TL;DR; If we overcome massive engineering challenges (such as capturing CO2, crafting materials that handle nuclear reaction at very hight temperature and manage to successfully confine all irradiated byproducts) we could theoretically decompose CO2 using nuclear reactors to overcome global warming.

My comment: Or maybe, just maybe we could plant a shitload of well chosen/engineered trees and algae that do the whole processes autonomously with less risks. And of course reduce current consumption is needed in every scenario.