Towards a more holistic sustainability assessment framework for agro-bioenergy systems — A review

The use of life cycle assessment (LCA) as a sustainability assessment tool for agro-bioenergy system usually has an industrial agriculture bias. Furthermore, LCA generally has often been criticized for being a decision maker tool which may not consider decision takers perceptions. They are lacking in spatial and temporal depth, and unable to assess sufficiently some environmental impact categories such as biodiversity, land use etc. and most economic and social impact categories, e.g. food security, water security, energy security. This study explored tools, methodologies and frameworks that can be deployed individually, as well as in combination with each other for bridging these methodological gaps in application to agro-bioenergy systems. Integrating agronomic options, e.g. alternative farm power, tillage, seed sowing options, fertilizer, pesticide, irrigation into the boundaries of LCAs for agro-bioenergy systems will not only provide an alternative agro-ecological perspective to previous LCAs, but will also lead to the derivation of indicators for assessment of some social and economic impact categories. Deploying life cycle thinking approaches such as energy return on energy invested-EROEI, human appropriation of net primary production-HANPP, net greenhouse gas or carbon balance-NCB, water footprint individually and in combination with each other will also lead to further derivation of indicators suitable for assessing relevant environmental, social and economic impact categories. Also, applying spatio-temporal simulation models has a potential for improving the spatial and temporal depths of LCA analysis.     

TiO2 nanoparticles influence on the environmental performance of natural and recycled mortars: A life cycle assessment

The World Meteorological Organization has recently reported that greenhouse gases have reached their highest level since 3–5 million years ago. A continuing rise would cause serious consequences e.g., rising temperatures, death of living beings, or water pollution. Cement is associated with those levels since its production encompasses around 8% of global CO₂ emissions. To increase the environmental performance of cementitious materials, different approaches could be followed, for instance, the reuse of waste materials such as recycled aggregate (RA) or the addition of TiO₂ nanoparticles due to its proactive effect during service life. However, no research has been found that examined the effect of nano-TiO₂ addition on recycled mortars in terms of environmental impact. Consequently, the main objective of this research is to evaluate the sustainability of TiO₂ nanoparticles in mortars made with either natural or recycled aggregate. Twelve mixtures with different percentages of nano-TiO₂ substitution (0%, 0.5%, 1%, 2% by the weight of cement) and RA replacement (0%, 50%, 100%) were studied. A life cycle assessment focused on material production (cradle-to-gate) was performed. The functional unit (FU) used was 1 m³ of mortar with a given compressive strength. The mix design was modified to meet the fixed strength defined in the FU. In terms of global warming potential, mortars with RA reduced the environmental impact when 0.5% of nano-TiO₂ was added. Considering waste generation and depletion of natural resources play a crucial role in the sustainability assessment of mortars with RA. Furthermore, when the compressive strength factor was considered in the FU, RA increased the total CO₂ emissions due to the higher amount of cement needed. Finally, despite the apparent harmful effect of nano-TiO₂ using a cradle-to-gate approach, these nanoparticles could highly enhance environmental performance due to their effects during service life.     

The contribution of sensor-based equipment to life cycle assessment through improvement of data collection in the industry

Within the paradigm of “Industry 4.0”, data collection and management acquire new relevance. In this context, the introduction of the Internet of Things (IoT) in the manufacturing field allows to develop information systems able to offer the possibility of using a large amount of data collected from heterogeneous sources in real time. The information thus obtained is functional not only to the attainment of an industrial development but also for evaluation and improvement of its sustainability. For example, the benefit obtainable for the life cycle assessment (LCA) methodology from the new digital configuration is represented by a greater specificity of data that wireless sensors networks (WSN) measure and transmit in a continuous way.This paper explores the benefit of using a sensor for the evaluation of the environmental impact, in particular for LCA, in an Italian company producing chemical formulations. The machinery electric consumption directly measured data is compared with the same data estimated with mathematical models. It highlights how much different approach of data measurement and calculation can affect the LCA results. The detection of the energy variable related to a single machine for a particular process, which has been described in the paper, represents a first step towards the implementation of a WSN, proposed by Scatol8 srl, to be used to produce in a more sustainable way.     

Sustainability assessment framework for scenarios – SAFS

To address current challenges regarding sustainable development and support planning for this form of development, new learning about different possible futures and their potential sustainability implications is needed. One way of facilitating this learning is by combining the futures studies and sustainability assessment (SA) research fields.This paper presents the sustainability assessment framework for scenarios (SAFS), a method developed for assessing the environmental and social risks and opportunities of future scenarios, provides guidelines for its application and demonstrates how the framework can be applied. SAFS suggests assessing environmental and social aspects using a consumption perspective and a life cycle approach, and provides qualitative results. SAFS does not suggest any modelling using precise data, but instead offers guidelines on how to carry out a qualitative assessment, where both the process of assessing and the outcome of the assessment are valuable and can be used as a basis for discussion.The benefits, drawbacks and potential challenges of applying SAFS are also discussed in the paper. SAFS uses systems thinking looking at future societies as a whole, considering both environmental and social consequences. This encourages researchers and decision-makers to consider the whole picture, and not just individual elements, when considering different futures.     

Life cycle assessment of a railway tracks substructures: Comparison of ballast and ballastless rail tracks

The increase of train speed and axle load is an essential goal to make the railway transport more and more competitive for passengers and freights. On this basis, the unevenness of the railway track is crucial for the safety of the railway due to the high speed of the vehicle. Although ballasted tracks represent by far the most used railway track substructure, in recent years the modernization process has led the development of the ballastless track substructures.In deciding between the use of ballasted or ballastless track substructure there are many important technical, economical and environmental factors that have to be addressed. Based on the above, the principal objective of this study was to evaluate the environmental impact of different railway track substructures including ballast, cast-in sleeper and embedded track systems on the short, medium and long term. To accomplish this task, a life cycle assessment (LCA) was carried out throughout the entire life cycle of the railway infrastructure by using the ReCiPe (H) method. Although such approach is commonly included in the environmental assessment of building products and buildings, it was rarely applied in the analysis of the environmental impacts of railway track substructure.Thus, the result of these LCA showed that ballasted tracks cause the lowest environmental impact for service lives of up to 75 years. On the other hand, the embedded track beds cause the highest environmental impacts, regardless of their service life. The highest contributor for the environmental impacts of the track beds was the steel production.The results of this study will provide relevant environmental information for engineers and decision makers to select the most adequate railway track substructures for addressing issues related to the pursuit of sustainable development.     

Life cycle assessment as an analytical tool in strategic environmental assessment. Lessons learned from a case study on municipal energy planning in Sweden

Life cycle assessment (LCA) is explored as an analytical tool in strategic environmental assessment (SEA), illustrated by case where a previously developed SEA process was applied to municipal energy planning in Sweden. The process integrated decision-making tools for scenario planning, public participation and environmental assessment. This article describes the use of LCA for environmental assessment in this context, with focus on methodology and practical experiences. While LCA provides a systematic framework for the environmental assessment and a wider systems perspective than what is required in SEA, LCA cannot address all aspects of environmental impact required, and therefore needs to be complemented by other tools. The integration of LCA with tools for public participation and scenario planning posed certain methodological challenges, but provided an innovative approach to designing the scope of the environmental assessment and defining and assessing alternatives.     

Life cycle assessment of traditional and alternative bricks: A review

Life cycle assessment (LCA) is a solid tool to assess the potential environmental impacts in construction industry, an important material in this industry is the brick, along time several traditional and alternative bricks were developed and assessed environmentally by LCA. The purpose of this article is to review the literature related to LCA of bricks, responding important topics to characterize and guide future studies. Out of Traditional Bricks (TB), there are Alternative Bricks with Organic (ABO) and Inorganic (ABI) additives, that use wastes from several industries and differ of TB in the omission of firing for a stabilization process, however, to omit firing is hard and stabilization still needs further improvements. The principal system boundaries and tools for LCA were also reviewed. Regarding the most present impact categories, they were: Climate change (CC), Human Toxicity (HT) and Freshwater Ecotoxicity (FE), in every category, production is the stage of highest impact, and in the productive process, drying and burning processes have the highest potential impacts. Future searches could continue to study on new materials (wastes) for development of new ABO and ABI, to quantify the benefits of reusing wastes, and to study, either the replacement of firing with stabilizing processes, or the use of biomass as fuel source in firing, and to develop studies in different countries to create national datasets that will make future studies more representative.     

Research trends in life cycle assessment research: A 20-year bibliometric analysis (1999–2018)

The life cycle assessment (LCA) is an important environmental management tool that has been developed since the 1960s and it is a widely accepted field of research in the scientific community. This paper focuses on the changes of research trends of this field in the recent two decades (1999–2018) from the perspective of bibliometrics. First, we use the Web of Science (WoS) database to collect relevant literature, which is a widely used database in the field of bibliometrics. Then, this paper analyzes in detail the amount of publications, citations, cooperation models and their evolution trends, and identifies the most productive countries, institutions and authors in this field. Finally, by studying the author-keyword co-occurrence networks of the LCA papers in different periods, the research hotspots and their changes in this field are explored. We hope that the research of this paper will contribute to the faster and better development of the LCA field.     

Conceptualising and managing trade-offs in sustainability assessment

One of the defining characteristics of sustainability assessment as a form of impact assessment is that it provides a forum for the explicit consideration of the trade-offs that are inherent in complex decision-making processes. Few sustainability assessments have achieved this goal though, and none has considered trade-offs in a holistic fashion throughout the process. Recent contributions such as the Gibson trade-off rules have significantly progressed thinking in this area by suggesting appropriate acceptability criteria for evaluating substantive trade-offs arising from proposed development, as well as process rules for how evaluations of acceptability should occur. However, there has been negligible uptake of these rules in practice. Overall, we argue that there is inadequate consideration of trade-offs, both process and substantive, throughout the sustainability assessment process, and insufficient considerations of how process decisions and compromises influence substantive outcomes. This paper presents a framework for understanding and managing both process and substantive trade-offs within each step of a typical sustainability assessment process. The framework draws together previously published literature and offers case studies that illustrate aspects of the practical application of the framework. The framing and design of sustainability assessment are vitally important, as process compromises or trade-offs can have substantive consequences in terms of sustainability outcomes delivered, with the choice of alternatives considered being a particularly significant determinant of substantive outcomes. The demarcation of acceptable from unacceptable impacts is a key aspect of managing trade-offs. Offsets can be considered as a form of trade-off within a category of sustainability that are utilised to enhance preferred alternatives once conditions of impact acceptability have been met. In this way they may enable net gains to be delivered; another imperative for progress to sustainability. Understanding the nature and implications of trade-offs within sustainability assessment is essential to improving practice.     

A thematic review of life cycle assessment (LCA) applied to pig production

Commercial livestock production is known to have significant impacts on the environment. Pig production is a complex system which involves the production of animal feed, transportation, animal rearing and waste management. One tool for assessing the environmental performance of such complex systems is life cycle assessment (LCA). LCA has been applied to pig production considerably to date. This paper provides a chronological review of state-of-the-art pig production LCAs under three themes: feed production; entire-system livestock rearing; and waste management. The study considers how LCA applications have addressed technological improvements in animal husbandry, and highlights methodological limitations, particularly related to cross-study comparisons. Recent research demonstrates crude protein reduction in feed and anaerobic treatment of pig excreta resulting in bioenergy production are the key targets for environmental performance improvements related to pig production.     

Regionalization of land use impact models for life cycle assessment: Recommendations for their use on the global scale and their applicability to Brazil

Life Cycle Assessment (LCA) is the main technique for evaluate the environmental impacts of product life cycles. A major challenge in the field of LCA is spatial and temporal differentiation in Life Cycle Impact Assessment (LCIA) methods, especially impacts resulting from land occupation and land transformation. Land use characterization modeling has advanced considerably over the last two decades and many approaches have recently included crucial aspects such as geographic differentiation. Nevertheless, characterization models have so far not been systematically reviewed and evaluated to determine their applicability to South America. Given that Brazil is the largest country in South America, this paper analyzes the main international characterization models currently available in the literature, with a view to recommending regionalized models applicable on a global scale for land use life cycle impact assessments, and discusses their feasibility for regionalized assessment in Brazil. The analytical methodology involves classification based on the following criteria: midpoint/endpoint approach, scope of application, area of data collection, biogeographical differentiation, definition of recovery time and reference situation; followed by an evaluation of thirteen scientific robustness and environmental relevance subcriteria. The results of the scope of application are distributed among 25% of the models developed for the European context, and 50% have a global scope. There is no consensus in the literature about the definition of parameters such biogeographical differentiation and reference situation, and our review indicates that 35% of the models use ecoregion division while 40% use the concept of potential natural vegetation. Four characterization models show high scores in terms of scientific robustness and environmental relevance. These models are recommended for application in land use life cycle impact assessments, and also to serve as references for the development or adaptation of regional methodological procedures for Brazil.     

Variability of building environmental assessment tools on evaluating carbon emissions

With an increasing importance of sustainability in construction, more and more clients and designers employ building environmental assessment (BEA) tools to evaluate the environmental friendliness of their building facilities, and one important aspect of evaluation in the BEA models is the assessment of carbon emissions. However, in the absence of any agreed framework for carbon auditing and benchmarking, the results generated by the BEA tools might vary significantly which could lead to confusion or misinterpretation on the carbon performance of a building. This study thus aims to unveil the properties of and the standard imposed by the current BEA models on evaluating the life cycle carbon emissions. The analyses cover the (i) weighting of energy efficiency and emission levels among various environmental performance indicators; (ii) building life cycle stages in which carbon is taken into consideration; (iii) objectiveness of assessment; (iv) baseline set for carbon assessment; (v) mechanism for benchmarking the emission level; and (v) limitations of the carbon assessment approaches. Results indicate that the current BEA schemes focus primarily on operational carbon instead of the emissions generated throughout the entire building life cycle. Besides, the baseline and benchmark for carbon evaluation vary significantly among the BEA tools based on the analytical results of a hypothetical building. The findings point to the needs for a more transparent framework for carbon auditing and benchmarking in BEA modeling.     

Global warming implications of facade parameters: A life cycle assessment of residential buildings in Bahrain

On a global scale, the Gulf Corporation Council Countries (GCCC), including Bahrain, are amongst the top countries in terms of carbon dioxide emissions per capita. Building authority in Bahrain has set a target of 40% reduction of electricity consumption and associated CO₂ emissions to be achieved by using facade parameters. This work evaluates how the life cycle CO₂ emissions of buildings are affected by facade parameters. The main focus is placed on direct and indirect CO₂ emissions from three contributors, namely, chemical reactions during production processes (Pco₂), embodied energy (Eco₂) and operational energy (OPco₂). By means of the life cycle assessment (LCA) methodology, it has been possible to show that the greatest environmental impact occurs during the operational phase (80–90%). However, embodied CO₂ emissions are an important factor that needs to be brought into the systems used for appraisal of projects, and hence into the design decisions made in developing projects. The assessment shows that masonry blocks are responsible for 70–90% of the total CO₂ emissions of facade construction, mainly due to their physical characteristics. The highest Pco₂ emissions factors are those of window elements, particularly aluminium frames. However, their contribution of CO₂ emissions depends largely on the number and size of windows. Each square metre of glazing is able to increase the total CO₂ emissions by almost 30% when compared with the same areas of opaque walls. The use of autoclaved aerated concrete (AAC) walls reduces the total life cycle CO₂ emissions by almost 5.2% when compared with ordinary walls, while the use of thermal insulation with concrete wall reduces CO₂ emissions by 1.2%. The outcome of this work offers to the building industry a reliable indicator of the environmental impact of residential facade parameters.     

An Optimization Model for Integrated Coastal Management: Development and a Case Study Using Italy’s Comacchio Municipality

In this paper, I develop an optimization model for integrated coastal management in which decisions arise from an area-based algorithm that minimizes predicted damage caused by beach erosion and inshore flooding, while accounting for economic, social, and environmental losses. The model favors the involvement of stakeholders in coastal management, but does not use complicated assessment procedures for non-economic indicators or relative weights to combine economic, social, and environmental indicators. Instead, the integration between economic activities or properties and the environmental status and landscape is represented objectively and non-linearly by referring to initial and sustainability conditions, combined with budgetary and environmental constraints. The model successfully accounted for both human and environmental dynamics by depicting delayed effects, neighborhood externalities, and feedback effects. It calculated a single optimal value for each integrated coastal management strategy, which permitted the support of future decisions and the evaluation of past decisions. The model’s insights were based on reliable estimates, with reliability determined by calculating the confidence level. The model was successfully applied to Italy’s Comacchio coastal municipality, where it revealed the priorities for optimal beach nourishment, dune fixation, and residential and holiday housing development based on budget constraints, beach losses, flood damage, pollution impacts, and land-use constraints.     

Life cycle assessment of two sustainable and old neighbourhoods affected by climate change in one city in Belgium: A review

Aware of the strong population growth expected in the coming years in cities, it is imperative to evaluate the impact of this new concentration on the environment, health and power consumption. Life Cycle Assessment (LCA) is the most appropriate method to quantify these different impacts. The aim of this study is to carry out the Life Cycle Analysis (LCA) in two sustainable and old neighbourhoods located in Belgium, while comparing different environmental impacts; but also, to determine the most important source of environmental change at the neighbourhood scale. This study begins with a strong review on LCA in residence buildings and neighbourhoods since 1996 up to 2018.Then followed by the assessment and comparison of the climate variation in six different periods (past, current, 2020,2050,2080 and 2100).In the same line, three scenarios (A2, B1 and A1B)were associated to several models of the Intergovernmental Panel on Climate Change (IPCC). We have combined three simulation tools, such as ALCYONE, COMFIE-PLEIADES and nova-EQUER. The main results showed the twelve environmental impacts studied in this research that does not always evolve in the same way. Indeed, it was noticed that the CO2 emissions were up to 36.6% higher in an old neighbourhood than in a sustainable one; while the energy demand was estimated at 62.6% and 37.4% in an old and a sustainable one, respectively. Good planning of the public space will play an important role to reduce in average up to 15% the eutrophication in both neighbourhoods. Globally, the renovation of residential buildings is very important, indeed, it allows mitigate in average up to 30% of environment impacts in both neighbourhoods.     

A framework for combining social impact assessment and risk assessment

An increasing focus on integrative approaches is one of the current trends in impact assessment. There is potential to combine impact assessment with various other forms of assessment, such as risk assessment, to make impact assessment and the management of social risks more effective. We identify the common features of social impact assessment (SIA) and social risk assessment (SRA), and discuss the merits of a combined approach. A hybrid model combining SIA and SRA to form a new approach called, ‘risk and social impact assessment’ (RSIA) is introduced. RSIA expands the capacity of SIA to evaluate and manage the social impacts of risky projects such as nuclear energy as well as natural hazards and disasters such as droughts and floods. We outline the three stages of RSIA, namely: impact identification, impact assessment, and impact management.     

Towards a green and fast production system: Integrating life cycle assessment and value stream mapping for decision making

Integrating environmental commitment to manufacturing concerns seems unavoidable towards a more sustainable conduct. In the contemporary scenario, Value Stream Mapping (VSM) has been bringing new perspectives into companies' economics, improving production performance, whereas Life Cycle Assessment (LCA) has been the most complete tool for environmental assessment. Therefore, the present study aims to propose a model based on the integration of LCA and VSM to improve environmental and manufacturing aspects of organizations, the LCA-VSM model. Possible spots for integration, overlaps between LCA and VSM and potential gains were identified. The LCA-VSM model provides a simple tool for prioritizing action measures to improve the environmental-economic performance, and unlike many existing methods, it encourages continuous improvement instead of a one-off approach. The company where a case study was conducted to test the LCA-VSM model is a manufacturer of tools and painting materials for the civil construction sector. The use of the proposed model guided actions that decreased from 5% to 15% of environmental impacts (across nine impact categories), and reduced both non-value adding (lead time went from 103.26 to 24.01 days) and value adding (cycle time went from 35.7 s to 33.75 s) time. The main contribution of this paper is providing a structured approach to a practical integration of LCA and VSM towards decision making, prioritizing action measures based on the following criteria: environmental preference, economic feasibility, and ease of implementation, aiding more eco-efficient practices.     

LCA Integrated ANP Framework for Selection of Sustainable Manufacturing Processes

In recent times, the focus of sustainable development has been shifted toward the process domain to achieve greater environmental benefits. Improved sustainability in the process domain can be achieved by selecting sustainable process or through improvement studies. In this study, sustainability performance of injection molding (IM) and selective laser sintering (SLS) processes are compared to select the sustainable process. Life cycle assessment (LCA) has been widely accepted for assessing the environmental performance of manufacturing process. However, the problem with LCA is the interpretation of impact category scores when comparing alternate processes. Therefore, an effort has been made to integrate analytical network process (ANP) methodology with LCA in which LCA methodology calculates the impact score and ANP computes the Single Point Process Sustainability Score (SPPSS) to compare alternate processes. Based on the inventory data collected for higher production rates, SPPSS for IM and SLS processes are computed as 0.038 and 0.068, respectively. Based on the score, IM has been identified as a sustainable process for higher production volume. Hence, the practical usability of the proposed methodology is validated by the study. This study also appreciates the application of ANP along with LCA for decision making in the real-time scenario.     

Benchmarking environmental and economic impacts from the HSR networks considering life cycle perspectives

This paper unprecedentedly benchmarks the environmental and economic impacts of notable High-speed rail (HSR) networks. The goals are to (i) point out the environmental impacts from the HSR networks and (ii) evaluate the whole life cycle cost of HSR systems. The emphasis of this study is placed on five HSR networks from five countries to depict the effectiveness of sustainable transport policies in each particular country. Both life cycle assessment (LCA) and life cycle cost (LCC) models are adopted for a new critical framework capable of benchmarking the lifecycle sustainability of HSR networks. The new findings exhibit that CRC's system is the leader in energy-saving, who consumes only 67.55 GJ/km yearly, and emits lowest CO₂ at an amount of 77,532.32 tCO₂/km annually. These impressive results are stemmed from key enabling policies related to eco-friendly rolling stock design, sustainable construction, and green energy grids. With respect to the LCC analysis, the SCNF network takes advantage in the economy of scale and unleashes the lowest cost among other networks. It estimates that the SNCF network spends approximately 1,990,599.51 £/km annually at a % discount rate. The implications of these finding are discussed that the initial project has a high chance to be successful on economic than the late project due to an influence of the time value of money.