Humans have difficulty thinking at the global scale. Yet as we come to understand our planet as a single, interconnected, complex system and encounter compelling evidence of human impact on Earth’s climate and biosphere, the need for a truly global effort is increasingly urgent. In this concise and accessible text, David P. Turner presents an overview of global environmental change and a synthesis of research and ideas from the rapidly evolving fields of earth system science and sustainability science that is suitable for anyone interested in humanity’s current predicaments and what we can do about them.