[ExI] Greening the Sahara

[Dan]

--- On Sat, 7/18/09, Henrique Moraes Machado <cetico.iconoclasta at gmail.com> wrote:
> --- 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.
> 
> Dan>Yes, I mentioned just this in another email.
> 
> Sorry I didn't see it. Good to know that I'm not so far out
> then.

No big deal -- just wanted to point out I did think a little further on this than that. :)
 
> Dan>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.
> 
> Kalahari in central Africa is like this.
> http://en.wikipedia.org/wiki/Kalahari_Desert

Yes, and some areas of other deserts too, IIRC. 
 
> > 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.
> 
> Dan>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.
> 
> Yes. Go that far. If one wants to do something big, one
> must bring on the big tools.

Well, yes, and one benefit of this is that space-based whatever can be reaimed later. Nuking is kind of a permanent change that allows a lot less room for altering once you've set the things off. (Of course, you'd probably do a pilot program first.)

And space-based whatever probably won't have the stigma of using nuclear weapons.

Regards,

Dan