This collective essay summarizes for a non-technical audience the findings of the Global Scenario Group. As an international cadre of researchers and funding, GSG was set up in 1995 by the Stockholm Environment Institute and the Tellus Institute to imagine the transition toward a sustainable and desirable planetary society. Building on what this task force has identified as historic roots, current dynamics, future perils, and alternative pathways for world development, the authors analyze the most likely prospective scenarios for the 21st century and advocate one of them, Great Transition, as the preferred route. Listing the requirements to successfully achieve this evolution, they highlight what would be the feasible strategies, the main agents and forces of change, as well as the core values needed to reach the targeted social and environmental objectives. Not the smallest interest of this work lies in the systemic research agenda proposed to make this future possible.