Publishing August 26, 2025

“Peter Brannen delivers a moving and magisterial tribute to the magic-seeming chemical interplay of air and rock, plant kingdom and ocean expanse, which scientists dryly call the “carbon cycle.” Upon it, he shows, absolutely all life rests — with growing, and unnerving, precarity." 
—David Wallace-Wells, New York Times bestselling author of The Uninhabitable Earth

“Peter Brannen offers a completely new vision of Earth and human history that will change your perspective forever. One vital, misunderstood molecule is revealed as the animating force behind everything that has ever happened on this planet—from the assembly of microscopic plankton seashells to the rise and fall of human empires. If we are smart, this impressive, beautifully written book will be a lodestar for the current generation’s most important decisions." 
—Rebecca Boyle, author of Our Moon

“As with everything Peter Brannen writes, this is fascinating; deep history brought vividly to life. But it's also crucial—our ability to understand and act on it will determine how the next period in earth's history unfolds." 
—Bill McKibben

“What a brilliant and epic book this is! From the magical transformation of CO2 into the first life to our current flailing attempts to pump less of it into our atmosphere, Brannen gives us a sweeping history of the planet in a single molecule. I study this stuff for a living and still learned so much—how coal nearly froze the planet, why the rocks beneath our feet allow us to breathe, and the origins of our modern industrial world. This book is a collection of wonderful things woven together into a fascinating, terrifying whole." 
—Kate Marvel, climate scientist and author of Human Nature

“In this urgent and astounding book, Brannen weaves together the entire history of Earth, and the origins and tribulations of life over billions of years, with the predicament we find ourselves in today. With the lyricism of John McPhee and scientific bona fides rivalling any academic geologist, Brannen is in a class of his own as the preeminent scribe of Earth science today. This is the book that I want all of my Earth science students to read, and every policymaker and politician too." 
—Steve Brusatte, University of Edinburgh paleontologist and New York Times/Sunday Times bestselling author of The Rise and Fall of the Dinosaurs

Every year, we are dangerously warping the climate by putting gigantic amounts of carbon dioxide into the air. But CO2 isn’t merely the byproduct of burning fossil fuels—it is also fundamental to how our planet works. All life is ultimately made from CO2, and it has kept Earth bizarrely habitable for hundreds of millions of years. In short, it is the most important substance on Earth. But how is it that CO2 is as essential to life on Earth as it is capable of destroying it?

In The Story of CO2 Is the Story of Everything, award-winning science journalist Peter Brannen reveals how carbon dioxide’s movement through rocks, air, water, and life has kept our planet’s climate livable, its air breathable, and its oceans hospitable to complex life. Starting at the dawn of life almost 4 billion years ago, and working all the way up through today’s global climate crisis and beyond, he illuminates how CO2 has been responsible for the planet’s many deaths and rebirths, for shaping the evolution of life, and for the development of modern human society. And he argues that it’s only by reckoning with this deep planetary history that we can understand the cosmic stakes of our current moment on Earth—and how dangerous our experiment with the climate really is.

With groundbreaking research and a clear-eyed perspective, Brannen shows how a deep exploration of the carbon cycle across our planet’s history can shed light on the way forward for humanity, as we try to avert environmental catastrophe in the future. And it all begins with a richer understanding of the critical role of CO2 in our world.