Tracing the ‘Green Sahara’ in Chad’s northern desert

A cloud of dust escapes from an excavation site in the sand of Chad’s arid north, where scientists are looking for signs of human habitation in an area once humid and called the “Green Sahara”.

Kneeling, armed with a brush and trowel inside the largest rock shelter at the Gaora Hallagana site in the Ennedi West province, Djimet Guemona, 35, meticulously removed every layer of sand.

“It’s as if we are turning the pages of a historic book to travel back in time,” said Guemona, an archaeologist at the National Centre for Research and Development.

His face lit up at the discovery of each fragment of pottery or scrap of charcoal.

The scientific mission, conducted over five days in late July some 30 kilometres (nearly 19 miles) from Fada, the main town in Ennedi West, brought together Chadia