Discovery Channel - Why Ancient Egypt Fell [HD]

The fall of Ancient Egypt, some 4,000 years ago, has long baffled the world. How could such a powerful Empire collapse so entirely? Was it political infighting that brought it to its knees? Was it invading Arab armies that killed the last great Dynasty? Now, scientists have developed a new theory and it's a chilling prophecy for our own time. Was the great empire of Egypt destroyed by Global Warming?