<P> The Neolithic Subpluvial began during the 7th millennium BCE and was strong for about 2,000 years ; it waned over time and ended after the 5.9 kiloyear event ( 3900 BCE ) . Then the drier conditions that prevailed prior to the Neolithic Subpluvial returned ; desertification advanced , and the Sahara Desert formed ( or re-formed ) . Arid conditions have continued through to the present day . </P>
<P> The Neolithic Subpluvial began during the 7th millennium BCE and was strong for about 2,000 years ; it waned over time and ended after the 5.9 kiloyear event ( 3900 BCE ) . Then the drier conditions that prevailed prior to the Neolithic Subpluvial returned ; desertification advanced , and the Sahara Desert formed ( or re-formed ) . Arid conditions have continued through to the present day . </P>
when was the last time the sahara was green
when was the last time the sahara was green
3900 BCE
3900 BCE