is characterized as an economic activity in which materials are taken
in, transformed and disbursed as products and dispensed of as waste. Over
the last two centuries, technology has afforded us many ways of transforming
materials so we have new, long-lived materials both as products and as
material cycles described in a previous section are part of our ecosystem.
Over billions of years, materials, energy and life have all evolved to
part of a natural ecology. In recent years, environmental problems and
resource depletion have led to the rethinking of industrial uses of materials.
The previous section gives some details of material use in industry. Whereas
it has been customary to dispose of materials at the end of their use,
industry especially in the U.S. and Europe, has begun to move toward a
better accounting of material use, to exploring ways of using less energy
and materials in production, and how to recycle materials and energy.
of industrial use of materials which tries to conserve and recycle materials
is called Industrial Ecology. Industrial Ecology represents significant
changes of mindset - or paradigm shift - from the previous centuries since
the Industrial Revolution. Prior to this philosophy, we extracted and
disposed of materials from nature as though nature provided us with an
inexhaustible supply and as though nature could simply absorb increasingly
large quantities of waste materials, some of which could not be degraded
by natural processes.
move was to remove pollutants from the environment or to reduce pollutant
emissions rather than to effect whole systemic changes. Resource depletion,
air pollution, and the shortage of land and energy led to the first examination
by industry of how to recover material from used items rather than keep
extracting new material from earth.
review of Industry from the early economic vantage point and from the
new ecological vantage point will give more background to the development
of Industrial Ecology and decision making techniques that have evolved
from the new paradigm of Industrial Ecology. Throughout the next sections,
Industrial Ecology may be referred to as I.E.