" In any case, increased CO2 levels are encouraging plant growth in the Sahara desert, shrinking the desert, but making more fertile and farmable land, and more land in which to live on."
I only found one scholarly reference on this subject during a quick search. A Florida State climatologist and a NASA climatologist reviewed 8 years of satellite pictures of the Sahara. During dry years the Sahara extended southward, but it retreated north to about the original boundaries during wet years. The net effect is that the Sahara remains about the same size. This was not a long term study; many of the other references on line seemed to say that the desert is expanding south. But they weren’t direct from the researchers.