“Before the last Ice Age, the Sahara was even larger and more inhospitable than it is today. Then, some 10,000 years ago, a shift in climate brought rainfall. In the ensuing years of plenty, a pastoral way of life thrived. The desert came back with a vengeance about 3,000 years ago and, as the remaining surface water supplies dwindled, the inhabitants were forced to dig for it below the ground.” The changes were recorded in rock art, but that art is in dancer of being destroyed by oil exploration in Libya…