Young-earth "proof" #23: The Sahara desert is expanding; it can only be a few thousand years old.

23. Bingo! Dr. Hovind got one right! The present Sahara Desert really is only a few thousand years old. About 7 or 8 thousand years ago the area underwent a pronounced wet phase and portions of it were habitable parkland where cattle could be grazed (The Times Atlas of World History, 1978). More than 10,000 years ago, during the last glaciation, lakes and streams were present in the Sahara, and elephants, giraffes, and other animals roamed the grasslands and forests which covered much of the region. Not long ago, radar techniques discovered a fossil river which once flowed across the Sahara; the river bed is now buried beneath the desert sands. By the way, what does any of this have to do with the age of the earth?