DOI: dx.doi.org/10.1065/lca2002.08.092 --- The impact assessment of the consumption of abiotic
resources, such as fossil fuels or minerals, is usually part of the
Life Cycle Impact Assessment (LCIA) in LCA studies. The problem
with the consumption of such resources is their decreasing
availability for future generations. In currently available LCA
methods (e.g. Eco-indicator´ 99/Goedkoop and Spriensma 1999,
CML/Guinée 2001), the consumption of various abiotic resources
is aggregated into one summarizing indicator within the
characterization phase of the LCIA. This neglects that many
resources are used for different purposes and are not equivalent
to each other. Therefore, the depletion of reserves of functionally
non-equivalent resources should be treated as separate environmental
problems, i.e. as separate impact sub-categories.
Consequently, this study proposes assigning the consumption
of abiotic resources to separate impact sub-categories and, if
possible, integrating them into indicators only according to their
primary function (e.g. coal, natural gas, oil -> consumption of
fossil fuels; phosphate rock -> consumption of phosphate). Since
this approach has been developed in the context of LCA studies
on agricultural production systems, the impact assessment of
the consumption of fossil fuels, phosphate rock, potash salt and
lime is of particular interest and serves as an example. Following
the general LCA framework (Consoli et al. 1993, ISO 1998),
a normalization step is proposed separately for each of the subcategories.
Finally, specific weighting factors have been calculated
for the sub-categories based on the ´distance-to-target´
principle. The weighting step allows for further interpretation
and enables the aggregation of the consumption of different
abiotic resources to one summarizing indicator, called the Resource
Depletion Index (RDI). The proposed method has been
applied to a wheat production system in order to illustrate the
conceptual considerations and to compare the approach to an
established impact assessment method for abiotic resources
(CML method, Guinée 2001). |
