Page 36 - Materials Chemistry, Second Edition

Chapter 3

Life cycle assessment in practice

Tim Grant

This chapter introduces and critically evaluates methods and approaches in LCA practice, both
in Australia and around the world. Generic reference to ‘life cycle assessment’ (LCA) includes
a wide range of practices and approaches, each with strengths and weaknesses and offering a
range of appropriateness to different settings and contexts. Cutting across this diversity,
however, runs a core set of elements that are common and necessary to all successful LCA
practice. These common elements are discussed, following an introduction to the diversity of
approaches used.

3.1 Introduction: a typology of practices
LCA is often referred to as a single technique. However, within the general principles of adding
up environmental impacts along a supply chain and representing these as environmental indi-
cators, there is a plethora of approaches and scales within which LCA is undertaken. Variation
in LCA practice is a result of differences in questions, availability of resources and data, and
variations in environmental or socioeconomic conditions. Added to this is a wide range of
approaches allowed by LCA standards, and significant differences across practitioners’ prefer-
ences, so it is unsurprising that there is considerable diversity in the way studies are conducted.
The description of the problem or question is the appropriate starting point in all LCA
studies. However, from this initial point, diversity in practice starts to creep in. The question
can be vague. For example: ‘Where are the environmental impacts in my supply chain?’ Or
very specific; for example: ‘Are plastic bumper bars superior from a greenhouse- and resource-
depletion perspective to steel bumper bars in Australian manufactured cars?’ The questions in
LCA can evolve over the study, and the extent to which resources are committed before the
first insights and answers are obtained is often the extent to which resources are wasted on the
wrong question. Efficient and agile use of LCA dictates an iterative approach which feeds back
early results of LCA studies into the later stages of data collection, reporting, impact assess-
ment and interpretation.
Diversity in practice then permeates the remainder of the LCA process, starting with the
establishment of the assessment’s scope. Three major variables in the scope are typically
adjusted according to the type of assessment being undertaken. They are:
s the number of life cycle stages
s the number of environmental impacts or indicators to be considered
s the quantity of data locally collected specifically for the LCA study.

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