Abundant Earth documents the loss of biodiversity underway and lays out the drivers of this destruction. It goes beyond the litany of causes—a growing population, rising livestock numbers, expanding economies and trade, and spreading infrastructures—to ask the question: Since it is well-understood that humanity’s expansionism is irreparably diminishing life’s richness, why are we not taking the needed steps to halt our expansionism? It argues that the worldview of human supremacy—the conviction that humans are superior to all other life-forms and entitled to use them and their places—stands in the way, for it normalizes humanity’s ongoing expansion. This worldview is an obstacle to recognizing that the conjoined strategy of scaling down the human enterprise and pulling back from expanses of land and seas is the means for addressing the ecological crisis and preempting the suffering and dislocations of both humans and nonhumans. Scaling down calls us to lower the global population within a human-rights framework, move toward deindustrializing food production, and work to localize economies and contract global trade. Pulling back is the project of restoring terrestrial and marine ecologies, so that life’s abundance may resurge. The book argues that humanity will not advance by entrenching its domination over the biosphere, but will stagnate in the debased identity of nature-colonizer and decline in the predicament of vying for “natural resources.” Instead, humanity can chart another course, choosing to live in fellowship with our Earthly wild and domestic cohort, within vibrant ecologies, nestling human inhabitation inside a biodiverse, living planet.