And green, growing rain forests are a large part of the solution.
The Sahara could bloom again, with verdant lush growth, all it needs is water. And there is reason to believe that the Sahara WAS a lush, green rain forest, not too far into the geologic past.
Just to the west of the coast of Africa, is a HUGE supply of water. Only problem, it is too saline for proper irrigation of fresh-water plant species. Short answer, desalinate the sea water, and use the desalinated water to send freshets of irrigation streams across the expanse of sand that is now there.
How to desalinate the sea water on massive scale? Proposal - build a quantity of Thorium-fueled molten-salt atomic reactors on the west coast of Morocco, and huge condensation towers. Let water in from the Atlantic into reservoirs, and heat this flow with heat emanating from the atomic reactor. As the water is vaporized, collect it in the condensation towers, and shunt the ever more concentrated brine off to the side, we will get back to it later. In large enough quantity, the distilled water collected this way will more than adequately initiate the greening of the Sahara, and where there is enough greenery, rain forests follow. Over time, decades or even centuries, the green belt will reach all the way across to Egypt, and the resulting alterations of weather patterns will continue to spread this higher moisture content even further east across the Fertile Crescent and perhaps as far as Afghanistan. Can you imagine the changes that would bring to the culture of the region?
Now getting back to this ever-growing pile of sea salt. Every element is dissolved in some measure, in sea water, the most common compound, of course, being sodium chloride.
Sodium chloride contains two very useful elements, sodium and chlorine, both of which are valuable industrial chemicals, and may be used as feedstock in the manufacture of a wide range of chemicals. It is only necessary to separate the ionic content and convert it back to elemental form.
This may be done by electrolysis, using the electricity generated by the operation of the Thorium-fueled molten salt reactors, with a portion of the energy used to generate electricity, while the “waste” heat energy is used to distill the incoming sea water. Once the sodium chloride is separated from the rest of the sea brine, (and you chemical engineers know all about crystallization differentials), the remaining brine is VERY high in potassium chloride, a valuable fertilizer component. Again separated by crystallization differentials, the other less common components of sea water, valuable industrial chemicals in their own right, may be successfully separated, even including some small portion of gold and other heavy metals, but that is merely a side product and while its recovery may help the overall economic return, by no means is the primary source of return on investment.
The flaw in that proposal is that the atmosphere flows east to west across the Sahara. All that wonderful water would have to be piped east all the way across the desert through a massive irrigation system. Even then, there’s a reason the Sahara desertified, and the prevailing conditions that caused that have not changed. You’d be fighting an uphill battle the whole time.
Then you get into the second-order consequences. What happens to the weather when you cut off the flow of hot dry air coming off that desert? Or alternately, what happens when that flow of hot air is already heavy with moisture before it reaches the Atlantic? What’s that going to do to the hurricane season here in the US? Does it go away? Does it get worse? What happens when you start dumping huge volumes of fresh water into the ocean there?
It’s a neat idea, but dinking around with the weather is just asking for problems.
And all that doesn’t even *begin* to address the idea of putting advanced nuclear reactors in Africa. Maybe once the Chinese are done colonizing it, you might have a chance.