Environmental Engineering Reference
In-Depth Information
Table 3.3
Action required for the prevention and
reversal of desertification
grass cover to be replaced by thorn scrub. On
satellite photography this appears as an
improvement in vegetative cover, yet from a
human and ecological viewpoint it is a retrograde
step (Warren and Agnew 1988). A more accurate
approach to land degradation might be to study
the soil. Vegetation responds rapidly to short-
term changes in moisture, but damage to soil
takes much longer to reverse. Thus, the
measurement of soil conditions—nutrient levels,
for example—might give a more accurate
indication of the extent of land degradation
(Pearce 1992f).
UNEP's insistence on explaining most
desertification as the result of human activities
may also have contributed to the
misrepresentation of the extent of the problem.
Natural causes such as short-term drought and
longer-term climatic change were ignored or
given less attention than they deserved, yet both
can produce desert-like conditions without
input from society. With short-term drought,
the vegetation recovers once the drought is over;
with changes induced by lengthier fluctuations,
little improvement is likely even if the human
use of the land is altered. The inclusion of areas
suffering from short-term drought may well
have inflated the final results in the UNEP
accounting of land degradation. Failure to
appreciate the various potential causes of
desertification would also limit the response to
the problem. Different causes would normally
elicit different responses, and UNEP's
application of the societal response to all areas,
without distinguishing the cause, may in part
explain the lack of success in dealing with the
problem (Pearce 1992f).
Perhaps sensing an increased vulnerability as a
result of the current controversy, and certainly
fearful of being left behind in the rush to deal
with the problems of the developed world, the
nations occupying the land affected appeared at
the Rio Earth Summit in 1992, and proposed a
Desertification Convention to address their
problems. Despite its lack of success following
UNDOC, the provisions of the Convention are
likely to be managed by UNEP, which has
The prevention and reversal of desertification
The debunking of some of the myths associated
with desertification, and the realization that even
after more than 15 years of study its nature and
extent are inadequately understood, does not
mean that desertification should be ignored.
There are undoubtedly major problems of land
degradation in many of the earth's arid lands.
