Finding Life Cycle Assessment Research Direction with the Aid of Meta-Analysis

R E S E A R C H A N D A N A LYS I S

Finding Life Cycle Assessment ResearchDirection with the Aid of Meta-AnalysisAlessandra Zamagni Paolo Masoni Patrizia Buttol Andrea Raggiand Roberto Buonamici

Keywords

industrial ecologylife cycle impact assessmentmethodological developmentmodelingresearch and development policysustainability

Supporting information is availableon the JIE Web site

Summary

Rapid growth in life cycle assessment (LCA) methodological developments has generateda large body of work that may appear to lack direction In this article we developed andapplied a structured approach inspired by the meta-analysis concept to examine literatureand identify research thrusts on how to further develop LCA The procedure consists of foursteps (1) definition of the research question (2) carrying out a literature review concerningmore than 280 articles selected from about 2000 articles according to predefined criteriawhich resulted in the identification of some 60 main methodological topics (3) research gapanalysis in which the methodological topics identified in the previous step were comparedwith the research priorities identified through a usersrsquo needs survey and (4) interpretationof results in which the results of both the previous steps were evaluated and organizedinto coherent research thrusts

Overall the analysis delivered two main research thrusts one devoted to increase thepracticability of LCA the other to increase model fidelity The former is aimed at makingknowledge available in an easily usable way while the latter focuses on better describingthe complexity of the systems analyzed and those interrelations that are really meaningfulSpecific research topics were identified for each thrust which suggests that sophisticationand practicability can and should coexist in the same method

Introduction

In recent years there has been an increasing awareness ofthe importance of life cycle thinking (LCT) (Fava et al 2009)and more specifically of the standardized life cycle assessment(LCA) method as a way to face the challenges posed by sustain-ability questions (Huppes and Ishikawa 2009) This awarenessis turning into a really striking effect at the European Unionpolicy level LCT and LCA are central themes of the recentSustainable Consumption and Production (SCP) Action Plan(CEC 2008) as well as in the Eco-Design Directive (EC 2009)the Waste Framework Directive (EC 2006) and the Environ-

Address correspondence to Alessandra Zamagni ENEA Via Martiri di Monte Sole 4 40129 Bologna ItalyE-mail alessandrazamagnieneait

ccopy 2012 by Yale UniversityDOI 101111j1530-9290201200467x

Volume 16 Number S1

mental Technologies Action Plan (CEC 2004) Moreover inthe Integrated Product Policy Communication the EuropeanCommission states that ldquoLCAs provide the best framework forassessing the potential environmental impacts of products cur-rently availablerdquo (CEC 2003) The recently published Inter-national Life Cycle Data System (ILCD) Handbook (JRC-IES2010) made available through the European Platform on LCAis a further confirmation of the importance of LCA as a decision-supporting tool in contexts ranging from product developmentto policy making In fact the handbook1 as a series of techni-cal guidance documents to the International Organization for

wwwwileyonlinelibrarycomjournaljie Journal of Industrial Ecology S39


Standardization (ISO) 14040 and 14044 standards (ISO 2006a2006b) will serve as a basis for comparable and reliable LCAapplications in business and public decision making

This increasing interest in LCT has been driven also by theconsiderable methodological development of LCA in the lastfew years as testified by the scientific articles published so far2

Indeed most of the developments have occurred in the last tenyears which was referred to by Guinee and colleagues (2011) asldquothe decade of elaborationrdquo Regarding the impact assessmentphase new impact categories indicators and characterizationfactors have been developed Moreover an increased sophisti-cation of the existing methods of characterization has been alsoproposed (eg with the introduction of spatial and temporal dif-ferentiation) In the realm of the inventory analysis the need toassess policies technological and structural choices character-ized by scarce reversibility long-term effects trade-offs betweenenvironment economy and society and so on has been drivingan expansion of the scope of LCA both in terms of the levelof analysis (from products to systems from micro to macro)and coverage of indicators (including also economic and so-cial aspects) Consequential LCA hybrid approaches combin-ing LCA and input-output analysis (IOA) scenario modelingand new efforts for developing social and economic assessmentmethods are only some examples of the developments LCAmethodology has been going through Overall it may appearthat LCA lacks direction on how to further develop

Starting from the considerations above we questionedwhether it would be possible to structure the present develop-ments and organize unexplored areas questions and researchpriorities to further develop LCA For this purpose the existingliterature on LCA was examined using an approach that wasinspired by the meta-analysis concept but differs in a numberof ways which are discussed below

Widely used in social and medical sciences meta-analysis isusually a quantitative statistical technique aimed at combiningthe results of several studies in order to test the pooled data forstatistical significance Even when used as a component of asystematic review procedure its focus is on the use of statisticalmethods as a way to combine evidence

As far as the scope of this article is concerned it is clear thatthe classic meta-analysis approach cannot be adopted becausethe object of study is represented by methodological develop-ments and not by analytical and quantitative studies whose re-sults can be coded by means of statistical parameters Howeverthe rationale behind the approach is fully applicable becausemeta-analysis is meant as the analyses ldquoof a large collection ofresults from individual studies for the purpose of integratingthe findingsrdquo (Glass 1976 3) For this reason inspired by themeta-analysis concept we developed a structured approach toexamine the existing literature on LCA The approach is char-acterized by a shared subjectivity in review rather than a trueobjectivity which can never be assured when qualitative ele-ments are dominant In fact the decisions made are public andtransparent and open to criticism from other researchers

First the article illustrates the approach starting with ananalysis of the existing literature on LCA As an intermediate

step the main methodological aspects the scientific commu-nity is working on are defined together with the research needsto fully develop them Then research gaps are identified withthe support of a survey on usersrsquo needs on how to further de-velop LCA Finally the results are discussed organized in tworesearch thrusts and in the last section the main conclusionsare drawn

A Structured Approach to Examining LifeCycle Assessment Literature

When research results accumulate it becomes increasinglydifficult to understand the direction they point out and whetheran unambiguous conclusion can be reached Under those cir-cumstances a feeling of confusion and frustration might arise(Rudner et al 2002) because consensus cannot be found in theliterature3 resulting in ambiguity and impossibility in makingknowledge available to final users (policy makers consumerstechnicians) in a fruitful way

Ambiguity arises whenever a contradiction exists on top-icsstudies on the same (and sometimes controversial) subjectThis is quite common in the scientific literature on method-ological developments that should explore by definition allthe maze of knowledge and also investigate options that seeminconclusive or even unfeasible at first glance However re-searchers do not always aim to validate previous findings or toexamine them critically Some authors present approaches forsolving a specific problem without duly taking previous worksinto consideration and thus without any criticism of themMoreover it is not always true that a lack of debate on a spe-cific issue is a symptom of consensus on that issue or vice versaIn this way it is not always possible to properly evaluate theconsensus of the LCA scientific community on the (relativeand absolute) relevance of an approach by means of a mereliterature review

We developed an approach to ldquoextract knowledge from stud-iesrdquo (Glass 1976) and to investigate the methodological devel-opments in which the literature review is coupled with an anal-ysis of usersrsquo needs and with expert judgment The purpose is toreduce the subjectivity in drawing conclusions In fact whileevery analysis requires a certain degree of subjectivity in makingdecisionsmdashfor example in relation to the identification and se-lection of the relevant literaturemdashin our approach choices arealways explicitly stated and therefore open to criticism

The approach consists of the following steps

bull Definition of the research questionThe question raised by the authors is the following given asituation of nonharmonized and sometimes diverging de-velopments in the literature over the last decade (Guineeet al 2011) how can the direction(s) in which LCA ispointing be identified How can coherent research thrustsbe identified

bull Carrying out the literature reviewInclusion and exclusion criteria for the studies to be ana-lyzed are set up The purpose is to identify methodological

S40 Journal of Industrial Ecology


approaches and related research needs on which the LCAcommunity is working

bull Research gap analysisIn this step the methodological approaches previouslyidentified are compared with research priorities identifiedby a usersrsquo needs survey (how users would like LCA to bedeveloped in the future to further support the decision-making process) The result consists of a list of prioritiesfor research not yet organized however into researchthrusts

bull Reporting and interpretation of resultsThe results of the literature review and of the usersrsquo needsare evaluated and organized into research thrusts by meansof expert judgment

A representation of the approach is provided in figure 1 to-gether with identification of the main elements that distinguishit from a meta-analysis

As can be seen in the right side of the figure quantitativeelements in the proposed method are missing Compared tothe classic meta-analysis here the purpose is not to establishthe presence of an effect or determine its magnitude but toidentify research priorities for further developing LCA Thereare not quantitative variables to be measured but trends to beidentified together with unexplored areas that deserve furtherinvestigative efforts The meta-analysis concept was not used asa rigid procedure but as a framework providing the conceptualrigor and objectivity necessary for the study In this respect theapproach goes beyond a classic literature review in relation totwo main aspects (1) the broader-than-usual coverage of theliterature review and (2) the use of surveys on usersrsquo needswhich make the analysis less subjective and responsive to whatis happening in the real world outside the (often considered)the so-called ivory tower of the research

Literature Review

After defining the research question the approach starts outby performing a literature review

The following criteria were adopted to ensure methodolog-ical soundness and that the selected studies were within thescope of the analysis

bull Identification of topics to be reviewed that is the mainissues from the methodological point of view like allo-cation system boundary definition uncertainty and soon This was done by interviewing LCA experts on whatthey considered to be the most challenging and emerg-ing issues and by examining the proceedings of con-ferences on LCA4 Overall about 2000 articles wereidentified

bull Classification of the identified topics according to thephases of the LCA procedure (goal and scope definitionlife cycle inventory [LCI] life cycle impact assessment[LCIA] and interpretation) Two additional separated sec-tions were included life cycle-based methods (life cycle

costing and social life cycle assessment) and data qualityand availability

bull Definition of criteria for screening the 2000 referencesresulting from the literature search (1) mainly officiallypeer-reviewed references published from 2000 to 2010were considered with a global geographic coverage Re-view articles were included as well (2) Case studies werereviewed only if they presented new methodological de-velopments This choice which may seem too restrictivewas aimed at selecting the highest possible quality level ofthe studies However these criteria were not completelyfulfilled for all approaches In particular grey literaturewas also consulted especially for novel developments thatwere not yet published in scientific journals Moreoverreferences before 2000 were also considered when theypresented interesting approaches not taken into accountin the more recent scientific literature All in all about60 approaches in more than 280 papers with differentdegrees of maturity were analyzed The complete list ofreferences is available as supporting information on theJournalrsquos Web site organized according to the differenttopics

bull For each topic identification of different approaches thatis solutions proposed by the authors to deal with theproblem The approaches were selected trying to covercomplementary authors and different schools of thought

bull Analysis of the approaches An evaluation grid was devel-oped structured along three levels (1) generalities whichinclude a description of the analyzed topicapproach thedeviationsdevelopments with respect to ISO standardsand the relevant references (2) analysis with a descrip-tion of the rationale (key principles of the approach whyit was implemented which needs the authors addressed)main advantages open questions and practicability as-pects and (3) comments in terms of research and de-velopment (RampD) needs and trends emphasized by theauthor(s)

The review of the literature was performed in the frameworkof the European Unionrsquos CALCAS (Co-ordination Action forInnovation in Life-Cycle Analysis for Sustainability) projectaimed at analyzing LCA approaches that have emerged duringthe last two decades and at indicating how the analysis mightbe improved by formulating research lines and roadmaps forsustainability decision support (Zamagni et al 2008 2009a)The work presented in this article was complemented by andbenefited from the articles published in 2009 2010 and partly in2011 including the review articles by Bare (2010) Finnvedenand colleagues (2009) and Reap and colleagues (2008a 2008b)which the reader is invited to refer to for details

Identification of Methodological DevelopmentsAbout 10 LCA experts selected according to their specific

competencies on all the topics identified in the review wereinvited to comment on a preliminary draft of the reviewrsquos resultsThe results of this consultation together with the outcome of

Zamagni et al Methodological Developments in LCA S41


Figure 1 The proposed approach to examine life cycle assessment literature The main elements that distinguish it from a meta-analysisare highlighted

the literature review represented the basis for the identificationof two main aspects (1) the main methodological questions thescientific community has been working on and (2) the researchneeds to fully develop them These are described in table 1

At the end of this step a very fragmented picture with nouniform view is obtained Therefore the research needs have tobe further analyzed and coded according to the characteristicsdefined in the next step

Research Gap Analysis

The next step consists of identifying gaps in the research top-ics listed in table 1 with respect to the needs and expectationsof LCA users For this purpose the authors analyzed the needsof different groups of users at the European level in terms ofhow stakeholders want LCA to develop in the future to makeit more useful in sustainability decision making

More specifically user needs were considered as a sort oflitmus test to evaluate how much methodological developmentsare in line with usersrsquo expectations and needs As a resultpriorities in research developments were established and newand innovative proposals were suggested to address researchgaps related to unsatisfied needs

The analysis performed within the CALCAS project (Ry-dberg et al 2008 2009) was carried out by means of a sur-vey targeted to different stakeholder groups The scope ofthe decision-making processes analyzed was quite wide rang-ing from high-level strategy choices to detailed technologyand product choices The survey was conducted by means of

semistructured interviews with key actors as well as question-naires to stakeholders

The following main groups of stakeholders were surveyed(Rydberg et al 2008)

bull Public authorities Life cycle analysis is not the referenceapproach in this context but they foresee a potentialuse of life cycle approaches in activities such as systemchoice (eg transport systems) and technology choices(eg waste management)

bull Business (industry retailers) They mainly use LCA asa decision support tool in product development (77)selection of raw materials (66) and choices of tech-nologies (55)

bull Nongovernmental organizations (NGOs including con-sumer associations) They make use of life cycle ap-proaches for communication purposes

bull RampD programmers (national funding organizations andresearch institutes) those who will finance future LCAresearch

The findings of the survey were discussed in a workshop with37 invited experts where the requests that had been identifiedin the usersrsquo needs survey as important for future development oflife cycle approaches were prioritized Moreover further needsand wishes about LCA development were discussed and pro-posed

For both the survey and the workshop the experts wereselected according to the following criteria



Table 1 Methodological topics and related research lines For each research line a selection of references is provided The full list isavailable as supporting information on the Web

Topics Research lines

Scenario analysis Uncertainty the knowledge generated by scenarios should be evaluated together with the associated uncertainty(Zurek and Henrichs 2007)

Relevance that is when the use of scenarios is relevant in life cycle assessment (LCA) and in which situationone approach to scenario analysis is more suited than others (Borjeson et al 2006 Rebitzer and Ekvall 2004)

Development of consistent and generic scenarios of different types that could be used by different practitioners(Hojer et al 2008)

ConsequentialLCA (CLCA)

Affected process (Lund et al 2010 Mathiesen et al 2009 Schmidt 2008 Weidema et al 2009)mdash identification of the affected process(es) and related uncertainty evaluationmdash collection of marginal dataEconomic models in CLCA (Earles and Halog 2011 Ekvall and Andrae 2006)mdash use of partial equilibrium models (PEMs)

when they are relevant data on price elasticities has to be estimated for many products they should be included in databases posted

in connection to ordinary LCI databasesmdash use of multimarket multiregion PEMs use of general equilibrium modelsmdash use of experience curves

how transfer of knowledge and experience among technologies and geographical regions should beaccounted for when applying experience curves

experience curves need to be established for more technologies Data can be included in databases posted inconnection to ordinary LCI databases

Hybrid approachescombininginput-outputanalysis (IOA)and LCA

mdash Work on methodological shortcomings of IOA approximation of the product of interest by its commodityproportionality between market price and environmental impacts noncompleteness of the product life cyclestages (Suh and Huppes 2005)

mdash Data issues improve the consistency among the different IO tables and build reliable and publicly availableenvironmental intervention databases for the IO tables (activities are in progress) (Suh and Huppes 2005Tukker et al 2009)

mdash Focus on uncertainty evaluation (uncertainty factors for IO data) (Nielsen and Weidema 2001)mdash Further explore new approaches of IOA combined with LCA for analyses with a regional resolution (Cicas

et al 2007 Yi et al 2007)mdash Accumulate experience from successful integrated hybrid analysis (Mattila et al 2010 Rowley et al 2009

Suh and Nakamura 2007)

Life cycle impactassessment

Improvements of existing characterization methodsmdash Spatial differentiation (Finnveden and Nilsson 2005 Gallego et al 2010 Seppala et al 2006[B34] Shah and

Ries 2009 Wegener Sleeswijk 2011 Wegener Sleeswijk and Heijungs 2010) development of methodology for the definition of the optimal regions for site-dependent characterization

factors (CFs) identification of impact categories for which more detailed regional data are necessary availability of regional emissions and environmental data to calculate regional CFs guidelines for practitioners and manageability quality control of locationcountry-specific elementary flows

mdash Improvement of existing approaches for the impact categories of human toxicity and ecotoxicity (Gandhi etal 2010 Rosenbaum et al 2008)

Development of midpoint and damage-oriented methods in a common framework (Goedkoop et al 2009 Itsubo andAtsushi 2007 Jolliet et al 2004)

mdash Provision of consistent and operational sets of methods and factors for LCIAmdash Uncertainty evaluation of damage function modelingDevelopment of new characterization methods and new impact categories (Althaus et al 2009a 2009b Hellweg et al

2009 Mila I Canals et al 2007a 2007b Nunez et al 2010 Pfister et al 2009 Zhang et al 2010)Developments in this field are growing exponentially Besides the categories of resource depletion noise land

use ionizing radiation water use and indoor and occupational exposure recently the following categorieshave been pointed out as relevant odor genetic pollution (due to genetically modified organisms)nonionizing radiation (electromagnetic waves) light (eg from greenhouses) and thermal pollution Forthese impact categories there is no consensus on their relevance of inclusion in LCAs on the inventoryitem(s) to which characterization models would attach on the exact impact pathways and on the impactindicators at the midpoint level The detailed list of references available as supporting information on the Webprovides all the necessary information

(Continued)



Table 1 (Continued)


(Environmental)Life cyclecosting (LCC)

mdash Conduct case studies to increase the knowledge and the practice (Hunkeler et al 2008 Swarr et al 2011)a

mdash Further deepen the question of a formal computational structure for LCC as for the opportunity to strengthenthe linkage with LCA (Settanni 2008)

Social life cycleassessment(S-LCA)

mdash Further analysis of the relevance of S-LCA (which questions to be answered and which stakeholders to beaddressed) (Swarr 2009 Zamagni et al 2011)

mdash Deepen the methodological questions related to the scope of the analysis further elaborating theconsequential concept (Joslashrgensen et al 2009)

mdash Selection and formulation of indicators (Joslashrgensen et al 2008 Kim and Hur 2009)mdash Data collection and availability (Benoıt et al 2010 Ciroth and Franze 2011 Franze and Ciroth 2011)mdash Characterization of social indicators (Dreyer et al 2010 Joslashrgensen et al 2010 Reitinger et al 2011)

Uncertainty mdash More investigation of correlations and interdependencies among parameters (Bojaca and Schrevens 2010)mdash Development of guidelines for supporting practitioners in the uncertainty analysis (Basson and Petrie 2007

Lloyd and Ries 2007)mdash Major effort should be spent on scenario uncertainty it should become routine practice due to the influence

of choices on the final LCA results (Benetto et al 2006 Huijbregts 1998 Huijbregts et al 2003)

Data availabilityquality andmanagement

mdash Approaches for developing inventory models for those products whose data availability is a critical aspect(Geisler et al 2004 Hischier et al 2005 Wernet et al 2009)

mdash Approaches to data transposition ie the use of European background data for countries outside Europe(Colodel et al 2009)

mdash Deepen the semantic web approach for LCA applications development of interfaces between theenvironmental data published on the semantic web and existing LCA tools (Moreno et al 2011)

mdash Finalization of core ontology necessary for LCA publication on the web (Moreno et al 2011)b

mdash Approaches for integrating data along the whole supply chain and from different sources (Buttol et al 2011)c

Notes CFs = characterization factorsaThe recently published environmental life cycle costing code (Swarr et al 2011) represents a significant step forward in the development of LCC and itis expected that the number of applications and case studies will increase in coming yearsbMoreno and colleagues 2011 Ontologies are (meta) data schemas providing a controlled vocabulary of concepts each with explicitly defined andmachine processable semantics By defining shared and common domain theories ontologies help to communicate concisely supporting the exchangeof semantics and not only syntax Hence the cheap and fast construction of domain-specific ontologies is crucial for the success and proliferation of thesemantic webcButtol and colleagues 2011 A system of data sharing within the whole supply chain would have a twofold approach (1) to improve data availability byallowing collecting data upstream and downstream in the supply chain with lower efforts (2) to optimize and make the whole production system coveredby the supply chain more efficient Moreover as several data useful for an LCA study are available in other sources and are managed by other tools (egcomputer-aided design [CAD] systems) efforts should be spent in exploiting the synergies among the different tools

bull good knowledge of the life cycle thinking and of the lifecycle assessment method

bull stakeholders who have responsibility in relation to sus-tainability decision making and

bull stakeholders who work in an organization where the lifecycle approach is considered to play an important role insupporting the decision-making process

The overall results for each stakeholder category are sum-marized in table 2

The comparison between the research topics of table 1 iden-tified by means of the literature review and the research needs oftable 2 expressed by the surveyed users shows a partial overlapIn fact there is a leitmotiv in all the stakeholdersrsquo categorieswhich is presently not fully addressed by the research commu-nity the need for simplified LCA methods and tools This inturn involves

bull simpler interfaces and less time-consuming models and

bull methods and software tailored to specific industrialsectors

Sustainability assessment is the other main topic pointedout in which there is a growing interest in the scientific com-munity (and not only) More specifically main needs and ex-pectations relate to

bull integration of economic and social elements in life cycleapproaches and

bull introduction of sustainability parameters in life cycle ap-proaches for all the main mid- and long-term technolog-ical and strategic choices such as energy and the envi-ronment transport systems urban policy issues planningand quality control in the service sector

The two major aspects highlighted above are dealt within the next section in which the last step of the procedure isdescribed The purpose is to organize the results of the literature



Table 2 Priority research needs expressed by different stakeholdersrsquo groups

Stakeholder group Research needs

Public authorities Include additional economic performance in LCA to increase the acceptance and the success of themethods

Include social effectsWork on making the results easy to understand

Business Increase transparency in modelsDevelop methods together with the industry not by the scientists aloneDevelop strategies on how LCA can be communicated within the supply and value chainsMake consumers understand their role in the life cycle of productsInclude future impacts in the modelsInclude risk analysis in environmental assessmentsIncrease validity and credibility of simplified life cycle approachesDevelop tools tailored to specific industrial sectorsIntroduce regional variations in the models

Nongovernmentalorganizations(NGOs)

Work on simplifying methods and making them less expensiveStrengthen educational activities on life cycle approachesIncrease the reliability of methods

Research anddevelopment(RampD)programmers

Develop models for sustainability evaluations integrating economic environmental and social dimensionsConduct more research to introduce sustainability parameters in life cycle approaches for all the main mid-

and long-term technological and strategic choices such as energy and the environment transportsystems urban policy issues planning and quality control in the service sector

Develop reference systems for quantitative knowledge (data)

Source Adapted from Rydberg and colleagues (2008)

review and of the usersrsquo needs into coherent research thrustswithin a uniform vision of where LCA is going and should go

Reporting and Interpretation of ResultsDefinition of Research Thrusts

The analysis described in the previous paragraphs confirmsthat two are the main research thrusts which take the pluralityof needs and the vision of the scientific community into consid-eration one devoted to an increased practicability and anotherto sophistication aimed at increasing model fidelity

In these terms such results are not surprising and can beconsidered even trivial5 However not so trivial is the iden-tification of the specific research topics that can contribute toincrease practicability and model fidelity also considering thatthese two different requirements could seem conflicting

The results and considerations are based on the judgment ofLCA experts This step could be affected by higher subjectivitythan the previous ones However to limit it and to avoid resultsthat are biased by the personal interests of the authors LCA ex-perts were selected who were not involved in the developmentof specific approaches

Increasing Practicability

Practicable is an adjective that refers to the capability ofbeing put into effect or being used Thus it involves the capa-bility of making knowledge available in an easily usable way

and one that is economically viable In the LCA context thiscan be translated in terms of making available user-friendlylow resource-demanding tools (methods and software) reliablebackground and foreground data to operate them and guidanceabout how to use them in the variety of applications

To reach these objectives research activities should be de-veloped along two main lines

bull simplification andbull the development of integrated approaches (ie methods

tools databases guidelines and training) supporting theapplication of LCA

Simplification is a crucial question for an extensive use of lifecycle information especially for small- and medium-size enter-prises that rarely have the knowledge and resources necessary toimplement LCA Facilitating access to reliable accurate andrelevant life cycle information means reducing the costs of theprocess of a productrsquos environmental improvement and bettercommunication along the supply chain Users mainly pose thequestion of simplification in terms of simpler interfaces and lesstime-consuming models However the topic deserves attentionalso from the methodological point of view considering that atpresent comprehensive approaches to simplification have notyet been developed

Simplification can be achieved in three main ways (1) re-ducing the number of environmental impact indicators (2)intervening at the level of methodological choices in the in-ventory phase and (3) working on data availability



The first approach is the most applied as testified by thewidespread use of the carbon footprint and by the ongoing de-velopment of the water footprint The use of such a reduced setof indicators increases communicability to final users and of-fers an answer to the growing concern over climate changeand water scarcity raised by several stakeholders Howeverthe risk of bias exists as the environmental implications ofthe assessment could be misleading and the basic principle ofLCAmdashits comprehensiveness that prevents burdens shiftingmdashcould be lost (SETAC Europe LCA Steering Committee2008)

Possible strategies at the inventory step are the exclusion ofphases of the life cycle and a reduction in the number of ele-mentary flows These choices should be made very carefully andcannot be generalized because of the risk of reducing reliabilityandor completeness of the assessment

Finally development of reliable and comprehensivedatabases which started almost in parallel with the first LCAapplications facilitates the work of practitioners and allowsthem to maintain the completeness of the assessment and topreserve the life cycle principles Some aspects deserve particu-lar attention for future and ongoing research initiatives

bull Enlargement of the number of products covered andactivities aimed at a global consistency of databasesThe latter aspect is addressed in the ldquoGlobal guidanceprinciples for life cycle assessment databasesrdquo (Sonne-mann and Vigon 2011) The document is expected toprovide global guidance on LCI data for widespreaduse thus contributing to increasing the credibility andaccessibility of existing LCA data (Sonnemann et al2011)

bull Further investigation of analytical models to produce LCIsof products There are some sectors (eg chemicals) inwhich due to the vast number of chemicals in produc-tion and the problem of data confidentiality a detailedinventory analysis is difficult if not unfeasible Differentstudies have been produced aimed at developing meth-ods for generating generalized data such as parameterizedinventories (Mueller et al 2004) LCIs for groups of ma-terials (Rydh and Sun 2005) LCIs of chemicals (Geisleret al 2004 Hischier et al 2005 Wernet et al 2009) butagreed solutions are still lacking

bull Investigation of approaches to data transposition thatis use of European background data for countries out-side Europe Although in the long term national LCIdatabases will become available in the meantime it isnecessary to provide practitioners with an intermediatesolution to properly take regional issues into accountFirst approaches under development (Colodel et al 2009)should be further investigated and tested in real casestudies

Not only does the issue of practicability have a method-ological connotation it also refers to the capability to set upan integrated approach supporting the application of LCA and

overcoming or reducing obstacles at the application level suchas costs usersrsquo knowledge and the availability of tools (softwareand databases) Such a system should be aimed at optimizingthe use of resources for the production of LCI data and spe-cialized databases and at offering training and guidance for theapplication of LCA (Buttol et al 2011)

Increasing Model Fidelity

Fidelity refers to the degree to which a model is able to rep-resent the reality described so that it is able to capture the com-plexity and those interrelations within the system that are reallymeaningful This concept is fundamental for all applicationsand becomes crucial for those with a broad scope andor objectof analysis like mid- and long-term technological and strategicchoices on energy the environment urban policy issues and soon In these cases interactions and feedback in the system aresignificant and generally perturbations introduced by the func-tional unit cannot be neglected Because classic LCA is a linearsteady-state model with a focus on environmental aspects itdoes not consider the complexities related to mechanisms andrelations besides the mere technological and environmentalones (Heijungs et al 2010) However researchers have startedinvestigating the feasibility of a more sophisticated LCA andthe literature review shows that methodological developmentsare going on in this direction

Based on these considerations two main research topics areconsidered relevant

bull strengthening the integration among LCA life cycle cost-ing (LCC) and social life cycle assessment (S-LCA) and

bull broadening and deepening the analysis addressing theproblem at different scales of application and effects (frommicro to macro)

A graphical representation of these two research topics isprovided in figure 2

Performing sustainability evaluations to accumulate knowl-edge about the interrelations among environmental economicand social effects is a clear need expressed by users within publicauthorities

The concepts of sustainability and sustainable developmentare very controversial and are disputed at both the scientific andsocial level In fact sustainability is a multidimensional conceptthat involves different areas (economic environmental andsocial) normative positions and empirical knowledge It coversmore aspects than LCA Thus in order to move from LCAto a life cycle-based analysis for sustainability it is necessaryfirst to broaden the scope by including economic and socialdimensions This is the present state of the art in LCA inwhich life cycle-based sustainability evaluations are performedaccording to the formula expressed by Kloepffer (2008)

Life Cycle Sustainability Assessment (LCSA)

= LC A+ LCC + S minus LC A



Figure 2 Representation of the research topics under the research thrusts ldquoincreasing model fidelityrdquo Adapted from Zamagni andcolleagues (2009b)

In figure 2 this is represented by the horizontal axis la-beled ldquobroadening the scope of indicatorsrdquo The three methodswhich have a different degree of development are applied at theproduct level independently one from another under specificconsistency requirements but without considering the mutualrelations that can arise

As a consequence synergies linkages and side effects acrossdifferent dimensions and across the boundaries of systems arenot lost while they represent the core of any sustainability prob-lems (Graedel and van der Voet 2010) Thus research should fo-cus on accumulating knowledge about the interrelations amongenvironmental economic and social effects answering thequestion of how to deal with the trade-offs among them Asdepicted in figure 2 two main components are necessary todescribe such complexities (Guinee et al 2011)

bull Deepening This can be achieved by adding further so-phistication to the modeling for example by adoptingspatially differentiated models andor by including morerelations in the analysis In the figure this is representedby the arrow that crosses the three layers An example ofdeepening is given by the consequential approach In factthe rationale behind it requires thinking about the con-sequences of the actionsmdashthe interrelationsmdashand thusprojecting the problem at the market level with all itsdynamics Thus consequential LCA represents a way to

further add sophistication to LCI modeling by giving theopportunity to introduce market mechanisms into LCAAnother example is represented by the use of hybrid ap-proaches combining IOA and LCA In fact they sharemodeling and data structure even with different routes ofdata supply With their flexible computational structurethey potentially open new perspectives not only towardsadding realism by including a more complete system butalso towards expanding the scope of LCA applications tohigher scales of analysis from ldquomicro questions on spe-cific products to meso questions on life styles up to macroquestions in which the societal structure is part of theanalysisrdquo (Heijungs et al 2010 422)

bull Broadening Besides extending the number of environ-mental indicators or also including the economic and so-cial ones in the analysis in an integrated way broadeningis achieved by shifting the analysis from individual prod-uct systems to sectors baskets of commodities marketsor whole economies (from the micro to meso and macrolevels) In figure 2 it is represented by the vertical axisldquobroadening the object of the analysisrdquo

An approach to this type of analysis has been developedby Guinee and colleagues (2011) leading to the proposal of alife cycle sustainability analysis a transdisciplinary integrationframework that works with several models The framework



drafted at a methodological level but not fully developed re-quires several research efforts as identified in the article byGuinee and colleagues (2009)

Discussion and Conclusion

Rapid growth in LCA methodological developments hasgenerated a large body of work that may appear to lack direc-tion We developed and applied a structured approach inspiredby the meta-analysis concept to examine the literature and toderive research thrusts for LCA in the future The main charac-teristic of this approach consists of coupling a literature reviewwith an analysis of usersrsquo needs and with expert judgment Inthis respect the approach goes beyond a classic literature reviewbecause it reduces the subjectivity of a judgment based entirelyon the opinions of the articlesrsquo authors

Overall the analysis delivered two main research thrusts onedevoted to increase the practicability of LCA and the other toincrease model fidelity

Practicability is the basic requirement to support real-worlddecisions in business and public policy making The main top-ics to be dealt with under this umbrella are those that wereat the core of the debate in the late 1990s Data qualityand availability at reduced costs simplified tools tailored tousersrsquo requirements and approaches to uncertainty analysisjust to mention a few are nowadays still the object of fur-ther development In this regard the harmonization work ofthe ILCD Handbook coordinated by the European Platformon LCA supports the defining of methodology recommenda-tions for LCA use in business and public policy contexts Fur-ther steps should be devoted to making the ILCD Handbookfully applicable with detailed provisions on how to solve themain methodological problems for a broad range of industrialapplications

Meanwhile research should proceed and the question of so-phistication and complexities should be considered There areplenty of examples in the literature of interesting approachesScientists have started going back to LCArsquos foundations (Zam-agni et al 2008) and have rediscovered its nature experimentedwith novel approaches and reproposed previous ones with a newappearance Even if historically the LCA framework works withthe support of other models and disciplines as clearly demon-strated in the impact assessment phase it seems that only inthe last decade have scientists become fully aware of that Thisattitude in the past could have been caused by the concernthat the contribution of other disciplines to further developingLCA methodology violated its inherent principles as definedin the ISO standards As LCA was highly criticized in the pastand only with standardization did it regain its reputation therewould be the fear that any major change could again endangerits credibility

Only recently have scientists started using LCA in combi-nationintegration with economic models ecological modelsand social theories (eg Joshi 1999 Venkatesh et al 2009)to make the methodology more complete better model the

system reduce uncertainty collect more representative datadefine scenarios and include other mechanisms than the en-vironmental and technological ones commonly considered inLCA (Heijungs et al 2010)

These main findings on the evolution of LCA show an ap-parently contradictory and diverging situation because on theone side further research is suggested towards increased modelfidelity and on the other side a focus on increasing usabil-ity is suggested However we believe that these two differentrequirements are not conflicting but they represent two sidesof the same coin In fact a correct and scientifically sounddevelopment of the simplification techniques requires a com-plete understanding of the complexities of the problems as apreliminary condition to decide where and how to introducesimplifications

Consequently the future challenge of research is to workon complexity taking advantage of the contributions fromother disciplines and making knowledge available with toler-able uncertainty If such an expanded LCA can still be con-sidered LCA is a question we open for debate in the researchcommunity

Acknowledgements

This article is partially based on work done for the CALCAS(Co-ordination Action for Innovation in Life Cycle Analy-sis for Sustainability) project which was funded by the Euro-pean Union as part of the 6th Framework Programme (Projectno 037075 see httpwwwcalcasprojectnet) The CALCASpartners are gratefully acknowledged for their contribution Fur-thermore three anonymous reviewers are gratefully acknowl-edged for their useful suggestions

Moreover we came to the conclusions by applying a trans-parent procedure based on an extensive review of the literatureover the last ten years coupled with an analysis of usersrsquo needsEven if the final result is a confirmation of the impressions theLCA community has been aware of for quite some time thisarticle is aimed at providing the supporting evidence for thisopening the door to the criticisms of other researchers

Notes

1 The Handbook includes explicit and goal-specific methodologicalrecommendations a multilanguage terminology a nomenclaturea detailed verificationreview frame and further supporting docu-ments and tools

2 Research done in the abstract and citation database SCOPUS usingthe keyword ldquolife cycle assessmentrdquo delivered 745 articles publishedin 2010 compared with 416 in 2007 and 188 in 2000

3 A curious example can be mentioned that shows why ambiguity inscience is so frustrating for decision makers US Senator WalterMondale expressed his concerns to the American PsychologicalAssociation in 1970 ldquoFor every study statistical or theoreticalthat contains a proposed solution or recommendation there isalways another equally well-documented study challenging theassumptions or conclusions of the first No one seems to agree with



anyone elsersquos approach But more distressing no one seems to knowwhat worksrdquo (Rudner et al 2002 4)

4 Conferences are the place in which new and novel approachesare presented aimed at advancing the state of the art For thisreason they were considered an important and reliable source ofinformation for a first selection of the methodological topics

5 However what we find surprising is that the topic of practicabilitydespite being addressed since the origins of LCA is still one ofthe main shortcomings that hampers a broad application of themethod especially in the industrial context

References

Althaus H J P de Haan and R W Scholz 2009a Traffic noise inLCA Part 1 State-of-science and requirement profile for consis-tent context-sensitive integration of traffic noise in LCA Inter-national Journal of Life Cycle Assessment 14(6) 560ndash570

Althaus H J P de Haan and R W Scholz 2009b Traffic noise inLCA Part 2 Analysis of existing methods and proposition of anew framework for consistent context-sensitive LCI modellingof road transport noise emission International Journal of Life CycleAssessment 14(7) 676ndash686

Bare J C 2010 Life cycle impact assessment research developmentsand needs Clean Technologies and Environmental Policy 12(4)341ndash351

Basson L and J G Petrie 2007 An integrated approach for theconsideration of uncertainty in decision making supported by lifecycle assessment Environmental Modelling amp Software 22(2) 167ndash176

Benetto E C Dujet and P Rousseaux 2006 Possibility theory Anew approach to uncertainty analysis International Journal of LifeCycle Assessment 11(2) 114ndash116

Benoıt C G A Norris D Ausilio S Rogers J Reed and S Overaker2010 Social hotspot database risk and opportunity table developmentYork Beach ME USA New Earth

Bojaca C R and E Schrevens 2010 Parameter uncertainty in LCAStochastic sampling under correlation International Journal of LifeCycle Assessment 15(3) 238ndash246

Borjeson L M Hojer K H Dreborg T Ekvall and G Finnveden2006 Scenario types and techniques Towards a userrsquos guide Fu-tures 38(7) 723ndash739

Buttol P R Buonamici L Naldesi C Rinaldi A Zamagni and PMasoni 2011 Integrating services and tools in an ICT platformto support eco-innovation in SMEs Clean Technologies and Envi-ronmental Policy doi 101007s10098-011-0388-7

CEC (Commission of the European Communities) 2003 Communica-tion from the Commission to the European Parliament the Councilthe European Economic and Social Committee and the Committeeof the Regions Integrated Product Policy Building on Environmen-tal Life-Cycle Thinking COM(2003)302 final Brussels BelgiumCEC

CEC (Commission of the European Communities) 2004 Communica-tion from the Commission to the European Parliament the Councilthe European Economic and Social Committee and the Committeeof the Regions Stimulating Technologies for Sustainable DevelopmentAn Environmental Technologies Action Plan for the European UnionCOM(2004) 38 final Brussels Belgium CEC

CEC (Commission of the European Communities) 2008 Communica-tion from the Commission to the European Parliament the Councilthe European Economic and Social Committee and the Committee of

the Regions on the Sustainable Consumption and Production and Sus-tainable Industrial Policy Action Plan COM(2008) 3973 BrusselsBelgium CEC

Cicas G C T Hendrickson A Horvath and H S Matthews 2007A regional version of a US economic input-output life cycle assess-ment model International Journal of Life Cycle Assessment 12(6)365ndash372

Ciroth A and J Franze 2011 LCA of an ecolabeled notebook Consid-eration of social and environmental impacts along the entire life cycleRaleigh NC USA lulucom

Colodel C M M Fischer S Morel J Stichling and A Forell 2009Regional inventories and opportunities in the car industrymdashTheRenault KOLEOS case study Paper presented at the 3rd Inter-national Seminar on Society and Materials SAM3 29ndash30 AprilFreiberg Germany

Dreyer L C M Z Hauschild and J Schierbeck 2010 Characterisa-tion of social impacts in LCA Part I Development of indicatorsfor labour rights International Journal of Life cycle Assessment 15(3)247ndash259

Earles J M and A Halog 2011 Consequential life cycle assessmentA review International Journal of Life Cycle Assessment 16(5) 445ndash453

EC (European Community) 2006 Directive 200612EC of the Euro-pean Parliament and of the Council of 5 April 2006 on wasteOfficial Journal of the European Union L1142742006 9ndash21

EC (European Community) 2009 Directive 2009125EC of the Eu-ropean Parliament and of the Council of 21 October 2009 es-tablishing a framework for the setting of ecodesign requirementsfor energy-related products Official Journal of the European UnionL28531102009 10ndash35

Ekvall T and A Andrae 2006 Attributional and consequential envi-ronmental assessment of the shift to lead-free solders InternationalJournal of Life Cycle Assessment 11(5) 344ndash353

Fava J S Baer and J Cooper 2009 Increasing demands for life cycleassessment in North America Journal of Industrial Ecology 13(4)491ndash494

Finnveden G M Z Hauschild T Ekvall J B Guinee R Heijungs SHellweg A Koehler D Pennington and S Suh 2009 Recentdevelopments in life cycle assessment Journal of EnvironmentalManagement 91(1) 1ndash21

Finnveden G and M Nilsson 2005 Site-dependent life-cycle impactassessment in Sweden International Journal of Life Cycle Assessment10(4) 235ndash239

Franze J and A Ciroth 2011 A comparison of cut roses from Ecuadorand the Netherlands International Journal of Life Cycle Assessment16(4) 366ndash379

Gallego A L Rodrıguez A Hospido M T Moreira and G Fei-joo 2010 Development of regional characterization factors foraquatic eutrophication International Journal of Life Cycle Assess-ment 15(1) 32ndash43

Gandhi N M Diamond D can de Meent M A J Huijbregts WJ G M Peijnenburg and J B Guinee 2010 New method forcalculating comparative toxicity potential of cationic metals infreshwater Application to copper nickel and zinc EnvironmentalScience amp Technology 44(13) 5195ndash5201

Geisler G T B Hofstetter and K Hungerbuhler 2004 Productionof fine and speciality chemicals Procedure for the estimationof LCIs International Journal of Life Cycle Assessment 9(2) 101ndash113

Glass G V 1976 Primary secondary and meta-analysis of researchEducational Researcher 5 3ndash8



Goedkoop M R Heijungs M A J Huijbregts A M De SchryverJ Struijs and R van Zelm 2009 ReCiPe 2008 ndash A life cycleimpact assessment method which comprises harmonised category in-dicators at the midpoint and the endpoint level First edition Re-port I Characterisation wwwlcia-recipenet Accessed January2011

Graedel T E E van der Voet (eds) 2010 Linkages of sustainabilityCambridge MA USA MIT Press

Guinee J B R Heijungs G Huppes A Zamagni P Masoni R Buon-amici T Ekvall and T Rydberg 2011 Life cycle assessment Pastpresent and future Environmental Science and Technology 45(1)90ndash96

Guinee J B G Huppes R Heijungs and E van der Voet 2009Research strategy programmes and exemplary projects on life cyclesustainability analysis (LCSA) Technical Report of the CALCASproject wwwcalcasprojectnet Accessed December 2010

Heijungs R G Huppes and G B Guinee 2010 Life cycle assessmentand sustainability analysis of products materials and technologiesTowards a scientific framework for sustainability life cycle analysisPolymer Degradation and Stability 95(3) 422ndash428

Hellweg S E Demou R Bruzzi A Meijer R K Rosenbaum M AJ Huijbregts and T M C McKone 2009 Integrating humanindoor air pollutant exposure within life cycle impact assessmentEnvironmental Science amp Technology 43(6) 1670ndash1679

Hischier R S Hellweg C Capello and A Primas 2005 Establish-ing life cycle inventories of chemicals based on differing dataavailability International Journal of Life Cycle Assessment 10(1)59ndash67

Hojer M S Ahlroth K H Dreborg T Ekvall G Finnveden OHjelm E Hochschorner M Nilsson and V Palm 2008 Scenar-ios in selected tools for environmental system analysis Journal ofCleaner Production 16(18) 1958ndash1970

Huijbregts M A J 1998 Part II Dealing with parameter uncertaintyand uncertainty due to choices in life cycle assessment Interna-tional Journal of Life Cycle Assessment 3(6) 343ndash351

Huijbregts M A J W Gilijamse A M J Ragas and L Reijnders2003 Evaluating uncertainty in environmental life cycle assess-ment A case study comparing two insulation options for a Dutchone-family dwelling Environmental Science and Technology 37(11)2600ndash2608

Hunkeler D D Lichtenvort and G Rebitzer (eds) 2008 Environ-mental life cycle costing Pensacola FL USA CRC SETAC USA

Huppes G and M Ishikawa 2009 Eco-efficiency guiding micro-levelactions towards sustainability Ten basic steps for analysis Eco-logical Economics 68(6) 1687ndash1700

ISO (International Organization for Standardization) 2006a ISO14040 Environmental management ndash Life cycle assessment ndash Princi-ples and framework Geneva Switzerland ISO

ISO (International Organization for Standardization) 2006b ISO14044 Environmental management ndash Life cycle assessment ndash Re-quirements and guidelines Geneva Switzerland ISO

Itsubo N and I Atsushi 2007 LIME2 ndash Development of the up-dated Japanese damage oriented LCIA methodology Paper pre-sented at SETAC Europe 17th annual meeting 20ndash24 May PortoPortugal

Jolliet O R Muller-Wenk J Bare A Brent M GoedkoopR Heijungs N Itsubo C Pena D Pennington J Pot-ting G Rebitzer M Stewart H Udo de Haes andBP Weidema 2004 The LCIA midpoint-damage frame-work of the UNEPSETAC life cycle initiative InternationalJournal of Life Cycle Assessment 9(6) 394ndash404

Joslashrgensen A M Z Hauschild M S Joslashrgensen and A Wangel2009 Relevance and feasibility of social life cycle assessmentfrom a company perspective International Journal of Life CycleAssessment 14(3) 204ndash214

Joslashrgensen A C H Lai Lufanna and M Z Hauschild 2010 Assessingthe validity of impact pathways for child labour and well-beingin social life cycle assessment International Journal of Life CycleAssessment 15(1) 5ndash16

Joslashrgensen A A Le Bocq L Nazarkina and M Hauschild 2008Methodologies for social life cycle assessment International Journalof Life Cycle Assessment 13(2) 96ndash103

Joshi S 1999 Product environmental life-cycle assessment usinginput-output techniques Journal of Industrial Ecology 3(2ndash3) 95ndash120

JRC-IES (Joint Research Centre Institute for Environment andSustainability) 2010 ILCD handbook General guide for life cycleassessment ndash Provisions and action steps Ispra Italy European Com-mission JRC-IES httplctjrceceuropaeupdf-directoryILCD-Handbook-General-guide-for-LCA-PROVISIONS-online-12March2010pdf Accessed December 2010

Kim I and T Hur 2009 Integration of working environment intolife cycle assessment framework International Journal of Life CycleAssessment 14(4) 290ndash301

Kloepffer W 2008 Life cycle sustainability assessment of productsInternational Journal of Life Cycle Assessment 13(2) 89ndash95

Lloyd S M and R Ries 2007 Characterizing propagating andanalysing uncertainty in life-cycle assessment Journal of Indus-trial Ecology 11(1) 161ndash179

Lund H B V Mathiesen P Christensen and J H Schmidt 2010Energy system analysis of marginal electricity supply in conse-quential LCA International Journal of Life Cycle Assessment 15(3)260ndash271

Mathiesen B V M Munster and T Fruegaard 2009 Uncertaintiesrelated to the identification of the marginal energy technology inconsequential life cycle assessment Journal of Cleaner Production17 1331ndash1338

Mattila T J S Pakarinen and L Sokka 2010 Quantifying the totalenvironmental impacts of an industrial symbiosis ndash A compar-ison of process- hybrid and input-output life cycle assessmentEnvironmental Science amp Technology 44(11) 4309ndash4314

Mila i Canals L C Bauer J Depestele A Dubreuil R FreiermuthKnuchel G Gaillard O Michelsen R Muller-Wenk and BRydgren 2007a Key elements in a framework for land use im-pact assessment within LCA International Journal of Life CycleAssessment 12(1) 5ndash15

Mila i Canals L R Muller-Wenk C Bauer J Depestele A DubreuilR Freiermuth Knuchel G Gaillard O Michelsen and B Ry-dgren 2007b Key elements in a framework for land use impactassessment in LCA International Journal of Life Cycle Assessment12(1) 2ndash4

Moreno A F Cappellaro P Masoni and A Amato 2011 Applica-tion of product data technology standards to LCA data Journal ofIndustrial Ecology 15(4)483ndash495

Mueller K M Lamperth and F Kimura 2004 Parameterised inven-tories for life cycle assessment International Journal of Life CycleAssessment 9 227ndash235

Nielsen A M and B P Weidema 2001 Inputoutput analysis ndash Short-cuts to life cycle data Environmental Project No 581 CopenhagenDenmark Danish Environmental Protection Agency

Nunez M B Civit P Munoz A P Arena J Rieradevall and AAnton 2010 Assessing potential desertification environmental



impact in life cycle assessment Part 1 Methodological aspectsInternational Journal of Life Cycle Assessment 15(1) 67ndash78

Pfister S A Koehler and S Hellweg 2009 Assessing the environ-mental impacts of freshwater consumption in LCA EnvironmentalScience amp Technology 43(11) 4098ndash4104

Reap J F Roman S Duncan and B Bras 2008a A survey of unre-solved problems in life cycle assessment Part 1 Goal and scopeand inventory analysis International Journal of Life Cycle Assess-ment 13(10) 290ndash300

Reap J F Roman S Duncan and B Bras 2008b A survey of unre-solved problems in life cycle assessment Part 2 Impact assessmentand interpretation International Journal of Life Cycle Assessment13(5) 374ndash388

Rebitzer G and T Ekvall (eds) 2004 Scenarios in life cycle assessment(LCAS) Pensacola FL USA SETAC

Reitinger C M Dumke M Barosevcic and R Hillerbrand2011 A conceptual framework for impact assessment withinSLCA International Journal of Life Cycle Assessment 16(4)380ndash388

Rosenbaum R K T M Bachmann R S Gold M A J HuijbregtsO Jolliet R Juraske A Kohler HF Larsen M MacLeod MMargni TE McKone J Payet M Schuhmacher D Van deMeent and MZ Hauschild 2008 USEtoxmdashthe UNEP-SETACtoxicity model Recommended characterisation factors for humantoxicity and freshwater ecotoxicity in life cycle impact assessmentInternational Journal of Life Cycle Assessment 13(7) 532ndash546

Rowley H V S Lundie and G M Peters 2009 A hybrid life cycle as-sessment model for comparison with conventional methodologiesin Australia International Journal of Life Cycle Assessment 14(6)508ndash516

Rudner L G V Glass D L Evartt and P J Emery 2002 A userrsquosguide to the meta-analysis of research studies Education ResourcesInformation Center Clearinghouse on Assessment and Evalua-tion University of Maryland College Park MD USA

Rydberg T A Oman I Joborn E Eriksson M Pitts SValdivia R Buonamici et al 2008 Sustainability decisionspractical survey Technical Report of the CALCAS projectwwwcalcasprojectnet Accessed December 2010

Rydberg T M Pitts U Pretato F Rubik K Suomalainen and SValdivia 2009 Demand for science in sustainability decision supportndash Identification of user needs Technical Report of the CALCASproject wwwcalcasprojectnet Accessed December 2010

Rydh C J and M Sun 2005 Life cycle inventory data for materi-als grouped according to environmental and material propertiesJournal of Cleaner Production 13(13ndash14) 1258ndash1268

Schmidt J H 2008 System delimitation in agricultural consequentialLCA ndash Outline of methodology and illustrative case study ofwheat in Denmark International Journal of Life Cycle Assessment13(4) 350ndash364

Seppala J M Posch M Johansson and J P Hettelingh 2006Country-dependent characterisation factors for acidification andterrestrial eutrophication based on accumulated exceedance asan impact category indicator International Journal of Life CycleAssessment 11(6) 403ndash416

SETAC (Society of Environmental Toxicology and Chemistry) Eu-rope LCA Steering Committee 2008 Standardisation effortsto measure greenhouse gases and lsquocarbon footprintingrsquo forproducts International Journal of Life Cycle Assessment 13(2)87ndash88

Settanni E 2008 The need for a computational structure of LCCInternational Journal of Life Cycle Assessment 13(7) 526ndash531

Shah V P and R J Ries 2009 A characterization model with spa-tial and temporal resolution for life cycle impact assessment ofphotochemical precursors in the United States International Jour-nal of Life Cycle Assessment 14(4) 313ndash327

Sonnemann G and B Vigon (eds) 2011 Global guidance principles forlife cycle assessment databases Pensacola FL USA SETAC LifeCycle Initiative

Sonnemann G B Vigon C Broadbent M A Curran M FinkbeinerR Frischknecht A Inaba A Schanssema M StevensonC M L Ugaya H Wang M A Wolf and S Valdivia 2011 Pro-cess on ldquoglobal guidance for LCA databasesrdquo International Journalof Life Cycle Assessment 16(1)95ndash97

Suh S and G Huppes 2005 Methods for life cycle inventory of aproduct Journal of Cleaner Production 13(7) 687ndash697

Suh S and S Nakamura 2007 Five years in the area of input-outputand hybrid LCA International Journal of Life Cycle Assessment12(6) 351ndash352

Swarr T 2009 Societal life cycle assessment ndash Could you repeatthe question International Journal of Life Cycle Assessment 14(4)285ndash289

Swarr T E D Hunkeler W Klopffer H L Pesonen A Ciroth AC Brent and R Pagan 2011 Environmental life cycle costing acode of practice Pensacola FL USA SETAC

Tukker A E Poliakov R Heijungs T Hawkins F Neuwahl JM Rueda-Cantuche S Giljum et al 2009 Towards a globalmulti-regional environmentally extended input-output databaseEcological Economics 68(7)1928ndash1937

Venkatesh G J Hammervold and H Bratteboslash 2009 CombinedMFA-LCA for analysis of wastewater pipeline networks Journalof Industrial Ecology 13(4) 532ndash550

Weidema B P T Ekvall and R Heijungs 2009 Guidelines for applica-tion of deepened and broadened LCA Deliverable of the CALCASproject wwwcalcasprojectnet Accessed January 2011

Wegener SleeswijkA 2011 Regional LCA in a global perspectiveA basis for spatially differentiated environmental life cycle as-sessment International Journal of Life Cycle Assessment 16(2)106ndash112

Wegener Sleeswijk A and R Heijungs 2010 GLOBOX A spatiallydifferentiated global fate intake and effect model for toxicityassessment in LCA Science of the Total Environment 408(14)2817ndash2832

Wernet G S Papadokonstantakis S Hellweg and K Hungerbuhler2009 Advanced neural network models for the prediction ofchemical production properties Paper presented at of SETACEurope 19th annual meeting 31 Mayndash4 June Goteborg Sweden

Yi I N Itsubo A Inaba and K Matsumoto 2007 Developmentof the interregional IO based LCA method considering region-specifics of indirect effects in regional evaluation InternationalJournal of Life Cycle Assessment 12(6) 353ndash364

Zamagni A O Amerighi and P Buttol Strengths or bias in so-cial LCA International Journal of Life cycle Assessment 16(7)596ndash598

Zamagni A R Buonamici P Buttol P L Porta and P Masoni2009a Main RampD lines to improve reliability significance and us-ability of standardised LCA Technical Report of the CALCASproject wwwcalcasprojectnet Accessed December 2010

Zamagni A P Buttol R Buonamici P Masoni JB GuineeG Huppes R Heijungs E van der Voet T Ekvall and TRydberg 2009b Blue paper on life cycle sustainability analysis2009 Deliverable 20 of Work Package 7 of the CALCAS projectwwwcalcasprojectnet Accessed December 2010



Zamagni A P Buttol P L Porta R Buonamici P Masoni J BGuinee R Heijungs T Ekvall R Bersani A Bienkowska andU Pretato 2008 Critical review of the current research needs andlimitations related to ISO-LCA practice Technical Report of theCALCAS project wwwcalcasprojectnet Accessed December2010

Zhang Y A Baral and B R Bakshi 2010 Accounting for ecosystemservices in life cycle assessment part II Toward an ecologicallybased LCA Environmental Science amp Technology 44(7) 2624ndash2631

Zurek M B and T Henrichs 2007 Linking scenarios across geograph-ical scales in international environmental assessments Technolog-ical Forecast and Societal Change 74(8) 1282ndash1295

About the Authors

Alessandra Zamagni a PhD candidate at University ldquoGdrsquoAnnunziordquo Pescara Italy is a researcher at the Italian Na-tional Agency for New Technology Energy and SustainableEconomic Development (ENEA) Bologna Italy Patrizia But-tol and Roberto Buonamici are respectively first researcherand research director at ENEA Bologna Italy Paolo Masoniis a research director and leads the LCA and Ecodesign Labora-tory at ENEA Bologna Italy Andrea Raggi is full professor inindustrial ecology at the University ldquoG drsquoAnnunziordquo PescaraItaly

Supporting Information

Additional supporting information may be found in the online version of this article

Supporting Information S1 This supporting information contains a detailed list of references analyzed in the literaturereview These references are organized according to the phases of LCA methodology

Please note Wiley-Blackwell is not responsible for the content or functionality of any supporting information sup-plied by the authors Any queries (other than missing material) should be directed to the corresponding author for thearticle



Standardization (ISO) 14040 and 14044 standards (ISO 2006a2006b) will serve as a basis for comparable and reliable LCAapplications in business and public decision making

This increasing interest in LCT has been driven also by theconsiderable methodological development of LCA in the lastfew years as testified by the scientific articles published so far2

Indeed most of the developments have occurred in the last tenyears which was referred to by Guinee and colleagues (2011) asldquothe decade of elaborationrdquo Regarding the impact assessmentphase new impact categories indicators and characterizationfactors have been developed Moreover an increased sophisti-cation of the existing methods of characterization has been alsoproposed (eg with the introduction of spatial and temporal dif-ferentiation) In the realm of the inventory analysis the need toassess policies technological and structural choices character-ized by scarce reversibility long-term effects trade-offs betweenenvironment economy and society and so on has been drivingan expansion of the scope of LCA both in terms of the levelof analysis (from products to systems from micro to macro)and coverage of indicators (including also economic and so-cial aspects) Consequential LCA hybrid approaches combin-ing LCA and input-output analysis (IOA) scenario modelingand new efforts for developing social and economic assessmentmethods are only some examples of the developments LCAmethodology has been going through Overall it may appearthat LCA lacks direction on how to further develop

Starting from the considerations above we questionedwhether it would be possible to structure the present develop-ments and organize unexplored areas questions and researchpriorities to further develop LCA For this purpose the existingliterature on LCA was examined using an approach that wasinspired by the meta-analysis concept but differs in a numberof ways which are discussed below

Widely used in social and medical sciences meta-analysis isusually a quantitative statistical technique aimed at combiningthe results of several studies in order to test the pooled data forstatistical significance Even when used as a component of asystematic review procedure its focus is on the use of statisticalmethods as a way to combine evidence

As far as the scope of this article is concerned it is clear thatthe classic meta-analysis approach cannot be adopted becausethe object of study is represented by methodological develop-ments and not by analytical and quantitative studies whose re-sults can be coded by means of statistical parameters Howeverthe rationale behind the approach is fully applicable becausemeta-analysis is meant as the analyses ldquoof a large collection ofresults from individual studies for the purpose of integratingthe findingsrdquo (Glass 1976 3) For this reason inspired by themeta-analysis concept we developed a structured approach toexamine the existing literature on LCA The approach is char-acterized by a shared subjectivity in review rather than a trueobjectivity which can never be assured when qualitative ele-ments are dominant In fact the decisions made are public andtransparent and open to criticism from other researchers

First the article illustrates the approach starting with ananalysis of the existing literature on LCA As an intermediate

step the main methodological aspects the scientific commu-nity is working on are defined together with the research needsto fully develop them Then research gaps are identified withthe support of a survey on usersrsquo needs on how to further de-velop LCA Finally the results are discussed organized in tworesearch thrusts and in the last section the main conclusionsare drawn

A Structured Approach to Examining LifeCycle Assessment Literature

When research results accumulate it becomes increasinglydifficult to understand the direction they point out and whetheran unambiguous conclusion can be reached Under those cir-cumstances a feeling of confusion and frustration might arise(Rudner et al 2002) because consensus cannot be found in theliterature3 resulting in ambiguity and impossibility in makingknowledge available to final users (policy makers consumerstechnicians) in a fruitful way

Ambiguity arises whenever a contradiction exists on top-icsstudies on the same (and sometimes controversial) subjectThis is quite common in the scientific literature on method-ological developments that should explore by definition allthe maze of knowledge and also investigate options that seeminconclusive or even unfeasible at first glance However re-searchers do not always aim to validate previous findings or toexamine them critically Some authors present approaches forsolving a specific problem without duly taking previous worksinto consideration and thus without any criticism of themMoreover it is not always true that a lack of debate on a spe-cific issue is a symptom of consensus on that issue or vice versaIn this way it is not always possible to properly evaluate theconsensus of the LCA scientific community on the (relativeand absolute) relevance of an approach by means of a mereliterature review

We developed an approach to ldquoextract knowledge from stud-iesrdquo (Glass 1976) and to investigate the methodological devel-opments in which the literature review is coupled with an anal-ysis of usersrsquo needs and with expert judgment The purpose is toreduce the subjectivity in drawing conclusions In fact whileevery analysis requires a certain degree of subjectivity in makingdecisionsmdashfor example in relation to the identification and se-lection of the relevant literaturemdashin our approach choices arealways explicitly stated and therefore open to criticism

The approach consists of the following steps

bull Definition of the research questionThe question raised by the authors is the following given asituation of nonharmonized and sometimes diverging de-velopments in the literature over the last decade (Guineeet al 2011) how can the direction(s) in which LCA ispointing be identified How can coherent research thrustsbe identified

bull Carrying out the literature reviewInclusion and exclusion criteria for the studies to be ana-lyzed are set up The purpose is to identify methodological








Literature Review

























































(Continued)



Table 1 (Continued)


































































































Acknowledgements



Notes









References









































































































About the Authors













Literature Review

























































(Continued)



Table 1 (Continued)


































































































Acknowledgements



Notes









References









































































































About the Authors



















































(Continued)



Table 1 (Continued)


































































































Acknowledgements



Notes









References









































































































About the Authors


































(Continued)



Table 1 (Continued)


































































































Acknowledgements



Notes









References









































































































About the Authors








Table 1 (Continued)


































































































Acknowledgements



Notes









References









































































































About the Authors










































































Acknowledgements



Notes









References









































































































About the Authors















































Acknowledgements



Notes









References









































































































About the Authors



























Acknowledgements



Notes









References









































































































About the Authors


















Acknowledgements



Notes









References









































































































About the Authors











References









































































































About the Authors

















































































About the Authors














































About the Authors











About the Authors







Documents

Finding Life Cycle Assessment Research Direction with the Aid of Meta-Analysis