Raw material criticality assessment as a complement to environmental life cycle assessment: Examining methods for product‐level supply risk assessment

The diversity of raw materials used in modern products, compounded by the risk of supply disruptions—due to uneven geological distribution of resources, along with socioeconomic factors like production concentration and political (in)stability of raw material producing countries—has drawn attention to the subject of raw material “criticality.” In this article, we review the state of the art regarding the integration of criticality assessment, herein termed “product‐level supply risk assessment,” as a complement to environmental life cycle assessment. We describe and compare three methods explicitly developed for this purpose—Geopolitical Supply Risk (GeoPolRisk), Economic Scarcity Potential (ESP), and the Integrated Method to Assess Resource Efficiency (ESSENZ)—based on a set of criteria including considerations of data sources, uncertainties, and other contentious methodological aspects. We test the methods on a case study of a European‐manufactured electric vehicle, and conclude with guidance for appropriate application and interpretation, along with opportunities for further methodological development. Although the GeoPolRisk, ESP, and ESSENZ methods have several limitations, they can be useful for preliminary assessments of the potential impacts of raw material supply risks on a product system (i.e., “outside‐in” impacts) alongside the impacts of a product system on the environment (i.e., “inside‐out” impacts). Care is needed to not overlook critical raw materials used in small amounts but nonetheless important to product functionality. Further methodological development could address regional and firm‐level supply risks, multiple supply‐chain stages, and material recycling, while improving coverage of supply risk characterization factors.     

Using anticipatory life cycle assessment to enable future sustainable construction

The built environment is the largest single emitter of CO₂ and an important consumer of energy. Much research has gone into the improved efficiency of building operation and construction products. Life Cycle Assessment (LCA) is commonly used to assess existing buildings or building products. Classic LCA, however, is not suited for evaluating the environmental performance of developing technologies. A new approach, anticipatory LCA (a‐LCA), promises various advantages and can be used as a design constraint during the product development stage. It helps overcome four challenges: (i) data availability, (ii) stakeholder inclusion, (iii) risk assessment, and (iv) multi‐criteria problems. This article's contribution to the line of research is twofold: first, it adapts the a‐LCA approach for construction‐specific purposes in theoretical terms for the four challenges. Second, it applies the method to an innovative prefabricated modular envelope system, the CleanTechBlock (CTB), focusing on challenge (i). Thirty‐six CTB designs are tested and compared to conventional walls. Inclusion of technology foresight is achieved through structured scenario analysis. Moreover, challenge (iv) is tackled through the analysis of different environmental impact categories, transport‐related impacts, and thickness of the wall assemblies of the CTB. The case study results show that optimized material choice and product design is needed to reach the lowest environmental impact. Methodological findings highlight the importance of context‐specific solutions and the need for benchmarking new products.     

Lifting the veil on the correction of double counting incidents in hybrid life cycle assessment

Life cycle assessment (LCA) and environmentally extended input–output analyses (EEIOA) are two techniques commonly used to assess environmental impacts of an activity/product. Their strengths and weaknesses are complementary, and they are thus regularly combined to obtain hybrid LCAs. A number of approaches in hybrid LCA exist, which leads to different results. One of the differences is the method used to ensure that mixed LCA and EEIOA data do not overlap, which is referred to as correction for double counting. This aspect of hybrid LCA is often ignored in reports of hybrid assessments and no comprehensive study has been carried out on it. This article strives to list, compare, and analyze the different existing methods for the correction of double counting. We first harmonize the definitions of the existing correction methods and express them in a common notation, before introducing a streamlined variant. We then compare their respective assumptions and limitations. We discuss the loss of specific information regarding the studied activity/product and the loss of coherent financial representation caused by some of the correction methods. This analysis clarifies which techniques are most applicable to different tasks, from hybridizing individual LCA processes to integrating complete databases. We finally conclude by giving recommendations for future hybrid analyses.     

A social life cycle assessment of vanadium redox flow and lithium-ion batteries for energy storage

Battery energy storage systems (BESS) are expected to fulfill a crucial role in the renewable energy systems of the future. Within current regulatory frameworks, assessing the sustainability as well as the social risks for BESS should be considered. In this research we conducted a social life cycle assessment (S-LCA) of two BESS: the vanadium redox flow battery (VRFB) and the lithium-ion battery (LIB). The S-LCA was conducted based on the guidelines set by UNEP/SETAC and using the PSILCA v.3 database. It was found that most social risks related to the life cycle of the batteries are associated with the raw material extraction stage, while sectors related to chemicals also entail considerable risks. Workers are the stakeholder group affected most. These results apply to supply chains located in both China and Germany, but risks were lower for similar supply chains in Germany. An LIB with a nickel manganese cobalt oxide cathode is associated with considerably larger risks compared to a LIB with lithium manganese oxide cathode. For a VRFB life cycle with an increased vanadium price, the social risks were higher than those of the VRFB supply chain with a regular vanadium price. Our paper shows that S-LCA through the PSILCA database can provide interesting insights into the potential social risks associated with a certain product's life cycle. Generalizations of the results are not recommended, and one should be careful with assessments for technologies that have not yet matured due to the cost sensitivity of the methodology.     

Review of impact categories and environmental indicators for life cycle assessment of geotechnical systems

Life cycle assessment (LCA) has only had limited application in the geotechnical engineering discipline, though it has been widely applied to civil engineering systems such as pavements and roadways. A review of previous geotechnical LCAs showed that most studies have tracked a small set of impact categories, such as energy and global warming potential. Accordingly, currently reported environmental indicators may not effectively or fully capture important environmental impacts and tradeoffs associated with geotechnical systems, including those associated with land and soil resources. This research reviewed previous studies, methods, and models for assessment of land use and soil‐related impacts to understand their applicability to geotechnical LCA. The results of this review show that critical gaps remain in current knowledge and practice. In particular, further development or refinement of environmental indicators, impact categories, and cause–effect pathways is needed as they pertain to geotechnical applications—specifically those related to soil quality, soil functions, and the ecosystem services soils provide. In addition, many existing methods emerge from research on land use and land use change related to other disciplines (e.g., agriculture). For applicability to geotechnical projects, the resolution of many of these methods and resulting indicators need to be downscaled from the landscape/macro scale to the project scale. In the near term, practitioners of geotechnical LCA should begin tracking changes to soil properties and report impacts to land and soil resources qualitatively.     

Approaches for inclusion of forest carbon cycle in life cycle assessment – a review

Forests are a significant pool of terrestrial carbon. A key feature related to forest biomass harvesting and use is the typical time difference between carbon release into and sequestration from the atmosphere. Traditionally, the use of sustainably grown biomass has been considered as carbon neutral in life cycle assessment (LCA) studies. However, various approaches to account for greenhouse gas (GHG) emissions and sinks of forest biomass acquisition and use have also been developed and applied, resulting in different conclusions on climate impacts of forest products. The aim of this study is to summarize, clarify, and assess the suitability of these approaches for LCA. A literature review is carried out, and the results are analyzed through an assessment framework. The different approaches are reviewed through their approach to the definition of reference land‐use situation, consideration of time frame and timing of carbon emissions and sequestration, substitution credits, and indicators applied to measure climate impacts. On the basis of the review, it is concluded that, to account for GHG emissions and the related climate impacts objectively, biomass carbon stored in the products and the timing of sinks and emissions should be taken into account in LCA. The reference situation for forest land use has to be defined appropriately, describing the development in the absence of the studied system. We suggest the use of some climate impact indicator that takes the timing of the emissions and sinks into consideration and enables the use of different time frames. If substitution credits are considered, they need to be transparently presented in the results. Instead of carbon stock values taken from the literature, the use of dynamic forest models is recommended.     

Site‐specific life cycle assessment of a pilot floating offshore wind farm based on suppliers’ data and geo‐located wind data

Renewable energy systems are essential in coming years to ensure an efficient energy supply while maintaining environmental protection. Despite having low environmental impacts during operation, other phases of the life cycle need to be accounted for. This study presents a geo‐located life cycle assessment of an emerging technology, namely, floating offshore wind farms. It is developed and applied to a pilot project in the Mediterranean Sea. The materials inventory is based on real data from suppliers and coupled to a parameterized model which exploits a geographic information system wind database to estimate electricity production. This multi‐criteria assessment identified the extraction and transformation of materials as the main contributor to environmental impacts such as climate change (70% of the total 22.3 g CO₂ eq/kWh), water use (73% of 6.7 L/kWh), and air quality (76% of 25.2 mg PM2.5/kWh), mainly because of the floater's manufacture. The results corroborate the low environmental impact of this emerging technology compared to other energy sources. The electricity production estimates, based on geo‐located wind data, were found to be a critical component of the model that affects environmental performance. Sensitivity analyses highlighted the importance of the project's lifetime, which was the main parameter responsible for variations in the analyzed categories. Background uncertainties should be analyzed but may be reduced by focusing data collection on significant contributors. Geo‐located modeling proved to be an effective technique to account for geographical variability of renewable energy technologies and contribute to decision‐making processes leading to their development.     

环境足迹的核算与整合框架——基于生命周期评价的视角

环境足迹及其与生命周期评价(LCA)的关系是工业生态学关注的新热点。从探讨环境足迹与LCA的关系入手,以碳足迹、水足迹、土地足迹和材料足迹为例,分别对每一项足迹指标两个版本的核算方法进行了比较。根据清单加和过程的特点,将所有足迹指标划分为基于权重因子和基于特征因子两类,总结了两者的适用性和局限性。在此基础上提出了一个环境足迹核算与整合的统一框架。该框架基于LCA视角建立,但对系统边界和清单数据的要求相对灵活,因而也适用于生命周期不甚明确的情形。研究在一定程度上揭示了足迹指标的方法学实质,同时也为环境影响综合评估提供了一条规范化的途径。     

A screening level life cycle assessment of the ABB EU 2000 air handling unit

The screening level LCA places itself amongst the many approaches to LCA, including full LCA and streamlined LCA. The screening level LCA combines the quantitative nature of the full LCA with the low effort of the streamlined LCA. This paper presents, as an example, a screening level LCA of the EU 2000 air handling unit from ABB Ventilation Products AB, Sweden, using the Danish EDIP impact assessment method, the EDIP software and database. This study proved that major improvement potentials can indeed be identified with screening level LCA, and argues that the screening level LCA is a suitable approach in the early stages of a company’s life cycle engineering efforts Contact for the screening level LCA method Corresponding author at ABB Corporate Research     

Quantifying environmental impacts of primary aluminum ingot production and consumption : A trade‐linked multilevel life cycle assessment

Aluminum is one of the most used metals of modern civilization, but its production is responsible for multiple adverse environmental impacts mostly due to aluminum smelting and alumina refining. Previous life cycle assessments (LCAs) have aggregated alumina refining into a single global process even though refining processes are highly spatially differentiated and alumina is highly traded. Our work improves on existing LCAs of primary aluminum by including temporal and spatial differentiation in alumina refining and aluminum smelting and trade of alumina and primary aluminum ingots. We build country‐level impact factors for primary aluminum ingot production and consumption, with the spatial distributions of environmental impacts, from 2000 to 2017, by combining a trade‐linked multilevel material flow analysis with LCA using six midpoint categories of the ReCiPe method. Climate change impacts of primary aluminum production range from 4.5 to 33.6 kg CO₂ eq./kg. We then estimate the life cycle production‐ and consumption‐based environmental burdens of primary aluminum ingot by country. High spatial variations exist among impact factors of primary aluminum production. Aggregating the alumina refining processes into a single process may cause important deviations on the impact factors of primary aluminum ingot production (up to 38% differences in climate change impacts). Finally, we estimate the climate change impacts of worldwide primary aluminum production at 1.2 Gt CO₂ eq. in 2017 and untangle their spatial origins, localized at 70% in China. Overall, we show the importance of spatial differentiation for highly traded products that rely on highly traded inputs and offer recommendations for LCA practitioners. This article met the requirements for a gold‐gold JIE data openness badge described at http://jie.click/badges .     

A region‐specific environmental analysis of technology implementation of hydrogen energy in Japan based on life cycle assessment

Energy systems using renewables with adequate energy carriers are needed for sustainability. Before accelerating technology implementation for the transition to the new energy system, region‐specific implementation effects should be carefully examined as a system. In this study, we aim to analyze an energy system using hydrogen as an energy carrier with the approach of combining life cycle assessment and a regional energy simulation model. The model calculates the emissions, such as CO₂, nitrogen oxides (NOx), sulfur oxides (SOx), and volatile organic compounds, and their impacts on human health, social assets, primary production, and an integrated index. The analysis quantitatively presented various environmental impacts by region, life cycle stage, and impact category. Climate change was dominant on the integrated index while the other impact categories were also important. Fuel cell vehicles were effective in mitigating local air pollution, especially in high‐population regions where many people are adversely affected. Although technology implementation contributes to mitigating environmental impacts at locations of energy users, it also has possibilities to have negative impacts at locations of device manufacturing and raw material processing. The definition of the regional division was also an important factor in energy system design because the final results of life cycle assessments are highly sensitive to region‐specific characteristics. The proposed region‐specific analysis is expected to support local governments and technology developers in designing appropriate energy systems for regions and building marketing plans for specific targets.     

A life cycle impact assessment procedure with resource groups as areas of protection

Goal and Background  Current Life Cycle Impact Assessment (LCIA) procedures have demonstrated certain limitations in the South African manufacturing industry context. The aim of this paper is to propose a modified LCIA procedure, which is based on the protection of resource groups. Methods  A LCIA framework is introduced that applies the characterisation procedure of available midpoint categories, with the exception of land use. Characterisation factors for land occupation and transformation is suggested for South Africa. A distanceto-target approach is used for the normalisation of midpoint categories, which focuses on the ambient quality and quantity objectives for four resource groups: Air, Water, Land and Mined Abiotic Resources. The quality and quantity objectives are determined for defined South African Life Cycle Assessment (SALCA) Regions and take into account endpoint or damage targets. Following the precautionary approach, a Resource Impact Indicator (RII) is calculated for the resource groups. Subjective weighting values for the resource groups are also proposed, based on survey results from the manufacturing industry sector and the expenditure trends of the South African national government. The subjective weighting values are used to calculate overall Environmental Performance Resource Impact Indicators (EPRIIs) when comparing life cycle systems with each other. The proposed approaches are evaluated with a known wool case study. Results and Discussion  The calculation of a RJI ensures that all natural resources that are important from a South African perspective are duly considered in a LCIA. The results of a LCIA are consequently not reliant on a detailed Life Cycle Inventory (LCI) and the number of midpoint categories that converge on a single resource group. The case study establishes the importance of region-specificity, for LCIs and LCIAs. Conclusions  The proposed LCIA procedure demonstrates reasonable ease of communication of LCIA results. It further allows for the inclusion of additional midpoint categories and is adaptable for specific regions. Recommendations and Outlook  The acceptance of the LCIA procedure must be evaluated for different industry and government sectors. Also, the adequate incorporation of Environmental Performance Resource Impact Indicators (EPRIIs) into decision-making for Life Cycle Management purposes must be researched further. Specifically, the application of the procedures for supply chain management will be investigated.     

Environmental Implications of Consumer Convenience: Coffee as a Case Study

Products of convenience are playing an increasingly large role in today's society. These products provide a competitive advantage over their conventional counterparts by requiring less time and effort to produce a similar service or experience. At the same time, these products are often also more materials intensive to produce and create a greater amount of waste. A comparative midpoint life cycle assessment of different coffee brewing systems is presented in order to explore the comparative impact of three different systems: drip filter, french press, and pod style (a product of convenience). Utilizing a comparative functional unit, the drip filter system method was found to have the greatest environmental impact in all impact categories, whereas the pod style had the least in six of the impact categories (with the french press having the least in two of the impact categories, and a tie between pod style and french press in a single impact category). This suggests that contrary to popular belief, the pod style coffee may be the more environmentally friendly option. The two most significant contributors to environmental impact in all of the categories considered was the amount of dry coffee utilized and the energy needed to brew the coffee, although in some categories considered transportation was also significant. There is the potential for the environmental impact of coffee brewing to shift if coffee wastage occurs (likely in the case of the drip filter and french press system) or if substantial changes in materials or energy consumption were to occur (in the case of the pod‐style brewing system). From the perspective of industrial ecology, this analysis suggests that, in regard to products of consumer convenience, the convenient alternative may not have a significantly greater environmental impact than its conventional counterpart, and that it may be time to question that often‐held assumption.     

Loss and Benefit Caused by a Diesel Engine: From the Perspective of Human Health

This article presents a model that quantifies the health loss and benefit triggered by the life cycle of a diesel engine. The health loss and benefit are expressed in the form of disability‐adjusted life years (DALY), a metric used by the World Health Organization to conduct health impact assessments. In order to quantify the health loss, life cycle assessment methodology is applied. To estimate the health benefit, the relationship between DALY per capita and gross domestic product (GDP) per capita is modeled. The change in GDP per capita, resulting from the change in the level of employee compensation caused by the life cycle of the diesel engine, is used to estimate the change in the level of DALY per capita. An economic input‐output model is applied to estimate the amount of employee compensation required over the life cycle of the diesel engine. This study concludes that the health benefit achieved by the socioeconomic growth, triggered by the life cycle of the diesel engine, is higher than the health loss caused by the pollutions produced over the life cycle of the diesel engine. Furthermore, the results support findings in the literature that socioeconomic growth generates a higher health benefit in a lower‐income country than in a higher‐income country. This also might be one of the reasons for another statement found in the literature that developing countries put higher priorities on economic development.     

Accounting for Emissions and Sinks from the Biogeochemical Cycle of Carbon in the U.S. Economic Input‐Output Model

Biogeochemical cycles are essential ecosystem services that continue to degrade as a result of human activities, but are not fully considered in efforts toward sustainable engineering. This article develops a model that integrates the carbon cycle with economic activities in the 2002 U.S. economy. Data about the carbon cycle, including emissions and sequestration flows, is obtained from the greenhouse gas inventory of the U.S. Environmental Protection Agency. Economic activities are captured by the economic input‐output model available from the Bureau of Economic Analysis. The resulting model is more comprehensive in its accounting for the carbon cycle than existing methods for carbon footprint (CF) calculations. Examples of unique flows in this model include the effect of land‐use and land‐cover change on carbon dioxide flow within the U.S. national boundary, carbon sequestration in urban trees, and emissions resulting from liming. This model is used to gain unique insight into the carbon profile of U.S. economic sectors by providing the life cycle emissions and sequestration in each sector. Such insight may be used to support policies, manage supply chains, and be used for more comprehensive CF calculations.     

Assessing the Greenhouse Gas Savings Potential of Extended Producer Responsibility for Mattresses and Boxsprings in the United States

Extended producer responsibility (EPR) legislation in the United States, which currently only exists on the state level, now includes three mattress EPR acts, which intend to shift the financial and operational burden of mattress end‐of‐life (EOL) management away from local and state government. It is important to keep in mind, however, that the original objective behind EPR is to reduce the environmental life cycle impacts of products. This article therefore quantifies the greenhouse gas (GHG) savings potential of mattress and boxspring recycling and reuse in the United States and also discusses labor implications and mattress design issues. We find that all three acts are unlikely to generate redesign incentives, but are expected to dramatically increase mattress collection and recycling. The collection and recycling of all 35 million EOL mattress and boxspring units estimated to reach the end of their lives in the United States every year would generate in the order of 10,000 jobs and GHG savings between 1 and 1.5 million metric tonnes.     

Effects of Using Heterogeneous Prices on the Allocation of Impacts from Electricity Use: A Mixed‐Unit Input‐Output Approach

Economic input‐output life cycle assessment (IO‐LCA) models allow for quick estimation of economy‐wide greenhouse gas (GHG) emissions associated with goods and services. IO‐LCA models are usually built using economic accounts and differ from most process‐based models in their use of economic transactions, rather than physical flows, as the drivers of supply‐chain GHG emissions. GHG emissions estimates associated with input supply chains are influenced by the price paid by consumers when the relative prices between individual consumers are different. We investigate the significance of the allocation of GHG emissions based on monetary versus physical units by carrying out a case study of the U.S. electricity sector. We create parallel monetary and mixed‐unit IO‐LCA models using the 2007 Benchmark Accounts of the U.S. economy and sector specific prices for different end users of electricity. This approach is well suited for electricity generation because electricity consumption contributes a significant share of emissions for most processes, and the range of prices paid by electricity consumers allows us to explore the effects of price on allocation of emissions. We find that, in general, monetary input‐output models assign fewer emissions per kilowatt to electricity used by industrial sectors than to electricity used by households and service sectors, attributable to the relatively higher prices paid by households and service sectors. This fact introduces a challenging question of what is the best basis for allocating the emissions from electricity generation given the different uses of electricity by consumers and the wide variability of electricity pricing.