Seaweed farming for carbon dioxide capture would take up too much of the ocean

Terraform Africa? Isn’t Africa already terraformed considering it’s on earth?

I'm a fan of nuclear, but I don't think you need nuclear in sunny Africa, especially sunny Sahara. Just fill as many hundreds of square kilometers as you want with solar panels, and you get more than enough electricity for all your needs. The bottleneck will not be electricity, but capital costs and governance.

I think Saudi Arabia stands a better chance, if only the king figures out planting trees in the desert is a better investment than building ghost cities.