Environmental Engineering Reference
In-Depth Information
isolation of the lecture hall or the comfort of an
armchair, it appears that all of the current global
environmental problems can be solved in that
way. They share the same overall cause—human
interference in the environment—and specific
causes are common to several of the issues. Acid
rain, increased atmospheric turbidity, the
intensification of the greenhouse effect and ozone
depletion could all be reduced with the exercise
of greater control over anthropogenic emission
of dust, smoke and gases. Those problems which
could not be solved completely might have their
effects mitigated. It is unlikely, for example, that
humankind will ever be able to prevent or control
drought, but, through the management of human
activities in areas prone to drought, problems of
famine and desertification might be alleviated.
The technology exists to tackle most if not all
of these problems, but the gap between theory
and practice is immense, perhaps
insurmountable. It is maintained, in large part,
by a combination of political intransigence and
the financial constraints under which government
and non-government organizations are forced to
work. Much of the difficulty arises out of the
socio-economic and political consequences of the
required changes, which are perceived by some
to be even more detrimental to society than the
continued existence of the problem. In short, the
disease is considered less damaging than the cure.
For example, a substantive diminution of acid
rain could be accomplished by restricting the use
of sulphur-rich, bituminous coal, but it would
have the effect of placing in jeopardy the
economic viability of the areas producing that
commodity. The economic, social and political
impact of the closure of dozens of mines,
accompanied by thousands of redundancies, may
be seen as much more serious than the death of
even several hundred lakes. Such concerns
continue to influence the methods adopted to
control acid rain. Rather than replacing the
sulphur-rich coal with a low-sulphur alternative,
the problem has been dealt with at the post-
combustion stage by the introduction of
scrubbers.
Socio-economic and political considerations
also limit some of the solutions that might be
applied to drought and famine. That problem
could be approached by letting nature take its
course, as was the norm in the not too distant
past. It can be argued that the present system of
providing food aid, and drilling wells in areas
suffering from famine and drought is the easiest
way to ensure that the problems will continue
well into the future. Cutting back on aid, or
removing it completely, would lead to largescale
starvation and death, but it would also reduce
stress on the environment, and allow the
restoration of some form of equilibrium to the
system. Current moral and ethical attitudes
would presumably prevent the adoption of such
a policy, and even the suggestion that it be
considered would have far-reaching political
implications.
Energy consumption is an element common
to many environmental problems, and its
treatment illustrates quite well some of the
difficulties faced in the search for solutions. The
reassessment of energy sources, leading
eventually to a reduction in fossil fuel use is seen
by many to provide the most likely solution to
the problems of atmospheric turbidity, acid rain
and global warming. It is particularly attractive
because it is a broad-spectrum solution, which
does not require separate technology to be
developed for each issue. Improved energy
efficiency, for example, would have a wide-
ranging impact. It would reduce the output of
CO
2
and CH
4
, the main greenhouse gases; it
would bring about a decline in atmospheric
acidity by reducing emissions of SO
2
and NO
x
; it
would create a cleaner and clearer atmosphere
by reducing the release of particulate matter. All
of these could be achieved without additional
technological developments. With cooperation
among the developed and developing nations it
is technically possible to lower atmospheric CO
2
to 1976 levels through improved efficiency
(Green 1992). In practical terms this is an unlikely
achievement, however. With all of the
uncertainties inherent in the global warming
predictions, the developed nations might be
reluctant to implement the necessary measures
