Our species has transitioned from being one among millions on Earth to the species that is single-handedly transforming the entire planet to suit its own needs. In order to meet the daunting challenges of environmental sustainability in this epoch of human domination—known as the Anthropocene—ecologists have begun to think differently about the interdependencies between humans and the natural world. This book provides the best available introduction to what this new ecology is all about—and why it matters more than ever before. It describes how the science of ecology is evolving to provide a better understanding of how human agency is shaping the natural world, often in never-before-seen ways. The book emphasizes the importance of conserving species diversity, because it can offer a portfolio of options to keep our ecosystems resilient in the face of environmental change. It envisions humans taking on new roles as thoughtful stewards of the environment to ensure that ecosystems have the enduring capacity to supply the environmental services on which our economic well-being—and our very existence—depend. It offers the ecological know-how to maintain and enhance our planet's environmental performance and ecosystem production for the benefit of current and future generations. The book shows how today's ecology can provide the insights we need to appreciate the crucial role we play in this era of unprecedented global environmental transition.