forget environmental preservation and remove all restrictions based on "moral" and "ethical" reasons like humane animal killing and restrictions on genetically altered "frankenfood"
That's how
Our planet could potentially support hundreds of billions of people, if not even trillions, if we said forget you to all other environmental systems and harnessed the planet's energy from the sun, converting it into calories.
It sounds terrible, but once humanity is a galactic civilization spanning hundreds, if not thousands of planets, I guarantee that we won't give two forgets about nature, because we will be completely independant from natural systems.
Just Nexus' thought o ze day