Environmental Engineering Reference
In-Depth Information
that means that anthropogenic contributions to
atmospheric turbidity are relatively
unimportant remains to be seen, and scientists
interested in the impact of human activities on
the atmosphere continue to search for an
answer.
by the new political reality, which has reduced
the military requirements of the superpowers, is
also a concern. Their ability to aid smaller
nations—particularly in politically unstable parts
of the world—to acquire or build nuclear devices
could lead to the proliferation of such weapons.
Although conflicts in these regions would not
match the size or severity of nuclear exchange
upon which the original nuclear winter
hypothesis was based, they would certainly have
significant local and regional environmental
impacts, which in some cases could have global
consequences.
Nuclear winter
Interest in nuclear winter has also waned from a
peak reached between 1983 and 1985. Intensive
investigation of the issue from 1983 on produced
increasing evidence that the climatic impact of
nuclear war had been overestimated in the
original study. The downgrading of the estimates
in the scientific and academic community was
inevitably accompanied by a general decline in
the level of public interest in the topic, and despite
a new examination of the theory by the original
investigators (Turco
et al.
1990)—which tends
to reaffirm the basic findings of the original
work—there has been no revival of interest.
As a result of recent political developments,
nuclear conflict does seem less likely, and the issue
of nuclear winter is regarded as irrelevant by
some. Certainly, large scale nuclear war between
the NATO and Warsaw Pact powers is no longer
a consideration. The events which reduced the
likelihood of superpower nuclear conflict did
nothing to reduce local and regional tensions,
however, and in some cases may even have
exacerbated them. With the dissolution of the
USSR into a number of separate states, for
example, central control over nuclear devices has
been lost, and the possibility of these weapons
being used in local conflicts cannot be ruled out.
However, in early 1994, Ukraine agreed to the
complete destruction or removal of all the nuclear
weapons it had inherited from the former USSR.
In the Middle East, Israel may already have a
nuclear capability, while other nations in the
region may be working towards that end. Both
India and Pakistan also have nuclear ambitions.
Elsewhere in Asia, North Korea has shown a
distinct reluctance to abstain from further
development of nuclear weapons. The availability
of nuclear weapon scientists, thrown out of work
Drought, famine and desertification
Drought, famine and desertification are related
problems of long standing in many parts of the
world. The disastrous droughts in the Sahel in
the 1960s and 1970s, for example, were only the
most recent in a series which can be traced back
several centuries. The earlier droughts, and their
accompanying famines, passed mostly unnoticed
outside the areas immediately affected. In
contrast, modern droughts have been
characterized by a high level of concern,
particularly in the developed nations of the
northern hemisphere. Concern is often media-
driven, rising rapidly, but falling just as quickly
when the drought breaks or the initial benefits
of food and medical aid become apparent. When
the rains returned to the Sahel in the late 1970s,
interest in the problems of the area declined,
although the improvements were little more than
minimal. Similarly, the concern raised by
television reports of drought and famine in
Ethiopia in the mid-1980s peaked at a very high
level in 1985 only to decline again within the
year. Such fluctuations give a false impression of
the problem. Drought and famine are endemic
in many parts of the world, and do not go away
when the interest of the developed nations
declines. In some areas, the return of the rains
does bring periodic relief and the land produces
a crop. Where the relief is infrequent or short-
lived, the desert advances inexorably into
previously habitable land. This is desertification
