Enric Sala wants to change the world—and in this compelling book, he shows us how. Once we appreciate how nature works, he asserts, we will understand why conservation is economically wise and essential to our survival. Here Sala, director of National Geographic's Pristine Seas project (which has succeeded in protecting more than 5 million sq km of ocean), tells the story of his scientific awakening and his transition from academia to activism—as he puts it, he was tired of writing the obituary of the ocean. His revelations are surprising, sometimes counterintuitive: More sharks signal a healthier ocean; crop diversity, not intensive monoculture farming, is the key to feeding the planet. Using fascinating examples from his expeditions and those of other scientists, Sala shows the economic wisdom of making room for nature, even as the population becomes more urbanized. In a sober epilogue, he shows how saving nature can save us all, by reversing conditions that led to the coronavirus pandemic and preventing other global catastrophes. With a foreword from Prince Charles and an introduction from E. O. Wilson, this powerful book will change the way you think about our world—and our future.