Chemistry Reference
In-Depth Information
Chapter 4: Green Chemistry and
Sustainable Development
THOMAS E. GRAEDEL
1 The Concept of Sustainability
the industry-environment relationship. It is the core
of our thinking in the evaluation of an individual
facility, an entire industrial sector or the entire tech-
nology of the planet. If a facility, a corporation or a
sector is to be truly 'sustainable', it must see its
activities not from a parochial viewpoint but from
one that encompasses the long-term requirements of
'Spaceship Earth'.
Few books result in major shifts in societal perspec-
tive, but one that did was
Our Common Future
, a 1987
product of the World Commission on Environment
and Development [1]. In that book, the committee
recognised that continued industrial and societal
development was necessary if a growing planetary
population was to be fed, housed and provided with
a satisfactory quality of life. It also recognised that
it was necessary to make such development sustain-
able over time, to 'meet the needs of the present
without compromising the ability of future genera-
tions to meet their own needs'. Twelve years later,
in
Our Common Journey
, the Board on Sustainable
Development of the US National Research Council
reinforced and expanded this basic concept [2].
As a result of these initiatives 'sustainable devel-
opment' has become a common phrase, and many
corporations advertise their operations as 'sustain-
able'. The use of the word is seldom defined in this
context, but it is clear that two central implications
are:
2 Green Chemistry and Sustainability's
Parameters
The keys to sustainable development, as expressed
by the Board on Sustainable Development [2], are
defining what should be sustained, by whom and
for how long. Figure 4.1 introduces the temporal
consideration. No-one seriously proposes trying to
maintain sustainable development over time spans
relevant to ice ages, major continental drift or
the life of the planet; as a society we clearly have
neither the knowledge nor the ability to plan such
a campaign. At the short end of the time scale, no
serious arguments are presented that sustainability
will be lost in the next decade or so (individual
plant and animal species excepted). It is perhaps
not impossible to argue for a half-millenium or
millenium focus, but none of our political or social
systems operate on anything like those time scales.
Inevitably, we are reduced to thinking about actions
that can be taken within the 20-100-year range.
Thus, the suggestion of the Board on Sustainable
Development [2] of a target time of perhaps two gen-
erations (50 years or thereabouts) seems as good a
choice as any.
What is it that we would like to sustain? From the
perspective of green chemists, there appear to be
four items of interest in this regard:
(1)
Using natural resources at rates that do not
unacceptably draw down supplies over the long
term.
(2)
Generating and dissipating residues at rates no
higher than can be assimilated readily by the
natural environment.
Accordingly, one cannot evaluate the environmen-
tal performance of a facility solely on the basis of
such classical green chemistry metrics as the rate of
reduction in the volume or toxicity of disposable by-
products. In addition, it is necessary to evaluate one's
processes and operations in terms of long time spans,
broad spatial scales and complex interactions with
natural systems, and taking actions that are indicated
by such an evaluation whether they are regulated or
not.
This perspective of sustainable development
demands new ways of measuring and understanding
(1)
Chemical feedstocks.
(2)
Energy for feedstock processing.
(3)
Water for feedstock processing.
(4)
An environment sufficiently resilient to be
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