The feasibility of including sustainability in LCA for product development

Journal of Cleaner Production 6 (1998) 289–298

The feasibility of including sustainability in LCA for productdevelopment

Karin Anderssona,b, Merete Høgaas Eidea, Ulrika Lundqvistc,*, Berit Mattssona

a SIK, The Swedish Institute for Food and Biotechnology, Box 5401, SE-402 29 Go¨teborg, Swedenb Current address: CIT Ekologik, Chalmers Teknikpark, SE-412 88 Go¨teborg, Sweden

c Department of Physical Resource Theory, Chalmers University of Technology and Go¨teborg University, SE-412 96 Go¨teborg, Sweden

Abstract

The feasibility of combining the concept of sustainability principles and the methodology of Life Cycle Assessment (LCA) isexamined. The goal is to achieve an operational tool that incorporates sustainability in product development and strategic planning.While the method outlined has the structure of LCA, it emphasises aspects and parameters often omitted from traditional LCA.The analysis and results can be either qualitative or semi-quantitative. Although a qualitative analysis is less time consuming, itcan still highlight the important issues. Qualitative information, which is easily lost in a quantitative analysis, can be emphasised.One of the conclusions is that the method is well suited for screening analysis. 1998 Elsevier Science Ltd. All rights reserved.

Keywords:Sustainability principles; Life cycle assessment; Environmental performance

1. Introduction

There is a growing awareness of the need to takeaction against pollution and resource depletion, althoughhow this should be done is not so obvious. Environmen-tal problems have changed in the past decades to becomemore global, diffuse, delayed and complex [1]. In thissituation, a systems perspective and a comprehensiveview are necessary. As discussed by Holmberg et al. [2],if one concentrates on effects late in the complex cause-and-effect chain (from activities in society to environ-mental effects), the uncertainties increase and it is diffi-cult to reach scientific consensus about the consequencesof actions. For example, it is hard to reach consensusabout actions that have the specific effect of avoidingconcentrations of polychlorinated biphenyls (PCBs) innature. However, if a decision is made early in the chainof causes and effects, for example whether or not theproduction of a persistent ecotoxic substance should beallowed, it is easier to reach consensus. Hence, there isan evident need for fundamental principles, which take

* Corresponding author. Tel:1 46-31-772-10-00; Fax:1 46-31-772-31-50.

0959-6526/98/$19.00 1998 Elsevier Science Ltd. All rights reserved.PII: S0959-6526 (98)00028-6

effect early in the cause-and-effect chain, for guidancein decision-making.

There are different tools which can be used to achieveenvironmental improvements, for example Life CycleAssessment (LCA) and the concept of sustainabilityprinciples. LCA is a method for assessment of theenvironmental impact of products, processes or servicesfrom raw materials to waste products. It is often used tocompare products with the same function. Another wayto use the method is to identify ‘hot spots’, that is partsof the life cycle that are critical to the total environmen-tal impact. The LCA method is still being worked out[3,4]. Harmonisation and standardisation are carried outby SETAC (The Society of Environmental Toxicologyand Chemistry) and ISO (The International Standardis-ation Organisation).

Sustainable development was defined in 1987 byWCED as ‘meeting the needs of the present withoutcompromising the ability of future generations to meettheir own needs’ [5]. Since then different approaches toachieve sustainable development have been discussed.One approach is to define a sustainability model whichcan provide a framework for society’s activities [2,6].Central to the model of sustainability is the cyclic prin-ciple, which means that the societal metabolism must be

290 K. Andersson et al. / Journal of Cleaner Production 6 (1998) 289–298

integrated with the cycles in nature. Based on the modelof sustainability, Holmberg et al. have formulated fourSocio-Ecological Principles: 1) Substances from thelithosphere must not systematically accumulate in theecosphere; 2) Substances produced by society must notsystematically accumulate in the ecosphere; 3) Thephysical basis for the productivity and diversity of theecosphere must not be systematically deteriorated; and4) Resources must be used fairly and efficiently withrespect to meeting human needs [2].

There are advantages and disadvantages with both theLCA method and the concept of sustainability. LCA hasthe advantage of being operational. So far, LCA has beenused mainly for comparison and optimisation of existingproduct systems. Using current production systems as astarting-point can be a drawback; there is a risk that onlysmall improvements can be achieved and that the devel-opment of completely new, more sustainable systems isdelayed or prevented. The Socio-Ecological Principleshave the advantage of being based on a model of sus-tainability. This is a strength that the current valuationmethods used in LCAs lack, although they all aim atenvironmental improvements. The ecoscarcity, theeffect-category and the EPS (Environmental PriorityStrategies) methods are examples of formalised, quanti-tative LCA valuation methods. While the ecoscarcity andthe effect-category methods relate the environmentalimpacts to given goals (often political), the EPS systemis based on willingness to pay for the restoration of five‘safe guard subjects’ (biodiversity, biological pro-duction, human health, resources and aesthetic values)[4]. Thus, these valuation methods are tied to economicand political issues. On the other hand, the Socio-Eco-logical Principles are difficult to use as an operationaltool either to achieve quick improvements or for com-parisons. However, they do function well for strategicplanning on higher management levels and with longertime perspectives.

In order to make the concept of sustainability oper-ational, quantitative indicators or indices, which can beused to determine whether a change is a step towardssustainability or not, have been designed. Narodoslaw-sky and Krotscheck have developed the concept of a sus-tainable process index, SPI [7]. The core of the SPIevaluation is the calculation of the land area needed toembed a process completely into the biosphere. Ragaset al. have outlined a method to calculate sustainabilityindicators for production systems [8]. With respect tothe four Socio-Ecological Principles, Azar et al. havepresented a framework of socio-ecological indicators,while Carlson et al. have worked out a set of socio-eco-logical indicators for a specific region [9,10].

Many Swedish corporations and municipalities arealready using the Socio-Ecological Principles in theirlong term strategic planning. However, as a complement,there is a need for an operational method. The objective

of this paper is to examine and discuss the feasibility ofincluding the four Socio-Ecological Principles, as cri-teria for sustainability, in the LCA methodology. Withthis combination we hope to achieve a method with theadvantages of both the four Socio-Ecological Principlesand LCA. The four Socio-Ecological Principles andLCA are explained in more detail in the section onmethod. For each LCA phase, the four Socio-EcologicalPrinciples are discussed with respect to use and benefit.The type of results that can be obtained when the methodis used for product development is illustrated by the useof examples from a case study of tomato ketchup carriedout using traditional LCA [11]. It is our belief that themethod outlined can be a valuable tool for qualitative orsemi-quantitative analyses. Thus, time and costs can besaved while the important issues are still highlighted.

2. Method

We have incorporated the Socio-Ecological Principlesin each of the four main steps of LCA: goal and scopedefinition, inventory analysis, impact assessment andimprovement assessment [12], and we describe how ourprocedure is different or new in comparison with tra-ditional LCA. Carrying out LCA studies is an iterativeprocedure. In the procedure outlined in the followingsections we start with aqualitative approach. After animpact assessment is concluded there is an option to goback and, for a selected part, make aquantitativeinven-tory analysis. For screening analysis, that is the identifi-cation of some particular characteristics or key issues[13], a qualitative study may be sufficient. Dependingon the intent of the study, it may be preferable to includea quantitative part as well. To illustrate our approach tothe LCA methodology, we use selected parts from a casestudy of tomato ketchup [11].

2.1. Goal and scope definition

The main goal of our approach to the LCA method-ology is to incorporate the sustainability perspective inthe development of products and processes. As criteriafor sustainability, we use the four Socio-Ecological Prin-ciples that are explained below [2].

Principle 1: substances from the lithosphere must notsystematically accumulate in the ecosphere

Substances from the lithosphere must not be spreadin the ecosphere faster than either the sedimentation pro-cesses return them to the lithosphere or they aredeposited as final deposits in the lithosphere. If such sub-stances accumulate, it is extremely hard to say at whatconcentration they will cause damage, because of com-plex causal chains and delay mechanisms in the eco-sphere. Often, it is possible to know only that therewill

291K. Andersson et al. / Journal of Cleaner Production 6 (1998) 289–298

bedamage if there is a systematic accumulation, but notwhen. In practical terms this means that the use of fossilfuels and mining (especially of scarce metals) must beradically decreased.

Principle 2: society-produced substances must not sys-tematically accumulate in the ecosphere

Society-produced substances (molecules and atomicnuclei of different kinds) must not be produced fasterthan they can be broken down and integrated in the biog-eochemical cycles or deposited in final deposits in thelithosphere. Otherwise, such substances will accumulatesomewhere in the ecosphere and the concentration willincrease towards often unknown limits beyond whichdamage occurs. In practical terms this means that boththe intentional and unintentional production of naturalsubstances that can accumulate must be decreased. Theuse of persistent substances foreign to nature must bephased out.

Principle 3: the physical conditions for production anddiversity within the ecosphere must not be systemati-cally deteriorated

Society must not systematically reduce the physicalconditions for production capacity in the ecosphere orthe diversity of the biosphere. Society must neither takemore resources from the ecosphere than are regeneratednor reduce natural productivity or diversity by manipul-ating natural systems. Our health and prosperity dependon the capacity of nature to concentrate and restructureused materials into resources. Society is dependent onthe long-term functions of the ecosystems. This depen-dence will become more obvious when the use of fossilfuels and uranium is reduced (according to Principles 1and 2). In practical terms this means much more efficientand careful use of areas productive for agriculture, for-estry and fishing. Likewise infrastructure needs to bemore carefully planned.

Principle 4: the use of resources must be efficient andjust with respect to meeting human needs

Principles 1, 2 and 3 imply major restrictions on thematerial flows to and from human societies. In order tofulfil human needs and to have an attractive society, inspite of these restrictions and a growing population, theresources and services obtained from nature must beused efficiently within the society. Efficiency also meansthat resources should be used where they are neededmost. Resources should be distributed among humansocieties and human beings to supply at least basicneeds. In practical terms, this means increased technicaland organisational efficiency as well as a more just dis-tribution of resources, including more resource-efficientlifestyles for the rich part of humankind.

Socio-Ecological Principle 3, concerning the physical

conditions for biological production and diversity, andPrinciple 4, concerning an efficient and fair use ofresources, make the perspective wider than that of tra-ditional LCA. Some aspects of Principle 4 should beconsideredbeforea proposed inventory analysis, sincethe result of such a consideration may be that the inven-tory analysis should not be performed at all, or shouldbe performed on an alternative production system.Aspects that should be take into account are whether theservicedelivered is suitable to provide in a sustainablesociety, based on the type of need that the service fulfils,and whether the service could be supplied by means ofotherstrategies, such as alternative products or processesthat would be more appropriate in a sustainable society.These aspects are discussed in more detail in the impactassessment section. In our example, the producer of tom-ato ketchup wishes to include environmental aspects inthe product development. The question is: what alter-ations are necessary in order to devise a more sustainableproduct, which will be competitive in the long run?

2.2. Inventory analysis

As in traditional LCA, the system under study isdefined and a flow chart illustrating the processesincluded is prepared. In the next step, energy andmaterial flows are identified as well as ecosystemmanipulations and aspects of Principle 4.

Ecosystem manipulations should be identified in orderto handle the aspects of Socio-Ecological Principle 3 thatdeal with long-term productivity and biodiversity withinthe ecosphere; these aspects can be difficult to quantify.Besides the exchange of energy and material betweennature and society, manipulation of subsystems of theecosphere has been identified as a major mechanism inthe physical influence of society on nature. The influenceon the ecosphere of society’s manipulation can take theform of:

I displacement of the ecosphere, that is the artefacts andactivities of society force away or disturb ecologicalsystems or geophysical functions, for instance by thehardening of surfaces;

I reshaping of structures of the ecosphere, for examplethe damming of rivers, ditching and ploughing; and

I guiding of processes and flows, for instance agricul-tural practices and manipulation of genes.

The application of Principle 4 (efficient and just useof resources) to a production system is less straightfor-ward than Principles 1 to 3. Examples of aspects thatshould be considered are: geographic location of pro-cesses, whether material flows are linear or cyclic, andthe levels of technology that are used in various pro-cesses. (Aspects of Principle 4 are described in moredetail in the impact assessment section.)

The tomato ketchup system studied is shown sche-


matically in Fig. 1. As regards the system boundaries,production of electricity is included and production ofcapital goods (physical plant) is excluded. The house-hold phase means the storage of ketchup bottles inrefrigerators. The inputs, outputs and ecosystem manipu-lations related to the subsystems in the ketchup systemare compiled in Table 1. Notice especially the ecosystemmanipulations. Aspects of Principle 4 were not includedin this table.

2.3. Impact assessment

The impact assessment presented here uses aqualitat-ive approach. Potentialhot spotsare discussed for eachSocio-Ecological Principle and examples of hot spots areidentified in the ketchup study.

Potential hot spots for Principle 1 are flows (inputsand outputs) of substances from the lithosphere that arescarcein the ecosphere. These substances have a greaterpotential to increase systematically in the ecospherewhen emitted, that is to violate Principle 1, than sub-stances that occur in larger quantities. Substancesextracted from the lithosphere may eventually disperseto the ecosphere unless action is taken to prevent thisfrom happening; inputs of such substances, therefore cangive early warning signals. The use of fossil fuels shouldalso be considered a potential hot spot. The use of thesefuels leads to emissions of several substances such aslithospheric carbon, sulphur and a notable amount of all

Fig. 1. Flow chart for the ketchup system studied [11].

sorts of metals that may systematically increase in theecosphere.

Threecategoriesof substances to consider in connec-tion with Principle 1 are listed in Table 2. We proposea gradingsystem in order to identify potential hot spots.Any societal influence on nature can under certain cir-cumstances give rise to environmental problems; accord-ingly, we suggest that all flows and manipulations shouldbe given at least one minus sign. Those with three minussigns are considered to be the worst potential hot spots.Metals and other substances from the lithosphere aregraded according to their occurrence in the ecosphere,and fossil fuels according to their rate of natural regener-ation, that is the rate at which carbon is removed fromthe ecosphere. The parameter that the grading is basedon is divided into three relatively equalranges, in pow-ers of ten, of the total (existing) range for that parameter.This can be illustrated with the proposed grading of met-als, here based on the global median soil content. Silveris one of the scarcest metals in soils, 0.05 mg/kg soil,while aluminium is the most abundant, 72,000 mg/kgsoil [14]. From this total range we have proposed thefollowing three ranges for the three grades: 0.01 (0 inTable 2) to 0.99; 1 to 99; and 100 to 100,000 mg/kg soil.Flows of substances identified in the inventory analysisfor the tomato ketchup study were sorted according tothe categories of Principle 1 and given grades, see Table2. In the ketchup study, the emissions of cadmium andthe use of oil, gas and coal are identified as potential hotspots for Principle 1.

Potential hot spots for Principle 2 are flows (inputsand outputs) of persistent substances (or substances withmetabolites that are persistent) and of substances not nat-urally occurring in the ecosphere. Such substances arepotentially more likely to increase systematically in theecosphere when emitted, that is to violate Principle 2.When we know more about cause-and-effect chains forsubstances, additional potential hot spots can be ident-ified as flows of substances with high potential to con-tribute to well-known environmental impacts or to bioac-cumulate. Examples of such categories to consider forPrinciple 2, with proposed ranges and correspondinggrades, are shown in Table 3. The ranges are defined ina way similar to that used for the categories for Principle1. It should be noted that some flows of substances aresorted to both Principles 1 and 2, and are therefore con-sidered twice in the method suggested. For example, car-bon dioxide emitted from fossil fuels, originates fromthe lithosphere but is also produced within society. Thisprocedure has a pedagogic value since it highlights theconnection between use of resources and potentialenvironmental effects. In the ketchup study, the potentialhot spots of Principle 2 are emissions of substancesgraded with three minus signs, for instance the refriger-ant CFC-11, nitrous oxide and phosphorous.

Potential hot spots for Principle 3 are harvesting and


Table 1The inputs, outputs and ecosystem manipulation related to the different processes in the ketchup system. Based on Andersson et al. [11]

Inputs Outputs Ecosystem manipulation

Agriculture

Gas, oil, coal; Phosphate rock; Potassium To air: SO2, NOx, N2O, CO, CO2, NH3, particulates, Agriculture (tomatoes, sugar beets); Watersalt or clay minerals. ash, fluorides, organic compounds (e.g. HC, CH4, use.

aldehydes);To water: solids, oil, phenol, organic matter, N,fluorides;To water and soil: pesticides and their intermediatesand degradation products, Cd, As, Zn; Solid waste.

Food processing

Gas, oil, coal; Peat; Hydropower; To air: SO2, NOx, N2O, CO, CO2, organic compounds Forestry (biofuela); Water use; AgricultureUranium; Cleaning agents; Process aids; (e.g. HC, ethanol, CH4, aldehydes), NH3, ash, (spicesa).Limestone; Alcohol. particulates, radon;

To water: solids, oil, phenol, organic matter, N, P,NH3, Cl−, Cu, Zn;Other: Radioactive waste; solid waste.

Transportation

Oil To air: SO2, NOx, CO, CO2, HC, particulates;To water: oil, phenol, organic matter, nitrogen.

Packaging

Gas, oil, coal; Peat; Hydropower; To air: SO2, NOx, N2O, CO, CO2, HC, aldehydes, Forestry (biofuela, wooda); Water use.Uranium; Fe, Al; Additives (e.g., BHT). NH3, CH4, particulates, ash, fluorides, smelly

substances, radon;To water: solids, oil, phenol, organic matter, N,nitrates, NH3, inorganic substances (e.g. Na+, Cl−,Fe2

+, SO42 2 , fluorides), organic substances;

Other: Radioactive waste; solid waste; BHT.

Household phase

Gas, oil, coal; Peat; Hydropower; To air: SO2, NOx, N2O, CO, CO2, HC, particulates, Forestry (biofuela)Uranium. ash, CH4, freons;

Other: Radioactive waste.

aNot included in the system boundaries for the original ketchup study by Andersson et al. [11]

Table 2General framework of impact assessment for Socio-Ecological Principle 1: categories with defined ranges and corresponding grades. An LCA studyperformed on tomato ketchup is used as an example [11]

Category [unit for range] Range Grade Example: Ketchup study

Metalsa 100– – Al, Fe[mg/kg soils] 1–99 – – Zn, As, U

0–0.99 – – – Cd

Other elementsa 100– – P[mg/kg soils] 1–99 – –

0–0.99 – – –

Fossil fuelsb 10– –[1012 kg C/yr] 0.1–9.9 – – Peat

0–0.099 – – – Oil, gas, coal

aGlobal median soil content [14];bRate of natural regeneration [14].


Table 3General framework of impact assessment for Socio-Ecological Principle 2: examples of categories with defined ranges and corresponding grades.An LCA study performed on tomato ketchup is used as an example [11]

Category [unit for range] Range Grade Example: Ketchup study

Global warminga 0–9.9 – CO2

[CO2 equiv.] 10–99 – – CH4100– – – – N2O

Ozone depletionb 0–0.099 –[CFC-11 equiv.] 0.1–0.99 – –

1– – – – CFC-11

Eutrophicationc 0–9.9 – NO3−, COD, NOx

[g O2/g] 10–99 – – NH3

100– – – – P

Acidificationd 0–1 –[mol H+/mol] 1 – – NOx, NH3

2 – – – SO2

Photo-oxidant formatione 0–0.0099 – CH40.01–0.099 – –

[ethene-equiv.] 0.1– – – – HC, aldehydes, ethanol

Human toxicityf 0–0.0099 – Fe(w), Zn(w,s), NO3−(w)[kg body weight/kg] 0.01–9.9 – – As(s), Cd(s), Cu(w), CO(a),

SO2(a), Phenol(w)10– – – –

aGlobal warming potential (GWP), 100 years [15];bOzone depletion potential (ODP), best estimate [16];cOxygen depletion, scenario maximum(including both terrestrial and aquatic systems, as well as systems limited in P and N) [4];dAmount of protons released [4];ePhotochemical ozonecreation potential (POCP) for Europe [3];fCML (Centre of Environmental Science, Leiden University, Leiden) weighting factors for air (a), water(w) and soil (s) [3].

manipulation of ecosystems, which threaten long-termproductivity and biodiversity. Examples of activities(categories) to consider are agriculture, forestry, fish-eries, water use and hardening of surface areas.

Agriculture and forestry are complex activities thatinvolve a variety of characteristics. To make the methodfeasible, we suggest the use of threeclassificationsofagriculture and forestry; these are characterised by spe-cific practices, based on their influence on long-term pro-ductivity and biodiversity. (Aspects related to the otherthree Socio-Ecological Principles could also beincluded.) The classification can be used as a basis forthe grading to identify potential hot spots (similar to theranges used for Principles 1 and 2). An example of aclassification offorestry could be as follows (startingwith the grade of three minus signs).

I Large-scale conventional forestryis characterised by,in the worst case, site clearing, clear-cutting, site prep-aration with establishment of protective ditches andplanting of a single species.

I Site-adapted forestrymeans that each site in a forestis cut and reforested according to the practices whichare best suited to producing a hardy regeneration anda high yield.

I Forestry according to preliminary criteria for an

environmental certificate of forestry, has the aim topreserve biodiversity and production capacity [17].

Agriculture could be classified in a similar way. Sus-tainable agriculture could include practices such ascovered fields during autumn and winter and coveredzones alongside watercourses (to reduce losses of nutri-ents and soil erosion), rotation of crops (to reduce theneed of pesticides) and using lighter agriculturalmachines (to prevent soil compaction). The use of ferti-lisers in sustainable agriculture should also be based onthe four Socio-Ecological Principles; the concentrationof cadmium should not be allowed to increase systemati-cally in the soil and losses of nutrients should be mini-mised both to avoid eutrophication and to use resourcesefficiently.Fisheriescould be classified according to fishspecies, fishing method and fishing ground. The har-vesting of fish should be cautious in order to avoid overharvesting. Theuse of fresh watercould be classifiedbased on the relative supply of water in a specific areaor season.Hardening of the surface areacould be classi-fied by the productivity of the area or by ecologicalvalues. For example, the hardening of highly productivearable land or rain forests should be graded with threeminus signs. Examples of classifications for these activi-ties are not included in this paper. In the ketchup


example, integrated production methods are used in theagriculture [18]. This implies that efforts have beenmade to minimise the use of fertilisers and pesticides.However, more detailed information is required to assessthe agricultural production according to Principle 3.

Potential hot spots for Principle 4 are low quality ser-vices, systems (products and processes) that do not fitin with a sustainable society, organisational inefficiencyand old technologies. The first two categories for Prin-ciple 4, services and strategies, should be assessedbeforethe inventory analysis since the result of such an assess-ment may be that the inventory analysis should not beperformed at all, or should be performed on a differentproduction system. However, the next two categories,organisational and technological efficiency, should beconsidered after the inventory analysis, since their aimis to improve the efficiency of theexistingsystem.

Theservicesthat products and processes provide varyin quality; two major types of variation are how essentiala given human need is and what proportion of the popu-lation can be satisfied. In fulfilling human needs,resources and services obtained from nature should beused where they are needed most, that is to supply prim-arily basic needs. In practical terms this means a morejustifiable distribution of resources among products andprocesses. To classify products and processes based onthe necessity of their service is apt to be controversialand loaded with subjective judgements.

There are differentstrategiesto provide a service; dif-ferent systems (products and processes) could be chosen.In order to avoid sub-optimisation when aiming towardssustainability, one should consider whether the existingsystem could provide the required service in a sus-tainable society or whether alternative (possiblyforthcoming) systems would be more favourable,according to the Socio-Ecological Principles. Systemscould be classified as being those heading towards a deadend that would not fit in a sustainable society, tran-sitional systems heading towards sustainability or sys-tems appropriate in a sustainable society. A conventionalsteam–electric coal power plant can be considered adead-end technology, while a coal integratedgasifier/combined cycle power plant may be a tran-sitional technology. The reason is that much of what hasbeen learned in developing this technology is readilytransferable to thebiomassintegrated gasifier/combinedcycle power plant which would probably fit into a sus-tainable society.

When the strategy to provide a particular service hasbeen chosen, the efficiency of the system selected maybe further improved. Both organisational and technologi-cal efficiency should be considered.Organisationalefficiencydepends on how, when and where differentactivities are performed and connected to each other.The degree of efficiency can be defined as the supply ofservices in relation to inputs of resources and outputs of

emissions. Planning, knowledge, interest and sense ofresponsibility increase the organisational efficiency.Examples of relevant issues are logistics, localisation,design and recycling.

Different technologiesvary in efficiency as shown bythe supply of services in relation to inputs of resourcesand outputs of emissions. Technological progress tendsto imply improved efficiency. A classification of tech-nology could be based on different stages of evolution,for example best available, average existing and oldtechnology.

After the identification of potential hot spots for allfour Socio-Ecological Principles, there is an option togo back and for selected parts to make aquantitativeinventory analysis or to continue with an improvementassessment. The selected parts could be, for example,flows and manipulations graded with three minus signsas well as flows and manipulations suspected to be rela-tively large, regardless of the grade. The environmentalinfluence caused by a flow or manipulation depends notonly on the quality of the flow or manipulation, shownby the grade, but also on the magnitude. A relativelylarge flow graded with only one minus sign can be moredamaging to the environment than a relatively small flowgraded with three minus signs. Consequently, relativelylarge flows and manipulations should also be consideredpotential hot spots. For instance, in global warming, theamount of CO2 emitted (graded minus one) is oftenextremely large compared with the flows of other sub-stances. For industrial combustion of heavy oil or coal,the amount of CO2 emitted is 5000 times higher thanthe amount of N2O. For N2O and CO2, the weightingfactors for contribution to global warming are 320 and1, respectively [15]. Although N2O was graded minusthree and CO2 only minus one in our example, it is ofequal or greater importance to reduce the emissions ofCO2, since the large amount means that it contributesmore to global warming than the N2O emissions.

2.4. Improvement assessment

When it is not a comparative study, the objective ofan LCA is to identify environmental problems and topoint out where improvements are most urgently needed.The improvement analysis should result in suggestionsfor the development of more sustainable products andprocesses [3].

General guidelines for the improvement assessmentare the following.

I Substitution of material flows [19] means that hazard-ous materials should be exchanged for less harmfulones, scarce materials for more abundant ones andnon-renewable materials for renewable ones.

I Dematerialisation [19] means that efforts should bemade to use smaller amounts of materials to provide


the same service. Whenever possible, the quality of aproduct should be improved to increase its life time.Linear flows should be replaced by cyclic flows,which can be achieved by reuse or recycling ofmaterials.

I With regard to ecosystem manipulation, measuresshould be taken to sustain or to improve the long-term productivity and biodiversity. In the choice ofstrategies for organisation and technology, care shouldbe taken to avoid sub-optimisations.

In our example, cadmium and the use of oil, gas andcoal violate Principle 1 and were given three minuses.Directly and indirectly, fossil fuels are used in all partsof the life cycle. They are used for heat production, asfuel in vehicles and, indirectly, in the production of rawmaterials such as nitrogen fertiliser. Whenever possible,energy use should be decreased by using more energyefficient transports, processes and energy recovery. Sub-stituting renewable fuels for non-renewable ones wouldbe an important step towards sustainability. Cadmiumoriginates from the phosphate rock used in fertiliser pro-duction. Even a very small amount leads to accumu-lation, and it is very toxic. The release of cadmium is aserious problem, especially since it is spread on arableland, and it has been known to end up in food crops.Improved recirculation of phosphorous in society wouldmean that the mining of phosphate rock and release ofcadmium would decrease. It is also possible to removecadmium from the phosphorous fertiliser through indus-trial cleaning processes.

Many emissions in the example are listed under Prin-ciple 2. Most of them originate from the use of fossilfuels which is covered by Principle 1. For example, SO2

contributes to acidification, while N2O and CO2 contrib-ute to global warming. The emissions of CO2 and SO2

could be decreased by using energy recovery and bychanging to renewable fuels. Since CFC-11 is a potentcontributor to ozone depletion, it should be replaced bya different, less harmful refrigerant as soon as possible.

Emissions of phosphorous to water contribute toeutrophication; this is a waste of a limited resource.Although phosphorous is common on Earth, workablephosphorous finds with a low content of heavy metalsare limited. Improved agricultural practice woulddecrease the problem. In food systems, the handling ofwaste water should also be given more attention, sincephosphorous can be recovered efficiently from wastewater sewage sludge. This means that, provided it hasnot been contaminated, the phosphorous can be recycledto agriculture, closing the flow.

Principle 3 deals with the conditions for future bio-logical production, which is naturally of vital interest forfood production and future survival. Our example showsthat a change to more sustainable farming practiceswould be desirable. Such a change would rule out the

current use of pesticides and fertilisers, inputs that arecovered by Principles 1 and 2. Pesticides are extremelydifficult to assess because of the great differences in tox-icity and persistency among different compounds.Whenever possible, pesticides should be replaced bynon-chemical crop protection or less harmful com-pounds. Reduced use of fertiliser would requireincreased nutrient recycling rates and improved utilis-ation of plant nutrients. However, more specific data onsoil properties and biodiversity are required in order tomake a complete assessment of the ecosystem manipu-lation.

According to Principle 4, ‘the use of resources mustbe efficient and just with respect to meeting humanneeds’. The product studied in our example, ketchup,probably cannot be said to fulfil an essential humanneed. However, we consider it to be a product whichcould fit in with a sustainable society, provided that theexisting production system is modified according toPrinciples 1 to 3 and that the organisational and techno-logical efficiencies are improved. How the ketchup pro-duct system could be made more efficient is studied bysimulations of production in different locations andmodifications of processes. Education and actions toinvolve the staff are measures which can help to increasethe organisational efficiency.

3. Conclusions and discussion

Our conclusion is that, in working out a tool that canbe used as a compass in the development of a more sus-tainable society, it is both feasible and practical toinclude sustainability aspects in LCA. The Socio-Eco-logical Principles of Holmberg et al. [2] have alreadybeen used successfully on a management level by manySwedish corporations and municipalities in their long-term strategic planning [6]. As a complement, they arelikely to need an operational tool as well; the methodpresented here could be useful.

For product development, process improvement andcomparative studies, LCA is already a useful tool. Themethod outlined fills a gap between traditional LCA andthe Socio-Ecological Principles. Most important is thatits starting-point is a defined model of sustainability,which provides a framework for the activities of society.Thus, the new method is not limited by present pro-duction systems, political or economic issues. This iswhy it can function as a compass that shows the direc-tion towards sustainability; then it is possible to movein this direction.

The method outlined concentrates on effects early inthe complex cause-and-effect chain. Thus, the methodalso gives guidance about substances for which theenvironmental effects are not yet known. The analysisand results can be either qualitative or semi-quantitative.


Although a qualitative analysis is less time consumingand costly, it can still highlight the important issues.With our procedure, it is possible to carry out a rapidscreening; it also eases the inclusion of qualitative infor-mation and aspects not usually included because they aredifficult to quantify. Sometimes it is obvious that thepresent system is unacceptable from an environmentalpoint of view; then it is not worthwhile to carry out acomplete quantitative traditional LCA (note that a tra-ditional LCA can also be qualitative). Determination ofhow and why the Socio-Ecological Principles are beingviolated (hot spot identification) may be enough to beginwith. Afterwards, the flows and ecosystem manipu-lations considered the most important may be concen-trated on in a more detailed quantitative study.

Socio-Ecological Principles 3 and 4 deal withimportant issues that are not usually emphasised in tra-ditional LCA studies. For instance, preservation of thephysical conditions for biological production and diver-sity is one of the key issues for future survival on ourplanet. Land use is closely related to this issue, howeverland use is seldom included in practice. If accounted for,the land area required and the duration of its use areincluded [3]. The EPS system for valuation goes a stepfurther by making a distinction between different typesof land and different ways of using them [4]. How tohandle land use in LCAs of systems including biologicalproduction, for instance agricultural production and for-estry, has been and is still being studied [20,21]. Anintroduction of sustainability goals into LCA wouldmean that the softer issues of Principles 3 and 4 wouldbe highlighted.

Principle 4 raises questions about the product and thesystem that should be taken into consideration preferablyin the goal definition.

I Is there a need for this product?I Can this production system be sustained in a just

world of 10 billion people, or is there a more sus-tainable alternative production system that could pro-vide the same service?

Questions like these are also necessary in avoidingsub-optimisation, which can be a consequence of startingfrom the present production system. Even though a sus-tainable production system cannot be achieved immedi-ately, efforts must be made to identify and choose sys-tems that have the potential to be transitional, and to leadtowards sustainability.

The grading systems constructed for the different cat-egories of Principles 1 and 2 are intended to be prelimi-nary examples to illustrate the method. For some of thecategories in Principle 2, for example photo-oxidant for-mation and human toxicity, there are other characteris-ation methods from which we have made choices. ForPrinciples 3 and 4, criteria for grading remain to be for-

mulated. The use of three grades can also be discussed:are three sufficient or should there be more?

While our new method enables the gain of some newtypes of information, another kind of information maybe lost. Qualitative information about, for example,agriculture, forestry, water use and efficiency is usuallylost in traditional LCA; however this method capturesit. Quantitative information, on the other hand, may belost. Special care should be taken to avoid missing thesignificance of large flows of substances when the sub-stances, themselves are graded as not very likely to dam-age the environment, for example CO2.

The method outlined needs to be worked out further,especially for the categories under Principles 3 and 4.In order to compare products and systems, quantitativemethods are required. To make our method quantitative,priorities must be assigned for both the Socio-EcologicalPrinciples and the categories. However for the appli-cations intended, product development aiming at sus-tainability and screening analysis, the method presentedcan be useful. Since it incorporates an incentive for con-tinuous improvement towards sustainability, we think ithas the potential of becoming a valuable tool to be used,for example, in environmental management systems.Changes towards sustainability are in the long run neces-sary for a company that wants to be competitive.

Acknowledgements

The authors wish to acknowledge John Holmberg,Tomas Rydberg, Tomas Ekvall and Thomas Ohlsson forstimulating discussions and their very useful commentson the manuscript. The following research councils areacknowledged for their financial support: the SwedishWaste Research Council, the Norwegian Research Coun-cil, the Norwegian Dairy Association, the SwedishCouncil for Planning and Co-ordination of Research andthe Swedish Farmers Foundation for AgriculturalResearch.

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The feasibility of including sustainability in LCA for product development