1. Desertification Desertification in the Sahel source: NASA Earth Observatory

2. What is a desert? Deserts cover about one fifth of the Earth's surface and occur where rainfall is less than 50 cm/year. World desert's map. Distribution of non-polar arid land. Source: USGS.USGS

3. What is desertification? the United Nations Convention to Combat Desertification which defines it as "land degradation in arid, semi-arid and dry sub-humid areas resulting from various factors, including climatic variations and human activities" Cattle concentrated around a waterhole near Bamako, Mali, Africa. From Manfred Schweda.

4. Desertification in Bara, Sudan due to restrictions on movement of herds of animals. Notice the devegetated areas around Bara. From United Nations Environmental Programme Natural Disasters and Desertification

5. The Namib Desert. Photo: Julien Fauqueur Is the problem of desertification unique to Africa and is it a new problem?

6. The Dust Bowl 1937

8. Desertification does not always happen in an area void of a water source. However, the water source may be so degraded that it is no longer of use to humans.

11. Risk of Desertification in Europe

12. Desertification in Austraillia

13. Desertification is not just the encroachment of giant sand dunes into normally fertile land. It is also the misuse of land through poor irrigation and agricultural practices that creates “dead” soil.

14. Nope, I don’t have the slides backwards…..under the right conditions it is possible to reverse the effects of desertification. YEAH! Something positive for a change!!!

15. http://www.loe.org/shows/segments.html?programID=10-P13-00023&segmentID=7

16. If this problem in this region can be solved by something so simple, what are other possibilities?