More likely it would be the UN that wrote it. Their charter of rights is already pretty solid.
Ok, what if they're given the supreme power you'd like to give them and then then they change it to something that's NOT "pretty solid"? Ever seen Star Wars?
So a unanimous vote? lol, what are you smoking? The Empire form Star Wars = universal government who threatens your home with a super-weapon if you don't obey them. 100% appropriate.
This is all drastically oversimplified. It isn't just a one time here is a consitutuoks someone whipped up. Vote yes or have it forced. They would form it together.
On the contrary, the devil is in all the tiny little details that benefit one country and rape others in the name of "greater good" or as the UN calls it "sustainable development"
Globalization is fine. A bureaucracy picking winners and losers is counterproductive to fair global trade. It only props up the monopolies that are responsible for it's existence.
Then dont have a bureaucracy picking winners and losers in trade. Free trade would work better. The less restrictions on the movement of assets the better.