[ExI] Greening the Sahara

[Dan]

--- On Fri, 7/17/09, Henrique Moraes Machado <cetico.iconoclasta at gmail.com> wrote:
> Dan> Any ideas on how to do this?
>> An idea I had was to cover strategic swaths of it with
>> dark material, thereby causing its daytime temperature to
>> rise causing the air to rise faster pulling in more moist
>> air from the costs. Once rainfall is higher, it seems the
>> greening would take care of itself.
> 
> The Sahara is a sand desert and it´s surface is highly
> mobile. The wind blows the sand and the dunes move a lot. I
> think that any dark material covering the sand would be
> quickly covered back with sand by the blowing winds.

Yes, I mentioned just this in another email. There are, however, areas of some deserts -- perhaps, including the Sahara; I forget at this time -- where there is little sand and the surface is mostly exposed rock or similar hard soil. This can be covered and the covering can be replaced -- as if the wind or sand doesn't foil it, eventually rains will.
 
> Here´s a thought. And this can be a complete nonsensical
> idea (almost certainly is). I don´t know how deep is the
> sand layer and what lies beneath, but what about digging big
> potholes (too bad we can´t use thermonuclear blasts to do
> this, because of the residual radiation) and fill them with
> seawater. These potholes evenly distributed across the
> desert could provide a lot of water for evaporation. 

Well, if you're going that far, one might use space based mirrors to bring in more radiation. That might warm the surface, fueling the desired convection.

Alternatively, one might nuke mountains to change weather patterns. I believe someone proposed this a long time ago for the Western US.

Regards,

Dan