The most pressing challenges of our time are fundamentally global. They require a concerted global effort to ensure a sustainable future. But human history has always been global. In this book, Jeffrey Sachs, a leading economist and expert on sustainable development, looks back at world history to show how we can respond to the challenges and opportunities of the 21st century. Sachs charts seven waves of technological and institutional change, beginning with the colonization of the planet by humans through long-distance migrations and concluding with reflections on globalization today. He considers how geography, technology, and institutions shaped the Neolithic Revolution, the role of the horse in the rise of empires, the expansion of land empires in the classical era, how sea routes from Europe to Asia and the Americas opened up global empires, and the changes that have occurred with the advent of the Industrial Age. The dynamics of these past waves, Sachs shows, provide new insights into the processes unfolding today: digitally enabled globalization. Sachs emphasizes the importance of finding new methods of international governance and cooperation to prevent conflict and achieve the economic, social, and environmental goals of sustainable development.