Answer: Hello!! 30 million years ago the Sahara desert was covered in grassland.
Explanation: According to a scientific research was actually a tropical place which received lot of rainfall in the past 6,000 year. But due to shifts in land and the continents it dried out. Which made all plant that were in the Sahara desert dry out. And today scientist are still trying to discover what was the major impact in such a larger climate change.