Page 48 - Materials Chemistry, Second Edition

AN OVERVIEW OF THE LIFE CYCLE ASSESSMENT METHOD 29

The practice of LCA is quite meagre, unfortunately. We still see many LCA
studies without uncertainty or sensitivity analysis, even though software
increasingly facilitates this. There is of course a psychological argument that
a contractor pays for finding out something, not for increasing the doubt.
And as many LCA practitioners spend several months on collecting data, it is
never a nice thing to waste this effort in a last-minute uncertainty analysis. But
decision-making obviously means also taking into account the limits of knowl-
edge. Moreover, as discussed before, a proper analysis of uncertainties and
sensitivities helps to prioritize the steps earlier on in the framework: collecting
data, setting boundaries, making choices.

2.1.5 LCA in Practice

In the text above, the emphasis has been on the generally accepted practice.
This is a mix of the ISO standards and a not precisely defined set of guidebooks.
These latter include the ILCD Handbook, the Dutch Handbook on LCA, the
guidelines from EPA, those from JEMAI, and others. All these texts inter-
pret, add, refine, or modify the ISO standards. As has been indicated at a few
places, the practice in LCA is sometimes different from what the ISO stan-
dards prescribe. There are differences in terminology (e.g., one seldom sees the
term intermediate products), in method (cf. the frequent use of the substitu-
tion method), in quality control (judged by frequent absence of uncertainty
analyses), etc.
There are also de facto additional standards, dictated by the use of soft-
ware and databases. Many software packages for LCA have built-in options
for impact assessment and uncertainty analysis, but nearly always in a
restricted form, allowing some variants and prohibiting other variants. LCI
databases are often constructed with pre-defined allocation methods and
cut-off rules, so the user cannot choose otherwise, and cannot carry out sen-
sitivity analyses.
One last, important aspect is the incorporation of new insights. The ISO
standards date from the period 1997-2000, and the 2006 update is not really
an update (just a merging). Meanwhile, numerous developments have
taken place. We mention just a few, without discussing their meaning or
importance:

• The distinction between attributional and consequential LCA;
• The development of input-output-based LCA and hybrid LCA;
• The incorporation of economic and behavioural mechanisms in
the LCA model;
• The development of new impact categories, e.g., for land use and
biodiversity;
• The development of life cycle costing and social LCA, and their
fusion into life cycle sustainability analysis (LCSA);
• The application of LCA to things other than products, like policies
and life styles.