Page 214 - Materials Chemistry, Second Edition
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198 4 Life Cycle Impact Assessment
whereas the distance with regard to other impact categories is, however, still
very high (implementation deficits). These rankings are not completely free of
arbitrariness, but can be applied by authorities in a responsible way for one nation
(here: Germany).
Several software tools have already integrated the grouping criteria without users
being aware of how these criteria were developed and on what value choices they
are the based. The following provides a short sample illustration of this approach
in the element ‘grouping’ by the method of the Federal Environmental Agency
(UBA). 43)
An overview of todays LCIA methods can be found in Section 4.5. The ranking
44)
of impact categories in the method applied by the Federal Environmental Agency
(UBA) refers to three criteria: ecological endangering, distance-to-target and specific
contribution.
1. Ecological Endangering According to this criterion impact categories are put
into an order according to the seriousness of the potential damage.
The following premises are defined for a characterisation of seriousness:
• Profound impacts at the level of the ecological system are more serious
than those at the level of organisms.
• Irreversible impacts are more serious than reversible ones.
• Ubiquitous impacts are more serious than spatially limited ones.
• Large uncertainty for the prognosis of an environmental impact because
of unsatisfactory scientific knowledge is serious.
Specialised departments of UBA provided expertise for ranking based on these
premises on impact categories. The advisory board graded impact categories
on a five-stage scale (A: highest priority to E: lowest priority, Table 4.3). It is
expressly stressed that this ranking is based on value choices of the UBA and
needs to be examined thoroughly for a scientific upgrade.
2. Distance-to-target According to this criterion impact categories are assigned
ranks by the seriousness of the distance between the status quo and political
and legal objectives concerning the environment. The following premises are
defined for a characterisation of seriousness:
• The larger the distance between the status quo and a quantified quality
goal of the environment, the more serious the deviation.
• A high diminution demand provided by an environmental action goal is
serious.
• Rising loads (e.g. emissions) are regarded as more serious than stagnating
or diminishing ones.
• Small enforceability and technical accessibility of a goal are regarded as
serious.
43) Schmitz and Paulini (1999).
44) Schmitz and Paulini (1999).