Page 239 - Materials Chemistry, Second Edition
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4.5 Impact Categories, Impact Indicators and Characterisation Factors 223
for hunting, is mostly ‘fostered’, that is, only hunted at certain times and fed on
in the winter. Such activities belong to the technosphere. Similar considerations
are valid for the fishery in rivers and lakes. Too large game populations imply
substantial damage to vegetation and these animals do not belong to species
threatened with extinction. Non-fostered wild game and those, which inspite of
protective regulations are illegally poached can belong to threatened species. In
general, animals and plants in nature with a high commercial value are threatened,
for example, as hunting trophies, nutrition, source for medical active substances
or for certain cultural or superstitious practices. The quoted subchapter of the final
report of the second SETAC Europe working group ‘Impact Assessment’ 115) besides
a detailed discussion of the protection goal provides a list of animals and plants,
threatened with extinction (extreme case) by overfishing, or by a drastic population
decrease, and so on. These species are, if relevant for a specific LCA, to be recorded
in the inventory and subsequently be assessed in the impact assessment as ‘biotic
resources’. Mueller Wenk estimates that of the many millions of species of (wild)
animals and plants only some thousands are used by humans as resources and only
some hundreds (above all, fish and tropical plants) are threatened by direct use.
The threat to a variety of species by destruction of habitats due to anthropogenic
land use is not considered. Also Mueller Wenk points to the fact that apart from
the shortage caused by land use a contribution to a reduction of the variety of
species or biological variety (biodiversity) is to be considered. 116) Its impairment is
an important impact category, unfortunately with no clear indicator yet (see Section
4.5.1.6), so that it can only indirectly be covered by other categories.
Impact Indicators and Characterisation Factors
If to be recorded separately, non-regenerative (finite) biotic resources, for example,
ecological systems like the tropical rain forest with its specific spectra of species
can be elaborated with similar impact indicators as discussed for abiotic non-
regenerative resources. In addition however tables with static ranges would have to
be present.
Shortage or scarceness as impact indicator is also valid for regenerative biotic
resources. Shortage occurs, if withdrawal – globally or in a specific region – exceeds
generation. For a quantification of regenerative biotic resources their formation rate
must be known. Contrary to finite resources – which by continuing withdrawal will
get exhausted in any case, being only a question of time – a sustainable use can be
achieved for regenerative resources, if the following permanently applies:
Withdrawal per time unit (world annual consumption) ≤ formation rate
The natural measure for the scarceness of regenerative resources is thus the
difference between the world’s annual consumption and the formation rate, related
to world reserves. In this case the resources scarcity factor R can be computed
i
according to Equation 4.8.
As with abiotic finite resources the world reserves of biotic resources can only
with difficulty be precisely established. Also the determination of formation rates
115) Mueller Wenk, in: Udo de Haes et al. (2002).
116) Koellner and Geyer (2013) special issue land use.