Uncertainty and sensitivity analysis of normalization factors to methodological assumptions
Normalisation factors are calculated as results of regional/global inventories of
emission and resources characterised trough impact assessment methods. Several
methodological assumptions are needed for building the inventory. Sala et al 2015
presented a set of normalisation factors for the EU 2010 defining a methodological
approach for sources selection and for building proxy indicators. Qualitative and
quantitative uncertainty evaluation is needed for assessing the robustness of final
figures. Five sources of uncertainty have been analysed in this work: (F1) the selection
of the sources of data; (F2) the classification of data as life cycle inventory (LCI)
elementary flows; (F3) the classification of substances for characterization; (F4) the
specification of the emission compartments; and (F5) the use of spatially differentiated
characterization factors. The sensitivity of the normalization factors to such
uncertainties were assessed through a global sensitivity method, for the impact
categories acidification (ACID), terrestrial eutrophication (ET), marine eutrophication
(EM), photochemical ozone formation (POF), respiratory inorganics/particulate matter
(RIPM) and water depletion (WD).The uncertainty associated with the methodological
choices made for calculating normalization factors (Sala et al 2015) was assessed.
Generally the value calculated by Sala et al (2015) compare well against average and
median values estimated in this analysis for ACID, ET, EM and POF. Instead, the
impact categories RIPM and WD show different patterns, for the former, although the
average value is very similar, the median value is far lower than the normalization
factor reported by Sala et al. (2015). For what concerns WD, the median value is much
higher. Future improvements of the normalization factors should therefore prioritize the
development of more detailed inventories of emissions by including: higher substance
resolution, height of emission as well as the use of spatially differentiated
characterization factors. The authors recommend that the normalization factors from
Sala et al. (2015) are applied together with two additional sets of normalization factors
i.e. the 'median values' and the set of 'average + standard deviation' values, so to
better capture their uncertainty. Similarly, the interpretation of the results should build
on the qualitative estimates of robustness provided by Sala et al. (2015).
BENINI Lorenzo;
SALA Serenella;
2016-01-21
SPRINGER HEIDELBERG
JRC98017
0948-3349,
http://link.springer.com/article/10.1007%2Fs11367-015-1013-5,
https://publications.jrc.ec.europa.eu/repository/handle/JRC98017,
10.1007/s11367-015-1013-5,
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