Emerging approaches, challenges and opportunities in life cycle assessment

Potential to curb the environmental burdens of American beef consumption using a novel plant-based beef substitute

The food demands of the United States (US) impart significant environmental pressures. The high rate of consumption of beef has been shown to be the largest driver of food-borne greenhouse gas emissions, water use and land occupation in the US diet. The environmental benefits of substituting animal products with vegetal foods are well documented, but significant psychological barriers persist in reducing meat consumption. Here we use life cycle assessment to appraise the environmental performance of a novel vegetal protein source in the mean US diet where it replaces ground beef, and in vegetarian and vegan diets where it substitutes for legumes, tofu and other protein sources. We find that relative to the mean US diet, vegetarian and vegan diets significantly reduce per-capita food-borne greenhouse gas emission (32% and 67%, respectively), blue water use (70% and 75%, respectively) and land occupation (70% and 79%, respectively), primarily in the form of rangeland. The substitution of 10%, 25% and 50% of ground beef with plant-based burger (PBB) at the national scale results in substantial reductions in annual US dietary greenhouse gas emissions (4.55-45.42 Mt CO2 equivalents), water consumption (1.30-12.00 km3) and land occupation (22300-190100 km2). Despite PBB's elevated environmental pressures compared to other vegetal protein sources, we demonstrate that minimal risk exists for the disservices of PBB substitution in non-meat diets to outweigh the benefits of ground-beef substitution in the omnivorous American diet. Demand for plant-based oils in PBB production has the potential to increase land use pressures in biodiversity hotspots, though these could be obviated through responsible land stewardship. Although the apparent environmental benefits of the PBB are contingent on actual uptake of the product, this study demonstrates the potential for non-traditional protein substitutes to play a role in a transition towards more sustainable consumption regimes in the US and potentially abroad.

Environmental Impacts of Future Urban Deployment of Electric Vehicles: Assessment Framework and Case Study of Copenhagen for 2016-2030

To move toward environmentally sustainable transport systems, electric vehicles (EVs) are increasingly seen as viable alternatives to internal combustion vehicles (ICVs). To ensure effectiveness of such deployment, holistic assessments of environmental impacts can help decision-makers determine optimized urban strategies in a long-term perspective. However, explicit guidance and conduct of such assessments are currently missing. Here, we therefore propose a framework using life cycle assessment that enables the quantification of environmental impacts of a transport system at full urban scale from a fleet-based, foresight perspective. The analysis of the passenger car fleet development in the city of Copenhagen for the years 2016-2030 is used as a proof-of-concept. We modeled and compared five powertrain technologies, and we assessed four fleet-based scenarios for the entire city. Our results showed relative environmental benefits from range-extended and fuel-cell EVs over ICVs and standard EVs. These results were found to be sensitive to local settings, like electricity grid mix, which could alter the relative environmental performances across EV technologies. The comprehensive framework developed here can be applied to other geographic areas and contexts to assess the environmental sustainability of transport systems.

Framework for integrating animal welfare into life cycle sustainability assessment

PURPOSE

This study seeks to provide a framework for integrating animal welfare as a fourth pillar into a life cycle sustainability assessment and presents three alternative animal welfare indicators.

METHODS

Animal welfare is assessed during farm life and during slaughter. The indicators differ in how they value premature death. All three consider (1) the life quality of an animal such as space allowance, (2) the slaughter age either as life duration or life fraction, and (3) the number of animals affected for providing a product unit, e.g. 1 Mcal. One of the indicators additionally takes into account a moral value denoting their intelligence and self-awareness. The framework allows for comparisons across studies and products and for applications at large spatial scales. To illustrate the framework, eight products were analysed and compared: beef, pork, poultry, milk, eggs, salmon, shrimps, and, as a novel protein source, insects.

RESULTS AND DISCUSSION

Insects are granted to live longer fractions of their normal life spans, and their life quality is less compromised due to a lower assumed sentience. Still, they perform worst according to all three indicators, as their small body sizes only yield low product quantities. Therefore, we discourage from eating insects. In contrast, milk is the product that reduces animal welfare the least according to two of the three indicators and it performs relatively better than other animal products in most categories. The difference in animal welfare is mostly larger for different animal products than for different production systems of the same product. This implies that, besides less consumption of animal-based products, a shift to other animal products can significantly improve animal welfare.

CONCLUSIONS

While the animal welfare assessment is simplified, it allows for a direct integration into life cycle sustainability assessment. There is a trade-off between applicability and indicator complexity, but even a simple estimate of animal welfare is much better than ignoring the issue, as is the common practice in life cycle sustainability assessments. Future research should be directed towards elaborating the life quality criterion and extending the product coverage.

Dietary Strategies to Reduce Environmental Impact: A Critical Review of the Evidence Base

The food system is a major source of environmental impact, and dietary change has been recommended as an important and necessary strategy to reduce this impact. However, assessing the environmental performance of diets is complex due to the many types of foods eaten and the diversity of agricultural production systems and local environmental settings. To assess the state of science and identify knowledge gaps, an integrative review of the broad topic of environment and diet was undertaken, with particular focus on the completeness of coverage of environmental concerns and the metrics used. Compared with the 14 discrete environmental areas of concern identified in the United Nations Sustainable Development Goals, the located journal literature mainly addressed greenhouse gas (GHG) emissions and, to a lesser extent, land and water use. Some relevant concerns were rarely addressed or not addressed at all. In the case of GHG emissions, changes in land use and soil carbon stocks were seldom considered. This represents a disconnect between the science informing strategic climate action in the agricultural sector and the science informing public health nutrition. In the case of land and water use, few studies used metrics that are appropriate in a life-cycle context. Some metrics produce inherently biased results, which misinform about environmental impact. The limited evidence generally points to recommended diets having lower environmental impacts than typical diets, although not in every case. This is largely explained by the overconsumption of food energy associated with average diets, which is also a major driver of obesity. A shared-knowledge framework is identified as being needed to guide future research on this topic. Until the evidence base becomes more complete, commentators on sustainable diets should not be quick to assume that a dietary strategy to reduce overall environmental impact can be readily defined or recommended.

Evaluation of bioaugmentation using multiple life cycle assessment approaches: A case study of constructed wetland

Bioaugmentation is a promising technology to enhance the removal of specific pollutants; however, environmental impacts of implementing bioaugmentation have not been considered in most studies. Appropriate methodology is required for the evaluation from both in-depth and comprehensive perspectives, which leads to this study initiating the application of life cycle assessment (LCA) of bioaugmentation. Two LCA methods (CML and e-Balance) were applied to a bioaugmentation case with the aim of illustrating how to evaluate the environmental impacts of bioaugmentation from different perspectives based on the selection of different LCA methods. The results of the case study demonstrated that the LCA methods with different methodology emphasis produced different outcomes, which could lead to differentiated optimization strategies depending on the associated perspectives. Furthermore, three important aspects are discussed, including coverage of impact categories, the selection of characterization modeling for specific pollutants, and the requirement of including economic indicators for future investigation.

Conceptualizing a circular framework of supply chain resource sustainability

Purpose

In response to calls for conceptual frameworks and generic theory building toward the advancement of sustainability in supply chain resource utilization and management, the purpose of this paper is to advance a circular framework for supply chain resource sustainability (SCRS), and a decision-support methodology for assessing SCRS against the backdrop of five foundational premises (FPs) deduced from the literature on resource sustainability.

Design/methodology/approach

Taking a conceptual theory-building approach, the paper advances a set of SCRS decision-support criteria for each of the theoretical premises advanced, and applies the theory of constraints to illustrate the conceptual and practical applications of the framework in SCRS decision making.

Findings

This study uses recent conceptualizations of supply chains as “complex adaptive systems” to provide a robust and novel frame and a set of decision rules with which to assess the interconnectedness of environmental, economic, and social capital of supply chain resources from pre-production to post-production.

Research limitations/implications

The paper contributes to theory building in sustainability research, and the SCRS decision framework developed could be applied in tandem with existing quantitative hybrid life-cycle and input-output approaches to facilitate targeted resource sustainability assessments, with implications for research and practice.

Originality/value

The novel SCRS framework proposed serves as a template for evaluating SCRS and provides a decision-support methodology for assessing SCRS against the five theorized FPs.

Visual Analytics Tools for Sustainable Lifecycle Design: Current Status, Challenges, and Future Opportunities

The rapid rise in technologies for data collection has created an unmatched opportunity to advance the use of data-rich tools for lifecycle decision-making. However, the usefulness of these technologies is limited by the ability to translate lifecycle data into actionable insights for human decision-makers. This is especially true in the case of sustainable lifecycle design (SLD), as the assessment of environmental impacts, and the feasibility of making corresponding design changes, often relies on human expertise and intuition. Supporting human sense-making in SLD requires the use of both data-driven and user-driven methods while exploring lifecycle data. A promising approach for combining the two is through the use of visual analytics (VA) tools. Such tools can leverage the ability of computer-based tools to gather, process, and summarize data along with the ability of human-experts to guide analyses through domain knowledge or data-driven insight. In this paper, we review previous research that has created VA tools in SLD. We also highlight existing challenges and future opportunities for such tools in different lifecycle stages-design, manufacturing, distribution & supply chain, use-phase, end-of-life, as well as life cycle assessment. Our review shows that while the number of VA tools in SLD is relatively small, researchers are increasingly focusing on the subject matter. Our review also suggests that VA tools can address existing challenges in SLD and that significant future opportunities exist.

Emerging role of Geographical Information System (GIS), Life Cycle Assessment (LCA) and spatial LCA (GIS-LCA) in sustainable bioenergy planning

Sustainability of a bioenergy project depends on precise assessment of biomass resource, planning of cost-effective logistics and evaluation of possible environmental implications. In this context, this paper reviews the role and applications of geo-spatial tool such as Geographical Information System (GIS) for precise agro-residue resource assessment, biomass logistic and power plant design. Further, application of Life Cycle Assessment (LCA) in understanding the potential impact of agro-residue bioenergy generation on different ecosystem services has also been reviewed and limitations associated with LCA variability and uncertainty were discussed. Usefulness of integration of GIS into LCA (i.e. spatial LCA) to overcome the limitations of conventional LCA and to produce a holistic evaluation of the environmental benefits and concerns of bioenergy is also reviewed. Application of GIS, LCA and spatial LCA can help alleviate the challenges faced by ambitious bioenergy projects by addressing both economics and environmental goals.

Subnational mobility and consumption-based environmental accounting of US corn in animal protein and ethanol supply chains

Corn production, and its associated inputs, is a relatively large source of greenhouse gas emissions and uses significant amounts of water and land, thus contributing to climate change, fossil fuel depletion, local air pollutants, and local water scarcity. As large consumers of this corn, corporations in the ethanol and animal protein industries are increasingly assessing and reporting sustainability impacts across their supply chains to identify, prioritize, and communicate sustainability risks and opportunities material to their operations. In doing so, many have discovered that the direct impacts of their owned operations are dwarfed by those upstream in the supply chain, requiring transparency and knowledge about environmental impacts along the supply chains. Life cycle assessments (LCAs) have been used to identify hotspots of environmental impacts at national levels, yet these provide little subnational information necessary for guiding firms' specific supply networks. In this paper, our Food System Supply-Chain Sustainability (FoodS3) model connects spatial, firm-specific demand of corn purchasers with upstream corn production in the United States through a cost minimization transport model. This provides a means to link county-level corn production in the United States to firm-specific demand locations associated with downstream processing facilities. Our model substantially improves current LCA assessment efforts that are confined to broad national or state level impacts. In drilling down to subnational levels of environmental impacts that occur over heterogeneous areas and aggregating these landscape impacts by specific supply networks, targeted opportunities for improvements to the sustainability performance of supply chains are identified.

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

Increasing needs for decision support and advances in scientific knowledge within life cycle assessment (LCA) led to substantial efforts to provide global guidance on environmental life cycle impact assessment (LCIA) indicators under the auspices of the UNEP-SETAC Life Cycle Initiative. As part of these efforts, a dedicated task force focused on addressing several LCIA cross-cutting issues as aspects spanning several impact categories, including spatiotemporal aspects, reference states, normalization and weighting, and uncertainty assessment. Here, findings of the cross-cutting issues task force are presented along with an update of the existing UNEP-SETAC LCIA emission-to-damage framework. Specific recommendations are provided with respect to metrics for human health (Disability Adjusted Life Years, DALY) and ecosystem quality (Potentially Disappeared Fraction of species, PDF). Additionally, we stress the importance of transparent reporting of characterization models, reference states, and assumptions, in order to facilitate cross-comparison between chosen methods and indicators. We recommend developing spatially regionalized characterization models, whenever the nature of impacts shows spatial variability and related spatial data are available. Standard formats should be used for reporting spatially differentiated models, and choices regarding spatiotemporal scales should be clearly communicated. For normalization, we recommend using external normalization references. Over the next two years, the task force will continue its effort with a focus on providing guidance for LCA practitioners on how to use the UNEP-SETAC LCIA framework as well as for method developers on how to consistently extend and further improve this framework.

Estimating 20-year land-use change and derived CO2 emissions associated with crops, pasture and forestry in Brazil and each of its 27 states

Land-use change (LUC) in Brazil has important implications on global climate change, ecosystem services and biodiversity, and agricultural expansion plays a critical role in this process. Concerns over these issues have led to the need for estimating the magnitude and impacts associated with that, which are increasingly reported in the environmental assessment of products. Currently, there is an extensive debate on which methods are more appropriate for estimating LUC and related emissions and regionalized estimates are lacking for Brazil, which is a world leader in agricultural production (e.g. food, fibres and bioenergy). We developed a method for estimating scenarios of past 20-year LUC and derived CO₂ emission rates associated with 64 crops, pasture and forestry in Brazil as whole and in each of its 27 states, based on time-series statistics and in accordance with most used carbon-footprinting standards. The scenarios adopted provide a range between minimum and maximum rates of CO₂ emissions from LUC according to different possibilities of land-use transitions, which can have large impacts in the results. Specificities of Brazil, like multiple cropping and highly heterogeneous carbon stocks, are also addressed. The highest CO₂ emission rates are observed in the Amazon biome states and crops with the highest rates are those that have undergone expansion in this region. Some states and crops showing large agricultural areas have low emissions associated, especially in southern and eastern Brazil. Native carbon stocks and time of agricultural expansion are the most decisive factors to the patterns of emissions. Some implications on LUC estimation methods and standards and on agri-environmental policies are discussed.

A step toward regionalized scale-consistent agricultural life cycle assessment inventories

Life cycle inventory (LCI) regionalization (i.e., the determination of input and output flows from production processes at a subcountry scale) is a priority in life cycle assessment (LCA) studies, particularly in the agri-food sector. Many regionalized LCAs fail to ensure that microlevel inventories are consistent with country-level aggregated data-or "scale consistent." They also fail to construct LCIs using international reference guidelines and trustworthy standardized data sources. This failure generates inaccuracies and biases in inventories and can compromise comparability among international LCA studies. Our study introduces scale consistency as a principle for regionalized agri-food LCIs. We present a generic procedure that defines how scale-dependent LCI flows should be regionalized, depending on data availability. We then present a list of inventory flows that require regionalization and their suggested calculation procedures (methods and models) from 2 methodological guides developed by projects Agribalyse and World Food LCA Database. As proof of concept, we apply the procedure to Portugal and assess whether the methods and models proposed for each type of inventory flow in both guides can potentially be applied consistently with the data available. For 17 inventory flows, we apply calculated scale-consistent inventory flows for Portuguese agriculture, covering 260 products that can be used in future LCA studies. Comparing results with international databases, we show that this procedure can improve country-level estimates significantly. Our study is the first step in introducing scale consistency as a guiding principle for regionalized LCIs for agri-food LCA studies. Integr Environ Assess Manag 2017;13:939-951. © 2017 SETAC.

Evaluating nanotechnology opportunities and risks through integration of life-cycle and risk assessment

It has been some 15 years since the topics of sustainability and nanotechnologies first appeared together in the scientific literature and became a focus of organizations' research and policy developments. On the one hand, this focus is directed towards approaches and tools for risk assessment and management and on the other hand towards life-cycle thinking and assessment. Comparable to their application for regular chemicals, each tool is seen to serve separate objectives as it relates to evaluating nanotechnologies' safety or resource efficiency, respectively. While nanomaterials may provide resource efficient production and consumption, this must balance any potential hazards they pose across their life-cycles. This Perspective advocates for integrating these two tools at the methodological level for achieving this objective, and it explains what advantages and challenges this offers decision-makers while highlighting what research is needed to further enhance integration.

Setting the stage for debating the roles of risk assessment and life-cycle assessment of engineered nanomaterials

Although technological and environmental benefits are important stimuli for nanotechnology development, these technologies have been contested from an environmental point of view. The steady growth of applications of engineered nanomaterials has heated up the debate on quantifying the environmental repercussions. The two main scientific methods to address these environmental repercussions are risk assessment and life-cycle assessment. The strengths and weaknesses of each of these methods, and the relation between them, have been a topic of debate in the world of traditional chemistry for over two decades. Here we review recent developments in this debate in general and for the emerging field of nanomaterials specifically. We discuss the pros and cons of four schools of thought for combining and integrating risk assessment and life-cycle assessment and conclude with a plea for action.

Resource Footprints are Good Proxies of Environmental Damage

Environmental footprints are increasingly used to quantify and compare environmental impacts of for example products, technologies, households, or nations. This has resulted in a multitude of footprint indicators, ranging from relatively simple measures of resource use (water, energy, materials) to integrated measures of eventual damage (for example, extinction of species). Yet, the possible redundancies among these different footprints have not yet been quantified. This paper analyzes the relationships between two comprehensive damage footprints and four resource footprints associated with 976 products. The resource footprints accounted for >90% of the variation in the damage footprints. Human health damage was primarily associated with the energy footprint, via emissions resulting from fossil fuel combustion. Biodiversity damage was mainly related to the energy and land footprints, the latter being mainly determined by agriculture and forestry. Our results indicate that relatively simple resource footprints are highly representative of damage to human health and biodiversity.

An Empirical Exploration, Typology, and Definition of Corporate Sustainability

The relationship between business and society is evolving. On the one hand, social, environmental, and long-term economic issues subsumed under the UN 2030 Agenda for Sustainable Development are inspiring intergovernmental organizations, governments, NGOs, NPOs, foundations, and civic society to legislate and regulate corporate behavior toward a greater concern for the wellbeing of groups, regions, or entire societies. On the other, a growing trend toward protectionism, nationalism, and populism may be the consequence or expression of a dissatisfaction with the perceived dissociation of the private sector from society. As a form of self-regulation, corporate responsibility deals with the complex responsibilities businesses have toward society. However, it tends to be hampered by an emphasis on theology and philosophy-based business ethics, which are difficult to integrate into day-to-day business operations or to translate between national or corporate cultures. In this article, we argue that corporate sustainability could be a more useful concept to help improve on how government, the private sector, and academia understand the links between business and society, and how to translate the interdependence between business and society from one culture to another. For this purpose, we empirically analyzed the relevant academic literature on corporate sustainability, using Content Configuration Analysis. Our analyses revealed three conceptual types and nine subtypes of corporate sustainability. Based on their assessment, we suggest conceptual preferences and a definition of corporate sustainability, which fulfil criteria that may render the concept more useful to global political and socioeconomic negotiations among stakeholder groups for the long-term benefit of business and society.

Life cycle assessment needs predictive spatial modelling for biodiversity and ecosystem services

International corporations in an increasingly globalized economy exert a major influence on the planet's land use and resources through their product design and material sourcing decisions. Many companies use life cycle assessment (LCA) to evaluate their sustainability, yet commonly-used LCA methodologies lack the spatial resolution and predictive ecological information to reveal key impacts on climate, water and biodiversity. We present advances for LCA that integrate spatially explicit modelling of land change and ecosystem services in a Land-Use Change Improved (LUCI)-LCA. Comparing increased demand for bioplastics derived from two alternative feedstock-location scenarios for maize and sugarcane, we find that the LUCI-LCA approach yields results opposite to those of standard LCA for greenhouse gas emissions and water consumption, and of different magnitudes for soil erosion and biodiversity. This approach highlights the importance of including information about where and how land-use change and related impacts will occur in supply chain and innovation decisions.

Life cycle assessments are used by corporations to determine the sustainability of raw source materials. Here, Chaplin-Kramer et al. develop an improved life cycle assessment approach incorporating spatial variation in land-use change, and apply this framework to a bioplastic case study.

The environmental impact of fertilizer embodied in a wheat-to-bread supply chain

Food production and consumption cause approximately one-third of total greenhouse gas emissions^1-3, and therefore delivering food security challenges not only the capacity of our agricultural system, but also its environmental sustainability^4-7. Knowing where and at what level environmental impacts occur within particular food supply chains is necessary if farmers, agri-food industries and consumers are to share responsibility to mitigate these impacts^7,8. Here we present an analysis of a complete supply chain for a staple of the global diet, a loaf of bread. We obtained primary data for all the processes involved in the farming, production and transport systems that lead to the manufacture of a particular brand of 800 g loaf. The data were analysed using an advanced life cycle assessment (LCA) tool⁹, yielding metrics of environmental impact, including greenhouse gas emissions. We show that more than half of the environmental impact of producing the loaf of bread arises directly from wheat cultivation, with the use of ammonium nitrate fertilizer alone accounting for around 40%. These findings reveal the dependency of bread production on the unsustainable use of fertilizer and illustrate the detail needed if the actors in the supply chain are to assume shared responsibility for achieving sustainable food production.

Assessing the environmental impacts of freshwater thermal pollution from global power generation in LCA

Freshwater heat emissions from power plants with once-through cooling systems constitute one of many environmental pressures related to the thermoelectric power industry. The objective of this work was to obtain high resolution, operational characterization factors (CF) for the impact of heat emissions on ecosystem quality, and carry out a comprehensive, spatially, temporally and technologically differentiated damage-based environmental assessment of global freshwater thermal pollution. The aggregation of CFs on a watershed level results in 12.5% lower annual impacts globally and even smaller differences for the most crucial watersheds and months, so watershed level CFs are recommended when the exact emission site within the basin is unknown. Long-range impacts account for almost 90% of the total global impacts. The Great Lakes, several Mississippi subbasins, the Danube, and the Yangtze are among the most thermally impacted watersheds globally, receiving heat emissions from predominantly coal-fuelled and nuclear power plants. Globally, over 80% of the global annual impacts come from power plants constructed during or before the 1980s. While the impact-weighted mean age of the power plants in the Mississippi ranges from 38 to 51years, in Chinese watersheds including the Yangtze, the equivalent range is only 15 to 22years, reflecting a stark contrast in thermal pollution mitigation approaches. With relatively high shares of total capacity from power plants with once-through freshwater cooling, and tracing a large part of the Danube, 1kWh of net electricity mix is the most impactful in Hungary, Bulgaria and Serbia. Monthly CFs are provided on a grid cell level and on a watershed level for use in Life Cycle Assessment. The impacts per generating unit are also provided, as part of our effort to make available a global dataset of thermoelectric power plant emissions and impacts.

Life cycle assessment in wastewater treatment: influence of site-oriented normalization factors, life cycle impact assessment methods, and weighting methods

This present study aims to analyze the differences in results of different site-directional life cycle assessment (LCA) methods applied in the field of wastewater treatment.

Understanding the LCA and ISO water footprint: A response to Hoekstra (2016) "A critique on the water-scarcity weighted water footprint in LCA"

Water footprinting has emerged as an important approach to assess water use related effects from consumption of goods and services. Assessment methods are proposed by two different communities, the Water Footprint Network (WFN) and the Life Cycle Assessment (LCA) community. The proposed methods are broadly similar and encompass both the computation of water use and its impacts, but differ in communication of a water footprint result. In this paper, we explain the role and goal of LCA and ISO-compatible water footprinting and resolve the six issues raised by Hoekstra (2016) in "A critique on the water-scarcity weighted water footprint in LCA". By clarifying the concerns, we identify both the overlapping goals in the WFN and LCA water footprint assessments and discrepancies between them. The main differing perspective between the WFN and LCA-based approach seems to relate to the fact that LCA aims to account for environmental impacts, while the WFN aims to account for water productivity of global fresh water as a limited resource. We conclude that there is potential to use synergies in research for the two approaches and highlight the need for proper declaration of the methods applied.

Life-cycle assessment of a biogas power plant with application of different climate metrics and inclusion of near-term climate forcers

This study assesses the environmental sustainability of electricity production through anaerobic co-digestion of sewage sludge and organic wastes. The analysis relies on primary data from a biogas plant, supplemented with data from the literature. The climate impact assessment includes emissions of near-term climate forcers (NTCFs) like ozone precursors and aerosols, which are frequently overlooked in Life Cycle Assessment (LCA), and the application of a suite of different emission metrics, based on either the Global Warming Potential (GWP) or the Global Temperature change Potential (GTP) with a time horizon (TH) of 20 or 100 years. The environmental performances of the biogas system are benchmarked against a conventional fossil fuel system. We also investigate the sensitivity of the system to critical parameters and provide five different scenarios in a sensitivity analysis. Hotspots are the management of the digestate (mainly due to the open storage) and methane (CH₄) losses during the anaerobic co-digestion. Results are sensitive to the type of climate metric used. The impacts range from 52 up to 116 g CO₂-eq./MJ electricity when using GTP100 and GWP20, respectively. This difference is mostly due to the varying contribution from CH₄ emissions. The influence of NTCFs is about 6% for GWP100 (worst case), and grows up to 31% for GWP20 (best case). The biogas system has a lower performance than the fossil reference system for the acidification and particulate matter formation potentials. We argue for an active consideration of NTCFs in LCA and a critical reflection over the climate metrics to be used, as these aspects can significantly affect the final outcomes.

Nanotechnology for environmentally sustainable electromobility

Electric vehicles (EVs) powered by lithium-ion batteries (LIBs) or proton exchange membrane hydrogen fuel cells (PEMFCs) offer important potential climate change mitigation effects when combined with clean energy sources. The development of novel nanomaterials may bring about the next wave of technical improvements for LIBs and PEMFCs. If the next generation of EVs is to lead to not only reduced emissions during use but also environmentally sustainable production chains, the research on nanomaterials for LIBs and PEMFCs should be guided by a life-cycle perspective. In this Analysis, we describe an environmental life-cycle screening framework tailored to assess nanomaterials for electromobility. By applying this framework, we offer an early evaluation of the most promising nanomaterials for LIBs and PEMFCs and their potential contributions to the environmental sustainability of EV life cycles. Potential environmental trade-offs and gaps in nanomaterials research are identified to provide guidance for future nanomaterial developments for electromobility.

Life-cycle assessment of a Waste-to-Energy plant in central Norway: Current situation and effects of changes in waste fraction composition

Waste-to-Energy (WtE) plants constitute one of the most common waste management options to deal with municipal solid waste. WtE plants have the dual objective to reduce the amount of waste sent to landfills and simultaneously to produce useful energy (heat and/or power). Energy from WtE is gaining steadily increasing importance in the energy mix of several countries. Norway is no exception, as energy recovered from waste currently represents the main energy source of the Norwegian district heating system. Life-cycle assessments (LCA) of WtE systems in a Norwegian context are quasi-nonexistent, and this study assesses the environmental performance of a WtE plant located in central Norway by combining detailed LCA methodology with primary data from plant operations. Mass transfer coefficients and leaching coefficients are used to trace emissions over the various life-cycle stages from waste logistics to final disposal of the ashes. We consider different fractions of input waste (current waste mix, insertion of 10% car fluff, 5% clinical waste and 10% and 50% wood waste), and find a total contribution to Climate Change Impact Potential ranging from 265 to 637gCO₂eq/kg of waste and 25 to 61gCO₂eq/MJ of heat. The key drivers of the environmental performances of the WtE system being assessed are the carbon biogenic fraction and the lower heating value of the incoming waste, the direct emissions at the WtE plant, the leaching of the heavy metals at the landfill sites and to a lesser extent the use of consumables. We benchmark the environmental performances of our WtE systems against those of fossil energy systems, and we find better performance for the majority of environmental impact categories, including Climate Change Impact Potential, although some trade-offs exist (e.g. higher impacts on Human Toxicity Potential than natural gas, but lower than coal). Also, the insertion of challenging new waste fractions is demonstrated to be an option both to cope with the excess capacity of the Norwegian WtE sector and to reach Norway's ambitious political goals for environmentally friendly energy systems.

Linking environment-productivity trade-offs and correlated uncertainties: Greenhouse gas emissions and crop productivity in paddy rice production systems

In comparative life cycle assessments of agricultural production systems, analyses of both the trade-offs between environmental impacts and crop productivity and of the uncertainties specific to agriculture such as fluctuations in greenhouse gas (GHG) emissions and crop yields are crucial. However, these two issues are usually analyzed separately. In this paper, we present a framework to link trade-off and uncertainty analyses; correlated uncertainties are integrated into environment-productivity trade-off analyses. We compared three rice production systems in Japan: a system using a pelletized, nitrogen-concentrated organic fertilizer made from poultry manure using closed-air composting techniques (high-N system), a system using a conventional organic fertilizer made from poultry manure using open-air composting techniques (low-N system), and a system using a chemical compound fertilizer (conventional system). We focused on two important sources of uncertainties in paddy rice cultivation-methane emissions from paddy fields and crop yields. We found trade-offs between the conventional and high-N systems and the low-N system and the existence of positively correlated uncertainties in the conventional and high-N systems. We concluded that our framework is effective in recommending the high-N system compared with the low-N system, although the performance of the former is almost the same as the conventional system.

Integrated resource efficiency: measurement and management

Purpose

Drawing on the systems theory and the natural resource-based view, the purpose of this paper is to advance an integrated resource efficiency view (IREV) and derive a composite “integrated resource efficiency index” (IRE-index) for assessing the environmental, economic, and social resource efficiencies of production economies.

Design/methodology/approach

Using sub-national input-output data, the IRE-index builds on the human development index (HDI) and the OECD green growth indicators by including functions for environmental resource efficiency, energy, and material productivity. The study uses multiple regressions to examine and compare the IRE-index of 40 countries, including 34 OECD nations. The study further compares the IRE-index to similar composite indicators such as the human sustainable development index (HSDI) and the ecological footprint.

Findings

The IRE-index reveals a discrepancy between social development and resource efficiency in many of the world’s wealthiest production economies. Findings also show that material productivity has been the key driver for observed improvements in IRE over time. The index is a robust macro-level methodology for assessing resource efficiency and sustainability, with implications for production operations in global supply chains.

Originality/value

The IREV and IRE-index both contribute towards advancing green supply chain management and sustainability, and country-level resource efficiency accounting and reporting. The IRE-index is a useful composite for capturing aggregate environmental, economic, and social resource efficiencies of production economies. The paper clearly outlines the managerial, academic, and policy implications of the IREV and resulting index.

Land Use in LCA: Including Regionally Altered Precipitation to Quantify Ecosystem Damage

The incorporation of soil moisture regenerated by precipitation, or green water, into life cycle assessment has been of growing interest given the global importance of this resource for terrestrial ecosystems and food production. This paper proposes a new impact assessment model to relate land and water use in seasonally dry, semiarid, and arid regions where precipitation and evapotranspiration are closely coupled. We introduce the Precipitation Reduction Potential midpoint impact representing the change in downwind precipitation as a result of a land transformation and occupation activity. Then, our end-point impact model quantifies terrestrial ecosystem damage as a function of precipitation loss using a relationship between woody plant species richness, water and energy regimes. We then apply the midpoint and end-point models to the production of soybean in Southeastern Amazonia which has resulted from the expansion of cropland into tropical forest, with noted effects on local precipitation. Our proposed cause-effect chain represents a complementary approach to previous contributions which have focused on water consumption impacts and/or have represented evapotranspiration as a loss to the water cycle.

Waste Informatics: Establishing Characteristics of Contemporary U.S. Landfill Quantities and Practices

Waste generation is expected to increase in most countries for many decades with landfill disposal still the dominant solid waste management method^1-3. Yet, operational characteristics of landfills are often poorly understood with comparative statistics substantially lacking. Here, we call for a more formal waste informatics to organize and standardize waste management knowledge at multiple spatial scales through analysis of recently reported data from 1232 U.S. landfills and other high resolution data sets. We create the first known estimate of available U.S. municipal waste stocks (8.5 billion tonnes) and go on to resolve these stocks at the county level, reflecting prospective urban mining opportunities. Our analysis of disposal rates and landfill capacities reveals that more than half of U.S. states have more than 25 years of life remaining. We also estimate the gross energy potential of landfill gas in the U.S. (338 billion MJ/yr) by examining 922 operational methane collection systems and demonstrate that the greatest energy recovery opportunities lie at landfills with existing collection systems and energy conversion infrastructure. Finally, we found that the number of landfills reaching the federally defined 30-year postclosure care period will more than triple in the coming two decades, with 264 sites expected by the year 2044, highlighting the need to develop and standardize metrics carefully to define and standardize when it is appropriate to end or scale back long-term landfill monitoring.

Benchmarking wastewater treatment plants under an eco-efficiency perspective

The new ISO 14045 framework is expected to slowly start shifting the definition of eco-efficiency toward a life-cycle perspective, using Life Cycle Assessment (LCA) as the environmental impact assessment method together with a system value assessment method for the economic analysis. In the present study, a set of 22 wastewater treatment plants (WWTPs) in Spain were analyzed on the basis of eco-efficiency criteria, using LCA and Life Cycle Costing (LCC) as a system value assessment method. The study is intended to be useful to decision-makers in the wastewater treatment sector, since the combined method provides an alternative scheme for analyzing the relationship between environmental impacts and costs. Two midpoint impact categories, global warming and eutrophication potential, as well as an endpoint single score indicator were used for the environmental assessment, while LCC was used for value assessment. Results demonstrated that substantial differences can be observed between different WWTPs depending on a wide range of factors such as plant configuration, plant size or even legal discharge limits. Based on these results the benchmarking of wastewater treatment facilities was performed by creating a specific classification and certification scheme. The proposed eco-label for the WWTPs rating is based on the integration of the three environmental indicators and an economic indicator calculated within the study under the eco-efficiency new framework.

Global Biodiversity Loss by Freshwater Consumption and Eutrophication from Swiss Food Consumption

We investigated water-related resource use, emissions and ecosystem impacts of food consumed in Switzerland. To do so, we coupled LCA methodologies on freshwater consumption, freshwater eutrophication and the consequent local and global biodiversity impacts with Swiss customs data and multiregional input-output analysis. Most of the resource use, emissions and impacts occur outside the national boundaries which illustrates the extent of environmental outsourcing facilitated by international trade. Countries that are severely affected by Swiss food consumption include Spain, the United States and Ecuador. Cocoa, coffee, and almonds stood out as products with high impacts. By identifying spatial hotspots and impactful products, awareness of policy-makers as well as individual consumers can be raised and efforts of detailed assessments can be streamlined. However, political and economic constraints and the resistance by individual consumers limit the high potential of changes in diets and trade relations to decrease the environmental impacts of food.

A framework for energy use indicators and their reporting in life cycle assessment

Energy use is a common impact category in life cycle assessment (LCA). Many different energy use indicators are used in LCA studies, accounting for energy use in different ways. Often, however, the choice behind which energy use indicator is applied is poorly described and motivated. To contribute to a more purposeful selection of energy use indicators and to ensure consistent and transparent reporting of energy use in LCA, a general framework for energy use indicator construction and reporting in LCA studies will be presented in this article. The framework differentiates between 1) renewable and nonrenewable energies, 2) primary and secondary energies, and 3) energy intended for energy purposes versus energy intended for material purposes. This framework is described both graphically and mathematically. Furthermore, the framework is illustrated through application to a number of energy use indicators that are frequently used in LCA studies: cumulative energy demand (CED), nonrenewable cumulative energy demand (NRCED), fossil energy use (FEU), primary fossil energy use (PFEU), and secondary energy use (SEU). To illustrate how the application of different energy use indicators may lead to different results, cradle-to-gate energy use of the bionanomaterial cellulose nanofibrils (CNF) is assessed using 5 different indicators and showing a factor of 3 differences between the highest and lowest results. The relevance of different energy use indicators to different actors and contexts will be discussed, and further developments of the framework are then suggested. Integr Environ Assess Manag 2016;12:429-436. © 2015 The Authors. Integrated Environmental Assessment and Management published by Wiley Periodicals, Inc. on behalf of SETAC.

Environmental Impacts of the U.S. Health Care System and Effects on Public Health

The U.S. health care sector is highly interconnected with industrial activities that emit much of the nation's pollution to air, water, and soils. We estimate emissions directly and indirectly attributable to the health care sector, and potential harmful effects on public health. Negative environmental and public health outcomes were estimated through economic input-output life cycle assessment (EIOLCA) modeling using National Health Expenditures (NHE) for the decade 2003-2013 and compared to national totals. In 2013, the health care sector was also responsible for significant fractions of national air pollution emissions and impacts, including acid rain (12%), greenhouse gas emissions (10%), smog formation (10%) criteria air pollutants (9%), stratospheric ozone depletion (1%), and carcinogenic and non-carcinogenic air toxics (1-2%). The largest contributors to impacts are discussed from both the supply side (EIOLCA economic sectors) and demand side (NHE categories), as are trends over the study period. Health damages from these pollutants are estimated at 470,000 DALYs lost from pollution-related disease, or 405,000 DALYs when adjusted for recent shifts in power generation sector emissions. These indirect health burdens are commensurate with the 44,000-98,000 people who die in hospitals each year in the U.S. as a result of preventable medical errors, but are currently not attributed to our health system. Concerted efforts to improve environmental performance of health care could reduce expenditures directly through waste reduction and energy savings, and indirectly through reducing pollution burden on public health, and ought to be included in efforts to improve health care quality and safety.

Personal Metabolism (PM) coupled with Life Cycle Assessment (LCA) model: Danish Case Study

Sustainable and informed resource consumption is the key to make everyday living sustainable for entire populations. An intelligent and strategic way of addressing the challenges related with sustainable development of the everyday living of consumers is to identify consumption-determined hotspots in terms of environmental and health burdens, as well as resource consumptions. Analyzing consumer life styles in terms of consumption patterns in order to identify hotspots is hence the focus of this study. This is achieved by taking into account the entire value chain of the commodities consumed in the context of environmental and human health burdens, as well as resource consumptions. A systematic commodity consumption, commodity disposal, and life style survey of 1281 persons living in urbanized Danish areas was conducted. The findings of the survey showed new impact dimensions in terms of Personal Metabolism (PM) patterns of residents living in urbanized areas of Denmark. Extending the PM analysis with Life Cycle Assessment (LCA) provided a clear picture of the per capita environmental and human health burdens, as well as resource consumptions, and the exact origin hereof. A generic PM-LCA Model for all the 1281 persons was set-up in Gabi 6. The assessment results obtained applying the model on all 1281 personal consumption scenarios yielded the 1281 Personal Impact Profiles (PIPs). Consumption of food and energy (electricity and thermal energy) proved to be the primary impact sources of PM, followed by transport. The PIPs further revealed that behavioral factors (e.g. different diets, use of cars, household size) affect the profiles. Hence, behavioral changes are one means out of many that humanity will most likely have to rely on during the sustainable development process. The results of this study will help the Danish and other comparable populations to identify and prioritize the steps towards reducing their environmental, human health, and resource consumption burdens.

Spatially Explicit Analysis of Biodiversity Loss Due to Global Agriculture, Pasture and Forest Land Use from a Producer and Consumer Perspective

Anthropogenic land use to produce commodities for human consumption is the major driver of global biodiversity loss. Synergistic collaboration between producers and consumers in needed to halt this trend. In this study, we calculate species loss on 5 min × 5 min grid level and per country due to global agriculture, pasture and forestry by combining high-resolution land use data with countryside species area relationship for mammals, birds, amphibians, and reptiles. Results show that pasture was the primary driver of biodiversity loss in Madagascar, China and Brazil, while forest land use contributed the most to species loss in DR Congo and Indonesia. Combined with the yield data, we quantified the biodiversity impacts of 1 m(3) of roundwood produced in 139 countries, concluding that tropical countries with low timber yield and a large presence of vulnerable species suffer the highest impact. We also calculated impacts per kg for 160 crops grown in different countries and linked it with FAO food trade data to assess the biodiversity impacts embodied in Swiss food imports. We found that more than 95% of Swiss consumption impacts rest abroad with cocoa, coffee and palm oil imports being responsible for majority of damage.

Potential for Integrating Diffusion of Innovation Principles into Life Cycle Assessment of Emerging Technologies

Life cycle assessment (LCA) measures cradle-to-grave environmental impacts of a product. To assess impacts of an emerging technology, LCA should be coupled with additional methods that estimate how that technology might be deployed. The extent and manner that an emerging technology diffuses throughout a region shapes the magnitude and type of environmental impacts. Diffusion of innovation is an established field of research that analyzes the adoption of new innovations, and its principles can be used to construct scenario models that enhance LCA of emerging technologies. Integrating diffusion modeling techniques with an LCA of emerging technology can provide estimates for the extent of market penetration, the displacement of existing systems, and the rate of adoption. Two general perspectives of application are macro-level diffusion models that use a function of time to represent adoption, and microlevel diffusion models that simulate adoption through interactions of individuals. Incorporating diffusion of innovation concepts complement existing methods within LCA to inform proactive environmental management of emerging technologies.

Intensification of phosphorus cycling in China since the 1600s

Phosphorus (P) is an essential nutrient for living systems with emerging sustainability challenges related to supply uncertainty and aquatic eutrophication. However, its long-term temporal dynamics and subsequent effects on freshwater ecosystems are still unclear. Here, we quantify the P pathways across China over the past four centuries with a life cycle process-balanced model and evaluate the concomitant potential for eutrophication with a spatial resolution of 5 arc-minutes in 2012. We find that P cycling in China has been artificially intensified during this period to sustain the increasing population and its demand for animal protein-based diets, with continuous accumulations in inland waters and lands. In the past decade, China's international trade of P involves net exports of P chemicals and net imports of downstream crops, specifically soybeans from the United States, Brazil, and Argentina. The contribution of crop products to per capita food P demand, namely, the P directly consumed by humans, declined from over 98% before the 1950s to 76% in 2012, even though there was little change in per capita food P demand. Anthropogenic P losses to freshwater and their eutrophication potential clustered in wealthy coastal regions with dense populations. We estimate that Chinese P reserve depletion could be postponed for over 20 y by more efficient life cycle P management. Our results highlight the importance of closing the P cycle to achieve the cobenefits of P resource conservation and eutrophication mitigation in the world's most rapidly developing economy.

Global spatially explicit CO2 emission metrics for forest bioenergy

Emission metrics aggregate climate impacts of greenhouse gases to common units such as CO2-equivalents (CO2-eq.). Examples include the global warming potential (GWP), the global temperature change potential (GTP) and the absolute sustained emission temperature (aSET). Despite the importance of biomass as a primary energy supplier in existing and future scenarios, emission metrics for CO2 from forest bioenergy are only available on a case-specific basis. Here, we produce global spatially explicit emission metrics for CO2 emissions from forest bioenergy and illustrate their applications to global emissions in 2015 and until 2100 under the RCP8.5 scenario. We obtain global average values of 0.49 ± 0.03 kgCO2-eq. kgCO2(-1) (mean ± standard deviation) for GWP, 0.05 ± 0.05 kgCO2-eq. kgCO2(-1) for GTP, and 2.14·10(-14) ± 0.11·10(-14) °C (kg yr(-1))(-1) for aSET. We explore metric dependencies on temperature, precipitation, biomass turnover times and extraction rates of forest residues. We find relatively high emission metrics with low precipitation, long rotation times and low residue extraction rates. Our results provide a basis for assessing CO2 emissions from forest bioenergy under different indicators and across various spatial and temporal scales.