Action News vol 5 no 1 1997 ISSN 1324-6011
By Adrian Hill, NSW Community Lead Advisory Service.
This article is based on an article called "Life Cycle Assessment - What it is and How to do it" by the United Nations Environment Programme, with thanks to Shenu Chanmagan.
Life cycle assessment (LCA) is a decision support tool supplying information on the environmental effects of products. It furnishes information on the environmental effects of all the stages of a product’s life cycle. This information can be used by governments and by companies as well as by NGOs and individual consumers when making decisions related to products. Eco-labelling, product and process improvements, and purchasing decisions, for example, can be supported by life cycle assessment.
Today, knowledge of how to carry out an LCA is improving rapidly. The value of the technique is being increasingly recognised and it is now being used for strategic decision making and for designing environmental policies.
Because LCA integrates all the environmental problems produced during the entire life cycle of a product or function, LCA can be used to prevent three common forms of problem shifting:
An LCA is an iterative process, in that the assessment is repeated several times, each time in more detail. First, a superficial analysis is made using approximate data; this results in a ‘quick-and-dirty’ assessment. Although such an analysis is sometimes all that is required, more often this first assessment is used to highlight the points on which to focus to obtain an improved assessment.
It is therefore important to know what level of sophistication should be associated with a certain type of application. In product design, for instance, results must be correct on average, that is most of the time; in eco-labelling, they must almost always be correct.
Another application of LCA is to compare product alternatives. In order to do this a suitable comparison criterion is needed and the most basic criterion is the function that the product is to fulfil.
It would be nonsensical to compare a disposable paper cup with a china cup, given that the life span of the two differs by a factor of at least 100. Instead, the function of the two alternatives, such as drinking one cup of coffee, could be compared. The function to be compared is referred to as the functional unit.
Problems caused by LCA
Three of the major problems in using LCA have to do with time:
The current complexity of LCA means that a long and careful study must be made before a public LCA can be produced, especially since stakeholders with opposed views will, if they can, justify their views by criticising the way an LCA is made. This is not a characteristic of LCA in particular but applies to all techniques of environmental analysis.
Although LCA often stimulates the development of cleaner products, companies can also claim that, since an LCA shows that ‘product A is best’ or an ecolabel has been awarded for a product, further innovation is not needed. One solution to this problem is to restrict the validity of an ecolabel, say to a three-year period. Consideration can also be given to extending the principle of an expiry date to other LCA applications
In response to the need for a unified framework for LCA, the following framework has been developed by the United Nations Environment Programme, based on one developed by SETAC (Society of Environmental Toxicology and Chemistry):-
Goal definition and scope
The product(s) to be assessed are defined, a functional basis for comparison is chosen and the required level of detail is defined.
The energy and raw materials used, and emissions to the atmosphere, water and land are quantified for each process and then combined in the process flow chart.
The effects of the resource use and emissions generated are grouped and quantified into a limited number of impact categories which may then be weighted for importance.
The results are reported in the most informative way possible and the need and opportunities to reduce the impact of the product(s) on the environment are systematically evaluated.
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