Paul Raskin uses the twenty-fifth anniversary of Tellus as an opportunity to reflect on the past, the current historical moment, and the challenges and possibilities that lie ahead. The evolution of the environment and development research program over the course of Tellus’s history has tracked the deepening interconnectedness, uncertainty, and globalization of the world itself and will continue to do so in the years ahead. The key to ensuring a humanistic and sustainable global transformation is our ability—as scientists, citizens, communities, and nations—to gain new insights, commit to new values, and take common actions to create more harmonious conditions for life on Earth.