I have pointed out in previous postings that North Africa was a lush verdant land until 5,500 years ago when, in less than 200 years, it became the Sahara Desert. I thought some might find additional information about the Sahara’s history interesting.
Scientists say that what is now North Africa was a shallow sea until 20 million years ago. At that point the African tectonic plate began to move north. As it pushed against the European plate the edge of it was pushed upward until it was above sea level and became North Africa. At that time there was no rain fall in that area so it quickly dried out and became a desert. It remained that way for thousands of years. Then it changed. It began to rain. This rain was the beginning of a cycle of change every 20,000 years. These cycles have taken North Africa from a lush verdant land full of life to a hot dry lifeless desert with every cycle. The predominate theory about the cause of these cycles is that they are caused by a wobble of the Earth’s axis. But it’s just a theory. No one knows for sure. What scientists have been able to demonstrate is that the cycle has been reliably repeating every 20,000 years.
The Great Lakes in America were long said to contain the largest single source of fresh water in the world and 20% of the world’s total. Recent research has revealed that this fact must be modified. Scientists now maintain that until 5,500 years ago fully 10% of North Africa was covered with lakes. Lakes so big they are called “Mega Lakes.” They were three times larger than the Great Lakes and connected by an extensive river system. It is known that extensive farming was taking place and the raising of animals. Fossils have been found of elephants, gazelles, hippos and crocodiles. Cave art has been found in the desert of people swimming. Perhaps the most interesting thing about that hot dry Sahara Desert today is that underneath of it there is still more water than is in the Great Lakes. Plans are afoot to pump that water to the surface for irrigation to allow the desert to be farmed. The problem is that it will be several thousand years before that reservoir under the desert will be refilled when the cycle returns to a rainy clime.