Passado, Presente, Futuro

"As an island in space, the world could not rely on imports from elsewhere; nevertheless, it was already heavily dependent upon imports from elsewhen. [...] The human species, through technological progress, had made itself more than ninety percent dependent on phantom carrying capacity – a term we must now define. Phantom carrying capacity means either the illusory or the extremely precarious capacity of an environment to support a given life form or a given way of living. It can be quantitatively expressed as that portion of a population that cannot be permanently supported when temporarily available resources become unavailable." Overshoot, William R. Catton