1990 setting the scene

Desertification

For the 80 million people who live on the margins of deserts throughout the world, the problem of increasing desertification of what amounts to about 20% of the Earth's surface is one requiring immediate action. The figure above shows those parts of the Earth's surface under threat from desertification.Worldwide nearly 21 million hectares of agricultural land has been made useless by the process of desertification and the area is expected to double by 2025. It is a problem which, as the map shows, is not restricted to poor countries - although these countries will find it harder to solve the problem.

Desertification is the process by which productive agricultural land is converted to useless desert. This process is not basically related to any change in climate. It appears to be the direct misuse of the environment. This misuse has occurred in the form of overgrazing, poor cultivation methods and poor irrigation methods.

Overgrazing of an area can result in the compaction of soil so that new plant growth cannot reach the surface. Overgrazing can also result in the death and destruction of existing plant growth which no longer binds the soil together. Winds remove the precious soil.

Poor cultivation methods often take place when farmers are lured into cropping marginal areas following a number of good rainfall seasons. Normal dry weather seasons replace the good seasons and farming collapses leaving the exposed soil open to the wind.

Poor irrigation methods have claimed large areas of farmland even in countries like Australia. The clearing of land of its tree cover followed by intensive watering results in the water table rising to the surface. If the land, like most parts of Australia, has been under the ocean at some time, harmful salts can be drawn up into the root zone and may even appear as deposits on the surface of the land. The land becomes useless for agriculture.

( exerpts from People and the Environment 3 : The Changing Landscape D.A.Lergessner, Macmillan Education Australia, 1992 )

International Year of Deserts & Desertification

The United Nations has identified the problem of expanding desert areas and the plight of people living in or near those areas as the focus of attention in 2006 International Year of Deserts and Desertification.

It will be interesting to see how the situation has changed since desertification first became a global issue in the early 1990s.