Amazonian Sahara?

[IndigoYeti]

I've always thought it'd be cool if the Sahara was a huge sprawling jungle. Let's assume a pre-historical POD for this river system to develop. If the Sahara had a large river system like the Amazon, as shown on my map, would that be enough to create jungle conditions, or would it just be well-watered savannah? What would the effects be for civilizations around the Sahrara?
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[Max Sinister]

That's pretty much ASB. In the grades of the Sahara, wind comes mostly from North-East - but there's only a lot of land, and clouds mostly come into existence over the sea. Either you have to change the direction of the winds (turning the Earth?), or remove parts of Africa or Eurasia so the Sahara is closer to the sea. So or so, it's ASB.

[Tom Veil]

The Sahara was in fact wet and tropical a few times in Earth's history, but I believe that all of those times were before the dawn of man under radically different world climates and continental arrangements. Since the dawn of man, the closest that we've had was a savannah, which died out for the last time right as the Egyptians were learning agriculture.
If you insist upon having a jungle, therefore, you either have to have Alien Space Bats fix the climate, or you have to have a POD so deep that, while humans would not be butterflied away, they might never leave Africa, which means that they might never develop agriculture. AFAIK, the only places to ever develop agriculture by themselves were Mesopotamia, the Yangste, and southern Mexico, and there's good evidence that it couldn't have happened in many other places.
If you're content with a Sarahan savannah, though, then you can have a post-Dawn of Man POD, which would basically be "random earthquake or meteor slightly changes the contours of the West African coast." The results of that could be similar to the Sea of Africa (http://www.alternatehistory.com/discussion/showthread.php?t=30705) thread.

[NapoleonXIV]

IIRC the Saharan savannah was supported by a Nile Amazon and this was fairly recent, about 10000 years ago, at least according to some theorists. One speculation is that Egypt was largely populated by people from the Saharan Savannah who were forced east by the Sahara's continuing desertification

[IndigoYeti]

I kept thinking whether or not to put this in the ASB section or not. I'm still new here:( .