Did humans create the Sahara desert?

[Claire.]

Did humans create the Sahara desert?

New research investigating the transition of the Sahara from a lush, green landscape 10,000 years ago to the arid conditions found today, suggests that humans may have played an active role in its desertification.

The desertification of the Sahara has long been a target for scientists trying to understand climate and ecological tipping points. A new paper published in Frontiers in Earth Science by archeologist Dr. David Wright, from Seoul National University, challenges the conclusions of most studies done to date that point to changes in the Earth's orbit or natural changes in vegetation as the major driving forces.

Read more: ScienceDaily[//url]

 

[Tatetopa]

Whoa. That puts global warming in perspective.  Nothing new under the sun.

[+Hammerclaw]

No. The advance and subsequent retreat of the ice sheets of the glacier periods cause alternate wet and dry periods in the Sahara history, The ice sheets were so tall they had the effect on weather patterns like mountains do, and pushed the rain belts further south. When the ice retreated, the rain belts shifted North, leaving the Sahara to dry out.

[Doug1029]

It's likely a combination of causes.  It took 11,000 years to go from the Last Glacial Maximum to the dry Sahara that developed during the Altithermal.  Or another way to look at it:  it took 3500 years to go from the end of the Younger Dryas to the warmest conditions of the Altithermal.  While loss of vegetation due to livestock grazing may have speeded up the process of creating the desert, natural processes had plenty of time to do it on their own.

North America underwent a similar process.  Look up Lake Lahontan and Lake Bonneville.  They were gigantic lakes in Utah and Nevada that were created by pluvial conditions during the ice age.  They turned into deserts the same way, but there were few humans present and virtually no livestock grazing.

Doug

[+DieChecker]

What I've read is that the continued using of the edges of the Sahara for livestock has doubled the size of the desert in just a thousand years. Continued overgrazing keeps the desert expanding.

[+Hammerclaw]

1 hour ago, DieChecker said:

What I've read is that the continued using of the edges of the Sahara for livestock has doubled the size of the desert in just a thousand years. Continued overgrazing keeps the desert expanding.

No doubt a contributing factor in limited areas where grazing is possible. The Ice sheet effect was global and impacted the southern regions of North America. Our desert areas flourished as did the flora and megafauna of our vast coastal plains, which stretched to the horizon, now long submerged.      https://youtu.be/j5_DaRqYuT4                            

 

Edited March 15, 2017 by Hammerclaw

[paperdyer]

On ‎3‎/‎14‎/‎2017 at 10:28 PM, Tatetopa said:

Whoa. That puts global warming in perspective.  Nothing new under the sun.

Yep we humans are getting blamed for everything.  I'm sure science with come up with the theory that over population is causing the shift in the Earth's axis, shift in the magnetic fields and slight rotational speed decrease. I'm also sure we are the cause of the current plight of the molten river of iron that was posted here a few weeks ago.  To save the Earth we must all leave NOW!  (Sorry, one of those days!)

To keep the desert from growing the animals should be fed from all the extra grain that can be grown.  The Oil Sheiks can afford to buy the grain to improve the quality of life for their people instead of just for themselves.