You seem to be very sure about knowing what I can or cannot grasp. You wield this sentence as some kind of weapon against me but the fact is you are not presenting any arguments.
Humanity has shown that it can do a lot if it just wants.
Look at the scale of world wars where large part of world's output was converted to war effort because we just didn't like the idea of being conquered by Nazis.
The great pyramid of Giza is 0.2% of cubic kilometers and it was literally built with sticks and rope, for vanity, with relatively few people.
Your claim that humanity can't crush a bunch of cubic km of rock and spread over vast areas of land when faced with existential crisis is shortsighted.
I keep saying "you don't grasp" the scale here because really you don't. Myself and others have explained how enormous this undertaking would be, but you haven't given any kind of solution to the manifold problems we outlined.
BTW, I worked as mechanic on heavy equip, crushers, drills, and haulage at many mines.
Also, no, I'm not wrong about the scale. This solution would require orders of magnitude times more mass than the oil/coal extraction you're describing. Again, you still aren't grasping how big this would be. It would require giant open pit mines to take out literal cubic kilometers of rock, and keep doing this for ages.