|WIT's World Ecology Report - Vol. 04, No. 6 - The Digest of Critical Environmental Information (WIT, 1992, 12 pages)|
SOURCE: The Sands of Change, United Nations
The United Nations Environment Programme (UNEP) estimates that about 3500 million hectares of land... an area the size of North and South America combined are affected by desertification. Every year about 6 million hectares of land are irretrievably lost to desertification, and a further 21 million hectares are so degraded that crop production becomes uneconomic.
While the terms "desertification" and "land degradation" are only now coming into popular usage, the problem has afflicted mankind for centuries. Historians believe, for example, that desertification played a role in the downfall of the Sumerian, Babylonian, Harappan and Roman civilizations.
Today many parts of the world's arable land is in jeopardy as is shown in the map above identifying existing deserts and those areas at high and moderate risk of becoming degraded.
Many believe that drought brings on encroachment of deserts and while drought can accelerate desertification, it is rarely caused by it.
The causes of desertification are varied and complex but it's important to emphasize that desertification is caused largely by human action... or the lack of it. Overgrazing, deforestation, intensive cash cropping on marginal land, poor management of wells and drilling and the settling of previously nomadic peoples all play a role.
One of the commonest causes of desertification is the salinization of irrigated land. Today nearly as much land is currently being lost to water logging and salinization as is being newly irrigated. Unless new irrigation methods pay careful attention to drainage, many areas will ultimately suffer from salinity, just as was the case with many of the great civilizations of the past.
Since desertification is caused by human action it can be cured and controlled by human action. The solutions are not technically difficult.
The basic answer is improved forms of land use: better farming systems, an end to over grazing and over cropping, sand dune fixation, the erection of windbreaks and shelter belts, reforestation, and improved soil and water conservation.
"The deserts are not invading from without; the land is deteriorating from within."
These techniques, when implemented, have generated many successes in recent years in regions around the world. Green belts, for example, have been planted around some of the Sahel's capital cities, such as Duagadouqou and Niamey. Algeria has reforested more than 250,000 hectares. Ethiopia is terracing eroded land on 35 watersheds in the central highland plateau. Sudan is restocking its gum belt and Peru has an enormous reforestation program to save some of its Andean Sierra. China has been reforesting close to 1.5 million hectares annually. Similar land conservation programs are under way in Niger, Syria, Korea, India and Nepal.
Despite these successes the battle to save the Earth from deforestation is being lost. One reason is that the lack of money necessary to finance local initiatives has not been made available on the scale required. Second, many affected countries have failed to take the problem seriously enough to develop long-term national plans.
The price of waiting is high and is counted in declining productivity, erosion, famine and political instability. At present over 1 billion of the world's poorest people are threatened by the sands of change.