A General Method of Life Cycle Assessment 2012-01-0649
In previous Life Cycle Assessment (LCA) methods, environmental
burden items to be analyzed, prior to a life cycle inventory
analysis, were assumed as the main factors of environmental
problems regardless of the product category. Next, the life cycle
inventory analysis, in which the total amount of environmental
burden items emitted during the life cycle of a product was
calculated, and an environmental impact assessment were performed.
The environmental impact assessment was based on the initially
assumed environmental burden items. The process, in other words,
was a particular solution based on this assumption. A general
solution unconstrained by this assumption was necessary.
The purpose of this study was to develop a general method of LCA
that did not require such initially assumed environmental burden
items, and to make it possible to perform a comprehensive
environmental impact assessment and strategically reduce
environmental burden of a product. This could be achieved by
combining scientific knowledge on environmental burden items that
could cause environmental problems, database on the environmental
burden items emitted during the material production and product
assembly, and sales portfolio of the product.
The general method of LCA was applied to passenger cars.
Dominant environmental burden items that could have environmental
impact were identified to focus attention on their reduction.
In the life cycle of a passenger car, CO₂, SOX, NOX, and
NMVOC were identified as dominant environmental burden items that
could cause global warming, acidification, and formation of
photochemical ozone. Efforts to reduce the environmental impact
were focused on the improvement of fuel efficiency for a new car
model. As a result, it was confirmed that the new car model emitted
5% less CO₂, 2% less SOX, 3% less NOX, and 2% less NMVOC than
The application of the general method of LCA to other products
needs to be studied further. Additionally, new scientific knowledge
on the environmental burden items needs to be reflected in the