Desertification

1. Kareem Washington Desertification

2. Desertification is the conversion of croplands into a desert environment Causedby dehydration of the top layers of soil near existing deserts Modern threat to agriculture Overview: Desertification

3. Result of drought and increased evaporation near deserts High winds and hot temperatures contribute to erosion Lack of deep rooted plants to hold in soil Process And causes

4. Desertification occurs naturally but is accelerated by human activity • By leaving topsoil vulnerable to erosion by water/wind • Overgrazing by large livestock on small portions of land • Improper soil and resource management • Leading to erosion, salinization, waterloggging How Humans Contribute

5. Cultivation of land with unsuitable terrain/soils Deforestation and surface mining without adequate replanting Soil compaction by farming machinery, cattle hooves, and raindrops on denuded soil All intensified by high populations, poverty, and poor land management How Humans Contribute cont.

6. Drought, famine, and unsustainable agriculture Costly process of regaining and fighting desertification Disputes over farmable land Leads to large number of “environmental refugees” Consequences of Dersertification

7. 35% of the Earth’s land surface, on which one-fifth of the world’s people survive is arid or semiarid desert • Rise in rural people affected by desertification • From 57 million in 1977 to 350 million in 2000 How people are affected

8. Moderate desertification causes a 10-25% drop in agriculture • Many farmers can undergo without notice • Severe desertification causes a 25-50% drop in agriculture • Very severe desertification causes 50% or more drop in agriculture • Results in massive gullies and sand dunes How people are affected cont.

9. Affected Ares: • Sub-Saharan Africa • Eastern and southern Africa • Australia • Western United States • Southern South America • South Central Asia • Over 2 billion acres of land in the last 50 years have become desertified • 15 million more acres are desertified every year Areas Affected by Desertification

10. 1977 government representatives gathered in Nairobi for United Nations Conference on Desertification • Plans to halt and reduce spread of desertification • Costs of plans priced at $141 billion • Cost of annual loss in agriculture: $26 billion • Inadequate funding have slowed efforts Prevention and Rehabilitation

11. Environmental Science • Third Edition - G. Tyler Miller Jr. Resources