Page 275 - Materials Chemistry, Second Edition

4.5 Impact Categories, Impact Indicators and Characterisation Factors 259

4.5.2.5.3 Regionalisation Attempts for a regionalisation of non-global impact
categories are based on complex models, which cannot be discussed here in detail.
The following is meant to provide an overview on the state of the art and should
entice further reading of the quoted primary literature.
Jos´ e Potting has for the first time pointed out that a neglect of spatial dimen-
sions in the impact assessment can imply wrong results for non-global impact
categories. 239) Deficits of the less-is-better approach in the characterisation model
‘acidification’, which have already been discussed, have transformed this category
into a test area for developments directed towards a more realistic spatial indicator
model, which should also consider impact thresholds or critical loads. 240) Newer
developments are directed to the calculation of (European) country-dependent
characterisation factors for SO ,NO and NH . As a prerequisite for the applica-
2 x 3
tion of these factors, an assignment to the European countries where the relevant
emissions originated (per fU) is necessary. This is without doubt easier for sta-
tionary emitters, like power plants than for product systems. The same applies
for all non-global impact categories. The resilience of ecosystems to be protected,
a concept which is not considered in the definition of the AP, is introduced by
means of critical loads 241) in divers regions. An atmospheric transport from emitting
countries to the sites of impact is simulated and models of diverse complexity are
applied. Within a critical evaluation of different approaches to the modelling 242) an
exact but necessarily very complex model 243) was used to test options for simpler
linear models. Advantages of simpler models in the context of impact assess-
ment are self-evident. A decision towards a best suited characterisation factor has
not yet been made. A useful characterisation factor independent of the model
may be the average accumulated exceedance 244) of critical load. Since however
the concept of critical load is not based on a dose-impact relation, from the
authors’ point of view further research is necessary whether critical loads may be
used as surrogate. The underlying problem being of course that limit values are
predominantly pragmatically defined and are not the result of precise scientific
analyses.
Bellekom et al. (2006, loc. cit.) investigated the feasibility of the application of a
site-dependent impact assessment for the impact category acidification within three
existing LCAs (linoleum 245) , rock wool 246) , water pipe systems). 247) To achieve this,
inventories, which usually do not list the origin of emissions, had to be extended.

239) Potting and Blok (1994) and Potting (2000).
240) Potting and Hauschild (1997a,b), Potting et al. (1998, 2002), Huijbregts et al. (2000a), Hauschild
and Potting (2001), Krewitt et al. (2001), Hettelingh, Posch and Potting (2005), Bellekom, Potting
and Benders (2006) and Sedlbauer et al. (2007).
241) Hettelingh, Posch and De Smet (2001).
242) Hettelingh et al. (2005).
243) The RAINS model used by Potting Amann et al. (1999) as well as the EcoSense model used by
Krewitt were ranked by Hettelingh et al. (2005) as complex models.
244) Average Accumulated Exceedance Posch, Hettelingh and De Smet (2001) and Sepp¨ al¨ a et al.
(2006).
245) Gorree et al. (2000).
246) Schmidt et al. (2004).
247) Boersma and Kramer (1999 (NL)), quoted in Bellekom et al. (2006).