DOI: http://dx.doi.org/10.1065/lca2003.02.105
AIM, SCOPE AND BACKGROUND. Given the communication limitation of a damage-oriented approach, the question addressed in this paper is how normalisation can be developed instead. Normalisation of product service systems without value choices is, in accordance to ISO 14042, suitable for external communication. Reason normalisation approaches use a geographically-defined baseline year of emissions, optionally combined with politically established target emissions (Guinée 2002, Stranddorf et al. 2001). In contradiction to these approaches, this paper aims to draw up the general structure of an alternative normalisation procedure. The normalisation procedure suggested here is based on environmental quality objectives (EQO), in order to streamline the result to include as few output parameters as possible, without compromising the scientific robustness of the method.
MAIN FEATURES. This article describes a normalisation procedure based on environmental quality objectives. Comparison between this approach and a damage-oriented approach is conducted. The relevant working area concerning dose and effect is evaluated. Then a discussion is conducted focusing on the trade-off necessary to achieve an integrated category indicator, covering the following issues; model reliability, user applicability and the unambiguously of the result.
RESULT. A damage-oriented approach will have to take into account all the defined consequences from all impact categories that affect the safeguards in parallel. In other words, each impact category indicator and its potential effects on all safeguards must be evaluated and accounted for. In the case where a single category indicator cannot be found without utilising value choices, a number of category indicators will then have to constitute an intermediate category indicator result, where weighting must be applied in order to streamline the result.
In contrast to the above approach, the suggested normalisation procedure utilises the precautionary principle with respect to the essential EQO in order to achieve a category indicator result, called a critical load category indicator result. In practice, this means that the number of figures in an LCIA-profile based on critical load will always be the same as the number of impact categories.
CONCLUSIONS. The suggested EQO normalisation procedure forms a set of critical loads per impact category, where each is defined by a critical load function where linearity is defined between a zero load and the critical load. This procedure will affect the temporal resolution and the field of application of the LCIA method. The positive aspect is that the suggested normalisation procedure renders the method applicable for long-lived products like, for example, buildings or other infrastructures. This aspect is gained by reducing the damage-oriented resolution.
Consequently, for long-lived products where the main environmental loads will appear in the future, it is hard to assess by a damage-oriented LCIA method (if all boundary conditions are not assumed to be fixed). The EQO normalisation method will, in this respect, improve the overall reliability of the outcome of an LCA when long-lived products are assessed. For short-lived products, adequate boundary conditions can be achieved, and for this reason a damage-oriented approach will have the possibility to address current consequences. Nevertheless, a damage-oriented approach working area is not applicable beneath thresholds unlike the EQO normalisation procedure. The most effective decision support of short-lived products is therefore achieved when both approaches are applied.
OUTLOOK. A complementary paper will be produced where the described normalisation procedure is exemplified in a case study, with special interest on assessment of chemical substances. |
