It has been said that, in the light of ecological overshoot, that human civilization faces two future possibilities: a Great Decoupling or a Great Collapse. In this book, two distinct positions to achieve the Great Decoupling are critically evaluated: Green Growth and Degrowth. It is concluded that neither Green Growth nor Degrowth will be able to achieve the Great Decoupling. The possibility for society to collapse is then raised, with the potential for a civilizational rebound pondered. Whether collapse may be a feature, and not a bug, of the long-run evolution of complex civilization is discussed.