'The stage was now set for the birth and growth of desert dunes': How the Sahara turned from a vast forest to the arid landscape we see today

In this extract from the book "When the Sahara Was Green", Martin Williams, professor of earth sciences at the University of Adelaide, explores how a vanishing ocean and global cooling set the stage for the birth of the Sahara desert.

via Livescience https://ift.tt/AQEaYMk