Page 52 - Materials Chemistry, Second Edition

A N OVERVIEW OF THE LIFE CYCLE ASSESSMENT METHOD 33

standardization for environmental policy raised serious problems, which have
not yet been solved adequately [52]:

• As life-cycle based carbon footprint calculations may constitute
the basis for decisions, e.g. granting subsidies to stimulate the use
of bio-energy, it is of utmost importance that the indicator results
be robust and lawsuit-proof/ This implies that the freedom of
methodological choices for the handling of data, e.g., biogenic
carbon balances and allocation, should be reduced to an absolute
minimum [53].
• Another topic is that the limited scope of carbon footprints is not
sufficiently accounted for when using the results. The scopes of
carbon footprint studies can be limited in geographic coverage
(dominated by Europe and North America), in feed stocks
covered, in the number of different emissions to the environ-
ment included, and in environmental impacts addressed (carbon
footprint studies are typically limited to global warming, while
other environmental impacts can be more important when assess-
ing the sustainability of products, for example, biofuels: eutrophi-
cation, acidification, ecotoxicity and human toxicity, biodiversity,
water use, etc.; [54]). These limitations should at least be clearly
reported as part of the conclusions of current, narrow-scope
carbon footprint studies.
• A final topic of concern is the translation from functional-unit-based
to real-world improvements. This may be the most difficult issue
to address. Side-effects such as indirect land use, rebound effects,
market mechanisms, and such all play a role in how large-scale
production of biofuels would affect the food market, scarcity,
social structure, land use, nature and other things that are impor-
tant for society. These are insufficiently addressed by current
LCA studies, as was identified and analyzed by Sheehan [55], van
der Voet and Lifset (li), and in the EU FP6 CALCAS project [56].
Although consequential LCA (e.g., [57]) is very strong in map-
ping impacts of indirectly affected processes of a decision, mod-
eling macroscopic land use changes on the basis of microscopic
consequential product LCAs (bottom-up) is not likely to result
in long-run sustainability. It may be more realistic to start think-
ing how more realistic, macroscopic scenarios for land use, water,
resources and materials, and energy (top-down) such as drafted
by the IPCC [58] and in the work by Graedel and van der Voet [59]
can be transposed to microscopic LCA scenarios.

The period 2000-2010 can be characterized as the decade of elaboration.
While the demand on LCA increases, the current period is characterized by a
divergence in methods again. As ISO never aimed to standardize LCA methods