Green Sahara
Parts of the Sahara held lakes and grasslands around 6,000 years ago. Precession changed northern summer sunlight, influencing the West African monsoon, with feedbacks such as vegetation amplifying the response. Later drying varied by region. Lake sediments in the Tibesti record wetter conditions; moist air from the Mediterranean also mattered for mountain rainfall. The globe uses present-reference terrain. The environmental illustration is conceptual, not a precise vegetation or lake reconstruction.
