Page 201 - Design for Environment A Guide to Sustainable Product Development

180 Cha pte r Ni ne

• Global warming potential due to the build-up of greenhouse
gases, such as carbon dioxide, methane, and nitrous oxide.
• Acidification due to emissions that increase the acidity of
water and soil systems.
• Eutrophication, meaning excessive plant growth (e.g., algae)
in surface waters due to elevated nutrient levels caused by
fertilizer runoff.
• Tropospheric ozone formation (i.e., smog) due to emissions
of nitrogen oxides and volatile organic compounds, which is
detrimental to human health and ecosystems.
• Human health criteria pollutants, including particulates that
may cause respiratory diseases such as asthma.
• Human health impacts due to chemical releases that may
cause cancer and other chronic diseases.
• Ecotoxicity due to chemical releases that may harm organ-
isms either through direct toxicity or ecological damage.
Based on the above categories, using simplified impact assess-
ment coefficients, it is possible to derive relative comparisons of
design options in terms of their potential adverse effects on humans or
the environment. To assess the actual risks of such effects requires
more detailed environmental risk assessment methods, as described
below under Risk Analysis.

Streamlined LCA
Because of the limitations mentioned above, many LCA practition -
ers have turned toward simplified LCA tools that provide results
more quickly, with less effort, and also with less precision. Espe-
cially in the early stages of product development, such tools may be
more appropriate for rapid design iteration. Alternative approaches
have emerged that are more comprehensive and more streamlined,
al though less fine-grained than conventional LCA. For example,
Carnegie Mellon University developed a tool that uses aggregate
input-output data to model the entire economy from a top-down per-
spective [16]. Such methods provide a useful complement to detailed,
bottom-up LCA. In particular, since streamlined LCA requires only
basic data about resource inputs, it is helpful in assessing new prod-
ucts when emissions data are not yet available. Streamlined methods
can also be combined with detailed methods through “hybrid” LCA
studies, which embed a focused LCA for specific industrial processes
within a broader “envelope” representing the rest of the economy.
Example: The Ohio State University has developed an online tool called Eco-
LCA™ that combines an economic input-output model of 488 sectors of the
U.S. economy with an ecological resource consumption model based on exergy
analysis, as described below. This tool enables immediate assessment or