Africa

In the Pleistocene epoch (1.6-11,000 years ago), the Sahara was subjected to humid and then to dry and arid phases, spreading the Sahara Desert into adjacent forests and green areas. About 5,000-6,000 years ago in the post glacial period of our modern epoch, the Holocene, a further succession of dry and humid stages further promoted desertification in the Sahara as well as the Kalahari in southern Africa.

Earth scientists say the expansion of the Sahara is still very much in evidence today, causing the desertification of farm and grazing land and presenting the omnipresent specter of famine in the Sahel (Saharan) region.