Aswan DamDon't know much about the Nile but they dredge the Mississippi so that it doesn't change course to Morgan City which is where it WILL eventually go despite man's best efforts to deny nature. It's not a question of if but when.
No, it's a question of priorities. If you want immortality and you're the Pharaoh, you can build one of the wonders of the world. They could have done plenty of other projects that that was their priority.It's really a question of math. Mother Nature has a tremendous resource of energy she can throw at us. The energy we can expend is limited by money.
I only gave examples of man choosing to alter his world (burning forests for pasture land is another) but there are examples of man ignorantly changing his world: there used to be lush forests on the Greek Islands until they cut down the trees for warships and let their topsoil wash into the sea. They literally changed their climate.