June 5, 2004

• People Pump

  During the times that humans have existed, the glaciers have advanced and retreated at least 27 times. During this period, one special place has become favorable to humankind, drawing them in during times of heavy glacial advance because the grasslands favor the animals we love to hunt for food, then casting them out as the land withers and becomes desert during glacial retreat. Currently a giant desert, this land we call the Sahara sits between Africa, where the human race probably originated, and the rest of the Eurasian continents.

  Humans began as wanderers, but our movements were most pronounced when the climate changed. We moved into the Sahara when it became fertile, then eastwards or northwards as it dried up. Every few thousand years, the Sahara would draw a new breath of people, from the south or from the east, to expell them a few centuries later.

  It was like the beat of a giant heart.

  When we discovered agriculture in the fertile crescent, it pushed us to circulate that knowledge into India and China.

  But then we tamed cattle, goats, sheep and pigs. This knowledge flowed from northeastern europe towards the south and west. The later domestication of the horse, in the steppes farther east, requiring great tracts of land to support the large herds that denoted power, led to conquests ever farther westwards. These movements were powered by the innovations themselves, not by the great pump of the Sahara.

  We are at the end of a glacial period. The last few glaciers are drying up and disappearing. The polar ice caps have diminished. The world is in a warming cycle.

  The Sahara is hot and dry.

  But the glaciers may come again. The poles may freeze up once more. The Sahara may bloom and become a fertile grassland once more.

  It may happen many more times.

  • 23:04
  • 2 Comments