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    Sahara Desert

    Ancient Humans Created the Sahara Desert, Says Archaeologist

    © AFP 2017/ HOCINE ZAOURA
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    A new paper authored by archeologists with Seoul National University has suggested that the Sahara Desert, once green and wet, dried out as a result of the actions of ancient peoples. The spread of agriculture depleted the Sahara’s plant life and caused the region’s the shift to a desert biome, the paper claims.

    Scientists have long known that, until fairly recently, the massive Sahara Desert was once verdant and teeming with life, until some 6,000 years ago, when rains ended and the desert became as it is today.

    The exact cause of the meteorological shift has been a subject of much study in recent years, as earth scientists believe it could teach us much more about the history of the planet's climate, as well as the evolution of early human civilizations in the region. A 1997 paper suggested that the shift was a natural consequence of the withdrawal of the glaciers, and has been, until now, traditionally considered to be the most credible explanation.

    Now, archaeologist David Wright has published a paper in Frontiers in Earth Science in which he argues that the cause of the Sahara's drying out was human activity in the region. Some 8,000 years ago, humanity had undergone the Neolithic Revolution, as a result of the invention of farming. Humans, building farms and domesticating animals, allowed livestock to eat large amounts of plants, which lowered the amount of Saharan vegetation.

    Plants do more than make oxygen, as they also cool the Earth by absorbing sunlight via photosynthesis. A decrease in the number of plants over a large area can increase that region's albedo (the amount of sunlight that reflects off the surface of a planet). When the Sahara's albedo rose, the surrounding atmosphere changed, enough to cause the monsoons that provided water to become far less prevalent.

    The drying of the Sahara caused plants to die, further increasing the albedo, further weakening the rains. This continued until early humans packed their bags and left for Egypt and Sumer, to start the first complex civilizations.

    Wright formed his hypothesis by collecting archaeological evidence from ancient pastoral communities in the area. "There were lakes everywhere in the Sahara at this time, and they will have the records of the changing vegetation," he said to phys.org. "We need to drill down into these former lake beds to get the vegetation records, look at the archaeology, and see what people were doing there. It is very difficult to model the effect of vegetation on climate systems. It is our job as archaeologists and ecologists to go out and get the data, to help to make more sophisticated models."

    "In East Asia there are long established theories of how Neolithic populations changed the landscape so profoundly that monsoons stopped penetrating so far inland," Wright said. He also mentioned that similar phenomena occurred elsewhere in the world in Europe, North America, and New Zealand.

    If early humans could have such an enormous impact on the climate, it begs the question of what a vastly more numerous and advanced people, such as ours, could do to our planet. "The implications for how we change ecological systems have a direct impact on whether humans will be able to survive indefinitely in arid environments," Wright stated.

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    Tags:
    climate change, history, ancient civilization, North Africa, Sahara
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    • AnomicDust
      The possibility that humans responded to climactic changes, rather than causing them, was too farfetched for this social scientist.
    • avatar
      Darrell R
      This idea of ancient agriculture creating the Sahara is nothing new. I was hearing this theory thirty years ago, now it's back again.
    • siberianhusky
      And we are still doing a great job of it creating waste land of good land. Sooner or later the Earth will bite back and it will not be pleasant for mankind and they deserve every bit of it.
    • avatar
      Marques rougesin reply toDarrell R(Show commentHide comment)
      Darrell R, Exactly, I remember reading that theory in scientific books about ecology, 30 years ago, too. Some authors even suspected that ALL deserts had human origins. The theory was cited as marginal, but not dismissed.

      That said, we have much older examples of desertification, like Australia which was at some point covered with humid forests, and became progressively dry long before any human was born ! So it's not excluded that other life forms had the same effect, it's well known that an overpopulation of grazing animals can destroy forests after some generations, be they dinosaurs or mammals. And in some specific soil and climatic conditions, once the forest gone, it won't come back on its own, with further soil degradation caused by rains when there is no vegetation to protect the soil anymore...
    • Preterist ADSeventy
      The flood of Noah caused the formation of the Sahara Desert, the polar icecaps, the Grand Canyon, etc., not humans. Before the flood the waters in the atmosphere (which fell during the flood) created a greenhouse effect causing a uniform temperature and climate around the entire globe. That's why there are fossil remains of plant and animal life found in the polar regions. The area of the Sahara could very well have been lush forests but after the flood the greenhouse effect was no longer and the equatorial regions of the earth got hit with direct sunlight causing the high temperatures. The polar regions also no longer had the green house effect and therefore the sunlight had to pass through more atmosphere and was less direct than the equatorial regions causing the lower temperatures.
    • sapper
      They got their info from Doctor Who!!!
    • avatar
      барба
      Anthropogenic deserts? Really? Ancient people caused global deserting. That's a new one
    • supportin reply tosapper(Show commentHide comment)
      sapper, Doctor Who is the only person who would talk to these "researchers." Also none of these researchers have bothered to talk to people who clear forests for a living, e.g., landscape contractors or construction site prep contractors or civil engineers.

      A better guess is that what with the combined demand for combustible wood for cooking and residential heat and for metals smelting, and th eneed for wood for boatbuilding, animal cart building, housing and weapons manufacture, the large-tree supply probably went away in 200 or so years but it is hard to believe it was 8,000 years ago when this happened.

      There wee ten times the number of potable & irrigation wells in the Sahara just 70 years ago but many of those have been poisoned for political and religious reasons. As an example, Saddam Hussein waged an entire internal war against Iraq's own very precisous and ancient marshland districts.

      I always try to stay away from countries which routinely produce excellent coffee. In the Middle East, their coffee is so good they went from being blue-eyed blondes 1,000 years ago to becoming olive-skinned with black hair. That is not that much of a joke as the Danae originally from Syria invaded Greece then were themselves chased north by invaders from Africa: they are the ancestors of today's Danish people which is confirmed by DNA research.

      Anyway, too much coffee all th etime means too excited all the time so ultimately everyone smashes everything until they run out of coffee. Then they calm down then get back to work if they have anything left.

      Every letter in the European alphabet is a tree name and tree symbol so naturally, conflicting cultures will seek to destroy the roots of language of those they choose to conquer. It is also important to understand that paper is made from trees which is funny that these researchers should miss this fact. Half of civilization's time has been scrupulously devoted for religious reasons to destroying other nations' libraries and repositories of knowledge. That makes for a happy life if you are a paper salesman or a printer but for silviculturists, not so much.
    • sapperin reply tosupport(Show commentHide comment)
      support, What is interesting is that you say conquerors routinely destroyed history. I follow Lada Ray's blog about Earthshift and she says there has been a massive cover-up to stop us all finding out who and what we really are. As regards paper at one time it apparantly was made from hemp until it was dicovered that it was cheaper to make paper out of wood, the only trouble being that you needed four times as much acreage of wood compared to hemp. At the moment all I can see is the rapid race to total destruction of the enviroment in the name of globalisation, profit and world government by the priviledged few. Where I live farmers and logging companies are happily chopping down more trees, the former to create more grazing for their ever increasing herds of livestock. What I am seeing here is a route to desertification in the long run. Weather is also a weapon being used against the vast majority and with droughts to order it only increases the prospect of more deserts. At some stage I have no doubt that nature will exact some sort of revenge/kick-back for all this meddling. Anyway thankyou for your infomative reply to me. Best regards.
    • avatar
      michael
      I'm waiting for a us senate enquiry to lead to a class action suit against these (long dead) people.:)
    • avatar
      evagas14
      If this is supposed to make people feel guilty it won't. We've all heard enough of this nonsense, how we're melting the poles, destroying the Amazon basin, and killed off all wildlife two weeks ago.
    • supportin reply tosapper(Show commentHide comment)
      sapper, thak you very much for your comment.

      My other guess as to the cause of desertification of the Sahara is that the dinosaurs one weekend decided to switch over to vodka from beer then started a fart-lighting contest, thereby initiating History's largest single forest fire.

      www.youtube.com/watch?v=zOuXE-X9ezQ
    • sapperin reply tosupport(Show commentHide comment)
      support, Obviously Doctor Who materialised at the wrong time and was consumed!!
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