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HTML Once lush Sahara was home to a surprisingly unique group of humans
gaiagraphia wrote 18 hours 53 min ago:
Fascinating looking at the valleys across the Sahara, and imagining
rivers once running through them.
There's some fascinating fuel for imagination when you focus on the
Sahara, and some very surprising features and remnants of life hanging
on. The best example is Siwa, which is an utterly magical place to
visit, and feels like a real edge of civiliation.
Climate change is always spoken about with negativity in the mainstream
narrative. However, I always wondered whether more heat = more
evaporation = more rain = more life; bringing regions like the Sahara
(and periphery regions like the Sahel) back to life .
Makes you wonder whether - in an alternate timeline - if a Mongol
messenger hadn't been backstabbed, Baghdad hadn't been sacked, and the
Islamic world went on to become today's centre of science, finance,
development, etc, wohether our current perception of climate change
would be seen as a global positive and catalyst for life?
chairmansteve wrote 9 hours 30 min ago:
There is some success in reversing desertification in the Sahel.
HTML [1]: https://www.youtube.com/watch?v=WCli0gyNwL0
kjkjadksj wrote 17 hours 18 min ago:
The issue with climate change is that we have invested a lot of time
and money farming our crops where they are, not in the sahel. So as
places such as farming regions in western India fall further into
desertification this leads to food insecurity rather than a shifting
of labor around what is most suitable to farm given climate change.
Some life will in fact âwinâ given climate change increasing
temperatures and metabolism but this wonât be human life. It will
be microbial or insect life that will probably go on to plague us
with a greater abundance.
antognini wrote 1 day ago:
There are around 10,000 megalith structures in the Sahara, most of
which were constructed between 3000 and 2000 BC, when desertification
was well underway. A large number of these were discovered within the
last 20 years using Google Earth. The megaliths come in a wide variety
of shapes (there are around 40 categories), but the more sophisticated
megaliths have a keyhole shape [1].
Like the better known megaliths in Europe they tend to have
astronomical alignments and have been used as funerary monuments. Most
of the megaliths point east and have male skeletons, but the few
megaliths with female skeletons are oriented towards the west.
(Shameless plug, but for anyone interested in learning more about this
sort of thing I have a podcast about the history of astronomy and one
of the episodes is about the astronomy of Saharan and Sub-Saharan
Africa [3].)
[1]
HTML [1]: https://www.researchgate.net/figure/Two-keyhole-structures-in-...
HTML [2]: https://songofurania.com/episode/029
easytiger wrote 22 hours 3 min ago:
I'll have to listen to the podcast later but what's the predicate for
the determination of their age?
antognini wrote 18 hours 9 min ago:
It has been a while since I looked at the papers but I believe it's
carbon dating of the human remains buried at the megaliths.
begueradj wrote 1 day ago:
A large part of the human history remains unknown because the Sahara is
very difficult to explore and study.
Who knows, maybe entire city states are hidden here and there within
endless quantities of sand.
chairmansteve wrote 9 hours 28 min ago:
And... sea levels were a lot lower 20,000 years ago.
ls612 wrote 19 hours 17 min ago:
I would think satellite observations would have thoroughly mapped the
immediate subsurface by now regardless of it being hard to explore
conventionally.
kjkjadksj wrote 17 hours 15 min ago:
Subsurface? No. Sahara is too vast and research is expensive. They
can barely get funding to do that sort of work where they already
know there is a Mayan temple under their feet.
user070223 wrote 23 hours 39 min ago:
Indeed, one great path to finding those lost civilizations is to
follow river vallies, Atlas pro[0] says there is no consensus on past
rivers/bodies of water as evident by different maps of the region,
but one can follow (underwater) river sediment which were deposited
to the sea. During oil search such area was found in Cap Timiris,
Mauritiania. Satelite radar image of the area from 2015 did reveal
those rivers beds, Tamanrasset River seems to be the biggest, with a
big drainage basin. Trees and shrubs indeed grow there.
[0]
HTML [1]: https://www.youtube.com/watch?v=r-dZj1ZdRtY
pjmlp wrote 1 day ago:
Most likely enough stuff for some adventure movies, the kind of
wearing hats or summer shorts heroes. :)
ridgeguy wrote 1 day ago:
You're probably right:
HTML [1]: https://earthobservatory.nasa.gov/features/SpaceArchaeology
shantara wrote 1 day ago:
I love this reconstruction of green Sahara map:
HTML [1]: https://www.flickr.com/photos/cchurchili/40921572803/
accrual wrote 1 day ago:
Amazing. I wish we had a way to actually see what it was like.
Although it's turning green again now, Antarctica also was once
closer to the equator and was apparently quite lush.
inetknght wrote 1 day ago:
So this is only loosely related to the posted article, but I found the
"great green wall" project from the U.N. to be super interesting. It
makes me wonder if the same concepts can (and should?) be applied to
other deserts, such as the American midwest.
HTML [1]: https://www.youtube.com/watch?v=4xls7K_xFBQ
thenthenthen wrote 21 hours 47 min ago:
There are some projects in China:
HTML [1]: https://en.m.wikipedia.org/wiki/Great_Green_Wall_(China)
zoklet-enjoyer wrote 1 day ago:
[1] It's not a wall, but similar idea
HTML [1]: https://en.m.wikipedia.org/wiki/Great_Plains_Shelterbelt
inetknght wrote 18 hours 34 min ago:
Oh that's a wonderful place to start learning about some of this in
the U.S.A.! Thanks :)
teruakohatu wrote 1 day ago:
According to Wikipedia the wall was reported to be 15% complete in
2019, but found to be actually just 4% complete in 2020, then
reportedly 18% in 2022 and 30% last year.
Given that is started over 15 years ago and there seems to be
significant differences between what countries report and what was
actually done when the UN commissioned a report in 2020, itâs
anyone guess what progress has actually been made.
In my opinion itâs probably around 10% or low teens now and would
be lucky to double that by the end of the project in 2030.
The project will probably report a much higher number when it
actually finishes.
Hopefully it will be funded to continue. Itâs probably one of the
most important global events environmental projects of the 21st
century.
HTML [1]: https://en.m.wikipedia.org/wiki/Great_Green_Wall_(Africa)
CobaltFire wrote 1 day ago:
If you dive into the report that states the 4% number itâs
measuring something entirely different than the other numbers, and
agrees with the 18% in 2022 number.
Specifically the higher percentages are in reported land
reclamation out of the 100Ha goal, which was at 17.8Ha in the 2020
report. The 4% is a composite of all targets for the 2030 goals, of
which the GGB is only one metric.
Be careful in taking these types of articles at face value.
BurningFrog wrote 1 day ago:
Big bold projects by African dictators to leapfrog the economy has a
truly atrocious track record. UN involvement makes it even worse.
That said, if it will work long term in some of the countries, that
would be great news.
I'm glad that it's still possible to destroy an ecosystem in order to
replace it with something better. That would never fly in the US. We
also have no need to produce more food, and our deserts are mostly
beloved natural wonders.
graemep wrote 1 day ago:
> Big bold projects by African dictators to leapfrog the economy
has a truly atrocious track record.
This is a multinational project with clear benefits.
It is very different from flashy projects like airports no one
uses.
inetknght wrote 1 day ago:
> Big bold projects by African dictators to leapfrog the economy
has a truly atrocious track record.
Perhaps, yes. But the Sahara is expanding and reducing the livable
area of land in those countries. That can only add to economic
strife. On the other hand, building a green wall reduces or
eliminates the expansion of the desert and also increases the
amount of food available to those countries. I believe that would
help reduce the strife between those countries. Yes there's risk of
abuse but I think everyone wants to be self-sufficient and anything
towards that is laudable.
> UN involvement makes it even worse.
Can you explain that further? The U.N. is terrible at directly
preventing conflict (just look at Ukraine) but I think it has a
decent track record of helping countries build their
infrastructure.
> I'm glad that it's still possible to destroy an ecosystem
What? You think building green savannahs is destroying an
ecosystem?
> That would never fly in the US.
I don't know about never but I do think it'd certainly be
difficult.
> We also have no need to produce more food
I disagree. I think we have no appetite to produce more food right
now, but the way we're currently growing food is rather asinine.
> and our deserts are mostly beloved natural wonders.
Mostly, yes. But I think there's plenty of deserts that aren't
quite natural wonders.
Xorakios wrote 14 hours 16 min ago:
The Sahara has generally been contracting for the last few
decades as the "greener" Sahel band expands north due to higher
average rainfall (individual years vary, and the effect is
stronger in the west than the east).
A Google search will likely list articles citing the 2018 study
from UofMaryland that showed approximately a 10% increase in the
Sahara's area from 1902-2012, ignoring the portions of that study
that said that breaking down by decade showed a reversal in the
1980's. [1] Google maps timeview has a fun animation if you
search for Sahara Desert.
HTML [1]: https://journals.ametsoc.org/view/journals/clim/31/9/jcl...
HTML [2]: https://earthengine.google.com/timelapse/
rayiner wrote 1 day ago:
> Can you explain that further? The U.N. is terrible at directly
preventing conflict (just look at Ukraine) but I think it has a
decent track record of helping countries build their
infrastructure
Some UN agencies are very effective, particularly the ones that
are basically run by Americans, such as the World Bank. The more
third world countries participate in any given agency, the more
of a tire fire it is.
inetknght wrote 18 hours 28 min ago:
> The more third world countries participate in any given
agency, the more of a tire fire it is.
I don't know about other U.N. agencies.
But I find Andrew Millison's youtube blogs [0] to be quite
interesting on the subject. His blog about refugees [1] for
example.
[0]: [1]:
HTML [1]: https://www.youtube.com/@amillison
HTML [2]: https://www.youtube.com/watch?v=jfiH9T-iR3E
MomsAVoxell wrote 1 day ago:
Could you be more imperialist?
Letâs see some examples of well-run UN agencies âstaffed by
Americansâ. I guarantee you they are a cesspool of
corruption and bigotry.
rayiner wrote 23 hours 30 min ago:
Incorrect. Source: am a third worlder, my dad was exiled from
the third world for being too conscientious and punctual and
spent his career working with UN agencies.
singularity2001 wrote 1 day ago:
One of the few cases were indigenous were not replaced by neolithic
newcomers but simply adopted their technology
csdvrx wrote 1 day ago:
If you find that interesting, read about the African Humid Period: [1]
The present day situation is fascinating: [1] #Present-d... : there is
an ongoing "greening" which seems caused by global warming and CO2
increases!
However, a 2003 study estimated only 45% of the Sahara could be covered
by vegetation, and a 2022 study found that it may not be sufficient to
start another AHP: it just "lowers the threshold for orbital changes to
induce Sahara greening"
HTML [1]: https://en.wikipedia.org/wiki/African_humid_period
HTML [2]: https://en.wikipedia.org/wiki/African_humid_period#Present-day...
User23 wrote 1 day ago:
I believe current evidence is that the Berber peoples have been in
North Africa at least 12,000 years.
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