Some numbers: The US Forest Service estimates that 1 acre of forest stores about 80 tons of carbon. You could store about 180 billion tons of carbon onto that

Some numbers: The US Forest Service estimates that 1 acre of forest stores about 80 tons of carbon. You could store about 180 billion tons of carbon onto that area if it were all a forest. CO2 makes up about 3 trillion tons of the atmosphere. ~27% of it is carbon, therefore there is roughly 800 billion tons of carbon in the atmosphere. It seems plausible that if we somehow planted a forest on the entire Sahara desert, that we could reduce the amount of carbon in the atmosphere by a significant amount. I hope I didn't make any errors in my calculations.