[JoeAltmaier]

Um. Cut down all the trees and a forest has a hard time recovering. The Sahara is likely man-made. Like almost all deserts on Earth except Namibia and Australian which are millions of years old, the rest are mere thousands.

Familiar story. America's Southwest used to be treed grasslands until overgrazing turned them to sand and wasteland.

[fred_is_fred]

I call bullshit. Where in the American Southwest was it treed grasslands until it was overgrazed? I've been through the whole region from west Texas to Arizona, NM, Colorado and the Oklahoma panhandle. There was certainly problems in some of those regions during the Dust Bowl, but your general statement reeks of fiction. Phoenix was never the Serengeti in any times where humans were grazing animals.

[aliswe]

It's not just a lack of trees. It's a lack of soil as well. And the temperatures are really unforgiving. Heard about al rub al khali, ie most of saudi arabia? Who cut down those trees you think?

I'm not saying overgrazing never happened, bit it was not nearly enough to explain the current desolation.

[aliswe]

Also, on the otger hand, check out the al bayda project in saudi arabia, the site of which was a forest just 100 years ago (according to the villagers)