Consuming the biosphere and polluting the biosphere are separate problems. If there are already more people than the planet can feed, someone has to die. Which of the horsemen will come for us? If I had to bet, I would put my money on bad people killing good people. If one believes that's the future, should one become a bad person? Should one redefine "bad"?

We have a very simple conceptual problem - management of the commons. Elinor Ostrom won a Nobel Prize for her work on that. Enforced cooperation is the solution to sharing. It works on the local level where the shared resources are adequate. What happens on a global scale when the resources aren't adequate isn't clear.