Desertification is the expansion of desert lands into previously non-desert areas. The process occurs due to both natural and human causes.
Deserts occur anywhere where there is less than 10 inches of rainfall each year. If an area receives only slightly
more than this, its ecosystem is fragile and is a candidate for desertification.Long droughts can cause desertification to take place by removing the soil. If humans cause the loss of the soil, such as by overgrazing, over-cultivation, deforestation, irrigation, and excessive plowing, desertification can follow.
In many developing countries, problems such as high population growth and poor land use are causing desertification. Presently, desertification is occurring with greatest rapidity in the African Sahel.
The desertification process can be a catastrophe for the inhabitants of an area. By
preventing the growing of food, desertification can lead to famine and poverty.
Already desertification has ruined huge amounts of land. Across the world, the total amount of land that has been lost is about equal to the size of Brazil (2 billion acres or 810 million hectares). Annually, 15 million acres (6 million hectares) are lost to desertification.
Today, in most developed counties, trees are being replanted faster than they
can be cut down, so desertification is not as severe a threat.
In developing countries, by contrast, poverty has created a threat to trees, which can be sold or used as fuel. In these areas erosion is also common, and along with deforestation, it is causing heavy desertification.
Desertification information network
The UN's Office to Combat Desertification and Drought