"The conditions that allowed humans to live on Earth are incredibly fragile. Climate variability has at times created new niches that humans or their ancestors could potentially exploit, and challenges that at times have spurred innovation. But there's a relatively narrow envelope of climate variability within which human civilization remains viable, and our survival depends on conditions remaining within that range. In this book, renowned climate scientist Michael Mann provides readers with the knowledge necessary to appreciate the gravity of the unfolding climate crisis, while emboldening them to act before it is too late"-- Provided by publisher.