Green Sahara proof of the man-made global warming hoax

In the African country of Niger, the Sahara Desert, a team from the University of Chicago searching for the remains of dinosaurs when they came across the remains of about 200 human graves, and remains of animals, large fish, and crocodiles Supposedly from a group of people called the Kiffan from about 8,000 to 10,000 years ago.

Which means at one time this desert region was lush with humans, animals and vegetation before the earth warmed and converted the area to a desert. Did the Kiffan people drive SUVs and engage in heavy industry which caused Al Gores man-made global warming hoax? Or did the earth warm up without any help from humans and just followed the natural cyclical earths path of warming and cooling?

Further proof man-made global warming is a hoax, unless one can prove President George Bush and Vice President Dick Cheney were driving SUVs in the region 10,000 years ago to kill off the vegetation for oil?