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3.6.2 ECO-INDICATOR 95 AS EXAMPLE OF A SINGLE INDEX
APPROACH
Eco-indicators are numbers that express the total environmental load of a product
or process. The eco-indicator 95 (Goedkoop, 1995) is one of the weighting methods
based on the “distance to target” in the same way as the similarly structured EDIP
method (Hauschild and Wenzel, 1998). The steps to achieve a weighting are:

1. Determine the relevant effects caused by a process or product.
2. Determine the extent of the effect; this is the normalization value. Divide
the effect by the normalization value. This step determines the contribution
of the product to the total effect. This is done because it is not the effect
that is relevant but rather the degree to which the effect contributes to the
total problem. An important advantage of the normalization stage is that
all the contributions are dimensionless.
3. Multiply the result by the ratio between the current effect and the target
value for that effect. The ratio, also termed the reduction factor, may be
seen as a measure of the seriousness of the effect.
4. Multiply the effect by a so-called subjective weighting factor to link
fatalities, health and ecosystem impairment.

An overview of the principle of eco-indicator 95 is given in Figure 3.7. The
problem, of course, lies in determining the weighting factors — the subjective
damage assessment phase. The eco-indicator 95 uses the so-called distance-to-target
principle to determine weighting factors. The underlying premise is that a correlation
exists between the seriousness of an effect and the distance between the current and
target levels. Thus, if acidification must be reduced by a factor of 10 in order to
achieve a sustainable society and smog by a factor of 5, acidification is regarded as
twice as serious. The reduction factor is the weighting factor.
To establish a correlation between these damage levels and the effects, a detailed
study of the actual state of the environment in Europe was carried out within the
eco-indicator 95 project. The resulting data were used to determine the level of an
environmental problem and by which factor the problem must be reduced to reach
an acceptable level. Table 3.7 lists the weighting factors and the criteria applied.

3.7 DAMAGE-ORIENTED METHODS

3.7.1 INTRODUCTION

All damage-oriented methods try to assess the environmental impacts — not in the
form of impact potentials, but at the damage level, that is, “further down” in the
cause–effect chain. In the case of human health effects, for example, this means not
as HTP but as cancer cases. In order to illustrate the theory behind these damage-
oriented methods, the eco-indicator 99 methodology (Goedkoop and Spriensma,
1999) and the uniform world model (Rabl et al., 1998) are introduced. Another
method based on the same principles has been developed by Steen (1999).

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