[ExI] Greening the Sahara

[Dan]

--- On Fri, 7/17/09, Fred C. Moulton <moulton at moulton.com> wrote:
> Whenever I hear of a large scale project like this I ask
> "what are the downside risks?"

Me too. There is one risk you don't mention and one that might be considered by most only minor in the scheme of things. This is the loss of fossils and other finds scattered about the Sahara. I've actually been thinking about this too.

One partial solution might be an exhaustive mapping of all surface finds in that desert. This seems impractical, but I was thinking of using high res sat imagery as well as ground rovers and having a lot of the stuff posted on the web in "mechanical turk" fashion to have humans scan for items that might be of interest. (The rovers might also be partly adapted to "notice" fossils. This seems an acquired skill in humans. I imagine rovers can be similarly trained.)
 
> The earth as a whole and weather in particular are not
> simple.  Do we
> know what greater rainfall in the Sahara would mean for
> rainfall else
> where?  How would weather change in other areas if
> weather changed in the Sahara?

I'm not sure and don't trust current climate models enough to say. A clue might come from some models or from looking at the past when the Sahara was warmer and wetter. (The actual desertification, in my understanding, is due to the region cooling and this changed weather patterns so that it received ever less rain.)
 
> I am not saying it is necessarily a bad idea.  I am
> just raising the
> question.  For example would in change the weather in
> Greece or Italy or Egypt or anywhere else?

I don't think you're wrong to consider these regional or global effects.

Regards,

Dan