Heonologist, you make a good point
Maybe Sahara is just a bald patch on Earth's head :D :D
If we compare the age of our planet with the age of a person, scientists claim the Planet is about 40 years old. Maybe it's just going bald in some places.
Romans were also responsible for killing most lions in North Africa, and many other wild animals for that matter. They used to kill animals for the games at the Colloseum. This is an interesting article http://www.endangeredspecieshandbook.org/persecution_roman.php
Simon
Thank you for all the interesting links. So, is it possible that the desertification was caused by monoculture? If they just cultivated the same plant for a hundred years, it is possible that the soil eroded.
First deforestation, then monoculture -- perhaps these two factors together have created the desert. I think this quote by Brazil’s former President Lula is a good one. He said in 2007 that “the wealthy countries are very smart, approving protocols, holding big speeches on the need to avoid deforestation, but they already deforested everything." I agree with his point, and have thought of that before. Nevertheless, the Amazon jungle are the last remaining lungs of the planet. If we cut down all the forests, and just have agricultural lands, the oxigen levels will decrease. It is bad enough as it is, with the exhaust fumes letting out huge quantities of carbon dioxide in the atmosphere.
The Planet now, compared to how it was 2 thousand years ago -- is like a 40 year old chain smoker who is going bald, and has a drug habit (the drug habit is all the pollution). It hasn't got much more time left to live.