Sahara went from Green to Sand in a flash

http://science.nbcnews.com/_news/2013/04/05/17620176-sahara-went-from-green-to-desert-in-a-flash?lite

Fascinating story. It seems that a study of dust samples in the med. Have confirmed what people have long suspected. The Sahara was once a green and verdant paradise. It had Hippos and lions. It had villages. If the change had never occurred, the history of the world would be very different
Firstly there would be no Sahara to act as a firebreak between the African jungles, and the rest of Eurasia. So the Entire Eurasian population would be exposed to the African disease system.
The civilization of Egypt might never arise. Or be very different, as the Nile would not be the life line round which the Pharoah's organize.  The horse nomads of Eurasia may well reach the Fish River in this universe.

From such turns and twists of fate is our world made.

Its interesting how much speculative fiction there has been about turning the Sahara green. In the TV series ``The Centurions''
http://en.wikipedia.org/wiki/The_Centurions_(TV_series) In the UK annual. The Sahara, was a green paradise transformed by advanced terraforming. I read a book, in which a free wheeling Yankee engineer, helped a Bonopartist Pretender save the French Empire by turning the