The earth is changing, with less ice present at the poles, and less water in many of the world’s largest lakes. Whether this change is a natural event or man made is something that is often debated, although the fact that change is occurring is beyond debate. Another change to this planet is taking place around the world’s deserts. Desert encroachment is something that doesn’t get as much publicity as the decline in the size of the ice fields but is a major problem in many areas of the world.
Desert encroachment and desertification are terms that are interchangeable, and in essence is the spread of desert conditions into habitable areas. This is normally most often demonstrated by the movement of sand dunes. With sand dunes covering farm land that was once many miles away from the desert.
There are a number of reasons put forward as to the cause of desert encroachment, although it is normally associated with over population and/or overgrazing of land. This has most often been demonstrated in China, when a large movement of people from the cities into the rural areas put excessive pressure on the land.
At the same time the lack of human presence in an area can also lead to desert encroachment. People working the land leads to irrigation and the planting of crops and trees. Water and plant life when used properly helps the soil to retain nutrients preventing desertification. When people leave, as happened in the United States in the 1930’s, it can create a desert environment, a Dust Bowl, although this can be reversed.
The fact that people leaving an area can help with desert encroachment is an indication that perhaps there is a natural element to the phenomenon. Geological and historical environmental studies of the major deserts shows that there is a long term cycle that includes growth and retreat of the sand, and the border lands of these deserts can be either desert or fertile land depending on the point in that cycle.
No matter whether desert encroachment is a natural event or a man made one doesn’t lessen the impact that it can have on people. Thousands of square miles every year are lost to the spread of the desert.
The edges of the Sahara are often the most well known examples of such desert spread, but it is a problem faced all over Africa and China in particular. As a result many people and organisations are attempting to limit the desert encroachment, although success has so far been limited. In most cases this has meant the planting of trees in an effort to bind the soil and keep it habitable. Such work has been undertaken by FADE in Nigeria, but similar efforts are happening all over the world. There have even been suggestions for the need to build walls all around the deserts to help prevent desert encroachment but this would be an expensive undertaking.