Quality Management and Safety Engineering (BSc) - MST 326
Life Cycle Assessment/Analysis (LCA).

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Life Cycle Assessment factsheet (InnProBio)
Resources for environmental impacts and Life Cycle Assessment (LCA)

Concern for environmental issues is not a new phenomenon: key dates ..and.. definitions of eco-efficiency.
A key political concept in this context is Sustainability, and related issues are covered on the Environmental Management Systems page.

Life Cycle Assessment

ISO14040:2006(E) defines four different phases for Life Cycle Assessment.  Brady [1] defines the four phases as follows:

  1. Goal and scope definition of the LCA: the goal and scope of the study are defined in the context of the intended application.
  2. Life Cycle Inventory analysis (LCI) phase: this involves the collection of data, and the calculation procedures, resulting in a table that quantifies the relevant inputs and outputs of the analysed system.
  3. Life Cycle Impact Assessment (LCIA) phase: this translates the results of the inventory analysis into environmental impacts (e.g. eutrophication) with the aim of evaluating the significance of the respective impacts.
  4. Life Cycle Interpretation phase: conclusions and recommendations for decision makers are drawn from the inventory analysis and impact assessment.

The framework set out in the standard then requires:

  1. reporting and critical review of the LCA
  2. limitations of the LCA
  3. relationships between the phases of the LCA, and
  4. conditions of use of value choices and optional elements.

ISO14040:2006(E) suggests that when "setting the system boundary, several life cycle stages, unit processes and flows should be taken into consideration, for example, the following:

There is a problem in measuring the "sustainability" of any particular set of circumstances. A fully Quantitative Life Cycle Analysis would address the balanced requirements arising from (technical), economic, environmental, social and governance issues (the latter three issues are often abbreviated to ESG). Further, there is growing momentum to consider direct (Scope 1), indirect within the company (Scope 2) and indirect within the value chain of the reporting company (Scope 3) emissions [What are Scope 3 emissions?, Carbon Trust].

However, there are a diverse set of issues addressed by different bodies and no agreed weighting, such that each analyst can produce results favourable to the case they wish to make. For example, the sources analysed in the Table below undertake very different analyses for sustainability criteria.

Green Guide to Composites[2] prepared by BRE Environment and NetComposites Azapagic, Emsley and Hamerton [3] DEFRA/DTI Strategy for Non-food Crops and Uses [4] Department of Trade and Industry Technology Programme 2005 Avery: Leadership for Sustainable Futures [5]
        Environmental factors
Climate change global warming potential air pollution
(including greenhouse gases)
  energy consumption ..
share of renewable energy resources
Fossil fuel depletion abiotic resource depletion substitution of fossil fuels energy intensity/mass intensity consumption of fossil fuels per capita
Ozone depletion ozone depletion potential      
Human toxicity in air and human toxicity in water human toxicity potential   toxicity and gas releases  
Ecotoxicity aquatic toxicity potential biodiversity    
Waste disposal   waste management
land pollution
Water extraction   water    
Acid deposition acidification potential      
Eutrophication (over-enrichment of water courses) eutrophication potential water pollution    
Summer smog (low level ozone creation) photochemical oxidants creation potential      
Minerals extraction abiotic resource depletion impacts on non-renewable resources .. resource depletion recycled/rare resources  
    impacts on renewable resources use of renewables .. recyclability  
      service life and intensity  
        Social issues
exposure to risk (to health at work)     health and safety  
    strengthening rural communities   exclusion from access to services
    rural employment generation employment low unemployment
    countryside recreation opportunities    
    social acceptability issues social conditions/inclusion social inequality
    animal welfare    
    genetic modification    
        chronic poverty
        crime level
        average life expectancy
        Economic issues
    economic performance    
    innovation   access to information
    human capital formation   under-education
        distribution of wealth

The Defra/DTI study further divides the issues it lists:

To quote Avery [5]:

"Pressure to focus on the environment in the USA now comes from the financial sector.  Some investors make financial decisions based on studies suggesting that environmentally friendly companies perform better financially [6].  Environmentalism is becoming a question of risk management and credit rating.  For example, insurance companies put environmental pressures on clients; banks and other financiers impose environmental conditions on firms seeking loans; some consumers consider environmental issues in purchasing decisions.  In these and other ways, the trend towards greater emphasis on the environment is translating into more traditional corporate terms of risk management, meeting consumer demands and the cost of capital.  This makes it less an external environmental issue than a strategic part of the business".

Azapagic et al [3, 7] have published a coherent system for the determination of environmental impact classification factors under the following eight categories:

Azapagic et al [3, 7] provide some guidance on the quantification of the above environmental impacts in Appendices to their books.  In [7], it is proposed that the Value Function Approach can be used to aggregate information from the three groups of sustainability factors (economic, environmental and social/cultural).  The most commonly used aggregation model is the additive aggregation in which the value function V(ai) is constructed from the partial value functions vj(ai) defined over a set of criteria j:

LCA value function

where wj is the weight given to each criterion j and ai is a particular alternative from amongst the set under consideration.  The partial value functions are usually standardised so that the worst outcomes are allocated a value of zero and the best outcomes are allocated a value of one (or 100).  The weighting is then indicative of the relative gain associated with an improvement in the system.

Life Cycle Assessment is the subject of the ISO14040 series of standards:

Ayres [8] has published an interesting critique of life cycle analysis and identifies that the methods and models underlying many scenario building efforts and the published LCAs are "inadequate to their stated purpose".

Whilst ISO/TR14047:2003 identifies eight factors for concern similar to the eight environmental impact classification factors in Azapagic et al, these are not necessarily the only issues that need to be considered.  A recent Global Innovation Outlook Report on Water states that "we have never learned how to efficiently manage water .. [but] we will not have the luxury of this ignorance in the future".  Professor John Anthony Allen introduced the concept of  "virtual water" in 1993.  It is a basic measurement of the water required to produce various goods, especially where those goods are traded.  The calculation includes irrigation, industrial processes (and discharges) and transport, but does not consider the source of the water being used.  Hoekstra developed the concept of a "water footprinting" to determine the total water impact of an individual, business or nation.  This measurement estimates the direct and indirect water consumed and/or polluted over unit time.  The measurement distinguishes between freshwater (blue water), evaporated water (green water) and polluted water (grey water).

The EU Concerted Action AIR-CT94-2028 considered harmonistion of environmental life cycle assessment for agriculture [9].

References for Life Cycle Analysis:

  1. John Brady (editor), Environmental Management in Organisations (The IEMA Handbook),
    Earthscan, London & Sterling VA, 2005, pp 229-238.  ISBN 1-83383-976-0.  Second edition, 2011.  PU CSH LibraryEbook ISBN 978-1-29-947658-5..
  2. BRE & NetComposites, Green Guide to Composites: An environmental profiling system for composite materials and products,
    BRE bookshop, 2004.  ISBN 1-86081-733-5.  PU CSH Library
  3. Adisa Azapagic et al, Polymers, the Environment and Sustainable Development,
    John Wiley & Sons, March 2003, ISBN 0-471-87741-7.  PU CSH Library
  4. A Strategy for Non-Food Crops and Uses: Creating Value from Renewable Materials,
    DEFRA/DTI PB9227, 2004.
  5. GC Avery, Leadership for Sustainable Futures - achieving success in a competitive world,
    Edward Elgar, Cheltenham, 2005.  ISBN 1-84542-173-6.  PU CSH Library.
  6. AJ Hoffman, Integrating environmental and social issues into corporate practice, Environment, 2000, 42(5), 22-33.
  7. A Azapagic, S Perdan and R Clift (editors), Sustainable Development in Practice - Case Studies for Engineers and Scientists,
    John Wiley & Sons, May 2004. ISBN 0-470-85609-2.  Second edition, 2011.  ISBN 978-0-470-71872-8.  PU CSH Library.
  8. RU Ayres, Life cycle analysis: a critique, Resources, Conservation and Recycling, September 1995, 14(3-4), 199-235.
  9. E Audsley (co-ordinator) and S Alber, R Clift, S Cowell, P Crettaz, G Gaillard, J Hausheer, O Jolliett, R Kleijn, B Mortensen, D Pearce, E Roger, H Teulon, B Weidema and H van Zeijts, Harmonistion of Environmental Life Cycle Assessment for Agriculture, European Commission DG VI Agriculture Concerted Action AIR-CT94-2028, 2003.

Additional resources

Return to MST 326 home page or to the Environmental Management Systems page
Created as a separate page (out of the above Environmental Management Systems page) by John Summerscales on 25 February 2006 and updated on 18-Feb-2022 8:43.
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