonly used technique to assess the environmental impact of a product is life cycle assessment (LCA). In this paper, a state-of-the-art review of LCA studies on the environmental impact of cheese production is presented.

Methods

Sixteen LCA studies, which explored the impact from the production of a variety of cheese types (fresh, mature and semi-hard) were examined and discussed. The four stages of the LCA were examined and the range of results of selected environmental impact categories (global warming potential, acidification potential and eutrophication potential) were detailed and discussed.

Results and discussion

For each of these environmental impact categories, raw milk production was consistently found to be the most significant contributor to the total impact, which was followed by processing. It was found that allocation between cheese and its by-products was crucial in determining the impact of cheese production and standardisation or guidelines may be needed. Very little information relating to wastewater treatment system and processes were reported and this leads to inaccurate environmental impact modelling relating to these aspects of the manufacture of cheese. Very few studies included the design of packaging in terms of reducing food waste, which may significantly contribute to the overall environmental impact.

Conclusions

As raw milk production was found to have the greatest contribution to environmental impact, mitigation strategies at farm-level, particularly in relation to enteric fermentation and manure management, need to be implemented. Additionally, based on the literature, there is a suggestion that fresh cheese has less of an environmental impact than semi-hard cheeses, particularly when examining direct energy consumption. However, there needs to be more case studies investigated to justify this statement.

     

Responsibility in life cycle assessment practice

The International Journal of Life Cycle Assessment -     

The guidelines for social life cycle assessment of products: just in time!

Purpose  

Authors of different sustainability journals, including authors of articles in past issues of the International Journal of Life Cycle Assessment have acknowledged the rising interest and the pressing need for a social and socio-economic life cycle assessment methodology and identified challenges in its development and implementation. Social life cycle assessment (LCA) allows identification of key issues, assessing, and telling the story of social conditions in the production, use, and disposal of products. In this article, the United Nations Environment Programme/The Society of Environmental Toxicology and Chemistry Guidelines for Social Life Cycle Assessment of Products will be presented.     

Life cycle assessment of soil and groundwater remediation technologies: literature review

Background, aim, and scope  

Life cycle assessment (LCA) is becoming an increasingly widespread tool in support systems for environmental decision-making regarding the cleanup of contaminated sites. In this study, the use of LCA to compare the environmental impacts of different remediation technologies was reviewed. Remediation of a contaminated site reduces a local environmental problem, but at the same time, the remediation activities may cause negative environmental impacts on the local, regional, and global scale. LCA can be used to evaluate the inherent trade-off and to compare remediation scenarios in terms of their associated environmental burden.     

Environmental and social life cycle assessment of growing media for urban rooftop farming

The International Journal of Life Cycle Assessment - New environmental strategies are emerging for cities to become more self-sufficient, such as hydroponic crop production. The implementation of...