Why Everything in the World Comes Down to Carbon Dioxide

As far as award-winning science journalist Peter Brannen is concerned, every aspect of life on Earth ultimately hinges on the fate of a single molecule: carbon dioxide. It’s a hugely consequential premise that Brannen unpacks in his new book, The Story of CO₂ Is the Story of Everything: How Carbon Dioxide Made Our World. “I wanted to give readers context about something that is fundamental to how our planet operates,” Brannen said.

Brannen recognized that his readers would likely be familiar with the essential role that a suitable level of atmospheric carbon dioxide plays in sustaining all animal life on the globe. The gas, of course, absorbs planetary heat and reradiates some of it back to the Earth’s surface. Too little CO₂ would cause an ice age, while too much would overheat us. But Brannen wanted to tell a much fuller story of how CO₂ originates, and how it affects the existence of every organism as it cycles through Earth’s atmosphere, oceans, and crust. “Everything about planet Earth is basically mediated through CO₂ somehow,” he said.

Rather than approach The Story of CO₂ as climate activism, Brannen essentially authored a four-billion-year-long biography of a single vital gas based on a decade’s worth of comprehensive research, interviews, and field work with geoscientists. “The science speaks for itself,” said Brannen. “I viewed my job as being an alien observer of Earth, describing what’s happening in a mechanistic way.”

Brannen became fascinated with the critical functions of carbon dioxide while writing his 2017 book The Ends of the World, about the five major mass extinction events in Earth’s history, the last of which took place about sixty-six million years ago. He said the delicate natural balance of CO₂ in the atmosphere has become disrupted at an exponentially rapid pace by the human consumption of fossil fuels, which release carbon dioxide when burned to produce energy. “In a matter of two centuries, we’ve ignited a planetary battery all at once,” he said. “It’s an unprecedented chemistry experiment.”

Brannen majored in English before going on to write about geology, climate, and ocean science for publications like The Atlantic and The New York Times. He credits BC’s formative education for inspiring him to explore humankind’s role in the universe, one that humbles him with its awesomely intricate design. “This planet is miraculous,” he said. “The overriding feeling I took away from this book was profound gratitude for being alive at all.” ◽