A New History of the Global Water Cycle

Water: We know that it is essential for all life on the planet. Yet, we know surprisingly little about how our water cycle evolved throughout Earth’s history. In this lecture I propose a new framework for the history of the global water cycle, and ask "how has the water cycle been altered by life?"  As we explore the answers to this question, we will examine major changes to the water cycle in Earth’s history, and how these changes altered the habitability of our planet.  I argue that this improved understanding of the history of the water cycle provides useful new perspectives for the future of our water cycle – one in which we face grand challenges in water availability.