Snowball Earth

Did the Earth once undergo a super ice age that froze the entire planet? In "Snowball Earth", Gabrielle Walker takes us on a natural history expedition in search of evidence for an audacious theory—that the Earth experienced a climatic cataclysm 600 million years ago that froze the entire planet from the poles to the equator. Because the global snowball happened so long ago the ice has now long gone - but it left its traces in rocks around the world. To see the evidence, Gabrielle travelled with geologists to remote deserts in Australia, Namibia, South Africa and Death Valley, USA. Part adventure story and part travel book, this is a tale of the ultimate human endeavour to understand our origins.


  • "Walker does a superb job of relating both the scientific and the human side of the controversy. Her prose, like her story, is likely to engage both scientists and general readers equally…an important, provocative book that is a joy to read."

    Publishers Weekly
  • "Walker has … crafted a superb page-turner. This is science writing at its best, a thoroughly engaging work that advances some serious ideas. Highly recommended."

    Library Journal
  • "The scene is superbly described… [Walker] provides nuggets of gold: simple explanations of complex evidence slip down with spoonfuls of scandal sugar. The book lucidly exposes the observations that shaped the hypothesis and its testing, the critics and the bases of their criticisms, and the subsequent growth of the idea."

  • "The details are entertainingly controversial. Walker captures this well and also has a fine time following field geologists from one exotic locale to another. Her book is part vivid scientific travelogue as well as an engaging account of a theory moving from speculation to something much more firmly established."

    The Guardian
  • "A thrilling tale…Walker has managed to turn what is, after all, a story of perplexing messages locked in ancient rocks into a kind of international thriller in which teams of brilliant researchers brave horrendous weather, treacherous field conditions and vicious tenure committees…To Walker’s immense credit, she succeeds in making the discovery and refinement of this theory not only crystal-clear but also wonderfully dramatic."

    Washington Post
  • "A tale told superbly, achieving a balance between science, personality and adventure…the book contains descriptions of the kind of places that only geologists and hard-core explorers get to visit. This is a great page-turner to read on a cold and stormy day."

    Sunday Morning Herald
  • "It's a controversial theory but compelling, and Walker, a science writer, does a fine job of chronicling the often-colorful travels of Hoffman and his supporters around the world looking for supporting proof."

    San Diego Union Tribune
  • "A very entertaining read…perfect for a journey or on the beach."

    The Independent
  • "This is science writing at its very best - cutting-edge, entertaining and downright enthralling."

    The Good Book Guide