Environmental Engineering Reference
In-Depth Information
evolution of this awareness has been traced by
William Kellogg (1987) who points out that as
long ago as the late nineteenth century, the first
tentative links between fossil fuels, atmospheric
carbon dioxide and world climate had been
explored. The results failed to elicit much interest
in the scientific community, however, and
remained generally unknown to the public at
large. Such a situation prevailed until the mid-
1960s. From that time on the cumulative effects
of a number of high-level national and
international conferences, culminating in the
Study of Critical Environmental Problems (SCEP)
in 1970, produced a growing awareness of global
environmental issues. The impact of human
activities on regional and global climates was
considered in the SCEP, and when it became clear
that the issue was of sufficient magnitude to
warrant further investigation, a follow-up
conference was convened. It focused on
inadvertent climate modification, and in 1971
produced a report entitled The Study of Man's
Impact on Climate (SMIC). The report was
recognized as an authoritative assessment of all
aspects of human-induced climatic change, and
it might even be considered as the final
contribution to the 'critical mass' necessary to
initiate the numerous and increasingly detailed
studies which characterized the next two decades.
The pace quickened in the late 1980s, with
international conferences on various aspects of
climate and the changing atmosphere being held
in Montreal, Toronto, Hamburg, London and
Geneva (see Chapter 8). A significant step
forward was the creation in 1988 of the
Intergovernmental Panel on Climate Change. Set
up to evaluate global climate trends—particularly
global warming—it provided major input for the
discussions leading up to the signing of the
convention on climate change at the United
Nations Conference on Environment and
Development in Rio de Janeiro in 1992.
One of the results of all that activity was the
positive identification of human interference as
a common element in many of the major
problems of the atmospheric environment. The
information gathered during the studies is quite
variable in content and approach. It has been
presented in highly technical scientific reports,
as well as in simple, basic articles prepared for
popular consumption. The latter are particularly
important as a means of disseminating
information to the wider audience which past
experience suggests must be educated before
progress can be made in dealing with
environmental problems. Because of the time and
space constraints and the marketing requirements
of modern journalism, however, the issues are
often treated with much less intellectual rigour
than they deserve. In addition, the topics are often
represented as being new or modern when, in
fact, most have existed in the past. Drought, acid
precipitation and the greenhouse effect all result
from natural processes, and were part of the
earth/atmosphere system even before the human
species came on the scene. Their current status,
however, is largely the result of human
intervention, particularly over the last 200 years,
and it is the growing appreciation of the impact
of this intervention that has given the issues their
present high profile. One topic that can be
classified as new is nuclear winter. Unlike the
others, which exist at present, and have
developed gradually as the accumulated results
of a variety of relatively minor inputs, nuclear
winter remains in the future, with an impact that
can only become reality following the major
catastrophic inputs of nuclear war. For many in
the mid-1980s it was seen as the ultimate
intervention; the ultimate blow to environmental
equilibrium. Despite this, nuclear winter is no
longer considered a major environmental issue
by most observers. Events such as the ending of
the Cold War, the break-up of the USSR and the
signing of a variety of arms control agreements
have reduced the potential for inter-continental
nuclear war, and as a result interest in nuclear
winter has declined almost to zero.
Present concerns may be seen to some extent
as the most recent elements in a continuum. In
the 1960s and early 1970s, the main
environmental issues were those associated with
pollution in its various forms. Pollution is the
contamination of the components of the earth/
