Sahara thousands years ago

Post on 02-Dec-2014

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Thousands years ago, Sahara wasn't a desert.

Transcript of Sahara thousands years ago

WHAT DID THE SAHARA LOOK LIKE SIX TO TEN THOUSAND YEARS AGO ?

Wendy Bintner

Sahara Irrigation Mega-Engineering Project

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GREEN SAHARA

What ? Wet and rainy conditions in the northern Africa

When ? 9 000 and 6 000 years ago How ? Climate change

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Green Sahara

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GREEN SAHARA

Water

• Rivers• Lakes

Life

• Fertile conditions • Animals

Humans

• Humans

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GREEN SAHARA

Crocodiles, elephants, giraffe, hippos, antelopes, fish, …

Civilization used rivers : boat, raft, fishing (hook, harpoon, line, …)

Civilization learned a lot : cooking (porridge, soup, …), pottery,

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HOW DO WE KNOW ?

Sediment : evidence of water Cave painting : evidence of civilization and

animals

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How Earth Made Us - Sahara

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WHAT’S HAPPENED

After 2 thousands years, the drier conditions that prevailed prior to the Green Sahara returned. Desertification advanced, and the Sahara desert formed (or re-formed). Arid conditions have continued through to the present day.

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A NEW GREEN SAHARA SOON ?

Computer model simulations : an expansion of the vegetation cover in the Sahara Desert ( human-driven climate change leads to aggressive global warming)

Sahara won’t actually become greener than it is today, as the simulations do not account for the influence of human activity in this area.

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Do you have any questions ?

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wendy.bintner(at)etu.emse.fr