Environmental Engineering Reference
In-Depth Information
8
Present problems, future prospects
Public interest in the global environmental
issues described in the preceding chapters has
waxed and waned over the past decade (see
Figure 8.1). At present, ozone depletion and
global warming elicit a high level of concern,
whereas drought and desertification, acid rain
and atmospheric turbidity have a much lower
profile than they once had. With the break-up of
the Soviet Union, the re-alignment of eastern
Europe and the end of the 'Cold War', nuclear
winter is no longer considered a serious threat
by most observers. This situation reflects
current perceptions of the seriousness of
particular problems. Perceptions can change,
however. Since few members of the general
public are in a position to read the original
scientific reports which address the issues, they
must depend upon an intermediary to satisfy
their interest. In modern society this interpretive
role has been filled by the media, and public
perception of the issues is formed to a large
extent by their rendition of research results.
Without them, the general level of
understanding of the problems would be much
lower than it is, but, as a group, the media have
also been accused of sensationalizing and
misinterpreting the facts supplied by the
scientific community. There can be no doubt
that some of the accusations are valid, but
scientists too may be partly to blame for
allowing conclusions to be presented as firm,
before all of the facts are in. Such was the case
with the initial investigation of nuclear winter,
and also with the discovery of the hole in the
ozone layer above the Antarctic in the mid-
1980s. Given the scale and complexity of
current environmental issues, problems of
interpretation and dissemination are inevitable.
They must not be allowed to divert attention
from the main task, however, which is the
search for solutions to the major issues.
CURRENT STATE OF THE ISSUES
Atmospheric turbidity
One of the first environmental issues to be
considered in a global context was the rising
level of atmospheric turbidity, which was the
centre of concern in the mid-1970s. It linked air
pollution with the cooling of the earth. Cooling
had been taking place since the 1940s, and some
writers saw the world descending into a new Ice
Age. It was clear a decade later that the cooling
had reversed, and atmospheric turbidity began
to receive less attention. Evidence also began to
appear indicating that increased atmospheric
turbidity might actually contribute to
atmospheric warming. Currently, it raises little
concern among the general public, except under
exceptional circumstances such as those created
by the Kuwaiti oil fires and the eruption of
Mount Pinatubo. Both of these events initiated
cooling and serve as a reminder that exceptional
conditions capable of augmenting turbidity
cannot be ignored. Although air pollution may
be serious in specific areas, the human
contribution to atmospheric turbidity is
generally smaller, and the overall impact much
less than that from natural sources—the cooling
associated with the oil fires in Kuwait, for
example, remained local, whereas that caused
by Mount Pinatubo was global. Whether or not
