The science of human sustenance is inherently a social science. Neither physics nor chemistry nor even biology is adequate to understand how it has been possible for one species to reshape both its own future and the destiny of an entire planet. This is the science of the Anthropocene. The idea that humans must live within the natural environmental limits of our planet denies the realities of our entire history, and most likely the future. Humans are niche creators. We transform ecosystems to sustain ourselves. This is what we do and have always done. Our planet’s human-carrying capacity emerges from the capabilities of our social systems and our technologies more than from any environmental limits.