How did the Sahara Desert change during the African Humid Period?

During the African Humid Period, which lasted from approximately 11,700 to 5,000 years ago, the Sahara underwent a dramatic transformation from an arid desert into a lush, verdant landscape.1

This change was driven by shifts in Earth’s precession, which increased solar radiation in the Northern Hemisphere. The resulting increase in regional heating created a vast area of rising warm air, which supercharged the West African monsoon. This strengthened monsoon was able to penetrate the entire desert, delivering sufficient rainfall to support rivers, lakes, grasslands, and woodlands.12

Evidence for this period includes geological depressions that once held lakes, as well as marine sedimentary records containing fossilized plant materials that indicate a significantly wetter environment than the one observed today.1