But how would precession lead to the desertification of the sahara?

you can see the expansion of rifts in Africa. In no way can CO2 be held responsible for this type of event.

Of course not, but the number of geological catastrophes is not rising. Only the number of reported ones is.

Even if the ship is actually sinking, we should not set it consciously on fire.

I agree that CO₂ is not our only problem, but most of the other problems I see are like CO₂ mostly made by ourself (except from a few earth-quakes here and there), and not by some widely unknown and badly documented astrophyical phenomenon.