Sahara desert once lush vegatative environment


At the end of the last Ice Age, the Sahara Desert was just as dry and uninviting as it is today. But sandwiched between two periods of extreme dryness were a few millennia of plentiful rainfall and lush vegetation.

During these few thousand years, prehistoric humans left the congested Nile Valley and established settlements around rain pools, green valleys, and rivers.

The ancient climate shift and its effects are detailed in the July 21 issue of the journal Science.

. . .

“The climate change at [10,500 years ago] which turned most of the [3.8 million square mile] large Sahara into a savannah-type environment happened within a few hundred years only, certainly within less than 500 years,” said study team member Stefan Kroepelin of the University of Cologne in Germany.

. . .

A timeline of Sahara occupation [See Map]:

  • 22,000 to 10,500 years ago: The Sahara was devoid of any human occupation outside the Nile Valley and extended 250 miles further south than it does today.
  • 10,500 to 9,000 years ago: Monsoon rains begin sweeping into the Sahara, transforming the region into a habitable area swiftly settled by Nile Valley dwellers.
  • 9,000 to 7,300 years ago: Continued rains, vegetation growth, and animal migrations lead to well established human settlements, including the introduction of domesticated livestock such as sheep and goats.
  • 7,300 to 5,500 years ago: Retreating monsoonal rains initiate desiccation in the Egyptian Sahara, prompting humans to move to remaining habitable niches in Sudanese Sahara. The end of the rains and return of desert conditions throughout the Sahara after 5,500 coincides with population return to the Nile Valley and the beginning of pharaonic society.

[tags]Sahara desert[/tags]

How sleep deprived are you?

(via LifeHacker)
British Airways has a page telling you that you need to get enough sleep (which we all know but don’t abide by) and tells you how to figure out if you are getting enough sleep. Since we all know that not sleeping enough makes you fat, this is the kind of thing you need to read to stay slim.

Time zone changes, internal body clock disruptions and irregular food and exercise patterns can all result in a sleep debt. Making difficult decisions is not easy if you are sleepy, jet lagged and not at your peak.

. . .

Work out how much sleep you owe your body and find out how to recover if your sleep account is in the red.

So go see how British Airways helps you stay healthier and start figuring out how to catch up on your sleep.

[tags]Sleep, British Airways[/tags]