How about this,
Cover the deserts with a massive roofing of solar panels. Use the power provided by the pannels to run grow lights as needed for 24 hour growth.
The shade from the panels might block sun to crops under them so grow lights might be needed a bit in the day also.
Plant all of the cooler now shaded desert lands with massive amounts of crops which will consume the most CO2 possible and be sellable, get some money back to help finance all this.
Now being the solar pannels are mounted in open air as a roof only and very high, they should remain fairly well air cooled. Moisture rising from the desert floor would collect on the bottom of the pannels and drip back down. Sort of like those plastic sheet survival water collectors but much larger, so now the deserts might have some rain once things get rolling. Less irigation needed later perhaps.
Probably allot of extra power would be generated, far more than needed to run grow lights. Run giant compressors as power is available to compress the air gasses to liquid. Drain off the liquid C02 into cheap containers that can hold it, release or sell the other liquid compressed gases. Selling the good usable compressed gasses could help finance the operation, like selling crops grown.
Now, all this compressed CO2 has to go somewhere, but not back into the air though. Shoot it into the Moon! Some simple blaster device to shoot the canistors into space that can break any tendancy to orbit or fall back to earth. Here's where it gets real good of course. All that CO2 we do not want here will eventaully create a C02 atmosphere on the Moon. Now what to do we do? Grow crops!
Once the Moon has enough CO2 to support trees, soybeans, corn etc... farm the Moon! Mostly crops like trees to eat CO2 that need only planted, not much looking after.
Of course what happens when plants are grown? Oxygen!
Soon (about a billion years) the Moon will have Oxygen to support human life, cows, chickens, etc...
Cut the trees we planted there and build houses, farm the lands, raise animals, etc...
And who says they aren't making any new land?
Ok, a total solution and even added benifits plus chance for tremendous profits in future Moon Condo sales.
Where do I pick up the check?
And I will be happy to be the first person on the Moon to plant the first tree! And of course raise the first wind genny
Ok, I know this idea will be shot down if anyone reads it. Like maybe no wind on the Moon, but there should be when we get a C02/Oxygen atmosphere up there. Maybe unfertile dirt? Hey blast some rotting organic materials up there too, also removes/prevents more CO2 here.
If all the money and resources waisted on wars were put into a plan like this, well... it would be far better than the wars are rather it worked or not!