I told him these numbers were hard to believe. “Do the arithmetic yourself sometime, then you won’t have to believe it, you’ll know it. - Daniel Quinn

When all else fails, it will be objected that the people of the world will not tolerate a limit on food. That may be, but it has nothing to do with the facts presented here.

The world of the Takers is one vast prison, and except for a handful of Leavers scattered across the world, the entire human race is now inside that prison. During the last century every remaining Leaver people in North America was given a choice: to be exterminated or to accept imprisonment. Many chose imprisonment, but not many were actually capable of adjusting to prison life.
"Yes, that seems to be the case."
Ishmael fixed me with a drooping, moist eye. "Naturally a well-run prison must have a prison industry. I'm sure you see why."
"Well…it helps to keep the inmates busy, I suppose. Takes their minds off the boredom and futility of their lives."
"Yes. Can you name yours?"
"Our prison industry? Not offhand. I suppose it's obvious."
"Quite obvious, I would say."
I gave it some thought. "Consuming the world."
Ishmael nodded. "Got it on the first try."

There’s nothing fundamentally wrong with people. Given a story to enact that puts them in accord with the world, they will live in accord with the world. But given a story to enact that puts them at odds with the world, as yours does, they will live at odds with the world. Given a story to enact in which they are the lords of the world, they will act like lords of the world. And, given a story to enact in which the world is a foe to be conquered, they will conquer it like a foe, and one day, inevitably, their foe will lie bleeding to death at their feet, as the world is now.