[HN Gopher] Once lush Sahara was home to a surprisingly unique g...
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       Once lush Sahara was home to a surprisingly unique group of humans
        
       Author : gmays
       Score  : 128 points
       Date   : 2025-04-10 13:16 UTC (2 days ago)
        
 (HTM) web link (www.sciencealert.com)
 (TXT) w3m dump (www.sciencealert.com)
        
       | User23 wrote:
       | I believe current evidence is that the Berber peoples have been
       | in North Africa at least 12,000 years.
        
       | csdvrx wrote:
       | If you find that interesting, read about the African Humid
       | Period: https://en.wikipedia.org/wiki/African_humid_period
       | 
       | The present day situation is fascinating:
       | https://en.wikipedia.org/wiki/African_humid_period#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"
        
       | singularity2001 wrote:
       | One of the few cases were indigenous were not replaced by
       | neolithic newcomers but simply adopted their technology
        
       | inetknght wrote:
       | 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.
       | 
       | https://www.youtube.com/watch?v=4xls7K_xFBQ
        
         | BurningFrog wrote:
         | 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.
        
           | inetknght wrote:
           | > _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.
        
             | rayiner wrote:
             | > 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.
        
               | MomsAVoxell wrote:
               | Could you be more imperialist?
               | 
               | Let's see some examples of well-run UN agencies 'staffed
               | by Americans'. I guarantee you they are a cesspool of
               | corruption and bigotry.
        
               | rayiner wrote:
               | 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.
        
               | inetknght wrote:
               | > _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]: https://www.youtube.com/@amillison
               | 
               | [1]: https://www.youtube.com/watch?v=jfiH9T-iR3E
        
             | Xorakios wrote:
             | 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. https://journals.am
             | etsoc.org/view/journals/clim/31/9/jcli-d-...
             | 
             | Google maps timeview has a fun animation if you search for
             | Sahara Desert. https://earthengine.google.com/timelapse/
        
           | graemep wrote:
           | > 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.
        
         | teruakohatu wrote:
         | 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,
         | it's anyone guess what progress has actually been made.
         | 
         | In my opinion it's 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. It's probably one of
         | the most important global events environmental projects of the
         | 21st century.
         | 
         | https://en.m.wikipedia.org/wiki/Great_Green_Wall_(Africa)
        
           | CobaltFire wrote:
           | If you dive into the report that states the 4% number it's
           | 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.
        
         | zoklet-enjoyer wrote:
         | https://en.m.wikipedia.org/wiki/Great_Plains_Shelterbelt
         | 
         | It's not a wall, but similar idea
        
           | inetknght wrote:
           | Oh that's a wonderful place to start learning about some of
           | this in the U.S.A.! Thanks :)
        
         | thenthenthen wrote:
         | There are some projects in China:
         | https://en.m.wikipedia.org/wiki/Great_Green_Wall_(China)
        
       | shantara wrote:
       | I love this reconstruction of green Sahara map:
       | 
       | https://www.flickr.com/photos/cchurchili/40921572803/
        
         | accrual wrote:
         | 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.
        
       | begueradj wrote:
       | 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.
        
         | ridgeguy wrote:
         | You're probably right:
         | 
         | https://earthobservatory.nasa.gov/features/SpaceArchaeology
        
         | pjmlp wrote:
         | Most likely enough stuff for some adventure movies, the kind of
         | wearing hats or summer shorts heroes. :)
        
         | user070223 wrote:
         | 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] https://www.youtube.com/watch?v=r-dZj1ZdRtY
        
         | ls612 wrote:
         | I would think satellite observations would have thoroughly
         | mapped the immediate subsurface by now regardless of it being
         | hard to explore conventionally.
        
           | kjkjadksj wrote:
           | 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.
        
       | antognini wrote:
       | 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]: https://www.researchgate.net/figure/Two-keyhole-
       | structures-i...
       | 
       | [2]: https://songofurania.com/episode/029
        
         | easytiger wrote:
         | I'll have to listen to the podcast later but what's the
         | predicate for the determination of their age?
        
           | antognini wrote:
           | 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.
        
       | gaiagraphia wrote:
       | 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?
        
         | kjkjadksj wrote:
         | 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 "win" given
         | climate change increasing temperatures and metabolism but this
         | won't be human life. It will be microbial or insect life that
         | will probably go on to plague us with a greater abundance.
        
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       (page generated 2025-04-12 23:01 UTC)