Desertification became well known in the 1930’s, when parts of the Great
Plains in the United States turned into the “Dust Bowl” as a result of
drought and poor practices in farming, although the term itself was not
used until almost 1950. During the dust bowl period, millions of people
were forced to abandon their farms and livelihoods. Greatly improved
methods of agriculture and land and water management in the Great Plains
have prevented that disaster from recurring, but desertification
presently affects millions of people in almost every continent.
[Illustration: Off-road vehicles significantly increase soil loss in the
delicate desert environment of the western United States. In a few
seconds, soils that took hundreds of years to develop can be destroyed
(photograph by Terrence Moore).]
Increased population and livestock pressure on marginal lands has
accelerated desertification. In some areas, nomads moving to less arid
areas disrupt the local ecosystem and increase the rate of erosion of
the land. Nomads are trying to escape the desert, but because of their
land-use practices, they are bringing the desert with them.
It is a misconception that droughts cause desertification. Droughts are
common in arid and semiarid lands. Well-managed lands can recover from
drought when the rains return. Continued land abuse during droughts,
however, increases land degradation. By 1973, the drought that began in
1968 in the Sahel of West Africa and the land-use practices there had
caused the deaths of more than 100,000 people and 12 million cattle, as
well as the disruption of social organizations from villages to the
national level.
While desertification has received tremendous publicity by the political
and news media, there are still many things that we don’t know about the
degradation of productive lands and the expansion of deserts. In 1988
Ridley Nelson pointed out in an important scientific paper that the
desertification problem and processes are not clearly defined. There is
no consensus among researchers as to the specific causes, extent, or
degree of desertification. Contrary to many popular reports,
desertification is actually a subtle and complex process of
deterioration that may often be reversible.
[Illustration: Goat seeks food in the sparsely vegetated Sahel of Africa
(photograph courtesy of the U.S. Agency for International Development).]