Ibrahim al-Koni, Libya's leading novelist, was raised as a Tuareg in the Fezzan. In his book The Bleeding of the Stone, he quotes a Sufi song:
The desert is a true treasure
for him who seeks refuge
from men and the evil of men.
In it is contentment,
in it is death and all you seek.
The Fezzan reveals thousands of years of life struggling against change, of humans adapting to a hostile environment. It is a time machine where the past slaps us in the face, and if we linger, things happen to our safe ideas.
We moderns have grudgingly accepted that the past is a record of shifts in climate, great migrations, the rise and fall of nations, yet we act as if our present is the final chapter. But in the Sahara a very long tale confronts any visitor, a reminder that this current chapter is thin and fragile.
Mattingly's investigations bring him to the Ubari Sand Sea, where there are, improbably, many tiny, gem-colored lakes—some purple, some orange from minerals and algae—that are the dried-up reminders of a previous time when groundwater lay closer to the surface than it does today. It's hard to imagine, but a lake the size of England, Lake Megafezzan, gleamed here about 200,000 years ago, when rainfall was abundant, and ancient channels testify that rivers ran in the center of the desert.
Climate change has been like an on-off switch in the Sahara. In dry times the lakes dwindled and the plants declined to niches. Then, when moister times returned, the lakes filled and parts of the Sahara were transformed to savanna. Human communities have pulsed here like the explosion of plants after a rare rain. When moist eras visited, they thrived. When the dry times returned, they shrank or collapsed.
How does one locate waterways of long ago? From way up high. Using radar images taken from space, Migrations Project team members Kevin White and Nick Drake have been able to map the location of mineral residues from ancient lakes and springs, then steer their Land Rovers to those spots, where paleoanthropologists Robert Foley and Marta Mirazón Lahr discovered stone tools, arrowheads, fireplaces, graves, and other clues to human occupation.
The earliest modern humans in the region were hunters and gatherers who lived in a savanna landscape about 130,000 years ago. Those people cleared out when the rains tapered off about 70,000 years ago, but then the rains returned and people moved in again. This back-and-forth migration is called the Saharan pump, a movement of people in and out of northern Africa as the climate shifted. Scratched on the desert's rocks are the memories of a wetter Sahara, when water-dependent creatures such as lions, elephants, and rhinoceroses lived here.