LCIA framework and cross-cutting issues guidance within the UNEP-SETAC Life Cycle Initiative

Assessment of microelement ecotoxicity in fen for ecological state monitoring

Wetlands, including bogs, fens, and swamps, play a crucial role in maintaining ecological balance by absorbing pollutants. They also conserve biodiversity and serve as breeding and migration sites for living organisms whose treated by pollutants entering to the wetland ecosystems. Pollutants entering wetland ecosystems can have detrimental effects on these important functions. The article introduces the method of toxicity assessment of microelements used in the environmental condition monitoring of the Ob River's floodplain fen (Tomsk Oblast, Russia). The impact of freshwater species (PAF m3day/kgemitted) is evaluated by calculating the Life Cycle Assessment Impact score for Be, V, Cr, Mn, Fe, Cu, Zn, As, Sr, Mo, Pb, Cd, Sb, Ba, and Tl at distances of 40, 100, and 160 m from the wastewater discharge site. The study considers the elemental composition and total volume of water from various areas within the research site for assessing freshwater ecotoxicity. 12 out of 15 investigated trace elements have the greatest impact on the freshwater system in the zone of 160 m from the site of anthropogenic impact on the water body. The sampling areas can be ranked based on their ∑IS value, with IS160 = 1.3E+11, followed by IS100 = 7.5E+10, and IS40 = 1.5E+10 [PAF m3day/kgemitted].

What Is the Impact of Accidentally Transporting Terrestrial Alien Species? A New Life Cycle Impact Assessment Model

Alien species form one of the main threats to global biodiversity. Although Life Cycle Assessment attempts to holistically assess environmental impacts of products and services across value chains, ecological impacts of the introduction of alien species are so far not assessed in Life Cycle Impact Assessment. Here, we developed country-to-country-specific characterization factors, expressed as the time-integrated potentially disappeared fraction (PDF; regional and global) of native terrestrial species due to alien species introductions per unit of goods transported [kg] between two countries. The characterization factors were generated by analyzing global data on first records of alien species, native species distributions, and their threat status, as well as bilateral trade partnerships from 1870-2019. The resulting characterization factors vary over several orders of magnitude, indicating that impact greatly varies per transportation route and trading partner. We showcase the applicability and relevance of the characterization factors for transporting 1 metric ton of freight to France from China, South Africa, and Madagascar. The results suggest that the introduction of alien species can be more damaging for terrestrial biodiversity as climate change impacts during the international transport of commodities.

What Is the Likely Impact of Alternative Proteins on Diet Quality, Health, and the Environment in Low- and Middle-Income Countries

Alternative protein (AP) foods are proposed to support a global protein transition. Whereas AP food innovation has been a strategy to promote consumption of protein sources with low environmental impact in high-income countries (HICs) diets, their relation to sustainable, high-quality diets in low- and middle-income countries (LMICs) remains to be established. AP foods vary in nutrient profile, processing requirements, costs, and environmental impact. Current literature regarding AP suitability in LMIC contexts is limited. This perspective examined environmental and nutritional metrics that can assess the sustainability of AP in LMICs. Current research areas needed to accurately assess environmental impacts while considering nutritional density were identified. An overview of the usability of relevant AP in both high- and low-resource settings was also explored. Metrics addressing diverse contextual synergies in LMICs, unifying nutritional, environmental, and socioeconomic considerations, were found necessary to guide the integration of AP into LMIC diets.

From full life cycle assessment to simplified life cycle assessment: A generic methodology applied to sludge treatment

Life cycle assessment is widely used to evaluate sludge treatment methods. However, detailed life cycle assessment is time-consuming and resource-intensive. In addition, the complex characteristics of sludge and the variety of treatment methods increase the difficulty of sludge treatment life cycle assessment. There is an urgent need to develop simplified life cycle assessment models to allow rapid decision-making. This study proposes a simplified method of sludge treatment life cycle assessment based on logistic regression analysis. The simplified model relies on the total environmental impact and very few or even a single input parameters. Contribution and data quality analysis were introduced to identify key input parameters and to obtain model training data. The method was eventually applied to traditional sludge treatment methods, showing that it can quickly and accurately predict environmental impact. Representative analysis showed that the model would be affected by technology and energy structure modification. It is hoped that this study will provide a reference and new perspectives for a simplified life cycle assessment of sludge treatment.

Biodiversity Impact Assessment Considering Land Use Intensities and Fragmentation

Land use is a major threat to terrestrial biodiversity. Life cycle assessment is a tool that can assess such threats and thereby support environmental decision-making. Within the Global Guidance for Life Cycle Impact Assessment (GLAM) project, the Life Cycle Initiative hosted by UN Environment aims to create a life cycle impact assessment method across multiple impact categories, including land use impacts on ecosystem quality represented by regional and global species richness. A working group of the GLAM project focused on such land use impacts and developed new characterization factors to combine the strengths of two separate recent advancements in the field: the consideration of land use intensities and land fragmentation. The data sets to parametrize the underlying model are also updated from previous models. The new characterization factors cover five species groups (plants, amphibians, birds, mammals, and reptiles) and five broad land use types (cropland, pasture, plantations, managed forests, and urban land) at three intensity levels (minimal, light, and intense). They are available at the level of terrestrial ecoregions and countries. This paper documents the development of the characterization factors, provides practical guidance for their use, and critically assesses the strengths and remaining shortcomings.

Development of an LCA characterization factor to account UHI local effect on terrestrial ecosystems damage category: Evaluation of European Bombus and Onthophagus genera heat-stress mortality

Life Cycle Assessment as currently implemented fails in detecting and measuring the interactions between urban climate and built environment, specifically the urban heat island, providing potentially misleading results. The present study offers an advancement in Life Cycle Assessment methodology, and specifically in ReCiPe2016 method, by (a) suggesting the implementation of the Local Warming Potential midpoint impact category where the variation of urban temperature converges; (b) developing a new characterization factor through the definition of damage pathways to assess the effect of urban heat island on terrestrial ecosystems damage category, specifically on European Bombus and Onthophagus genera; (c) defining local endpoint damage categories where environmental local impacts can be addressed. The developed characterization factor has been applied to the case study of an urban area in Rome, Italy. The results show that the evaluation of the effects of urban overheating on local terrestrial ecosystems is meaningful and may support urban decision-makers who want to holistically assess urban plans.

To Split or Not to Split: Characterizing Chemical Pollution Impacts in Aquatic Ecosystems with Species Sensitivity Distributions for Specific Taxonomic Groups

Bridging applied ecology and ecotoxicology is key to protect ecosystems. These disciplines show a mismatch, especially when evaluating pressures. Contrasting to applied ecology, ecotoxicological impacts are often characterized for whole species assemblages based on Species Sensitivity Distributions (SSDs). SSDs are statistical models describing per chemical across-species sensitivity variation based on laboratory toxicity tests. To assist in the aligning of the disciplines and improve decision-support uses of SSDs, we investigate taxonomic-group-specific SSDs for algae/cyanobacteria/aquatic plants, invertebrates, and vertebrates for 180 chemicals with sufficient test data. We show that splitting improves pollution impact assessments for chemicals with a specific mode of action and, surprisingly, for narcotic chemicals. We provide a framework for splitting SSDs that can be applied to serve in environmental protection, life cycle assessment, and management of freshwater ecosystems. We illustrate that using split SSDs has potentially large implications for the decision-support of SSD-based outputs around the globe.

Advancing water footprint assessments: Combining the impacts of water pollution and scarcity

Several water footprint indicators have been developed to curb freshwater stress. Volumetric footprints support water allocation decisions and strive to increase water productivity in all sectors. In contrast, impact-oriented footprints are used to minimize the impacts of water use on human health, ecosystems, and freshwater resources. Efforts to combine both perspectives in a harmonized framework have been undertaken, but common challenges remain, such as pollution and ecosystems impacts modelling. To address these knowledge gaps, we build upon a water footprint assessment framework proposed at conceptual level to expand and operationalize relevant features. We propose two regionalized indicators, namely the water biodiversity footprint and the water resource footprint, that aggregate all impacts from toxic chemicals, nutrients, and water scarcity. The first impact indicator represents the impacts on freshwater ecosystems. The second one models the competition for freshwater resources and its consequences on freshwater availability. As part of the framework, we complement the two indicators with a sustainability assessment representing the levels above which ecological and human freshwater needs are no longer sustained. We test our approach assessing the sustainability of water use in the European Union in 2010. Water stress hampers 15 % of domestic, agricultural and industrial water demand, mainly due to irrigation and pesticide emissions in southern Europe. Moreover, damage to the freshwater ecosystems is widespread and mostly resulting from chemical emissions from industry. Approximately 5 % of the area is exceeding the regional sustainability limits for ecosystems and human water requirements altogether. Concerted efforts from all sectors are needed to reduce the impacts of emissions and water consumption under the sustainability limits. These advances are considered an important step toward the harmonization of volumetric and impact-oriented approaches to achieve consistent and holistic water footprinting as well as contributing to strengthen the policy relevance of water footprint assessments.

Global water consumption impacts on riverine fish species richness in Life Cycle Assessment

Reduced river discharge and flow regulation are significant threats to freshwater biodiversity. An accurate representation of potential damage of water consumption on freshwater biodiversity is required to quantify and compare the environmental impacts of global value chains. The effect of discharge reduction on fish species richness was previously modeled in life cycle impact assessment, but models were limited by the restricted geographical scope of underlying species-discharge relationships and the small number of species data. Here, we propose a model based on a novel regionalized species-discharge relationship (SDR). Our SDR-based model covers 88 % of the global landmass (2320 river basins worldwide excluding deserts and permanently frozen areas) and is based on a global dataset of 11,450 riverine fish species, simulated river discharge, elevation, and climate zones. We performed 10-fold cross-validation to select the best set of predictors and validated the obtained SDRs based on observed discharge data. Our model performed better than previous SDRs employed in life cycle impact assessment (Kling-Gupta efficiency coefficient about 4 times larger). We provide both marginal and average models with their uncertainty ranges for assessing scenarios of small and large-scale water consumption, respectively, and include regional and global species loss. We conducted an illustrative case study to showcase the method's applicability and highlight the differences with the currently used approach. Our models are useful for supporting sustainable water consumption and riverine fish biodiversity conservation decisions. They enable a more specific, reliable, and complete impact assessment by differentiating impacts on regional riverine fish species richness and irreversible global losses, including up-to-date species data, and providing spatially explicit values with high geographical coverage.

Linking freshwater ecotoxicity to damage on ecosystem services in life cycle assessment

Freshwater ecosystems provide major benefits to human wellbeing-so-called ecosystem services (ES)-but are currently threatened among others by ecotoxicological pressure from chemicals reaching the environment. There is an increased motivation to incorporate ES in quantification tools that support decision-making, such as life cycle assessment (LCA). However, mechanistic models and frameworks that can systematically translate ecotoxicity effect data from chemical tests into eventual damage on species diversity, functional diversity, and ES in the field are still missing. While current approaches focus on translating predicted ecotoxicity impacts to damage in terms of species loss, no approaches are available in LCA and other comparative assessment frameworks for linking ecotoxicity to damage on ecosystem functioning or ES. To overcome this challenge, we propose a way forward based on evaluating available approaches to characterize damage of chemical pollution on freshwater ES. We first outline an overall framework for linking freshwater ecotoxicity effects to damage on related ES in compliance with the boundary conditions of quantitative, comparative assessments. Second, within the proposed framework, we present possible approaches for stepwise linking ecotoxicity effects to species loss, functional diversity loss, and damage on ES. Finally, we discuss strengths, limitations, and data availability of possible approaches for each step. Although most approaches for directly deriving damage on ES from either species loss or damage to functional diversity have not been operationalized, there are some promising ways forward. The Threshold Indicator Taxa ANalysis (TITAN) seems suitable to translate predicted ecotoxicity effects to a metric of quantitative damage on species diversity. A Trait Probability Density Framework (TPD) approach that incorporates various functional diversity components and functional groups could be adapted to link species loss to functional diversity loss. An Ecological Production Function (EPF) approach seems most promising for further linking functional diversity loss to damage on ES flows for human wellbeing. However, in order to integrate the entire pathway from predicted freshwater ecotoxicity to damage on ES into LCA and other comparative frameworks, the approaches adopted for each step need to be harmonized in terms of assumptions, boundary conditions and consistent interfaces with each other.

Ecotoxicity characterization of chemicals: Global recommendations and implementation in USEtox

Chemicals emitted to the environment affect ecosystem health from local to global scale, and reducing chemical impacts has become an important element of European and global sustainability efforts. The present work advances ecotoxicity characterization of chemicals in life cycle impact assessment by proposing recommendations resulting from international expert workshops and work conducted under the umbrella of the UNEP-SETAC Life Cycle Initiative in the GLAM project (Global guidance on environmental life cycle impact assessment indicators). We include specific recommendations for broadening the assessment scope through proposing to introduce additional environmental compartments beyond freshwater and related ecotoxicity indicators, as well as for adapting the ecotoxicity effect modelling approach to better reflect environmentally relevant exposure levels and including to a larger extent chronic test data. As result, we (1) propose a consistent mathematical framework for calculating freshwater ecotoxicity characterization factors and their underlying fate, exposure and effect parameters; (2) implement the framework into the USEtox scientific consensus model; (3) calculate characterization factors for chemicals reported in an inventory of a life cycle assessment case study on rice production and consumption; and (4) investigate the influence of effect data selection criteria on resulting indicator scores. Our results highlight the need for careful interpretation of life cycle assessment impact scores in light of robustness of underlying species sensitivity distributions. Next steps are to apply the recommended characterization framework in additional case studies, and to adapt it to soil, sediment and the marine environment. Our framework is applicable for evaluating chemicals in life cycle assessment, chemical and environmental footprinting, chemical substitution, risk screening, chemical prioritization, and comparison with environmental sustainability targets.

Green Methane as a Future Fuel for Light-Duty Vehicles

Food waste (FW) has traditionally been disposed by incineration or landfilling; however, it can be converted to green methane (GM) via anaerobic digestion, and GM can be used as fuel for light-duty natural gas vehicles (LDNGVs). A lifecycle assessment (LCA) of FW-based GM production and LDNGV operation in China, a new scenario, was performed. The LCA results were compared with those for the conventional FW treatment, where a “well-to-wheel” system boundary including FW collection, GM production from FW, and vehicle manufacturing, operation, and disposal was defined. The LCA results showed that the global warming impacts of the new FW scenario are 44.3% lower than those of the conventional option. The fine particulate matter formation impact of the new FW scenario was dominated by the displacement effect of electricity supply to anaerobic digestion, followed by CO2 adsorption by the primary source. The sensitivity analysis showed that hydroelectric power as the best primary source for electricity supply could substantially reduce both global warming and FRS in the new scenario. In the short term, the proposed FW scenario could be a feasible option for achieving sustainable society by minimizing environmental impacts of FW treatment.

Life Cycle Analysis Challenges through Building Rating Schemes within the European Framework

The decarbonisation of buildings is a crucial milestone if European cities mean to reach their mitigation targets. The construction sector was responsible for 38% of the GHG emissions in 2020. From these emissions, 11% is calculated to be currently embodied in building materials. In this context, an evaluation from a life cycle perspective is becoming increasingly necessary to achieve the objectives set. Currently, there are different building rating systems (BRS) at European level that allow the evaluation of the degree of sustainability of buildings. During this study, the authors have evaluated to what extent and how the most extended five BRS (NF Habitat HQE, VERDE, DGNB, BREEAM, and HPI systems) in the European framework have integrated the life cycle methodology during their evaluation process. Four methodologies have been used in the research in order to analyse these five systems: quantitative assessment, multi-level perspective, mapping–gap analysis, and expert interviews. Although each methodology has produced different results, the need to harmonise the evaluation criteria at the European level, the insufficient consistency of data software, and the availability of skilled LCA professionals for wider LCA market penetration, among others, should be highlighted. The quality and harmonised data of construction products is required for LCA to give aggregated and transformative results.

Towards a LCA Database for the Planning and Design of Zero-Emissions Neighborhoods

The integration of science-based knowledge on greenhouse gas (GHG) emissions into practice-based neighborhood design and planning is key to inform and implement climate mitigation strategies. LCA is a method that is commonly used to provide objective and science-based information on the environmental impacts of specified systems or products. To use a LCA methodology at neighborhood scale is in turn dependent on the development of a common structure for life cycle inventory data. Such a LCA database does not operate on its own, but functions as a structured source of relevant high-quality data inputs linked to other different analytical tools. The aim of this study is to analyze the needs and requirements and provide a foundation for a LCA database at neighborhood scale that can provide users with an interface to find and access life cycle data in the users’ preferred format. The result of this study is the outline of the foundations of a user-centric LCA database for neighborhoods, including several sub-systems (buildings, infrastructure, mobility, and energy supply). Recommendations are given in the Conclusions Section to provide harmonized decision support on reducing GHG emissions at local levels in the planning and design of urban development projects at the neighborhood scale.

Modeling the Impact of Salinity Variations on Aquatic Environments: Including Negative and Positive Effects in Life Cycle Assessment

Salinity is changing in aquatic systems due to anthropogenic activities (like irrigation or dam management) and climate change. Although there are studies on the effects of salinity variations on individual species, little is known about the effects on overall ecosystems, these impacts being more uncertain in transitional waters such as estuaries or fiords. The few works that do address this topic have considered these impacts using ecotoxicity models. However, these models state that an increase in the concentration of a pollutant generates an increase in the impacts, disregarding the effects of water freshening. The present research work introduces a general framework to address the impacts of salinity variations, including emission-related positive effects. We validated this framework by applying it to an estuarine area in Galicia (northwestern Spain), where sharp drops in the salt concentration have caused mass mortalities of shellfish in recent decades. This research work addresses for the first time the potential effects on the environment derived from a decrease in the concentration of essential substances, where the effects of an emission can also generate positive impacts. Moreover, it is expected that the framework can also be applied to model the environmental impacts of other essential substances in life cycle assessment (LCA), such as metals and macronutrients.

Considering habitat conversion and fragmentation in characterisation factors for land-use impacts on vertebrate species richness

Human land use is one of the primary threats to terrestrial species richness and is considered a priority for meeting global sustainability and biodiversity targets. Decision-support tools, such as life cycle assessment (LCA), are widely used for developing strategies to achieve such objectives. Currently available life cycle impact assessment (LCIA) methods apply the countryside species-area relationship (c-SAR) to quantify habitat conversion impacts on species richness. However, additional effects of habitat fragmentation are yet ignored in these assessments. We use the species-habitat relationship (SHR), an adaptation of the c-SAR that considers both habitat conversion and fragmentation effects, to develop a new set of land-use characterisation factors for 702 terrestrial ecoregions (in 238 countries), four land-use types (urban, cropland, pasture, and forestry), and four taxonomic groups (amphibians, birds, mammals, and reptiles; plus the aggregate of these vertebrate groups). The SHR generally predicts higher per-area impacts of land-use than the impacts estimated by the c-SAR (a median relative difference of +9%), indicating that land-use impacts may be systematically underestimated when ignoring fragmentation effects. Whereas per-area impacts of land-use on regional species richness are highest in temperate regions, reflecting the diminished extent of natural habitat, per-area impacts of land-use on global species richness are highest in the subtropics, reflecting the importance of tropical regions and islands to global vertebrate species diversity. The large variety in magnitude of land-use impacts across the world's regions emphasizes the importance of regionalised assessments. The set of characterisation factors proposed here can be readily used in environmental decision-making.

Climate Change Warning Labels on Gas Pumps: The Role of Public Opinion Formation in Climate Change Mitigation Policies

This article analyzes City of Cambridge, Massachusetts legislation that requires all gasoline and diesel pumps to display a consumer warning label outlining the climate change and public health impacts from fuel combustion. This review of empirical and theoretical scholarship on efficacy of carbon label programs and health warning labels suggests government-sponsored "warming labels" may increase self-efficacy beliefs. The analysis reveals warming labels may activate extant climate concern norms and shift public opinion toward long term support of sustainable transportation emissions policies and practices.

Life cycle assessment (LCA): informing the development of a sustainable circular bioeconomy?

The role of life cycle assessment (LCA) in informing the development of a sustainable and circular bioeconomy is discussed. We analyse the critical challenges remaining in using LCA and propose improvements needed to resolve future development challenges. Biobased systems are often complex combinations of technologies and practices that are geographically dispersed over long distances and with heterogeneous and uncertain sets of indicators and impacts. Recent studies have provided methodological suggestions on how LCA can be improved for evaluating the sustainability of biobased systems with a new focus on emerging systems, helping to identify environmental and social opportunities prior to large R&D investments. However, accessing economies of scale and improved conversion efficiencies while maintaining compatibility across broad ranges of sustainability indicators and public acceptability remain key challenges for the bioeconomy. LCA can inform, but not by itself resolve this complex dimension of sustainability. Future policy interventions that aim to promote the bioeconomy and support strategic value chains will benefit from the systematic use of LCA. However, the LCA community needs to develop the mechanisms and tools needed to generate agreement and coordinate the standards and incentives that will underpin a successful biobased transition. Systematic stakeholder engagement and the use of multidisciplinary analysis in combination with LCA are essential components of emergent LCA methods. This article is part of the theme issue 'Bio-derived and bioinspired sustainable advanced materials for emerging technologies (part 1)'.

Using Naturalness for Assessing the Impact of Forestry and Protection on the Quality of Ecosystems in Life Cycle Assessment

A novel approach is proposed to evaluate the impact of forestry on ecosystem quality in life cycle assessment (LCA) combining a naturalness assessment model with a species richness relationship. The approach is applied to a case study evaluating different forest management strategies involving concomitantly silvicultural scenarios (plantation only, careful logging only or the current mix of both) combined with an increasing share of protected area for wood production in a Québec black spruce forest. The naturalness index is useful to compare forest management scenarios and can help evaluate conservation needs considering the type of management foreseen for wood production. The results indicate that it is preferable to intensify forest management over a small proportion of the forest territory while ensuring strict protection over the remaining portion, compared to extensive forest management over most of the forested area. To explore naturalness introduction in LCA, a provisory curve relating the naturalness index (NI) with the potential disappeared fraction of species (PDF) was developed using species richness data from the literature. LCA impact scores in PDF for producing 1 m3 of wood might lead to consistent results with the naturalness index but the uncertainty is high while the window leading to consistent results is narrow.

Exposure and Toxicity Characterization of Chemical Emissions and Chemicals in Products: Global Recommendations and Implementation in USEtox

PURPOSE

Reducing chemical pressure on human and environmental health is an integral part of the global sustainability agenda. Guidelines for deriving globally applicable, life cycle based indicators are required to consistently quantify toxicity impacts from chemical emissions as well as from chemicals in consumer products. In response, we elaborate the methodological framework and present recommendations for advancing near-field/far-field exposure and toxicity characterization, and for implementing these recommendations in the scientific consensus model USEtox.

METHODS

An expert taskforce was convened by the Life Cycle Initiative hosted by UN Environment to expand existing guidance for evaluating human toxicity impacts from exposure to chemical substances. This taskforce evaluated advances since the original release of USEtox. Based on these advances, the taskforce identified two major aspects that required refinement, namely integrating near-field and far-field exposure and improving human dose-response modeling. Dedicated efforts have led to a set of recommendations to address these aspects in an update of USEtox, while ensuring consistency with the boundary conditions for characterizing life cycle toxicity impacts and being aligned with recommendations from agencies that regulate chemical exposure. The proposed framework was finally tested in an illustrative rice production and consumption case study.

RESULTS AND DISCUSSION

On the exposure side, a matrix system is proposed and recommended to integrate far-field exposure from environmental emissions with near-field exposure from chemicals in various consumer product types. Consumer exposure is addressed via submodels for each product type to account for product characteristics and exposure settings. Case study results illustrate that product-use related exposure dominates overall life cycle exposure. On the effect side, a probabilistic dose-response approach combined with a decision tree for identifying reliable points of departure is proposed for non-cancer effects, following recent guidance from the World Health Organization. This approach allows for explicitly considering both uncertainty and human variability in effect factors. Factors reflecting disease severity are proposed to distinguish cancer from non-cancer effects, and within the latter discriminate reproductive/developmental and other non-cancer effects. All proposed aspects have been consistently implemented into the original USEtox framework.

CONCLUSIONS

The recommended methodological advancements address several key limitations in earlier approaches. Next steps are to test the new characterization framework in additional case studies and to close remaining research gaps. Our framework is applicable for evaluating chemical emissions and product-related exposure in life cycle assessment, chemical alternatives assessment and chemical substitution, consumer exposure and risk screening, and high-throughput chemical prioritization.

Green Nanofabrication Opportunities in the Semiconductor Industry: A Life Cycle Perspective

The turn of the 21st century heralded in the semiconductor age alongside the Anthropocene epoch, characterised by the ever-increasing human impact on the environment. The ecological consequences of semiconductor chip manufacturing are the most predominant within the electronics industry. This is due to current reliance upon large amounts of solvents, acids and gases that have numerous toxicological impacts. Management and assessment of hazardous chemicals is complicated by trade secrets and continual rapid change in the electronic manufacturing process. Of the many subprocesses involved in chip manufacturing, lithographic processes are of particular concern. Current developments in bottom-up lithography, such as directed self-assembly (DSA) of block copolymers (BCPs), are being considered as a next-generation technology for semiconductor chip production. These nanofabrication techniques present a novel opportunity for improving the sustainability of lithography by reducing the number of processing steps, energy and chemical waste products involved. At present, to the extent of our knowledge, there is no published life cycle assessment (LCA) evaluating the environmental impact of new bottom-up lithography versus conventional lithographic techniques. Quantification of this impact is central to verifying whether these new nanofabrication routes can replace conventional deposition techniques in industry as a more environmentally friendly option.

Environmental Impact and Levelised Cost of Energy Analysis of Solar Photovoltaic Systems in Selected Asia Pacific Region: A Cradle-to-Grave Approach

Sustainability has been greatly impacted by the reality of budgets and available resources as a targeted range of carbon emission reduction greatly increases due to climate change. This study analyses the technical and economic feasibility for three types of solar photovoltaic (PV) renewable energy (RE) systems; (i) solar stand-alone, a non-grid-connected building rooftop-mounted structure, (ii) solar rooftop, a grid-connected building rooftop-mounted structure, (iii) solar farm, a grid-connected land-mounted structure in three tropical climate regions. Technical scientific and economic tools, including life cycle assessment (LCA) and life cycle cost assessment (LCCA) with an integrated framework from a Malaysian case study were applied to similar climatic regions, Thailand, and Indonesia. The short-term, future scaled-up scenario was defined using a proxy technology and estimated data. Environmental locations for this scenario were identified, the environmental impacts were compared, and the techno-economic output were analysed. The scope of this study is cradle-to-grave. Levelised cost of energy (LCOE) was greatly affected due to PV performance degradation rate, especially the critical shading issues for large-scale installations. Despite the land use impact, increased CO2 emissions accumulate over time with regard to energy mix of the country, which requires the need for long-term procurement of both carbon and investment return. With regards to profitably, grid-connected roof-mounted systems achieve the lowest LCOE as compared to other types of installation, ranging from 0.0491 USD/kWh to 0.0605 USD/kWh under a 6% discounted rate. A simple payback (SPB) time between 7–10 years on average depends on annual power generated by the system with estimated energy payback of 0.40–0.55 years for common polycrystalline photovoltaic technology. Thus, maintaining the whole system by ensuring a low degradation rate of 0.2% over a long period of time is essential to generate benefits for both investors and the environment. Emerging technologies are progressing at an exponential rate in order to fill the gap of establishing renewable energy as an attractive business plan. Life cycle assessment is considered an excellent tool to assess the environmental impact of renewable energy.

Controlling biodiversity impacts of future global hydropower reservoirs by strategic site selection

Further reservoir-based hydropower development can contribute to the United Nations' sustainable development goals (SDGs) on affordable and clean energy, and climate action. However, hydropower reservoir operation can lead to biodiversity impacts, thus interfering with the SDGs on clean water and life on land. We combine a high-resolution, location-specific, technical assessment with newly developed life cycle impact assessment models, to assess potential biodiversity impacts of possible future hydropower reservoirs, resulting from land occupation, water consumption and methane emissions. We show that careful selection of hydropower reservoirs has a large potential to limit biodiversity impacts, as for example, 0.3% of the global hydropower potential accounts for 25% of the terrestrial biodiversity impact. Local variations, e.g. species richness, are the dominant explanatory factors of the variance in the quantified biodiversity impact and not the mere amount of water consumed, or land occupied per kWh. The biodiversity impacts are mainly caused by land occupation and water consumption, with methane emissions being much less important. Further, we indicate a trade-off risk between terrestrial and aquatic biodiversity impacts, as due to the weak correlation between terrestrial and aquatic impacts, reservoirs with small aquatic biodiversity impacts tend to have larger terrestrial impacts and vice versa.

Quantification and valuation of ecosystem services in life cycle assessment: Application of the cascade framework to rice farming systems

The integration of ecosystem service (ES) assessment with life cycle assessment (LCA) is important for developing decision support tools for environmental sustainability. A prequel study has proposed a 4-step methodology that integrates the ES cascade framework within the cause-effect chain of life cycle impact assessment (LCIA) to characterize the physical and monetary impacts on ES provisioning due to human interventions. We here follow the suggested steps in the abovementioned study, to demonstrate the first application of the integrated ES-LCIA methodology and the added value for LCA studies, using a case study of rice farming in the United States, China, and India. Four ES are considered, namely carbon sequestration, water provisioning, air quality regulation, and water quality regulation. The analysis found a net negative impact for rice farming systems in all three rice producing countries, meaning the detrimental impacts of rice farming on ES being greater than the induced benefits on ES. Compared to the price of rice sold in the market, the negative impacts represent around 2%, 6%, and 4% of the cost of 1 kg of rice from China, India, and the United States, respectively. From this case study, research gaps were identified in order to develop a fully operationalized ES-LCIA integration. With such a framework and guidance in place, practitioners can more comprehensively assess the impacts of life cycle activities on relevant ES provisioning, in both physical and monetary terms. This may in turn affect stakeholders' availability to receive such benefits from ecosystems in the long run.

Global characterization factors for terrestrial biodiversity impacts of future land inundation in Life Cycle Assessment

Life Cycle Assessment (LCA) is a tool for analyzing and comparing environmental impacts of products throughout their life cycles, facilitating shifts towards more environmentally friendly products. However, LCA does currently not address terrestrial biodiversity impacts related to the conversion of terrestrial habitat into aquatic habitat. This conversion can occur because of sea level rise, establishment of new land-based aquaculture, as well as reservoir expansion or creation. Here, we focus on land occupation and terrestrial biodiversity impacts, while transformation impacts, and habitat gain for aquatic species were beyond the scope of the study. To be able to estimate the regional and global terrestrial biodiversity impacts of future land occupation from terrestrial to aquatic habitat in LCA, we developed new characterization factors (CFs) for 781 terrestrial ecoregions, 5 land cover/use types, and 4 taxonomic groups. The basis for the development of the proposed CFs is the model concept of the currently recommended method for quantifying land use impacts on biodiversity in LCA by the Life Cycle Initiative hosted by United Nations Environmental Program. The global CFs vary between 7.44 E-20 PDF/m² and 6.25 E-09 PDF/m², showing that a highly variable terrestrial biodiversity impact of land inundation between land cover/use types, taxonomic groups and ecoregions exists.

Comments on the international consensus model for the water scarcity footprint (AWARE) and proposal for an improvement

Life Cycle Assessment (LCA) provides a structured framework, addressing environmental impacts of human activities. LCA requires consensual and scientifically sound characterisation factors to quantify impacts and allow comparisons. This is the objective of the AWARE model, recently published by an international consortium, which is now the reference for water impact in LCA. Looking back at the shape of the equation, linking human water use and water impact, we discuss the limits of the AWARE model and the associated cut-offs. They imply that all regions in a less than fair ecosystem condition are treated at the same level of severity, regardless of the extent of degradation. From this statement, we propose to define the impact by the ratio between the ecosystem demands and the remaining after human activities (DTR model). We use the marginal and average approaches, common approaches in LCA, to determine the corresponding characterisation factors. Through a sensitivity analysis with respect to parameters used (total water availability, ecosystem demand, human consumption and area of the region), we show that the DTR-based characterisation factors have the same properties than the AWARE-based ones between cut-offs. This article therefore provides a new alternative way of quantifying the impact of water use, in line with the AWARE model features, but without its validity limits and induced thresholds.

A Regionalised Life Cycle Assessment Model to Globally Assess the Environmental Implications of Soil Salinization in Irrigated Agriculture

We present a global, locally resolved life cycle assessment (LCA) model to assess the potential effects on soil quality due to the accumulation of water-soluble salts in the agricultural soil profile, allowing differentiation between agricultural practices. Using globally available soil and climate information and crop specific salt tolerances, the model quantifies the negative implications that salts in irrigation water have on soil quality, in terms of change in the soil electrical conductivity and the corresponding change in the amount of crops that can be grown at increasing soil salinity levels. To facilitate the use of the model, we provide a life cycle inventory tool with information on salts emitted with irrigation water per country and 160 crops. Global average soil susceptibility is 0.19 dS/m per grams of salt in 1 m³ of soil, and the average resulting relative crop diversity loss is 5.7 × 10^-2 per grams of salt in 1 m³ of soil. These average values vary tangibly as a function of the location. In most humid regions worldwide, the characterization factor is null, showing that in these cases soil salinization due to irrigation does not contribute to soil degradation. We displayed how to apply the model with a case study. The model serves for guiding decision-making processes toward improving the sustainability of irrigated agriculture.

Quantifying the handprint-Footprint balance into a single score: The example of pharmaceuticals

Life Cycle Assessment typically focuses on the footprint of products and services, expressed on three Areas of Protection (AoP): Human Health, Ecosystems and Resources. While the handprint is often expressed qualitatively, quantified handprints have recently been compared directly to the footprint concerning one AoP: Human Health. We propose to take this one step further by simultaneously comparing the quantified handprint and footprint on all AoPs through normalization and weighting of the results towards a single score. We discuss two example cases of a pharmaceutical treatment: mebendazole to treat soil-transmitted helminthiases and paliperidone palmitate to treat schizophrenia. Each time, treatment is compared to 'no treatment'. The footprint of health care is compared to the handprint of improved patient health. The handprint and footprint were normalized separately. To include sensitivity in the normalization step we applied four sets of external normalization factors for both handprint (Global Burden of Disease) and footprint (ReCiPe and PROSUITE). At the weighting step we applied 26 sets of panel weighting factors from three sources. We propose the Relative Sustainability Benefit Rate (RSBR) as a new metric to quantify the relative difference in combined handprint and footprint single score between two alternatives. When only considering the footprint, the first case study is associated with an increased single score burden of treatment compared to 'no treatment', while in the second case study treatment reduces the single score burden by 41.1% compared to 'no treatment'. Also including the handprint provided new insights for the first case study, now showing a decrease of 56.4% in single score burden for treatment compared to 'no treatment'. For the second case study the reduction of single score burden was confirmed as the handprint burden was also decreased because of treatment by 9.9%, reinforcing the findings.

Methodological review and detailed guidance for the life cycle interpretation phase

Life cycle interpretation is the fourth and last phase of life cycle assessment (LCA). Being a "pivot" phase linking all other phases and the conclusions and recommendations from an LCA study, it represents a challenging task for practitioners, who miss harmonized guidelines that are sufficiently complete, detailed, and practical to conduct its different steps effectively. Here, we aim to bridge this gap. We review available literature describing the life cycle interpretation phase, including standards, LCA books, technical reports, and relevant scientific literature. On this basis, we evaluate and clarify the definition and purposes of the interpretation phase and propose an array of methods supporting its conduct in LCA practice. The five steps of interpretation defined in ISO 14040-44 are proposed to be reorganized around a framework that offers a more pragmatic approach to interpretation. It orders the steps as follows: (i) completeness check, (ii) consistency check, (iii) sensitivity check, (iv) identification of significant issues, and (v) conclusions, limitations, and recommendations. We provide toolboxes, consisting of methods and procedures supporting the analyses, computations, points to evaluate or check, and reflective processes for each of these steps. All methods are succinctly discussed with relevant referencing for further details of their applications. This proposed framework, substantiated with the large variety of methods, is envisioned to help LCA practitioners increase the relevance of their interpretation and the soundness of their conclusions and recommendations. It is a first step toward a more comprehensive and harmonized LCA practice to improve the reliability and credibility of LCA studies.

Environmental co-benefits and adverse side-effects of alternative power sector decarbonization strategies

A rapid and deep decarbonization of power supply worldwide is required to limit global warming to well below 2 °C. Beyond greenhouse gas emissions, the power sector is also responsible for numerous other environmental impacts. Here we combine scenarios from integrated assessment models with a forward-looking life-cycle assessment to explore how alternative technology choices in power sector decarbonization pathways compare in terms of non-climate environmental impacts at the system level. While all decarbonization pathways yield major environmental co-benefits, we find that the scale of co-benefits as well as profiles of adverse side-effects depend strongly on technology choice. Mitigation scenarios focusing on wind and solar power are more effective in reducing human health impacts compared to those with low renewable energy, while inducing a more pronounced shift away from fossil and toward mineral resource depletion. Conversely, non-climate ecosystem damages are highly uncertain but tend to increase, chiefly due to land requirements for bioenergy.

Towards integrating the ecosystem services cascade framework within the Life Cycle Assessment (LCA) cause-effect methodology

The assessment of ecosystem services (ES) is covered in a fragmented manner by environmental decision support tools that provide information about the potential environmental impacts of supply chains and their products, such as the well-known Life Cycle Assessment (LCA) methodology. Within the flagship project of the Life Cycle Initiative (hosted by UN Environment), aiming at global guidance for life cycle impact assessment (LCIA) indicators, a dedicated subtask force was constituted to consolidate the evaluation of ES in LCA. As one of the outcomes of this subtask force, this paper describes the progress towards consensus building in the LCA domain concerning the assessment of anthropogenic impacts on ecosystems and their associated services for human well-being. To this end, the traditional LCIA structure, which represents the cause-effect chain from stressor to impacts and damages, is re-casted and expanded using the lens of the ES 'cascade model'. This links changes in ecosystem structure and function to changes in human well-being, while LCIA links the effect of changes on ecosystems due to human impacts (e.g. land use change, eutrophication, freshwater depletion) to the increase or decrease in the quality and/or quantity of supplied ES. The proposed cascade modelling framework complements traditional LCIA with information about the externalities associated with the supply and demand of ES, for which the overall cost-benefit result might be either negative (i.e. detrimental impact on the ES provision) or positive (i.e. increase of ES provision). In so doing, the framework introduces into traditional LCIA the notion of "benefit" (in the form of ES supply flows and ecosystems' capacity to generate services) which balances the quantified environmental intervention flows and related impacts (in the form of ES demands) that are typically considered in LCA. Recommendations are eventually provided to further address current gaps in the analysis of ES within the LCA methodology.

Assessing the impact of space debris on orbital resource in life cycle assessment: A proposed method and case study

The space sector is a new area of development for Life Cycle Assessment (LCA) studies. However, it deals with strong particularities which complicate the use of LCA. One of the most important is that the space industry is the only human activity crossing all stages of the atmosphere during the launch event or the atmospheric re-entry. As a result, interactions occur not only with the natural environment but also with the orbital environment during the use phase and the end-of-life of space missions. In this context, there is a lack of indicators and methods to characterise the complete life-cycle of space systems including their impact on the orbital environment. The end-of-life of spacecraft is of particular concern: space debris proliferation is today a concrete threat for all space activities. Therefore, the proposed work aims at characterising the orbital environment in term of space debris crossing the orbital resource. A complete methodology and a set of characterisation factors at midpoint level are provided. They are based on two factors: (i) the exposure to space debris in a given orbit and (ii) the severity of a potential spacecraft break-up leading to the release of new debris in the orbital environment. Then, we demonstrate the feasibility of such approach through three theoretical post-mission disposal scenarios based on the Sentinel-1A mission parameters. The results are discussed against the propellant consumption needed in each case with the purpose of addressing potential 'burden shifting' that could occur between the Earth environment and the orbital one.

Overview and recommendations for regionalized life cycle impact assessment

PURPOSE

Regionalized life cycle impact assessment (LCIA) has rapidly developed in the past decade, though its widespread application, robustness, and validity still faces multiple challenges. Under the umbrella of UNEP/SETAC Life Cycle Initiative, a dedicated cross-cutting working group on regionalized LCIA aims to provides an overview of the status of regionalization in LCIA methods. We give guidance and recommendations to harmonize and support regionalization in LCIA for developers of LCIA methods, LCI databases, and LCA software.

METHOD

A survey of current practice among regionalized LCIA method developers was conducted. The survey included questions on chosen method spatial resolution and scale, the spatial resolution of input parameters, choice of native spatial resolution and limitations, operationalization and alignment with life cycle inventory data, methods for spatial aggregation, the assessment of uncertainty from input parameters and model structure, and variability due to spatial aggregation. Recommendations are formulated based on the survey results and extensive discussion by the authors.

RESULTS AND DISCUSSION

Survey results indicate that majority of regionalized LCIA models have global coverage. Native spatial resolutions are generally chosen based on the availability of global input data. Annual modelled or measured elementary flow quantities are mostly used for aggregating characterization factors (CFs) to larger spatial scales, although some use proxies, such as population counts. Aggregated CFs are mostly available at the country level. Although uncertainty due to input parameter, model structure, and spatial aggregation are available for some LCIA methods, they are rarely implemented for LCA studies. So far, there is no agreement if a finer native spatial resolution is the best way to reduce overall uncertainty. When spatially differentiated models CFs are not easily available, archetype models are sometimes developed.

CONCLUSIONS

Regionalized LCIA methods should be provided as a transparent and consistent set of data and metadata using standardized data formats. Regionalized CFs should include both uncertainty and variability. In addition to the native-scale CFs, aggregated CFs should always be provided, and should be calculated as the weighted averages of constituent CFs using annual flow quantities as weights whenever available. This paper is an important step forward for increasing transparency, consistency and robustness in the development and application of regionalized LCIA methods.

Spatially explicit LCA analysis of biodiversity losses due to different bioenergy policies in the European Union

In this study, the potential global loss of species directly associated with land use in the EU and due to trade with other regions is computed over time, in order to reveal differences in impacts between the considered alternatives of plausible bioenergy policies development in the EU. The spatially explicit study combines a life cycle analysis (LCA) for biodiversity impact assessment with a global high resolution economic land use model. Both impacts of domestic land use and impacts through imports were included for estimating the biodiversity footprint of the member states of the (EU28). The analyzed scenarios assumed similar biomass demand until 2020 but differed thereafter, from keeping the growth of demand for bioenergy constant (CONST), to a strong increase of bioenergy in line with the EU target of decreasing greenhouse gas (GHG) emissions by 80% by 2050 (EMIRED) and with the baseline (BASE) scenario falling between the other two. As a general trend, the increasing demand for biomass was found to have substantial impact on biodiversity in all scenarios, while the differences between the scenarios were found to be modest. The share caused by imports was 15% of the overall biodiversity impacts detected in this study in the year 2000, and progressively increased to 24% to 26% in 2050, depending on the scenario. The most prominent future change in domestic land use in all scenarios was the expansion of perennial cultivations for energy. In the EMIRED scenario, there is a larger expansion of perennial cultivations and a smaller expansion of cropland in the EU than in the other two scenarios. As the biodiversity damage is smaller for land used for perennial cultivations than for cropland, this development decreases the internal biodiversity damage per unit of land. At the same time, however, the EMIRED scenario also features the largest outsourcing of damage, due to increased import of cropland products from outside the EU for satisfying the EU food demand. These two opposite effects even out each other, resulting in the total biodiversity damage for the EMIRED scenario being only slightly higher than the other two scenarios. The results of this study indicate that increasing cultivation of perennials for bioenergy and the consequent decrease in the availability of cropland for food production in the EU may lead to outsourcing of agricultural products supply to other regions. This development is associated with a leakage of biodiversity damages to species-rich and vulnerable regions outside the EU. In the case of a future increase in bioenergy demand, the combination of biomass supply from sustainable forest management in the EU, combined with imported wood pellets and cultivation of perennial energy crops, appears to be less detrimental to biodiversity than expansion of energy crops in the EU.

Resource depletion potentials from bottom-up models: Population dynamics and the Hubbert peak theory

Life cycle impact assessment uses so-called characterization factors to address different types of environmental impact (e.g. climate change, particulate matter, land use…). For the topic of resource depletion, a series of proposals was based on heuristic and formal arguments, but without the use of expert-based models from relevant research areas. A recent study in using fish population models has confirmed the original proposal for characterization factors for biotic resources of the nineties. Here we trace the milestones of the arguments and the designs of resource depletion, delivering an ecological-based foundation for the biotic case, and extend it by a novel analysis of the Hubbert peak theory for the abiotic case. We show that the original abiotic depletion potential, used for two decades in life cycle assessment, estimates accurately a marginal depletion characterization factor obtained from a dynamic model of the available reserve. This is illustrated for 29 metal resources using published data.

Ecosystem damage from anthropogenic seabed disturbance: A life cycle impact assessment characterisation model

Despite the high amount of pressure placed on benthic habitats by anthropogenic activities, particularly in coastal shelf areas, as yet, the impact of seabed damaging activities on ecosystem quality has not been included in Life Cycle Assessment (LCA). We present a globally applicable impact characterisation approach, parameterized within 17 marine ecoregions in Europe. Our modelling approach includes two perspectives: the single-impact perspective and the repeated-impact perspective. The approach for the single-impact perspective is a function of the spatio-temporal scale and intensity of the anthropogenic disturbance, the initial benthic response, and an estimated ecological recovery period. The approach for the repeated-impact perspective additionally accounts for the industry-specific interval between disturbance events, allowing for consideration of potentially incomplete ecological recovery between disturbance events and therefore the potential for both recoverable and non-recoverable potential impacts. We exemplify the repeated-impact perspective for the benthic trawl fishing industry in Europe. Analogous to current approaches for characterizing land use impacts in LCA, we quantify characterisation factors (CFs) for both occupation and transformation impacts. CFs for occupation impacts are ecoregion-specific. CFs for transformation impacts are spatially differentiated at the resolution of seabed substrate type, categories of hydrodynamic energy, i.e. water movement due to the influence of waves and currents, fisheries management zone (repeated-impact perspective only) and marine ecoregion. We estimate ecological recovery times with consideration of the influence of seabed substrate type, hydrodynamic energy at the seabed and the stock of potential recolonizers. The characterisation factors allow for quantifying indicators of ecosystem damage from seabed disturbance in terms of a time-integrated relative species loss. With a single-impact perspective, the largest impact intensities are found in areas with the longest estimated ecological recovery time. In the repeated-impact perspective, the largest intensity of time-integrated non-recoverable impact occurs when the disturbance interval is equal to half the ecological recovery time.

Defining freshwater as a natural resource: A framework linking water use to the area of protection natural resources

PURPOSE

While many examples have shown unsustainable use of freshwater resources, existing LCIA methods for water use do not comprehensively address impacts to natural resources for future generations. This framework aims to (1) define freshwater resource as an item to protect within the Area of Protection (AoP) natural resources, (2) identify relevant impact pathways affecting freshwater resources, and (3) outline methodological choices for impact characterization model development.

METHOD

Considering the current scope of the AoP natural resources, the complex nature of freshwater resources and its important dimensions to safeguard safe future supply, a definition of freshwater resource is proposed, including water quality aspects. In order to clearly define what is to be protected, the freshwater resource is put in perspective through the lens of the three main safeguard subjects defined by Dewulf et al. (2015). In addition, an extensive literature review identifies a wide range of possible impact pathways to freshwater resources, establishing the link between different inventory elementary flows (water consumption, emissions and land use) and their potential to cause long-term freshwater depletion or degradation.

RESULTS AND DISCUSSION

Freshwater as a resource has a particular status in LCA resource assessment. First, it exists in the form of three types of resources: flow, fund, or stock. Then, in addition to being a resource for human economic activities (e.g. hydropower), it is above all a non-substitutable support for life that can be affected by both consumption (source function) and pollution (sink function). Therefore, both types of elementary flows (water consumption and emissions) should be linked to a damage indicator for freshwater as a resource. Land use is also identified as a potential stressor to freshwater resources by altering runoff, infiltration and erosion processes as well as evapotranspiration. It is suggested to use the concept of recovery period to operationalize this framework: when the recovery period lasts longer than a given period of time, impacts are considered to be irreversible and fall into the concern of freshwater resources protection (i.e. affecting future generations), while short-term impacts effect the AoP ecosystem quality and human health directly. It is shown that it is relevant to include this concept in the impact assessment stage in order to discriminate the long-term from the short-term impacts, as some dynamic fate models already do.

CONCLUSION

This framework provides a solid basis for the consistent development of future LCIA methods for freshwater resources, thereby capturing the potential long-term impacts that could warn decision makers about potential safe water supply issues in the future.

Advancements in Life Cycle Human Exposure and Toxicity Characterization

BACKGROUND

The Life Cycle Initiative, hosted at the United Nations Environment Programme, selected human toxicity impacts from exposure to chemical substances as an impact category that requires global guidance to overcome current assessment challenges. The initiative leadership established the Human Toxicity Task Force to develop guidance on assessing human exposure and toxicity impacts. Based on input gathered at three workshops addressing the main current scientific challenges and questions, the task force built a roadmap for advancing human toxicity characterization, primarily for use in life cycle impact assessment (LCIA).

OBJECTIVES

The present paper aims at reporting on the outcomes of the task force workshops along with interpretation of how these outcomes will impact the practice and reliability of toxicity characterization. The task force thereby focuses on two major issues that emerged from the workshops, namely considering near-field exposures and improving dose–response modeling.

DISCUSSION

The task force recommended approaches to improve the assessment of human exposure, including capturing missing exposure settings and human receptor pathways by coupling additional fate and exposure processes in consumer and occupational environments (near field) with existing processes in outdoor environments (far field). To quantify overall aggregate exposure, the task force suggested that environments be coupled using a consistent set of quantified chemical mass fractions transferred among environmental compartments. With respect to dose–response, the task force was concerned about the way LCIA currently characterizes human toxicity effects, and discussed several potential solutions. A specific concern is the use of a (linear) dose–response extrapolation to zero. Another concern addresses the challenge of identifying a metric for human toxicity impacts that is aligned with the spatiotemporal resolution of present LCIA methodology, yet is adequate to indicate health impact potential.

CONCLUSIONS

Further research efforts are required based on our proposed set of recommendations for improving the characterization of human exposure and toxicity impacts in LCIA and other comparative assessment frameworks. https://doi.org/10.1289/EHP3871.

Ecosystem Services in Life Cycle Assessment: A novel conceptual framework for soil

Ecosystem Services (ES) are the direct and indirect contributions of ecosystems to human well-being, which include provision of food and water, regulation of flood and erosion processes, soil formation and non-material benefits such as recreation. The integration of ES impact modeling in Life Cycle Assessment (LCA) still has limitations regarding the typology embodied and some conceptual errors in not actually evaluating the benefits provided by ES. In this context, soil is an important resource and provides a wide diversity of ES. Therefore, this article aims to: (i) Review the evolution of ES assessment in LCA and the current methods used to study the biophysical aspects of ES; (ii) Compare the ES cascade model and LCA environmental mechanism for land use impacts; and (iii) Improve and synthesize a new conceptual framework for soil-ES assessment in LCA studies. Results show that the cascade model provides a useful framework for operationalizing ES assessment and should integrate LCA. Thus, this study proposes a new conceptual framework for soil-ES including the main soil processes, functions, services, benefits and values. Each of these cascade model steps is aligned with LCA terminology in order to match the usual midpoint or endpoint levels of modeling. Future works should focus on new indicators to measure the supply of ES and their benefit to humans as well as indicators to their value.

Toward harmonizing ecotoxicity characterization in life cycle impact assessment

Ecosystem quality is an important area of protection in life cycle impact assessment (LCIA). Chemical pollution has adverse impacts on ecosystems on a global scale. To improve methods for assessing ecosystem impacts, the Life Cycle Initiative hosted by the United Nations Environment Programme established a task force to evaluate the state-of-the-science in modeling chemical exposure of organisms and the resulting ecotoxicological effects for use in LCIA. The outcome of the task force work will be global guidance and harmonization by recommending changes to the existing practice of exposure and effect modeling in ecotoxicity characterization. These changes will reflect the current science and ensure the stability of recommended practice. Recommendations must work within the needs of LCIA in terms of 1) operating on information from any inventory reporting chemical emissions with limited spatiotemporal information, 2) applying best estimates rather than conservative assumptions to ensure unbiased comparison with results for other impact categories, and 3) yielding results that are additive across substances and life cycle stages and that will allow a quantitative expression of damage to the exposed ecosystem. We describe the current framework and discuss research questions identified in a roadmap. Primary research questions relate to the approach toward ecotoxicological effect assessment, the need to clarify the method's scope and interpretation of its results, the need to consider additional environmental compartments and impact pathways, and the relevance of effect metrics other than the currently applied geometric mean of toxicity effect data across species. Because they often dominate ecotoxicity results in LCIA, we give metals a special focus, including consideration of their possible essentiality and changes in environmental bioavailability. We conclude with a summary of key questions along with preliminary recommendations to address them as well as open questions that require additional research efforts. Environ Toxicol Chem 2018;37:2955-2971. © 2018 SETAC.

On the feasibility and interest of applying territorial Life Cycle Assessment to determine subnational normalisation factors

Normalisation is an optional step in Life Cycle Assessment (LCA), often used in decision making since it helps interpreting the results of LCA studies with regard to some reference information. The applicable ISO standard recommends considering different reference systems to guarantee the robustness of the normalisation step, and so the availability of different normalisation datasets becomes of high relevance. Life Cycle Impact Assessment (LCIA) methods provide normalisation factors (NFs) for global and regional areas, but no NFs are proposed for smaller areas such as local or subnational scales. The aim of this paper is to evaluate the feasibility of using territorial LCA approach to determine subnational NFs. Normalisation datasets for both Galician (NW Spain) production and consumption activities have been calculated considering a life cycle perspective. In addition to this, the normalisation datasets calculated for Galicia have been used to evaluate two food products produced and/or consumed in the region as case studies. Then, the normalised results have been compared to those obtained using different reference systems (Europe and the World), calculated following the same methodology (ReCiPe). A qualitative uncertainty analysis of the NFs has been carried out, and the usefulness of territorial LCA to determine them has been discussed. It was concluded that territorial LCA is a promising way to determine NFs but that some improvements could be made, which have also been pointed out here.

A Multimedia Hydrological Fate Modeling Framework To Assess Water Consumption Impacts in Life Cycle Assessment

Many new methods have recently been developed to address environmental consequences of water consumption in life cycle assessment (LCA). However, such methods can only partially be compared and combined, because their modeling structure and metrics are inconsistent. Moreover, they focus on specific water sources (e.g., river) and miss description of transport flows between water compartments (e.g., from river to atmosphere via evaporation) and regions (e.g., atmospheric advection). Consequently, they provide a partial regard of the local and global hydrological cycle and derived impacts on the environment. This paper proposes consensus-based guidelines for a harmonized development of the next generation of water consumption LCA indicators, with a focus on consequences of water consumption on ecosystem quality. To include the consideration of the multimedia water fate between compartments of the water cycle, we provide spatial regionalization and temporal specification guidance. The principles and recommendations of the paper are applied to an illustrative case study. The guidelines set the basis of a more accurate, novel way of modeling water consumption impacts in LCA. The environmental relevance of this LCA impact category will improve, yet much research is needed to make the guidelines operational.

Ecosystem quality in LCIA: status quo, harmonization, and suggestions for the way forward

PURPOSE

Life cycle impact assessment (LCIA) results are used to assess potential environmental impacts of different products and services. As part of the UNEP-SETAC life cycle initiative flagship project that aims to harmonize indicators of potential environmental impacts, we provide a consensus viewpoint and recommendations for future developments in LCIA related to the ecosystem quality area of protection (AoP). Through our recommendations, we aim to encourage LCIA developments that improve the usefulness and global acceptability of LCIA results.

METHODS

We analyze current ecosystem quality metrics and provide recommendations to the LCIA research community for achieving further developments towards comparable and more ecologically relevant metrics addressing ecosystem quality.

RESULTS AND DISCUSSION

We recommend that LCIA development for ecosystem quality should tend towards species-richnessrelated metrics, with efforts made towards improved inclusion of ecosystem complexity. Impact indicators-which result from a range of modeling approaches that differ, for example, according to spatial and temporal scale, taxonomic coverage, and whether the indicator produces a relative or absolute measure of loss-should be framed to facilitate their final expression in a single, aggregated metric. This would also improve comparability with other LCIA damage-level indicators. Furthermore, to allow for a broader inclusion of ecosystem quality perspectives, the development of an additional indicator related to ecosystem function is recommended. Having two complementary metrics would give a broader coverage of ecosystem attributes while remaining simple enough to enable an intuitive interpretation of the results.

CONCLUSIONS

We call for the LCIA research community to make progress towards enabling harmonization of damage-level indicators within the ecosystem quality AoP and, further, to improve the ecological relevance of impact indicators.

LCA Capability Roadmap: Product System Model Description and Revision

Life cycle assessment (LCA) practitioners face many challenges in their efforts to describe, share, review, and revise their product system models; and to reproduce the models and results of others. Current Life cycle inventory modeling techniques have weaknesses in the areas of describing model structure; documenting the use of proxy or non-ideal data; specifying allocation; and including modeler's observations and assumptions -- all affecting how the study is interpreted and limiting the reuse of models. Moreover, LCA software systems manage modeling information in different and sometimes non-compatible ways. Practitioners must also deal with licensing, privacy / confidentiality of data, and other issues around data access which impact how a model can be shared. The aim of this SETAC North America working group is to define a roadmap of the technical advances needed to achieve easier LCA model sharing and improve replicability of LCA results among different users in a way that is independent of the LCA software used to compute the results and does not infringe on any licensing restrictions or confidentiality requirements.