Anne-Marie Boulay

Review of methods addressing freshwater use in life cycle inventory and impact assessment

PurposeIn recent years, several methods have been developed which propose different freshwater use inventory schemes and impact assessment characterization models considering various cause–effect chain relationships. This work reviewed a multitude of methods and indicators for freshwater use potentially applicable in life cycle assessment (LCA). This review is used as a basis to identify the key elements to build a scientific consensus for operational characterization methods for LCA.MethodsThis evaluation builds on the criteria and procedure developed within the International Reference Life Cycle Data System Handbook and has been adapted for the purpose of this project. It therefore includes (1) description of relevant cause–effect chains, (2) definition of criteria to evaluate the existing methods, (3) development of sub-criteria specific to freshwater use, and (4) description and review of existing methods addressing freshwater in LCA.Results and discussionNo single method is available which comprehensively describes all potential impacts derived from freshwater use. However, this review highlights several key findings to design a characterization method encompassing all the impact pathways of the assessment of freshwater use and consumption in life cycle assessment framework as the following: (1) in most of databases and methods, consistent freshwater balances are not reported either because output is not considered or because polluted freshwater is recalculated based on a critical dilution approach; (2) at the midpoint level, most methods are related to water scarcity index and correspond to the methodological choice of an indicator simplified in terms of the number of parameters (scarcity) and freshwater uses (freshwater consumption or freshwater withdrawal) considered. More comprehensive scarcity indices distinguish different freshwater types and functionalities. (3) At the endpoint level, several methods already exist which report results in units compatible with traditional human health and ecosystem quality damage and cover various cause–effect chains, e.g., the decrease of terrestrial biodiversity due to freshwater consumption. (4) Midpoint and endpoint indicators have various levels of spatial differentiation, i.e., generic factors with no differentiation at all, or country, watershed, and grid cell differentiation.ConclusionsExisting databases should be (1) completed with input and output freshwater flow differentiated according to water types based on its origin (surface water, groundwater, and precipitation water stored as soil moisture), (2) regionalized, and (3) if possible, characterized with a set of quality parameters. The assessment of impacts related to freshwater use is possible by assembling methods in a comprehensive methodology to characterize each use adequately.

Regional Characterization of Freshwater Use in LCA: Modeling Direct Impacts on Human Health

Life cycle assessment (LCA) is a methodology that quantifies potential environmental impacts for comparative purposes in a decision-making context. While potential environmental impacts from pollutant emissions into water are characterized in LCA, impacts from water unavailability are not yet fully quantified. Water use can make the resource unavailable to other users by displacement or quality degradation. A reduction in water availability to human users can potentially affect human health. If financial resources are available, there can be adaptations that may, in turn, shift the environmental burdens to other life cycle stages and impact categories. This paper proposes a model to evaluate these potential impacts in an LCA context. It considers the water that is withdrawn and released, its quality and scarcity in order to evaluate the loss of functionality associated with water uses. Regionalized results are presented for impacts on human health for two modeling approaches regarding affected users, including or not domestic uses, and expressed in disability-adjusted life years (DALY). A consumption and quality based scarcity indicator is also proposed as a midpoint. An illustrative example is presented for the production of corrugated board with different effluents, demonstrating the importance of considering quality, process effluents and the difference between the modeling approaches.

Complementarities of water-focused Life Cycle Assessment and Water Footprint Assessment

We shed light on this argument andclarify the objectives of both approaches, their strengths andcomplementarities, in the hope that less energy can be investedin debating these approaches and more on applying anddeveloping them further.Both methodologies have the indirect goal to help theirpractitioners preserve water resources, however, the way theyachieve this differs. The LCA methodology aims at quantifyingpotential environmental impacts generated by a human activityon a wide range of environmental issues (climate change,human respiratory impacts, land use, etc.). One of the potentialcauses of impact is water use. LCA therefore includes potentialimpacts from depriving human users and ecosystems of waterresources, as well as specific potential impacts from the emittedcontaminants affecting water, through different environmentalimpact pathways and indicators (mainly eutrophication,acidification and toxicity to human and ecosystems). TheLCA methodology includes four phases: goal and scope,inventory accounting, impact assessment and interpretation.Quantitative impact indicators are at the core of the impactassessment phase.The WFA methodology addresses freshwater resourcesappropriation in a four-step approach including setting goalsand scope, water footprint accounting, sustainability assess-ment, and response formulation. The accounting phaseincludes the quantification and mapping of freshwater usewith three distinct types of water use: the blue, gray and greenwater footprints. WFA is primarily designed to support betterwater management, including its use and allocation and hasplayed an important role in the awareness raising of waterissues in the past decade.Both WFA and LCA use quantitative indicators, but indifferent phases of the assessment. This can be more easilyunderstood when comparing the frameworks of both method-ologies (see Figure 1). WFA particularly relies on water useindicators in the inventory phase, while LCA focuses on impactindicators in the impact phase. This is the primary source ofconfusion for practitioners as indicators are to be understood inthe right context.WFA defines the water footprint (WF) as a spatiotemporallyexplicit indicator of freshwater appropriation in the accountingphase. The “water footprint sustainability assessment” phasefocuses on a multifaceted analysis of the environmentalsustainability, economic efficiency and social equity of fresh-water use and allocation. Here, WFs are put into context, forexample by comparing WFs of activities or products to

Global guidance on environmental life cycle impact assessment indicators: findings of the scoping phase

Olivier Jolliet & Rolf Frischknecht & Jane Bare & Anne-Marie Boulay & Cecile Bulle & Peter Fantke & Shabbir Gheewala & Michael Hauschild & Norihiro Itsubo & Manuele Margni & Thomas E. McKone & Llorenc Mila y Canals & Leo Postuma & Valentina Prado-Lopez & Brad Ridoutt & Guido Sonnemann & Ralph K. Rosenbaum & Tom Seager & Jaap Struijs & Rosalie van Zelm & Bruce Vigon & Annie Weisbrod & with contributions of the other workshop participants

Analysis of water use impact assessment methods (part A): evaluation of modeling choices based on a quantitative comparison of scarcity and human health indicators

PurposeIn the past decade, several methods have emerged to quantify water scarcity, water availability and the human health impacts of water use. It was recommended that a quantitative comparison of methods should be performed to describe similar impact pathways, namely water scarcity and human health impacts from water deprivation. This is precisely the goal of this paper, which aims to (1) identify the key relevant modeling choices that explain the main differences between characterization models leading to the same impact indicators; (2) quantify the significance of the differences between methods, and (3) discuss the main methodological choices in order to guide method development and harmonization efforts.MethodsThe modeling choices are analysed for similarity of results (using mean relative difference) and model response consistency (through rank correlation coefficient). Uncertainty data associated with the choice of model are provided for each of the models analysed, and an average value is provided as a tool for sensitivity analyses.ResultsThe results determined the modeling choices that significantly influence the indicators and should be further analysed and harmonised, such as the regional scale at which the scarcity indicator is calculated, the sources of underlying input data and the function adopted to describe the relationship between modeled scarcity indicators and the original withdrawal-to-availability or consumption-to-availability ratios. The inclusion or exclusion of impacts from domestic user deprivation and the inclusion or exclusion of trade effects both strongly influence human health impacts. At both midpoint and endpoint, the comparison showed that considering reduced water availability due to degradation in water quality, in addition to a reduction in water quantity, greatly influences results. Other choices are less significant in most regions of the world. Maps are provided to identify the regions in which such choices are relevant.ConclusionsThis paper provides useful insights to better understand scarcity, availability and human health impact models for water use and identifies the key relevant modeling choices and differences, making it possible to quantify model uncertainty and the significance of these choices in a specific regional context. Maps of regions where these specific choices are of importance were generated to guide practitioners in identifying locations for sensitivity analyses in water footprint studies. Finally, deconstructing the existing models and highlighting the differences and similarities has helped to determine building blocks to support the development of a consensual method.

Global guidance on environmental life cycle impact assessment indicators: progress and case study

PurposeThe life cycle impact assessment (LCIA) guidance flagship project of the United Nations Environment Programme (UNEP)/Society of Environmental Toxicology and Chemistry (SETAC) Life Cycle Initiative aims at providing global guidance and building scientific consensus on environmental LCIA indicators. This paper presents the progress made since 2013, preliminary results obtained for each impact category and the description of a rice life cycle assessment (LCA) case study designed to test and compare LCIA indicators.MethodsThe effort has been focused in a first stage on impacts of global warming, fine particulate matter emissions, water use and land use, plus cross-cutting issues and LCA-based footprints. The paper reports the process and progress and specific results obtained in the different task forces (TFs). Additionally, a rice LCA case study common to all TF has been developed. Three distinctly different scenarios of producing and cooking rice have been defined and underlined with life cycle inventory data. These LCAs help testing impact category indicators which are being developed and/or selected in the harmonisation process. The rice LCA case study further helps to ensure the practicality of the finally recommended impact category indicators.Results and discussionThe global warming TF concludes that analysts should explore the sensitivity of LCA results to metrics other than GWP. The particulate matter TF attained initial guidance of how to include health effects from PM2.5 exposures consistently into LCIA. The biodiversity impacts of land use TF suggests to consider complementary metrics besides species richness for assessing biodiversity loss. The water use TF is evaluating two stress-based metrics, AWaRe and an alternative indicator by a stakeholder consultation. The cross-cutting issues TF agreed upon maintaining disability-adjusted life years (DALY) as endpoint unit for the safeguard subject “human health”. The footprint TF defined main attributes that should characterise all footprint indicators. “Rice cultivation” and “cooking” stages of the rice LCA case study contribute most to the environmental impacts assessed.ConclusionsThe results of the TF will be documented in white papers and some published in scientific journals. These white papers represent the input for the Pellston workshop™, taking place in Valencia, Spain, from 24 to 29 January 2016, where best practice, harmonised LCIA indicators and an update on the general LCIA framework will be discussed and agreed on. With the diversity in results and the multi-tier supply chains, the rice LCA case study is well suited to test candidate recommended indicators and to ensure their applicability in common LCA case studies.

Consistent characterisation factors at midpoint and endpoint relevant to agricultural water scarcity arising from freshwater consumption

PurposeThe shortage of agricultural water from freshwater sources is a growing concern because of the relatively large amounts needed to sustain food production for an increasing population. In this context, an impact assessment methodology is indispensable for the identification and assessment of the potential consequences of freshwater consumption in relation to agricultural water scarcity. This paper reports on the consistent development of midpoint and endpoint characterisation factors (CFs) for assessing these impacts.MethodsMidpoint characterisation factors focus specifically on shortages in food production resulting from agricultural water scarcity. These were calculated by incorporating country-specific compensation factors for physical availability of water resources and socio-economic capacity in relation to the irrigation water demand for agriculture. At the endpoint, to reflect the more complex impact pathways from food production losses to malnutrition damage from agricultural water scarcity, international food trade relationships and economic adaptation capacity were integrated in the modelling with measures of nutritional vulnerability for each country.Results and discussionThe inter-country variances of CFs at the midpoint revealed by this study were larger than those derived using previously developed methods, which did not integrate compensation processes by food stocks. At the endpoint level, both national and trade-induced damage through international trade were quantified and visualised. Distribution of malnutrition damage was also determined by production and trade balances for commodity groups in water-consuming countries, as well as dependency on import ratios for importer countries and economic adaptation capacity in each country. By incorporating the complex relationships between these factors, estimated malnutrition damage due to freshwater consumption at the country scale showed good correlation with total reported nutritional deficiency damage.ConclusionsThe model allows the establishment of consistent CFs at the midpoint and endpoint for agricultural water scarcity resulting from freshwater consumption. The complex relationships between food production supply and nutrition damage can be described by considering the physical and socio-economic parameters used in this study. Developed CFs contribute to a better assessment of the potential impacts associated with freshwater consumption in global supply chains and to life cycle assessment and water footprint assessments.

Making sense of the minefield of footprint indicators.

Bradley Ridoutt,*,† Peter Fantke,‡ Stephan Pfister, Jane Bare, Anne-Marie Boulay, Francesco Cherubini, Rolf Frischknecht, Michael Hauschild,‡ Stefanie Hellweg, Andrew Henderson, Olivier Jolliet, Annie Levasseur, Manuele Margni, Thomas McKone, Ottar Michelsen, Llorenc Mila i Canals, Girija Page, Rana Pant, Marco Raugei, Serenella Sala, Erwan Saouter, Francesca Verones, and Thomas Wiedmann †Commonwealth Scientific and Industrial Research Organisation (CSIRO), Clayton, Victoria 3169, Australia ‡Technical University of Denmark (DTU), Department for Management Engineering, Division for Quantitative Sustainability Assessment, 2800 Kgs. Lyngby, Denmark ETH Zurich, Institute of Environmental Engineering, 8093 Zurich, Switzerland United States Environmental Protection Agency, Sustainable Technology Division, Systems Analysis Branch, National Risk Management Research Laboratory, Cincinnati, Ohio 45268, United States CIRAIG, Ecole Polytechnique de Montreal, Montreal, Canada Norwegian University of Science and Technology (NTNU), Industrial Ecology Programme, Department of Energy and Process Engineering, NO-7491 Trondheim, Norway treeze Ltd., Uster, Switzerland University of Texas Health Science Center, School of Public Health, Division of Epidemiology, Human Genetics and Environmental Sciences, Houston, Texas 77030, United States University of Michigan, School of Public Health, Environmental Health Sciences, Ann Arbor, Michigan 48109, United States University of California, Lawrence Berkeley National Laboratory and School of Public Health, Berkeley, California 94720, United States Norwegian University of Science and Technology (NTNU), Division for Finance and Property, NO-7491 Trondheim, Norway United Nations Environment Programme (UNEP), Division for Technology, Industry and Economics, 15 Rue de Milan, 75009 Paris, France University of Western Sydney, School of Science and Health, Penrith, NSW 2751, Australia European Commission, Joint Research Centre, Institute for Environment and Sustainability, Via Enrico Fermi 2749, Ispra, I-21027, Italy Oxford Brookes University, Department of Mechanical Engineering and Mathematical Sciences, Oxford OX33 1HX, United Kingdom UNSW Australia, Sustainability Assessment Program, School of Civil and Environmental Engineering, Sydney, NSW 2052, Australia

Analysis of water use impact assessment methods (part B): applicability for water footprinting and decision making with a laundry case study

PurposeThe integration of different water impact assessment methods within a water footprinting concept is still ongoing, and a limited number of case studies have been published presenting a comprehensive study of all water-related impacts. Although industries are increasingly interested in assessing their water footprint beyond a simple inventory assessment, they often lack guidance regarding the applicability and interpretation of the different methods available. This paper aims to illustrate how different water-related methods can be applied within a water footprint study of a laundry detergent and discuss their applicability.MethodsThe concept of water footprinting, as defined by the recently published ISO Standard (ISO 2014), is illustrated through the case study of a load of laundry using water availability and water degradation impact categories. At the midpoint, it covers scarcity, availability, and pollution indicators such as eutrophication, acidification, human, and eco-toxicity. At the endpoint, impacts on human health and ecosystems are covered for water deprivation and degradation. Sensitivity analyses are performed on the most sensitive modeling choices identified in part A of this paper.Results and discussionThe applicability of the different methodologies and their interpretation within a water footprint concept for decision making is presented. The discussion covers general applicability issues such as inventory flow definition, data availability, regionalization, and inclusion of wastewater treatment systems. Method-specific discussion covers the use of interim ecotoxicity factors, the interaction of scarcity and availability assessments and the limits of such methods, and the geographic coverage and availability of impact assessment methods. Lastly, possible double counting, databases, software, data quality, and integration of a water footprint within a life cycle assessment (LCA) are discussed.ConclusionsThis study has shown that water footprinting as proposed in the ISO standard can be applied to a laundry detergent product but with caveats. The science and the data availability are rapidly evolving, but the results obtained with present methods enable companies to map where in the life cycle and in the world impacts might occur.

Area of concern : a new paradigm in life cycle assessment for the development of footprint metrics

PurposeAs a class of environmental metrics, footprints have been poorly defined, have shared an unclear relationship to life cycle assessment (LCA), and the variety of approaches to quantification have sometimes resulted in confusing and contradictory messages in the marketplace. In response, a task force operating under the auspices of the UNEP/SETAC Life Cycle Initiative project on environmental life cycle impact assessment (LCIA) has been working to develop generic guidance for developers of footprint metrics. The purpose of this paper is to introduce a universal footprint definition and related terminology as well as to discuss modelling implications.MethodsThe task force has worked from the perspective that footprints should be based on LCA methodology, underpinned by the same data systems and models as used in LCA. However, there are important differences in purpose and orientation relative to LCA impact category indicators. Footprints have a primary orientation toward society and nontechnical stakeholders. They are also typically of narrow scope, having the purpose of reporting only in relation to specific topics. In comparison, LCA has a primary orientation toward stakeholders interested in comprehensive evaluation of overall environmental performance and trade-offs among impact categories. These differences create tension between footprints, the existing LCIA framework based on the area of protection paradigm and the core LCA standards ISO14040/44.Results and discussionIn parallel to area of protection, we introduce area of concern as the basis for a universal footprint definition. In the same way that LCA uses impact category indicators to assess impacts that follow a common cause-effect pathway toward areas of protection, footprint metrics address areas of concern. The critical difference is that areas of concern are defined by the interests of stakeholders in society rather than the LCA community. In addition, areas of concern are stand-alone and not necessarily part of a framework intended for comprehensive environmental performance assessment. The area of concern paradigm is needed to support the development of footprints in a way that fulfils their distinctly different purpose. It is also needed as a mechanism to extricate footprints from some of the provisions of ISO 14040/44 which are not considered relevant. Specific issues are identified in relation to double counting, aggregation and the selection of relevant indicators.ConclusionsThe universal footprint definition and related terminology introduced in this paper create a foundation that will support the development of footprint metrics in parallel with LCA.