Showing papers in "International Journal of Life Cycle Assessment in 2015"
TL;DR: In this article, a comparative analysis of protein substitutes' environmental performance in order to estimate the most promising options is presented. But the results of the comparison were highly dependable on selected FUs.
Abstract: Food production is among the highest human environmental impacting activities. Agriculture itself accounts for 70–85 % of the water footprint and 30 % of world greenhouse gas emissions (2.5 times more than global transport). Food production’s projected increase in 70 % by 2050 highlights the importance of environmental impacts connected with meat production. The production of various meat substitutes (plant-based, mycoprotein-based, dairy-based, and animal-based substitutes) aims to reduce the environmental impact caused by livestock. This article outlined the comparative analysis of meat substitutes’ environmental performance in order to estimate the most promising options. The study considered “cradle-to-plate” meal life cycle with the application of ReCiPe and IMPACT 2002+ methods. Inventory was based on literature and field data. Functional unit (FU) was 1 kg of a ready-to-eat meal at a consumer. The study evaluated alternative FU (the equivalent of 3.75 MJ energy content of fried chicken lean meat and 0.3 kg of digested dry matter protein content) as a part of sensitivity analysis. Results showed the highest impacts for lab-grown meat and mycoprotein-based analogues (high demand for energy for medium cultivation), medium impacts for chicken (local feed), and dairy-based and gluten-based meat substitutes, and the lowest impact for insect-based and soy meal-based substitutes (by-products allocated). Alternative FU confirmed the worst performance of lab-grown and mycoprotein-based analogues. The best performing products were insect-based and soy meal-based substitutes and chicken. The other substitutes had medium level impacts. The results were very sensitive to the changes of FU. Midpoint impact category results were the same order of magnitude as a previously published work, although wide ranges of possible results and system boundaries made the comparison with literature data not reliable. The results of the comparison were highly dependable on selected FU. Therefore, the proposed comparison with different integrative FU indicated the lowest impact of soy meal-based and insect-based substitutes (with given technology level development). Insect-based meat substitute has a potential to be more sustainable with the use of more advanced cultivation and processing techniques. The same is applicable to lab-grown meat and in a minor degree to gluten, dairy, and mycoprotein-based substitutes.
TL;DR: In this paper, an overview of existing and applied life cycle based energy indicators and a unifying approach to establish characterisation factors for the cumulative energy demand indicator are provided, illustrated in a building's LCA case study.
Abstract: Environmental life cycle assessment (LCA) is today an important methodology to quantify the life cycle based environmental impacts of products, services or organisations. Since the very first LCA studies, the cumulative energy demand CED (also called ‘primary energy consumption’) has been one of the key indicators being addressed. Despite its popularity, there is no harmonised approach yet and the standards and guidelines define the cumulative energy demand differently. In this paper, an overview of existing and applied life cycle based energy indicators and a unifying approach to establish characterisation factors for the cumulative energy demand indicator are provided. The CED approaches are illustrated in a building’s LCA case study. The five approaches are classified into two main concepts, namely the energy harvested and the energy harvestable concepts. The two concepts differ by the conversion efficiency of the energy collecting facility. A unifying ‘energy harvested’ approach is proposed based on four theses, which ensure consistent accounting among renewable and non renewable energy resources. The indicator proposed is compared to four other CED indicators, differing in the characterisation factors of fossil and biomass resources (upper or lower heating value), the characterisation factor of uranium and the characterisation factors of renewable energy resources (amount harvested or amount harvestable). The comparison of the five approaches is based on the cumulative energy demand of a newly constructed building of the city of Zurich covering the whole life cycle, including manufacturing and construction, replacement and use phase, and end of life. The cumulative energy demand of the life cycle of the building differs between 336 MJ oil-eq/m2a (‘CED uranium low’) and 836 MJ oil-eq/m2a (‘CED energy statistics’). The main differences occur in the use phase. The main reason for the large differences in the results are the different concepts to determine the characterisation factors for renewable and nuclear energy resources. The energy harvested approach ‘CED standard’ is a consistent approach, which quantifies the energy content of all different (renewable and non-renewable) energy resources. The ‘CED standard’ approach and the impact category indicator results computed with this approach reflect the safeguard subject ‘energy resources’ but not (no other) environmental impacts. The energy harvested approach proposed in this paper can readily be implemented in different contexts and applied to various data sets.
TL;DR: In this paper, the authors combined the life cycle sustainability assessment (LCSA) framework and the multicriteria decision-making (MCDM) methodology for sustainability assessment and determined the most sustainable scenario for bioethanol production in China according to the preferences of the decision-makers/stakeholders.
Abstract: The study objectives are twofold: (i) combining the life cycle sustainability assessment (LCSA) framework and the multicriteria decision-making (MCDM) methodology for sustainability assessment and (ii) determining the most sustainable scenario for bioethanol production in China according to the preferences of the decision-makers/stakeholders. Life cycle assessment (LCA), life cycle costing (LCC), and social life cycle assessment (SLCA) are combined to collect the corresponding criteria data on environmental, economic, and social aspects, respectively. The study develops a novel SLCA method for quantifying the social criteria. The decision-makers/stakeholders can use linguistic terms to assess these criteria, and fuzzy theory is used to transform the linguistic variables into real numbers. Once the sustainability assessment criteria are determined, the study develops an MCDM method that combines the analytic hierarchy process (AHP) and the VIKOR method to prioritize the alternatives. The AHP is used to determine the criteria weights that are a prerequisite when using VIKOR; the VIKOR method is then used to determine the sustainability sequence of the scenarios. The study’s proposed method investigates an illustrative case about three alternative bioethanol production scenarios (wheat-based, corn-based, and cassava-based): The prior sequence (based on the sustainability performances) in descending order is cassava-based, corn-based, and wheat-based. The proposed methodology results allow Chinese decision-makers/stakeholders to select the most sustainable scenario among many alternatives. The proposed methodology is generic, meaning that further alternatives can be studied and the most sustainable option can be ultimately determined. The main study contribution is to test the combination of an MCDM methodology and LCSA for sustainability decision-making by studying three alternative pathways for bioethanol production in China. The proposed method feasibly enables the decision-makers/stakeholders to find the most sustainable scenario to achieve their objectives among various alternatives.
TL;DR: A framework for normalisation against carrying capacity-based references is presented and average normalisation references (NR) for Europe and the world for all those midpoint impact categories commonly included in LCA that link to the natural environment area of protection are developed.
Abstract: There is currently a weak or no link between the indicator scores quantified in life cycle assessment (LCA) and the carrying capacity of the affected ecosystems. Such a link must be established if LCA is to support assessments of environmental sustainability and it may be done by developing carrying capacity-based normalisation references. The purpose of this article is to present a framework for normalisation against carrying capacity-based references and to develop average normalisation references (NR) for Europe and the world for all those midpoint impact categories commonly included in LCA that link to the natural environment area of protection. Carrying capacity was in this context defined as the maximum sustained environmental intervention a natural system can withstand without experiencing negative changes in structure or functioning that are difficult or impossible to revert. A literature review was carried out to identify scientifically sound thresholds for each impact category. Carrying capacities were then calculated from these thresholds and expressed in metrics identical to midpoint indicators giving priority to those recommended by ILCD. NR was expressed as the carrying capacity of a reference region divided by its population and thus describes the annual personal share of the carrying capacity. The developed references can be applied to indicator results obtained using commonly applied characterisation models in LCIA. The European NR are generally lower than the global NR, mainly due to a relatively high population density in Europe. The NR were compared to conventional normalisation references (NR′) which represent the aggregated interventions for Europe or the world in a recent reference year. For both scales, the aggregated intervention for climate change, photochemical ozone formation and soil quality were found to exceed carrying capacities several times. The developed carrying capacity-based normalisation references offer relevant supplementary reference information to the currently applied references based on society’s background interventions by supporting an evaluation of the environmental sustainability of product systems on an absolute scale. Challenges remain with respect to spatial variations to increase the relevance of the normalisation references for impact categories that function at the local or regional scale. The sensitivity of NR to different choices, e.g. threshold value, should be quantified with the aim of understanding and managing uncertainties of NR. For complete coverage of the midpoint impact categories, normalisation references based on sustainability preconditions should be developed for those categories that link to the areas of protection human health and natural resources.
TL;DR: In this article, the authors presented a life cycle assessment (LCA) of an all-composite airplane, based on a Boeing 787 Dreamliner, using SimaPro 7.2 in combination with Ecoinvent.
Abstract: Carbon-fibre-reinforced polymers (CFRP) have been developed by the aviation industry to reduce aircraft fuel burn and emissions of greenhouse gases. This study presents a life cycle assessment (LCA) of an all-composite airplane, based on a Boeing 787 Dreamliner. The global transition of aircraft to those of composite architecture is estimated to contribute 20–25 % of industry CO2 reduction targets. A secondary stage of the cradle-to-grave analysis expands the study from an individual aircraft to the global fleet. An LCA was undertaken utilising SimaPro 7.2 in combination with Ecoinvent. Eco-indicator 99 (E) V2.05 Europe EI 99 E/E was the chosen method to calculate the environmental impact of the inventory data. The previously developed aviation integrated model was utilised to construct a scenario analysis of the introduction of composite aircraft against a baseline projection, through to 2050, to model CO2 emissions due to their particular relevance in the aviation sector. The analysis demonstrated CFRP structure results in a reduced single score environmental impact, despite the higher environmental impact in the manufacturing phase, due to the increased fossil fuel use. Of particular importance is that CFRP scenario quickly achieved a reduction in CO2 and NOx atmospheric emissions over its lifetime, due to the reduced fuel consumption. The modelled fleet-wide CO2 reduction of 14–15 % is less than the quoted emission savings of an individual aircraft (20 %) because of the limited fleet penetration by 2050 and the increased demand for air travel due to lower operating costs. The introduction of aircraft based on composite material architecture has significant environmental benefits over their lifetime compared to conventional aluminium-based architecture, particularly with regards to CO2 and NOx a result of reduced fuel burn. The constructed scenario analyses the interactions of technology and the markets they are applied in, expanding on the LCA, in this case, an observed fleet-wide reduction of CO2 emission of 14–15 % compared to an individual aircraft of 20 %.
TL;DR: In this article, the authors analyse the environmental and economic performance of roof greenhouses in Barcelona and find that the environmental burdens and economic costs of adapting greenhouse structures to the current building legislation are a limitation of these systems in the literature.
Abstract: Purpose Rooftop greenhouses (RTGs) are increasing as a new form of urban agriculture. Several environmental, economic, and social benefits have been attributed to the implementation of RTGs. However, the environmental burdens and economic costs of adapting greenhouse structures to the current building legislation were pointed out as a limitation of these systems in the literature. In this sense, this paper aims to analyse the environmental and economic performance of RTGs in Barcelona.
TL;DR: In this paper, the authors presented a life cycle assessment (LCA) of power-to-gas systems, evaluating the main parameters influencing global warming potential (GWP) and primary energy demand.
Abstract: Power-to-gas technology enables storage of surplus electricity from fluctuating renewable sources such as wind power or photovoltaics, by generating hydrogen (H2) via water electrolysis, with optional methane (CH4) synthesis from carbon dioxide (CO2) and H2; the advantage of the latter is that CH4 can be fed into existing gas infrastructure. This paper presents a life cycle assessment (LCA) of this technological concept, evaluating the main parameters influencing global warming potential (GWP) and primary energy demand. The conducted LCA of power-to-gas systems includes the production of H2 or CH4 from cradle to gate. Product utilization was not evaluated but considered qualitatively during interpretation. Material and energy balances were modeled using the LCA software GaBi 5 (PE International). The assessed impacts of H2 and CH4 from power-to-gas were compared to those of reference processes, such as steam reforming of natural gas and crude oil as well as natural gas extraction. Sensitivity analysis was used to evaluate the influence of the type of electricity source, the efficiency of the electrolyzer, and the type of CO2 source used for methanation. The ecological performance of both H2 and CH4 produced via power-to-gas strongly depends on the electricity generation source. The assessed impacts of H2 production are only improved if GWP of the utilized electricity does not exceed 190 g CO2 per kWh. Due to reduced efficiency, the assessed impacts of CH4 are higher than that of H2. Thus, the environmental break-even point for CH4 production is 113 g CO2 per kWh if utilized CO2 is treated as a waste product, and 73 g CO2 per kWh if the CO2 separation effort is included. Electricity mix of EU-27 countries is therefore not at all suitable as an input. Utilization of renewable H2 and CH4 in the industry or the transport sector offers substantial reduction potential in GWP and primary energy demand. H2 and CH4 production through power-to-gas with electricity from renewable sources, such as wind power or photovoltaics, offers substantial potential to reduce GWP and primary energy demand. However, the input of electricity predominately generated from fossil resources leads to a higher environmental impact of H2 and CH4 compared to fossil reference processes and is not recommended. As previously bound CO2 is re-emitted when CH4 is utilized for instance in vehicles, the type of CO2 source and the allocation method have a significant influence on overall ecological performance.
TL;DR: In this paper, the authors identify and compare the rationales for (and limitations of) different common approaches to solving multi-functionality problems in LCA, and their respective rationales are analyzed.
Abstract: The ISO 14044 standard for life cycle assessment (LCA) provides the reference decision hierarchy for dealing with multi-functional processes. We observe that, in practice, the consistent implementation of this hierarchy by LCA practitioners and LCA guidance document developers may be limited. In an attempt to explain this observation, and to offer suggestions as to how consistency in LCA practice might be improved, we identify and compare the rationales for (and limitations of) different common approaches to solving multi-functionality problems in LCA. The different prevalent understandings of specific approaches for dealing with multi-functional processes were identified, and their respective rationales were analyzed. This takes into account identifying the implicit underlying assumptions regarding the nature and purpose of LCA that support each approach. We identified what we believe to be three internally consistent but mutually exclusive schools of thought amongst LCA practitioners, which differ in subtle but important ways in terms of their understanding of the nature and purpose of LCA, and the multi-functionality solutions necessary to support them. These three divisions follow two demarcations. The first is between consequential and attributional data modeling approaches. The second is between adherence to a natural science-based approach (privileging physical allocation solutions) and a socioeconomic approach (favoring economic allocation solutions) in attributional data modeling. We conclude that the ISO 14044 multi-functionality hierarchy should explicitly differentiate between attributional and consequential data modeling applications. We question the feasibility and practical utility of system expansion (currently privileged in the ISO hierarchy) in attributional data modeling applications. We suggest that ISO 14044 should also make explicit its rationale for privileging natural science-based approaches to solving multi-functionality problems and to more clearly differentiate between natural science and social science-based approaches. We also call for the formulation of additional guidance for solving multi-functionality problems, in particular for justifying the use of lower-tier solutions from the ISO hierarchy when these are applied in LCA studies. We suggest that this additional guidance and clarity in ISO 14044 will contribute to increased consistency in LCA practice and also increase the potential for users of information from LCA studies to make informed decisions as to their relevance within the context of specific intended applications.
TL;DR: In this paper, the authors present the state of the art in LCA and an overview of the EPD programmes in five European countries (Austria, Belgium, France, Germany, Switzerland) based on the workshop and a comprehensive description and comparison of the PEF method and EN 15804 in the second part.
Abstract: Growing awareness of the environmental performance of construction products and buildings brings about the need for a suitable method to assess their environmental performance. Life cycle assessment (LCA) has become a widely recognised and accepted method to assess the burdens and impacts throughout the life cycle. This LCA-based information may be in the form of environmental product declarations (EPD) or product environmental footprints (PEF), based on reliable and verifiable information. All of these use LCA to quantify and report several environmental impact categories and may also provide additional information. To better understand on the one hand existing EPD programmes (EN 15804) for each country and on the other the recent developments in terms of EU reference document (e.g. PEF), the authors decided to write this review paper based on the outcomes of the EPD workshop that was held prior to SB13 Graz conference. This paper presents the state of the art in LCA and an overview of the EPD programmes in five European countries (Austria, Belgium, France, Germany, Switzerland) based on the workshop in the first part and a comprehensive description and comparison of the PEF method and EN 15804 in the second part. In the last part, a general conclusion will wrap up the findings and results will provide a further outlook on future activities. The high number of EPD programmes underlines the fact that there is obviously a demand for assessments of the environmental performance of construction materials. In the comparison between and experiences of the different countries, it can be seen that more similarities than differences exist. A comparison between PEF and EPD shows differences, e.g. LCIA impact categories and recycling methodology. Independent of raising awareness of the construction material environmental performance, the existence of so many environmental claims calls for clarification and harmonisation. Additionally, construction materials being assessed in the voluntary approaches have to follow the harmonised approach following the principles of the European Construction Products Regulation (regulated) not to foster barriers of trade. The authors therefore highly appreciate the most recent activities of the sustainability of construction works (CEN/TC 350 committee http://portailgroupe.afnor.fr/public_espacenormalisation/CENTC350/index.html ) currently working on these issues at the EU level. Finally, the LCA community is further encouraged to increase the background life cycle inventory data and life cycle inventory modelling as well as the meaningfulness of certain environmental impact categories, such as toxicity, land use, biodiversity and resource usage.
TL;DR: By identifying global hotspots in the LCA research, this study provides a useful reference to researchers for the future research directions and showed that the pace of publishing in this field increased exponentially over past 16 years.
Abstract: A bibliometric analysis of life cycle assessment (LCA)-related research literature is reported in this study. Based on databases of Science Citation Index (SCI), Social Science Citation Index (SSCI), Conference Proceedings Citation Index—Science (CPCI-S), and Conference Proceedings Citation Index—Social Science & Humanities (CPCI-SSH), this study aims to evaluate the research trends of LCA-related research literature from 1998 to 2013 by using bibliometric techniques. The documents were analyzed according to their type, language(s), subject(s), journal(s), citation analysis of articles, authors’ address information, and keyword distribution, etc. H-index and impact factor (IF) were applied to characterize the LCA publications. Furthermore, co-word analysis and social network analysis (SNA) were employed to evaluate the interactions in this research field. The findings showed that the pace of publishing in this field increased exponentially over past 16 years. A total of 6616 records were obtained from the four databases. Journal articles are the most frequently used document type representing 74.33 % (4918) of the records, and English is the dominant language with 5914 records (97.53 %). The most common subject category is environmental sciences, and the most productive journal is International Journal of Life Cycle Assessment. The USA, focusing on “energy,” “industrial ecology,” and “greenhouse gas emissions,” is the most productive country in the research field of LCA. Technology University of Denmark is the most productive institute all over the world over the past 16 years. According to the ranking of keywords, “greenhouse gas,” “energy”, and “biofuel” are the hotspots of LCA research. The main purpose of LCA is sustainability assessment whereas climate change is one of the most outstanding environmental issues. By identifying global hotspots in the LCA research, this study provides a useful reference to researchers for the future research directions.
TL;DR: In this article, the authors explore the literature surrounding the environmental impact of mobile phones and the implications of moving from the current business model of selling, using and discarding phones to a product service system based upon a cloud service.
Abstract: Purpose The aim of this study is to explore the literature surrounding the environmental impact of mobile phones and the implications of moving from the current business model of selling, using and discarding phones to a product service system based upon a cloud service. The exploration of the impacts relating to this shift and subsequent change in scope is explored in relation to the life cycle profile of a typical smartphone. Methods A literature study is conducted into the existing literature in order to define the characteristics of a Btypical^ smartphone. Focus is given to greenhouse gas (GHG) emissions in different life cycle phases in line with that reported in the majority of literature. Usage patterns from literature are presented in order to show how a smartphone is increasingly responsible for not only data consumption but also data generation. The subsequent consequences of this for the balance of the life cycle phases are explored with the inclusion of wider elements in the potential expanded mobile infrastructure, such as servers and the network. Results and discussion From the available literature, the manufacturing phase is shown to dominate the life cycle of a Btypical^ smartphone for GHG emissions. Smartphone users are shown to be increasingly reliant upon the internet for provision of their communications. Adding a server into the scope of a smartphone is shown to increase the use phase impact from 8.5 to 18.0 kg CO2-eq, other phases are less affected. Addition of the network increases the use phase by another 24.7kgCO2-eq.Inaddition,itisshownthattake-back of mobile phones is not effective at present and that prompt returnofthe phonescould resultinreductioninimpactbybest reuse potential and further reduction in toxic emissions through inappropriate disposal. Conclusions The way in which consumers interact with their phones is changing, leading to a system which is far more integrated with the internet. A product service system based upon a cloud service highlights the need for improved energy efficiency to make greatest reduction in GHG emissions in the use phase, and gives a mechanism to exploit residual value of the handsets by timely return of the phones, their components and recovery of materials.
TL;DR: In this paper, the authors compare the performances of two passenger cars: an electric vehicle (EV) and an internal combustion engine vehicle (ICEV) paying particular attention to the production of electricity that will charge the EV.
Abstract: PURPOSE: The purpose of the study is to compare the performances of two passenger cars: an electric vehicle (EV) and an internal combustion engine vehicle (ICEV) paying particular attention to the production of electricity that will charge the EV. Even if many similar comparative life cycle assessments (LCAs) exist (Nordelof et al. J Life Cycle Assess 19(11):1866–18990, 2014), only few have focused their attention on evaluating which is the kind of electricity that will recharge EV batteries (Hawkins et al. Int J Life Cycle Assess 17(8):997–1014, 2012). METHODS: Despite its relevance, many EV LCA studies have used a ready-to-use dataset to evaluate the power mix that supplies electricity to EV. The present paper tries to better define the power mix that recharges EV batteries in Italy according to the national power system and the national electric market rules. A 2013 and a 2030 scenario have been developed in order to understand effects in short and middle term. Life cycle inventory of electricity for EV has been estimated modifying available datasets according to official Italian data on power plants’ efficiency and emission rates. Finally, also for the ICEV use phase, existing dataset have been modified for fuel consumption and regulated emission according to the National Inventory Report results (ISPRA 2014) RESULTS AND DISCUSSION: In both 2013 and 2030 scenarios, the power mix that in Italy supplies energy to EV is dominated by fossil fuel power plants. Nevertheless, due to the fact that more than the 60 % of this energy is produced in efficient combined cycle gas turbine power plants, EV performs better than ICEV in almost all the impact categories considered except for human toxicity and eutrophication, the only two impact categories in which the EV car, mainly due to battery manufactory, presents more relevant potential impacts. ICEV impacts are always dominated by well to wheel phases (use phase and fuel production). EV car and battery manufacturing have higher impacts for all categories than ICEV car manufacturing. CONCLUSIONS: The study demonstrates that electricity supplied in Italy to EV today is, and will probably be in 2030, mainly produced by fossil fuel power plants. Nevertheless, the EV proves to be able to reduce, with respect to ICEV, those impacts it is supposed to reduce: air acidification, photochemical oxidant formation, and also greenhouse gases. Trade-offs are, as foreseeable, eutrophication and human toxicity due to EV car and battery manufacturing.
TL;DR: In this article, the problems and differences of existing LCA studies of forest production with a special focus on Global Warming Potential (GWP) were analyzed and a quantitative analysis was purchased where the results of the reviewed studies were analyzed.
Abstract: Life cycle assessment (LCA) techniques have been developed since the late 1960s in order to analyze environmental impacts of various products or companies. Although LCA techniques of forest production have been already conducted since the early 1990s, consistent and comprehensive LCA studies are still lacking for the forestry sector. In order to support better comparability between LCA studies, we analyzed the problems and differences by conducting a descriptive and quantitative analysis of existing LCA studies of forest production with special focus on Global Warming Potential (GWP). We analyzed 22 different peer-reviewed studies, four original reports and two databases. Important issues were, among others, the goal of the studies, system boundaries, functional units, impact categories and involved processes. In addition, a quantitative analysis was purchased where the results of the GWP of the reviewed studies were analyzed. The studies showed large differences between methodical assumptions and their subsequent results. For the GWP, we found a range of 2.4–59.6 kg CO2-equiv.*m−3 over bark (ob; median = 11.8; n = 41) from site preparation to forest road and 6.3–67.1 kg CO2-equiv.*m−3 ob (median = 17.0; n = 36) from site preparation to plant gate or consumer. Results varied as a function of the included processes and decisive assumptions, e.g., regarding productivity rates or fuel consumption of machineries. Raw wood products are widely declared as “carbon neutral,” but the above-mentioned results show that absolute carbon neutrality is incorrect, although the GWP is low compared with the carbon storage of the raw wood product (range of C-emitted/C-stored in wood is 0.008–0.09 from forest to plant gate or consumer). Thereby, raw wood products can be described as “low emission raw materials” if long-term in situ carbon losses by changed forest management or negative direct or indirect land use change effects (LUC, iLUC) can be excluded. In order to realize improved comparisons between LCA studies in the forestry sector in the future, we propose some methodical approaches regarding the harmonization of system boundaries, functional units, considered processes, and allocation assumptions. These proposals could help to specify the description of the forest production outlined in existing Product Category Rules for Environmental Product Declarations (e.g., EN ISO 16485 2014 or EN ISO 15804 2012) following EN ISO 14025 (2011) and for carbon footprinting standards like the Publicly Available Specification (PAS) 2050 (2011) or the European Environmental Footprinting Initiative.
TL;DR: In this paper, a procedure for using such global goals for setting impact-reduction targets at the scale of products for use, for example, in life cycle assessment (LCA) contexts, e.g. as a basis for evaluating the potential of interventions to reduce the environmental impact of products.
Abstract: The planetary boundaries (PBs) framework suggests global limits for environmental interventions which could be used to set global goals for reducing environmental impacts. This paper proposes a procedure for using such global goals for setting impact-reduction targets at the scale of products for use, for example, in life cycle assessment (LCA) contexts, e.g. as a basis for evaluating the potential of interventions to reduce the environmental impact of products. The procedure consists of four steps: (i) identifying the PBs quantified in literature that correspond to an impact category which is studied in the product assessment context in question; (ii) interpreting what the identified PBs imply in terms of global impact-reduction targets; (iii) translating the outcome of (ii) to reduction targets for the particular global market segment to which the studied product belongs; and (iv) translating the outcome of (iii) to reduction targets for the studied product. The procedure requires some assumptions and value-based choices—the influence of these is tested by applying the procedure in a specific LCA context: a study of Swedish clothing consumption. The application of the procedure in an LCA context suggested the need for eliminating all or nearly all impact of Swedish clothing consumption for most impact categories. Thus, it is improbable that a single type of impact-reduction intervention (e.g. technological development or changed user behaviour) is sufficient. The outcome’s strong dependence on impact category suggests that the procedure can help in prioritising among impact categories. Furthermore, the outcome exhibited a strong dependence on the chosen method for allocating the globally allowed impact between regions—this was tested by applying different principles identified in a literature review on the allocation of emissions rights. The outcome also strongly depended on the geographical scope—this was tested by changing the geographical scope from Sweden to Nigeria. The proposed procedure is feasible to use for LCA practitioners and other environmental analysts, and data is available to apply the procedure in contexts with different geographical scopes. Value-based choices are, however, unavoidable and significantly influence the outcome, which accentuates the subjectivity and potentially controversial nature of allocating a finite impact space to certain regions, market segments and products. How to match PBs with appropriate LCA impact categories is an important area for future research.
École Polytechnique de Montréal1, United States Environmental Protection Agency2, Food and Agriculture Organization3, Goethe University Frankfurt4, World Resources Institute5, Potsdam Institute for Climate Impact Research6, Qantas7, Kogakuin University8, Tokyo City University9, National Institute of Advanced Industrial Science and Technology10, Wageningen University and Research Centre11, Commonwealth Scientific and Industrial Research Organisation12, Nestlé13, University of Tsukuba14, Tokyo Institute of Technology15, ETH Zurich16
TL;DR: The WULCA group, active since 2007 on Water Use in LCA, commenced the development of consensus-based indicators in January 2014 as mentioned in this paper, which covers human health, ecosystem quality, and a stress-based indicator.
Abstract: Purpose The WULCA group, active since 2007 on Water Use in LCA, commenced the development of consensus-based indicators in January 2014. This activity is planned to last 2 years and covers human health, ecosystem quality, and a stress-based indicator. This latter encompasses potential deprivation of both ecosystem and human, hence aiming to represent potential impacts more comprehensively than any other available LCA-oriented method assessing the “water scarcity footprint” (ISO 2014).
TL;DR: The comparison showed that considering reduced water availability due to degradation in water quality, in addition to a reduction in water quantity, greatly influences results, making it possible to quantify model uncertainty and the significance of these choices in a specific regional context.
Abstract: In the past decade, several methods have emerged to quantify water scarcity, water availability and the human health impacts of water use. It was recommended that a quantitative comparison of methods should be performed to describe similar impact pathways, namely water scarcity and human health impacts from water deprivation. This is precisely the goal of this paper, which aims to (1) identify the key relevant modeling choices that explain the main differences between characterization models leading to the same impact indicators; (2) quantify the significance of the differences between methods, and (3) discuss the main methodological choices in order to guide method development and harmonization efforts. The modeling choices are analysed for similarity of results (using mean relative difference) and model response consistency (through rank correlation coefficient). Uncertainty data associated with the choice of model are provided for each of the models analysed, and an average value is provided as a tool for sensitivity analyses. The results determined the modeling choices that significantly influence the indicators and should be further analysed and harmonised, such as the regional scale at which the scarcity indicator is calculated, the sources of underlying input data and the function adopted to describe the relationship between modeled scarcity indicators and the original withdrawal-to-availability or consumption-to-availability ratios. The inclusion or exclusion of impacts from domestic user deprivation and the inclusion or exclusion of trade effects both strongly influence human health impacts. At both midpoint and endpoint, the comparison showed that considering reduced water availability due to degradation in water quality, in addition to a reduction in water quantity, greatly influences results. Other choices are less significant in most regions of the world. Maps are provided to identify the regions in which such choices are relevant. This paper provides useful insights to better understand scarcity, availability and human health impact models for water use and identifies the key relevant modeling choices and differences, making it possible to quantify model uncertainty and the significance of these choices in a specific regional context. Maps of regions where these specific choices are of importance were generated to guide practitioners in identifying locations for sensitivity analyses in water footprint studies. Finally, deconstructing the existing models and highlighting the differences and similarities has helped to determine building blocks to support the development of a consensual method.
TL;DR: In this article, the authors discuss the determination of geologic resources stocks and outline an approach for the estimation of the resource stocks ultimately available for human use in the long-term.
Abstract: The depletion of abiotic resources needs to be discussed in the light of available geologic stocks. For the evaluation of long-term resource availability under consideration of the resources’ functional relevance, the abiotic resource stock that is ultimately available for human purposes needs to be identified. This paper discusses the determination of geologic resources stocks and outlines an approach for the estimation of the resource stocks ultimately available for human use in the long-term. Based on these numbers, existing characterization factors for the assessment of resource depletion by means of the anthropogenic stock extended abiotic depletion potential (AADP) model can be updated. For the assessment of long-term resource availability, the share of abiotic resources ultimately available for human extraction needs to be inferred from the quantity of the elements available in the earth’s crust. Based on existing data on crustal concentrations and assumptions regarding the maximal extractable amount of resource, three different approaches for the determination of ultimately extractable reserves are proposed. The different resource numbers are compared, and their effects on the resulting characterization factors derived from the abiotic depletion potential (ADP) and the AADP models are analyzed. A best estimate for the determination of ultimately extractable reserves is proposed. Based on this new resource number, AADP characterization factors for 35 materials are calculated. The use of ultimately extractable reserves leads to an improved applicability of the AADP model and increases the overall significance of the results. Resource security is a premise for sustainable development. The use of resources needs to be evaluated in the context of their decreasing availability for future generations. Thus, resource choices should also be based on an analysis of available resource stocks. The proposed AADP characterization factors based on ultimately extractable reserves will enable a more realistic evaluation of long-term resource availability for human purposes.
TL;DR: In this article, numerical and methodological differences of two existing LCA databases for building LCAs are compared for 28 building materials using Life Cycle Impact Assessment (LCIA) indicators of the EN 15804 standard calculated based on cradle-to-gate ecoinvent and EPD Life Cycle Inventories.
Abstract: The Life Cycle Assessment (LCA) has been applied in the construction sector since the 1990s and is now more and more embedded in European public policies, e.g., for Environmental Product Declaration regulation or for building labeling schemes. As far as the authors know, these initiatives mainly rely on background impact data of building products provided by different databases’ providers. The new product-specific and company-specific EPD data allow having more than one data for describing a building material. But are these new databases really displaying similar LCA results compared to generic databases? Does it depend on which impact category (e.g., global warming, acidification, toxicity) is considered? To answer these research questions, this paper assesses numerical and methodological differences of two existing LCA databases for building LCAs: the ecoinvent generic database and one Environmental Product Declaration (EPD) database developed in France. After reviewing the main assumptions of these databases, numerical values of environmental impact are compared for 28 building materials using Life Cycle Impact Assessment (LCIA) indicators of the EN 15804 standard calculated based on cradle-to-gate ecoinvent and EPD Life Cycle Inventories (LCI). Global results at the database level indicate deviations of different magnitudes depending on the LCIA indicators and the building materials. While indicators correlated to fossil fuel consumption, such as the ADP, the GWP, and the primary energy demand, exhibit a small deviation (approximately 25 %), other indicators, such as the photochemical ozone formation (POCP), radioactive waste, and ADP elements, are found to be more variable between EPD and generic data (sometimes by more than 100 %). Three indicators are found to be systematically different between EPD and generic data (i.e., the EPD value being either higher or lower for all materials). Similarly, five building materials show systematic differences for all LCIA indicators. Specific deviations for one indicator and one material are also reported. The application of the two databases on three building LCA case studies (brick, reinforced concrete, and timber frame structures) identifies deviations due to the most influential materials. Current generic and EPD databases can present very different values at the database scale which depend on the type of environmental indicator. For building LCA results, the situation is different as generally speaking a limited number of materials controlled the impacts. Finally, recommendations are presented for each environmental indicator to improve the consistency of the building assessment from generic to product- and country-specific information.
TL;DR: In this article, a social life cycle impact assessment (sLCIA) method is developed and a case study of a building construction project in Hong Kong is performed, which demonstrates that the studied project has positive social impacts in general, while the construction stage performs better than the material stage.
Abstract: Social life cycle assessment (S-LCA) is a relatively new technique that is under rapid development. To further improve the reliability of S-LCA, more case studies and methodologies are of paramount importance. This study aims to develop a S-LCA model for building construction projects in Hong Kong, namely, the Social-impact Model of Construction (SMoC). In this paper, a social life cycle impact assessment (sLCIA) method is developed and a case study of a building construction project in Hong Kong is performed. The development of SMoC is composed of three stages. Stage one strives to establish the sLCIA method which includes the characterization, normalization and weighting. In stage two, a questionnaire survey is conducted to collect the weighting factors and to unveil the social impacts of on-site construction practices. Based on that, the SMoC model which consists of a set of functional worksheets is built. In stage three, a case study following the four-phase structure of S-LCA suggested by the UNEP/SETAC guidelines is conducted. Of the selected subcategories, local experts believed that health and safety (worker) is the most important social aspect. The questionnaire survey also suggests that the environmental-friendly on-site construction activities as identified in this research are beneficial to the society in general. However, adoption of precast concrete components can lead to negative impacts on fair salary and local employment, since the precast concrete is normally produced outside Hong Kong. The case study demonstrates that the studied project has positive social impacts in general, while the construction stage performs better than the material stage. The sensitivity analysis indicates that inclusion of environmental-friendly construction practices can significantly improve the social performance of the studied building construction project. The developed SMoC model and the case study should provide a comprehensive framework of S-LCA for building construction in Hong Kong. Despite being the first attempt of S-LCA in Hong Kong, the results help inform the local industry the social performance of their construction projects from a life cycle perspective.
TL;DR: In this paper, the authors proposed an alternative method for calculating the environmental credits associated with material recycling in life cycle assessment (LCA) of waste management systems, which is more consistent with the general attributional approach in LCA than the hitherto common practice of simply assuming a 1:1 substitution of primary material production.
Abstract: This paper aims to provide an alternative method for calculating the environmental credits associated with material recycling in life cycle assessment (LCA) of waste management systems. The method proposed here is more consistent with the general attributional approach in LCA than the hitherto common practice of simply assuming a 1:1 substitution of primary material production. The formula proposed for estimating the environmental credit is applicable for the recovered materials that are reintroduced into the market (outputs of the recycling facilities), after all process losses in the various stages of the waste management system have been accounted for. It considers the displacement of materials by using the mix of virgin and recycled materials for each individual material that is used in the market for the production of goods. Moreover, it also considers the changes in the inherent properties of the materials undergoing a recycling process (‘downcycling’), by introducing a quality (Q) factor, affecting the proportion of virgin material that is accounted for. Example applications of the proposed formula to a number of different materials (aluminium, steel, paper and cardboard and plastics) illustrate the range of possible results obtained. The environmental credit calculated using the proposed formula can be interpreted as an indication of the remaining margin for improvement, since it depends on the existing mix of virgin and recycled materials already on the market and on the potential of the recycled material to actually replace the primary one on a functional basis. We also discuss the possible use of a material’s Q factor to estimate the maximum allowable % of recycled material in a product consistent with the quality demands of selected applications. We have introduced here a consistent and unified formula for the evaluation of the credits associated with material recovery of all waste materials in waste management systems (paper, glass, plastics, metals, etc.). Such a formula requires the knowledge of the current average market consumption mixes of primary and secondary materials (or the application-specific average mixes when the final application of the recovered materials is known) and of suitable Q factors for the material(s) that are recycled. As the latter are often not readily available, more research is called for to arrive at a ready-to-use Q factor database.
TL;DR: Li et al. as discussed by the authors compared the potential of reducing emissions and saving energy and natural resources in Chinese cement industry through the comparative analysis, and identified potentials for reducing emissions, saving energy, and saving natural resources.
Abstract: Cement production is associated with a considerable environmental load, which needs to be fully understood before effective measures can be taken. The existing literature did not give detailed life cycle assessment (LCA) study of China and had limited potential for investigating how best available techniques (BATs) would provide a maximum benefit when they are applied in China. Japan was selected as a good example to achieve better environmental performance of cement production. We identified potentials for reducing emissions and saving energy and natural resources in Chinese cement industry through the comparative analysis. This paper follows the principal of Life Cycle Assessment and International Reference Life Cycle Data System (ILCD). The functional units are “1 t of portland cement” and with 42.5 MPa of strength grade. The input (limestone, sandstone, ferrous tailings, coal, and electricity) and output (CO2 from limestone decomposition and coal combustion, NOx, PM, and SO2) of cement manufacturing were calculated by use of on-site measurements, calculation by estimated coefficients, and derivation by mass and heat balance principle. The direct (cement manufacturing) and indirect (electricity production) LCI are added to be total LCI results (cement production). The impact categories of global warming potential (GWP), acidification potential (AP), eutrophication potential (EP), photochemical oxidant formation potential (POCP), and human toxicity potential (HTP) are used to calculate environmental impact. Only in GWP of cement manufacturing China has advantage. Japanese cement industry shows remarkable superiorities in the environmental impacts of AP, POCP, HTP, and EP due to advanced technologies. SO2 emissions make the corresponding AP and HTP. PM emissions result in part of HTP. The NOx emissions are the major contributors of POCP, AP, EP, and HTP in China. China emits fewer CO2 emissions (2.09 %) in cement manufacturing than Japan but finally makes higher total GWP than Japan due to more GWP of electricity generation in power stations. The waste heat recovery technology can save electricity but bring more coal use and CO2 emissions. The alternative fuel and raw materials usage and denitration and de-dust technologies can relieve the environmental load. Using the functional unit with the strength grade, the life cycle impact assessment (LCIA) results are affected. LCA study allows a clear understanding from the view of total environmental impact rather than by the gross domestic product (GDP) unit from an economic development perspective. In an LCA study, the power generation should be considered in the life cycle of cement production.
TL;DR: In this paper, a new organizational perspective to boost product social life cycle assessment (SLCA) is proposed, the social organizational LCA (SOLCA), which adapts product SLCA to the organizational perspective.
Abstract: Current product social life cycle assessment (SLCA) addresses social aspects from a life cycle perspective, but it is not yet broadly implemented in practice We propose a new organizational perspective to boost SLCA—the social organizational LCA (SOLCA) The paper answers four guiding questions: Why do we need SOLCA? How can we apply it? How can its implementation benefit from existing experience? Which are the foreseen limitations? First, challenges of SLCA which may be overcome by an organizational perspective are identified, and potential solutions are described An analysis of the indicators proposed by SLCA is conducted Second, first ideas for a conceptual framework for SOLCA are developed The two underlying methodologies: the guidelines for SLCA of products and the guidance on organizational LCA (OLCA)—which adapts product LCA to the organizational perspective—were reviewed, compared and adapted to a social organizational perspective Third, different implementation pathways were identified, showing how SOLCA could be applied in practice by considering different levels of organizations’ experiences with social and environmental assessments Existing SLCA case studies do not really evaluate the social performance of products From the 189 indicators proposed in SLCA, only eight refer to the product level, while 127 and 69 refer to the organizational and country level, respectively—including overlaps and according to the methodological sheets This fact clearly favors an organizational approach to social LCA SOLCA may streamline allocation, data collection, and application in practice The conceptual framework for SOLCA is focused on scope and inventory, which were found to differ most from SLCA and OLCA; all relevant steps like definition of unit of analysis or multi-functionality are addressed Three SOLCA implementation pathways are proposed Existing experience of organizations in social organizational approaches —like Global Reporting Initiative (GRI) or product SLCA— and environmental approaches —like environmental management systems (EMS) or OLCA— can be used as starting points as they can provide useful information on the organization´s structure, value chain, etc SOLCA helps to overcome some major challenges of SLCA and thus is a promising approach for putting it into practice The frameworks of SLCA and OLCA can be integrated into SOLCA, and existing experience from organizations can be used for implementing it However, new challenges arise This includes potential difficulties for primary data collection in complex organizations with many different sites or the difficulty to distribute or aggregate social aspects within the organization Further development and testing of SOLCA is recommended
TL;DR: In this article, the authors present total air pollutant emissions and water withdrawal impacts through the lifetime of a transit bus with different fuel options, including diesel, biodiesel, compressed natural gas (CNG), liquefied natural gas(LNG), hybrid (diesel-electric), and battery electric (BE) transit buses.
Abstract: Alternative fuel options are gaining popularity in the vehicle market. Adopting alternative fuel options for public transportation compared to passenger vehicles contributes exponentially to reductions in transportation-related environmental impacts. Therefore, this study aims to present total air pollutant emissions and water withdrawal impacts through the lifetime of a transit bus with different fuel options. In consideration of market share and future development trends, diesel, biodiesel, compressed natural gas (CNG), liquefied natural gas (LNG), hybrid (diesel-electric), and battery electric (BE) transit buses are analyzed with an input-output (IO)-based hybrid life cycle assessment (LCA) model. In order to accommodate the sensitivity of total impacts to fuel economy, three commonly used driving cycles are considered: Manhattan, Central Business District (CBD), and Orange County Transit Authority (OCTA). Fuel economy for each of these driving cycles varies over the year with other impacts, so a normal distribution of fuel economy is developed with a Monte Carlo simulation model for each driving cycle and corresponding fuel type. Impacts from a solar panel (photovoltaic, PV) charging scenario and different grid mix scenarios are evaluated and compared to the nation’s average grid mix impacts from energy generation to accommodate the lifetime electricity needs for the BE transit bus. From these results, it was found that the BE transit bus causes significantly low CO2 emissions than diesel and other alternative fuel options, while some of the driving cycles of the hybrid-powered transit bus cause comparable emissions to BE transit bus. On the other hand, lifetime water withdrawal impacts of the diesel and hybrid options are more feasible compared to other options, since electricity generation and natural gas manufacturing are both heavily dependent on water withdrawal. In addition, the North American Electricity Reliability Corporation’s (NERC) regional electricity grid mix impacts on CO2 emissions and water withdrawal are presented for the BE transit bus. As an addition of current literature, LCA of alternative fuel options was performed in this paper for transit buses with the consideration of a wide variety of environmental indicators. Although the results indicate that BE and hybrid-powered buses have less environmental emissions, the US’s dependency on fossil fuel for electricity generation continues to yield significant lifetime impacts on BE transit bus operation. With respect to water withdrawal impacts, we believe that the adoption of BE transit buses will be faster and more environmentally feasible for some NREC regions than for others.
Technical University of Denmark1, University of Michigan2, Harvard University3, Cyprus University of Technology4, University of California5, Health Effects Institute6, National Institute for Health and Welfare7, University of California, Berkeley8, Boston University9, University of Arizona10, University of Minnesota11, University of Cambridge12, Polish Academy of Sciences13, Lawrence Berkeley National Laboratory14
TL;DR: The goal of this paper is to summarize the current knowledge and practice for assessing health effects from PM2.5 exposure and to provide recommendations for their consistent integration into LCIA, and to build a global guidance framework and to determine characterization factors that are more reliable for incorporating thehealth effects from exposure to PM 2.5.
Abstract: Fine particulate matter (PM2.5) is considered to be one of the most important environmental factors contributing to the global human disease burden. However, due to the lack of broad consensus and harmonization in the life cycle assessment (LCA) community, there is no clear guidance on how to consistently include health effects from PM2.5 exposure in LCA practice. As a consequence, different models are currently used to assess life cycle impacts for PM2.5, sometimes leading to inconsistent results. In a global effort initiated by the United Nations Environment Programme (UNEP)/Society for Environmental Toxicology and Chemistry (SETAC) Life Cycle Initiative, respiratory inorganics’ impacts expressed as health effects from PM2.5 exposure were selected as one of the initial impact categories to undergo review with the goal of providing global guidance for implementation in life cycle impact assessment (LCIA). The goal of this paper is to summarize the current knowledge and practice for assessing health effects from PM2.5 exposure and to provide recommendations for their consistent integration into LCIA. A task force on human health impacts was convened to build the framework for consistently quantifying health effects from PM2.5 exposure and for recommending PM2.5 characterization factors. In an initial Guidance Workshop, existing literature was reviewed and input from a broad range of internationally recognized experts was obtained and discussed. Workshop objectives were to identify the main scientific questions and challenges for quantifying health effects from PM2.5 exposure and to provide initial guidance to the impact quantification process. A set of 10 recommendations was developed addressing (a) the general framework for assessing PM2.5-related health effects, (b) approaches and data to estimate human exposure to PM2.5 using intake fractions, and (c) approaches and data to characterize exposure-response functions (ERFs) for PM2.5 and to quantify severity of the diseases attributed to PM2.5 exposure. Despite these advances, a number of complex issues, such as those related to nonlinearity of the ERF and the possible need to provide different ERFs for use in different geographical regions, require further analysis. Questions of how to refine and improve the overall framework were analyzed. Data and models were proposed for harmonizing various elements of the health impact pathways for PM2.5. Within the next two years, our goal is to build a global guidance framework and to determine characterization factors that are more reliable for incorporating the health effects from exposure to PM2.5 into LCIA. Ideally, this will allow quantification of the impacts of both indoor and outdoor exposures to PM2.5.
TL;DR: In this article, a product-centric approach to recycling, building on the extensive expertise, knowhow and tools of the mineral-centric classical minerals and metallurgical processing, should be core to Design for Resource Efficiency (DfRE).
Abstract: This paper illustrates how a product-centric approach to recycling, building on the extensive expertise, knowhow and tools of the mineral-centric classical minerals and metallurgical processing, should be core to Design for Resource Efficiency (DfRE). Process simulation (HSC Sim 1974-2014, Outotec's design tool) and environmental software (GaBi 2014) are applied to quantify resource efficiency (RE) in a rigorous manner. These digitalisation tools are linked and will be used to show how the environmental performance of copper primary production, the processing of residues and the recycling of e-waste, e.g. light emitting diode (LED) lamps as well as the production of nickel pig iron can be evaluated. The paper also shows how technologies can be compared relative to a precise thermodynamic and techno-economic baseline. The results include simulation-based environmental indicators, exergy, recycling and recovery rates, as well as the qualities and quantities of the recyclates, losses and emissions of materials during production recycling. The complete mass and energy balance simulation provides the mineralogical detail of all streams (both mineral and recyclate as well as offgas and dust) to define and improve environmental assessment, while at the same time revealing the aspects of LCA databases and their results that require improvement. Furthermore, this paper presents an approach for industry to implement life-cycle methods in practice. It shows that the DfRE is all about predicting stream grades and thus is equivalent to Design for Recyclate grade and quality (as this determines whether a recyclate or product stream has economic value and can be treated or processed further). DfRE also reveals especially the grade, composition, minerals etc. of the leakage streams, i.e. diffuse emissions, thus permitting a more precise evaluation of environmental impact. The prediction of recyclate and stream compositions and grade makes the environmental analysis of systems more precise and will help to expand the detail that defines these flows on environmental databases. This is especially valuable for DfR, where the methodological rigour suggested in this paper is a very necessary addition and requirement for estimating the true environmental impact of product redesigns and the resource efficiency of processing technology and complete recycling systems. The methodology produces mass- and energy-consistent, economically viable best available technique (BAT) process blocks, the inclusion of which on environmental databases will be invaluable in benchmarking technology and systems in terms of estimating the achievable resource efficiency baseline.
TL;DR: In this article, the authors investigated alternative approaches for handling coproduction of wool and live weight (LW, for meat) from dual purpose sheep systems to the farm-gate.
Abstract: Purpose Methodology of co-product handling is a critical determinant of calculated resource use and environmental emissions per kilogram (kg) product but has not been examined in detail for different sheep production systems. This paper investigates alternative approaches for handling coproduction of wool and live weight (LW, for meat) from dual purpose sheep systems to the farm-gate. Methods Seven methods were applied; three biophysical allocation (BA) methods based on protein requirements and partitioning of digested protein, protein mass allocation (PMA), economic allocation (EA) and two system expansion (SE) methods. Effects on greenhouse gas (GHG) emissions, fossil energy demand and land occupation (classified according to suitability for arable use) were assessed using four contrasting case study (CS) farm systems. A UK upland farm (CS 1) and a New Zealand hill farm (CS 2) were selected to represent systems focused on lamb and coarse-textured wool for interior textiles. Two Australian Merino sheep farms (CS 3, CS 4) were selected to represent systems focused on medium to superfine garment wool, and lamb. Results and discussion Total GHG emissions per kilogram total products (i.e. wool+LW) were similar across CS farms. However, results were highly sensitive to the method of coproduct handling. GHG emissions based on BA of wool protein to wool resulted in 10–12 kg CO2-e/kg wool (across all CS farms), whereas it increased to 24–38 kg CO2-e/kg wool when BA included a proportion of sheep maintenance requirements. Results for allocation% generated using EA varied widely from 4 % (CS 1) to 52 % (CS 4). SE using beef as a substitution for sheep meat gave the lowest, and often negative, GHG emissions from wool production. Different methods were found to re-order the impacts across the four case studies in some instances. A similar overall pattern was observed for the effects of co-product handling method on other impact categories for three of the four farms. Conclusions BA based on protein partitioning between sheep wool and LW is recommended for attributional studies with the PMA method being an easily applied proxy for the more detailed BA methods. Sensitivity analysis using SE is recommended to understand the implications of system change. Sensitivity analysis using SE is recommended to investigate implications of choosing alternative products or systems, and
TL;DR: In this paper, the benefits and environmental burden of two different strategies (incineration vs anaerobic digestion followed by composting) to manage the organic fraction of municipal solid waste were assessed.
Abstract: Purpose The benefits and environmental burden of two different strategies (incineration vs anaerobic digestion followed by composting) to manage the organic fraction of municipal solid waste were assessed. Particular attention was also focused on system components, including collection, treatment, facility construction, and disposal, as well as the effect of the energetic context. Source segregation intensities considered for the scenario with incineration and with anaerobic digestion followed by composting were respectively of 0 and 52 %.
TL;DR: In this paper, the application of a land-use baseline in attributional life cycle assessment (ALCA) for product systems involving land use, through consideration of the fundamental purpose of land use.
Abstract: This paper aims to clarify the application of a land-use baseline in attributional life cycle assessment (ALCA) for product systems involving land use, through consideration of the fundamental purp ...
TL;DR: In this article, a clear definition of the delineation between the product system model (life cycle inventory, technosphere) and the natural environment (LCIA, ecosphere) is established via consensus building.
Abstract: Purpose Pesticides are applied to agricultural fields to optimise crop yield and their global use is substantial. Their consideration in life cycle assessment (LCA) is affected by important inconsistencies between the emission inventory and impact assessment phases of LCA. A clear definition of the delineation between the product system model (life cycle inventory—LCI, technosphere) and the natural environment (life cycle impact assessment—LCIA, ecosphere) is missing and could be established via consensus building. Methods Aworkshop held in 2013 in Glasgow, UK, had the goal of establishing consensus and creating clear guidelines in the following topics: (1) boundary between emission inventory and impact characterisation model, (2) spatial dimensions
TL;DR: In this paper, the authors evaluate the environmental impacts of textiles from a life cycle perspective to improve the sustainability of textile especially for China, the biggest producer, exporter, and consumer in the world.
Abstract: Nowadays, environmental sustainability of textile has gained much attention from government and suppliers due to the resource consumption and pollutant emissions. Besides, different consumer behaviors can result in quite different environmental consequences mainly in terms of water and energy consumption. Therefore, it is necessary to systematically evaluate the environmental impacts of textiles from a life cycle perspective to improve the sustainability of textiles especially for China, the biggest producer, exporter, and consumer in the world. This study is conducted according to the International Organizations for Standardization’s (ISO) 14040 standard series. The declared unit is a piece of 100 % cotton short-sleeved T-shirt. The production data mainly come from field investigations of representative mills in China. The use-phase data are mainly from 924 questionnaires of Chinese residents. The secondary data from databases, literatures, and authoritative statistical data are supplemented in case primary data are not available. The potential environmental impacts are evaluated using the CML2001 and USEtox methodologies built into the GaBi version 6.0 software. We determine hotspots throughout the life cycle of the cotton textile considering the impact categories of abiotic depletion, acidification potential, global warming potential, photochemical ozone creation potential, eutrophication potential, water use, and toxicity. The results of the study show that cotton cultivation, dyeing, making-up, and use-phases are the main contributors to the environmental impacts. In particular, fertilizer, pesticide, and water use in cotton cultivation, coal, dyes, and auxiliaries use in dyeing, electricity use in making-up, detergent and water use in washing, and electricity use in spinning are the hotspots based on the life cycle impact assessment (LCIA) results. The use-phase scenario analysis shows that compared with machine washing, electric drying, and ironing share the majority of electricity consumption. Compared with Americans, Chinese washing habits are much more environmental-friendly and bring much lower environmental impacts in the use stage. Energy consumption, chemical use, and water use are main contributors to most impact categories, which help us to find hotspots and potential improvements of sustainability.