The international scientific community has launched Future Earth, a major initiative that promises to strengthen the integration and policy-relevance of global change research. A defining feature of our era has been the recognition of the earth as a single, rapidly-changing social-ecological system. Over recent decades, the need to improve scientific understanding of the dynamics of the global system and threats to its resilience has stimulated numerous research foci: climate, biodiversity, atmosphere, ocean, land, water, social institutions, and other subsystems. These programs have made important strides, advancing our knowledge of key components and their interactions, but the fragmented institutional landscape has not been ideal for addressing the holistic challenges of generating a true Earth System science and identifying the human actions needed for fashioning a sustainable twenty-first century civilization. Future Earth, by offering a common platform that underscores integrated research and action, adds an important new institutional foundation for generating the knowledge foundation for a Great Transition.