Page 127 - Materials Chemistry, Second Edition

L1644_C03.fm Page 102 Tuesday, October 21, 2003 3:11 PM

For fossil fuels, surplus energy is based on future use of nonconventional
resources, especially oil shale and tar sands. In this case, the model for the surplus
energy is constructed by means of descriptions of the typical characteristics of the
fossil resources and with data on the increased extraction energy for nonconventional
resources.

3.7.5.4 Weighting in the Eco-Indicator 99 Method

With respect to weighting step, different schemes for the evaluation of environmental
damages have been developed. The most fundamental problem in damage estima-
tions is that the final outcome often refers to value choices and thus the weighting
scheme of the decision-maker. A single truth simply does not exist as long as value
choices are necessary. For example, in the case of the YLD and YOLL (previously
seen), because value choices are necessary for weighting, they strongly depend on
the attitude of the person carrying out the weighting step. Moreover, a YOLL at the
age of 20 and a YOLL at the age of 60 are not equally appreciated in every
socioeconomic perspective. Therefore, the DALY concept is linked to the Cultural
Theory earlier described. Moreover, a panel approach is used as another weighting
scheme.

3.7.5.5 The Panel Approach and Graphical Representation

Because weighting should represent the views of society or groups of stakeholders,
the panel approach and the revealed preference were used by eco-indicator 99. The
procedure was developed by Mettier (1998), based on previous experiences with
panel and Delphi methods in LCA (Udo de Haes, 1996), and consists of a five-part
questionnaire to be answered by the panel:
1. An introduction containing a brief description of the purpose, the outline
and intended application of the eco-indicator 99 methodology, and a
description of the damage categories (human health, ecosystems health
and resources)
2. Ranking of the three damage categories (in order of decreasing impor-
tance)
3. Assigning weights
4. Linkages to cultural perspectives
5. Background questions (age, sex, etc.)

The results given by the panel can be represented on a triangle graphic (Figure 3.11).

3.7.5 UNIFORM WORLD MODEL
Based on the Impact Pathway Analysis (IPA) studies on a European level in the
ExternE Project (see in Chapter 4 for more details), Rabl et al. (1998) compared the
results of detailed site-specific calculations for more than 50 electric power stations

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