What is Life-cycle Assessment (LCA)?
Phases of a product's lifecycle
Every product that you use has impacts on the environment.
Those impacts happen not just while you own the product,
but also before and after you own it. Nearly every product
passes through several phases in its lifetime:
Raw materials: The materials that are used to manufacture
the product are either extracted from the Earth by mining,
drilling and similar processes, or they are recycled from
previous products.
Manufacturing: In order to fabricate the product, a factory
consumes energy and materials. Some of the materials, especially
process chemicals, do not end up in the product, but rather are
discarded and therefore have environmental impacts that are not
easily known by the consumer.
Packaging, storage and transportation: The packaging used to
transport and sell the product consumes energy and materials
in its manufacture. Transportation of the product from the
factory to store shelves, and then to the purchaser's home,
also costs energy. Even storage of the product in a warehouse
has impacts associated with construction and use of the warehouse.
Use: Some products have large environmental impacts while they
are under use by the consumer. For instance, automobiles output
large quantities of air pollutants and greenhouse gases as they
are used, and homes consume large quantities of energy when they
are heated and cooled.
Disposal: Most discarded products become "municipal solid waste,"
meaning they are either buried in a landfill or incinerated. Some
products are partially or fully recycled, a process that itself
requires certain amounts of heat, transportation and chemicals.
Environmental Impacts
Traditionally, environmental impacts of a given product or phase of
a product are catalogued across a spectrum of environmental realms,
for instance, air quality, water quality and land use. ILEA has
chosen instead to measure the environmental impacts of each phase
of a product's lifecycle by measuring the total energy consumed
during that phase. Read more about why we make this choice in
the Why Energy section.
By adding together the energy consumed in each product phase,
one can calculate an energy content for the product: the total
amount of energy consumed during the product's entire lifetime.
The energy content is also known as the "embodied energy" of the
product, and is a rough but effective measure of that product's
total environmental impact.
Things you do each day can also be thought of as products.
For instance, taking a shower is equivalent to purchasing a
certain quantity of hot water, and vacuuming the living room
is equivalent to purchasing a certain quantity of electricity.
This way you can know the environmental impacts not just of
what you buy in the store, but also of many other activities
in life.
Last Modified on October. 1, 2004.
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