What is The Ends of the World: Volcanic Apocalypses, Lethal Oceans, and Our Quest to Understand Earth's Past Mass Extinctions about?

Peter Brannen is a science journalist who spent years reporting on paleontology and geology, and The Ends of the World is the result of that work: a deep history of the five major mass extinctions in Earth's past, told through visits to the scientists who decode them and the rock formations that preserve their evidence. The book is both a scientific account and a sustained meditation on scale — the scale of geological time, the scale of planetary catastrophe, and the difficulty of fitting either into ordinary human comprehension.

Each of the five mass extinctions gets its own chapter or set of chapters, organized around the specific mechanism proposed for each event. The end-Ordovician extinction, roughly 445 million years ago, appears to have been driven by glaciation and a collapse of shallow marine ecosystems. The Late Devonian, 375 million years ago, may have been caused partly by the spread of the first forests, which altered the chemistry of shallow seas. The end-Permian, the largest extinction in Earth's history, killed more than 90 percent of marine species and appears to be closely tied to massive volcanic activity in what is now Siberia, warming the oceans and acidifying them simultaneously. The end-Triassic shares some of those same signatures. And the end-Cretaceous — the asteroid impact — is the most recent and the one most people know.

What connects the book's chapters is Brannen's attention to the chemistry of the oceans and atmosphere. In most of the extinction events, the villain is elevated CO2, either from volcanism or from the disruption of the carbon cycle, and the mechanism involves rapid ocean acidification, warming, and oxygen depletion. Brannen draws this comparison to current conditions carefully, never melodramatically, but the implication accumulates across the chapters: the signature of the past extinctions looks uncomfortably similar to what is now being measured.

The scientists Brannen profiles are a particular strength of the book. They are portrayed as people who work on timescales that require a different kind of imagination from most research, staring at slabs of rock to read the chemical diary of a dead ocean. The writing is vivid, the science is current through the mid-2010s, and the overall effect is to make deep time feel specific and strange rather than abstract and remote.