Environmental Engineering Reference
In-Depth Information
product in a sustainable manner. The product and service concepts must be
developed explicitly using the triple bottom line to estimate market yield.
2.4 LIFE CYCLE ANALYSIS
Life cycle analysis (LCA) is the primary tool used to develop that guide
sustainable growth (Klöpffer, 2003). It is a recent (dates back to the 1970s),
still evolving, and flexible methodology with a general framework
standardizedinISO14040(andASTME1991-05intheUnitedStates)series
of standards. A holistic comprehensive analysis has value as a management
tool. Unfortunately, it often can be complex and an expensive undertaking
and is therefore limited to larger organizations. LCA can be effectively used
within an organization or an industry to recognize areas of improvements
from a sustainability standpoint.
Perhaps, the most important caution in using LCA is to recognize that its
findings are particularly sensitive to the scope and objectives adopted in
the assessments. The results depend heavily on the scope, specific system
boundaries adopted, simplifying assumptions made, and the quality of data
used (Hottle et al., 2013). Metrics for an identical product (e.g., a plastic
bag) manufactured by different fabricators or even by a single manufacturer
but studied by different analysts can yield very different LCA outcomes.
At the outset, the “life cycle” itself needs to be defined, usually selecting
one of the three popular formats illustrated in
Figure 2.7
. All three start
with the extraction of fossil fuel raw materials (
cradle
) but adopt different
endpoints in the life of a product. Cradle-to-gate considers the lifetime up
to the factory gate; cradle-to-grave includes the use and disposal (
grave
);
and cradle-to-cradle includes recovery of the postuse waste and recycling.
It is these boundaries that indicate the scope of analysis adopted in these
LCA studies. The longer the life cycle to be covered, the more information is
required, meaning a more complex and expensive study.
