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I sometimes wonder if places like Egypt used to be covered in much more fertile land and perhaps they overdid the agriculture for a couple 100 years which turne

by sva_ 4y ago

I sometimes wonder if places like Egypt used to be covered in much more fertile land and perhaps they overdid the agriculture for a couple 100 years which turned it into an arid wasteland (I'm a total geology noob.)

rqtwteye 4y ago
Ancient Egypt relied on the Nile flooding the land. Now with the dams the flopding has stopped but they are also having trouble with the soil.
version_five 4y ago
Sahara's Abrupt Desertification Started By Changes In Earth's Orbit, Accelerated By Atmospheric And Vegetation Feedbacks https://www.sciencedaily.com/releases/1999/07/990712080500.htm https://www.sciencedaily.com/releases/1999/07/990712080500.h... Via the wikipedia article on the Sahara desert. I think many deserts come and go based on climate patterns
- yesenadam 4y ago
  Fascinating article, thanks. The main author Martin Claussen has many papers on that and related subjects, available here: https://mpimet.mpg.de/en/staff/martin-claussen/publications/peer-reviewed-articles https://mpimet.mpg.de/en/staff/martin-claussen/publications/... Claussen on Google scholar: https://scholar.google.com/citations?user=udBYQ-cAAAAJ&hl=en https://scholar.google.com/citations?user=udBYQ-cAAAAJ&hl=en
akiselev 4y ago
No, ancient Egyptian civilization was always been dependent on the Nile not just for water but for the flooding that brings eroded trace minerals and deposits them along the basin. That's why we have so much material on ancient Egyptian civilization: the desert is so arid and has been for Egypt's entire history that the normal processes that would break down papyrus or other organic matter were significantly slowed down as long as they were buried far enough away from the Nile.
wahern 4y ago
A recent HN comment implied that camel herding was a significant factor in aridification of North Africa and the Middle East. The context and tone made me wonder if the comment simply reflected anti-nomad (i.e. anti-Bedouin, anti-Berber) prejudice, but there could just as well be something to it. I'm trying to avoid rabbit holes so I put it out of mind.
- veqq 4y ago
  The comment seems incorrect. Herds are good for the soil. They flatten grasses keeping moisture in, allowing for more growth. In the past, people believed the opposite - and this is perhaps still believed in parts of the world. Such flawed thoughts about desertification led them to kill off tens of thousands of elephants in Southern Africa, which sped the process up much faster. Allan Savory: https://www.fastcompany.com/2681518/this-man-shot-40000-elephants-before-he-figured-out-that-herds-of-cows-can-save-the-planet https://www.fastcompany.com/2681518/this-man-shot-40000-elep... https://www.sciencedirect.com/science/article/pii/S0167880921004060 https://www.sciencedirect.com/science/article/pii/S016788092...
  - mythrwy 4y ago
    Managed properly, yes. The soils of the Midwestern US were formed largely by herds of migratory bison for instance. The problem comes in when you don't defer grazing or give things a chance to regrow (see video in sib comment below). That absolutely can lead to desertification. As populations increase and nomadism becomes nonviable (so ground is not given a rest from grazing) it appears that's what happens.
  - sva_ 4y ago
    > The comment seems incorrect. Herds are good for the soil. They flatten grasses keeping moisture in, allowing for more growth. In the past, people believed the opposite - and this is perhaps still believed in parts of the world. For some reason, the idea of complex organisms (in this case: mammals) migrating to new lands and fertilizing it seems counter-intuitive to me, but it does make sense in some way. I would've assumed that more simple organisms took this land long before mammals emerged. The biggest gripe I'd have with it would be: why would they move into those lands? There's nothing there for them. But the idea of them slowly extending fertilized soil does seem intriguing. It appears sort of counter-factual to me that we, who are (presumably) even more complex, seem to reverse this process. There seems to be a sweet-spot in evolution of a species to benefit the land on which they live on (and that around it), and we seem to be past it.
powvans 4y ago
Yes, the desert hasn’t always been desert, though the shifts aren’t attributed to human activity. https://www.livescience.com/4180-sahara-desert-lush-populated.html https://www.livescience.com/4180-sahara-desert-lush-populate...
veqq 4y ago
10,000 years ago monsoons hit the sahara, but they stopped about 5000 years ago and it turned back to desert. There are carved stones of giraffes and such. The society with Pharaohs etc. emerged around the time the sahara dried. https://www.historytoday.com/archive/history-matters/swimming-sahara https://www.historytoday.com/archive/history-matters/swimmin...
s3000 4y ago
Make it a couple of 1000 years: https://en.wikipedia.org/wiki/Mesopotamia#Agriculture https://en.wikipedia.org/wiki/Mesopotamia#Agriculture >Over time the southernmost parts of Sumerian Mesopotamia suffered from increased salinity of the soils, leading to a slow urban decline and a centring of power in Akkad, further north.

by sva_ 4y ago

rqtwteye 4y ago

Ancient Egypt relied on the Nile flooding the land. Now with the dams the flopding has stopped but they are also having trouble with the soil.

version_five 4y ago

Sahara's Abrupt Desertification Started By Changes In Earth's Orbit, Accelerated By Atmospheric And Vegetation Feedbacks https://www.sciencedaily.com/releases/1999/07/990712080500.htm https://www.sciencedaily.com/releases/1999/07/990712080500.h... Via the wikipedia article on the Sahara desert. I think many deserts come and go based on climate patterns

yesenadam 4y ago
Fascinating article, thanks. The main author Martin Claussen has many papers on that and related subjects, available here: https://mpimet.mpg.de/en/staff/martin-claussen/publications/peer-reviewed-articles https://mpimet.mpg.de/en/staff/martin-claussen/publications/... Claussen on Google scholar: https://scholar.google.com/citations?user=udBYQ-cAAAAJ&hl=en https://scholar.google.com/citations?user=udBYQ-cAAAAJ&hl=en

akiselev 4y ago

No, ancient Egyptian civilization was always been dependent on the Nile not just for water but for the flooding that brings eroded trace minerals and deposits them along the basin. That's why we have so much material on ancient Egyptian civilization: the desert is so arid and has been for Egypt's entire history that the normal processes that would break down papyrus or other organic matter were significantly slowed down as long as they were buried far enough away from the Nile.

wahern 4y ago

A recent HN comment implied that camel herding was a significant factor in aridification of North Africa and the Middle East. The context and tone made me wonder if the comment simply reflected anti-nomad (i.e. anti-Bedouin, anti-Berber) prejudice, but there could just as well be something to it. I'm trying to avoid rabbit holes so I put it out of mind.

veqq 4y ago
The comment seems incorrect. Herds are good for the soil. They flatten grasses keeping moisture in, allowing for more growth. In the past, people believed the opposite - and this is perhaps still believed in parts of the world. Such flawed thoughts about desertification led them to kill off tens of thousands of elephants in Southern Africa, which sped the process up much faster. Allan Savory: https://www.fastcompany.com/2681518/this-man-shot-40000-elephants-before-he-figured-out-that-herds-of-cows-can-save-the-planet https://www.fastcompany.com/2681518/this-man-shot-40000-elep... https://www.sciencedirect.com/science/article/pii/S0167880921004060 https://www.sciencedirect.com/science/article/pii/S016788092...
- mythrwy 4y ago
  Managed properly, yes. The soils of the Midwestern US were formed largely by herds of migratory bison for instance. The problem comes in when you don't defer grazing or give things a chance to regrow (see video in sib comment below). That absolutely can lead to desertification. As populations increase and nomadism becomes nonviable (so ground is not given a rest from grazing) it appears that's what happens.
- sva_ 4y ago
  > The comment seems incorrect. Herds are good for the soil. They flatten grasses keeping moisture in, allowing for more growth. In the past, people believed the opposite - and this is perhaps still believed in parts of the world. For some reason, the idea of complex organisms (in this case: mammals) migrating to new lands and fertilizing it seems counter-intuitive to me, but it does make sense in some way. I would've assumed that more simple organisms took this land long before mammals emerged. The biggest gripe I'd have with it would be: why would they move into those lands? There's nothing there for them. But the idea of them slowly extending fertilized soil does seem intriguing. It appears sort of counter-factual to me that we, who are (presumably) even more complex, seem to reverse this process. There seems to be a sweet-spot in evolution of a species to benefit the land on which they live on (and that around it), and we seem to be past it.

powvans 4y ago

Yes, the desert hasn’t always been desert, though the shifts aren’t attributed to human activity. https://www.livescience.com/4180-sahara-desert-lush-populated.html https://www.livescience.com/4180-sahara-desert-lush-populate...

veqq 4y ago

10,000 years ago monsoons hit the sahara, but they stopped about 5000 years ago and it turned back to desert. There are carved stones of giraffes and such. The society with Pharaohs etc. emerged around the time the sahara dried. https://www.historytoday.com/archive/history-matters/swimming-sahara https://www.historytoday.com/archive/history-matters/swimmin...

s3000 4y ago

Make it a couple of 1000 years: https://en.wikipedia.org/wiki/Mesopotamia#Agriculture https://en.wikipedia.org/wiki/Mesopotamia#Agriculture >Over time the southernmost parts of Sumerian Mesopotamia suffered from increased salinity of the soils, leading to a slow urban decline and a centring of power in Akkad, further north.