In this sweeping work of science and history, the renowned climate scientist and author of The New Climate War shows us the conditions on Earth that allowed humans not only to exist but thrive, and how they are imperilled if we veer off course. For the vast majority of its 4.54 billion years, Earth has proven it can manage just fine without human beings. Then came the first proto-humans, who emerged just a little more than 2 million years ago - a fleeting moment in geological time. What is it that made this benevolent moment of ours possible? Ironically, it's the very same thing that now threatens us - climate change. The drying of the tropics during the Pleistocene period created a niche for early hominids, who could hunt prey as forests gave way to savannahs in the African tropics. The sudden cooling episode known as the 'Younger Dryas' 13,000 years ago, which occurred just as Earth was thawing out of the last Ice Age, spurred the development of agriculture in the fertile crescent. The 'Little Ice Age' cooling of the 16th-19th centuries led to famines and pestilence for much of Europe, yet it was a boon for the Dutch, who were able to take advantage of stronger winds to shorten their ocean voyages. The conditions that allowed humans to live on this earth are fragile, incredibly so. 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 civilisation remains viable. And our survival depends on conditions remaining within that range. In this book, renowned climate scientist Michael Mann arms readers with the knowledge necessary to appreciate the gravity of the unfolding climate crisis, while emboldening them - and others - to act before it truly does become too late. 'This detailed and yet marvelously readable look at our climatic past offers us the information we need to understand our climatic future - and more importantly, to act to shape that future in the here and now.' -Bill McKibben, author of The End of Nature 'Mann has a tremendous depth of knowledge about the history of our planet's climate, which is why his words of warning and optimism are so important. This book provides important lessons from humanity's past to empower readers to help protect our future.' -Former US Vice President Al Gore 'Reading Our Fragile Moment is like taking a spectacular hike through billions of years of Earth's climate history with one of the great scientists of our time. Oh look - there's the meteor that wiped out the dinosaurs! There's the great ocean conveyor! There's the Rossby waves! When you reach the summit of Mann's wonderful book, you will understand just how rare and beautiful our moment is - and why we need to fight harder to protect it.' -Jeff Goodell, author of The Heat Will Kill You First