Paleobiologist Anthony D. Barnosky weaves together evidence from the deep past and the present to alert us to the looming Sixth Mass Extinction and to offer a practical, hopeful plan for avoiding it. Writing from the front lines of extinction research, Barnosky tells the overarching story of geologic and evolutionary history and how it informs the way humans inhabit, exploit, and impact Earth today. He presents compelling evidence that unless we rethink how we generate the power we use to run our global ecosystem, where we get our food, and how we make our money, we will trigger what would be.