Frozen Earth

September 13, 2004
With all the concern about global warming, it may be surprising to read that "today's climate is just a geologically short warm spell in a continuing ice age." In this lucid and informative book, Macdougall (A Short History of Planet Earth
), an earth science professor at the Scripps Institution of Oceanography, introduces some of the scientists who have studied the Earth's ice ages, including the celebrated 19th-century naturalist Louis Agassiz, who put forth the theory, revolutionary at the time, of a global ice age; the amateur scientist James Croll, who propounded the idea that cycles of glacial and interglacial climates are related to changes in Earth's orbit around the Sun; and J. Harlan Bretz, who studied the catastrophic glacial flood that produced the "Channeled Scablands" of Washington state. That glaciers once extended from the North Pole to the Mediterranean was a fact accepted only gradually, and Macdougall examines in detail the clues—rock formations, glacial deposits, fossils and sediment cores—that scientists have used to prove the existence of continental ice sheets, as well as to study them. He closes with a discussion of our current ice age, suggesting that global warming may bring it to a premature end. Some of the science can get a bit technical, but Macdougall's readable style makes it accessible to the interested layperson. Illus. not seen by PW
. Agent, Rick Balkin.

Starred review from October 1, 2004
Like Gabrielle Walker's Snowball Earth, this book is serious science made accessible to armchair geologists and adult readers interested in natural history. Macdougall (earth science, Univ. of California, San Diego) explores the causes of ice ages, beginning with the earliest known glaciation nearly three billion years ago, and the effects they have had on Earth's geography, climate, and even human evolution and culture. The author brings to life the scientists of the past 200 years who have made the study of ice ages their life's work. This is really their story, as it chronicles the discoveries, ideas, and opinions that have shaped our understanding of our planet's history today and may help us understand the climate changes of tomorrow. The book is packed with detailed information, and Macdougall's engaging style makes it a pleasurable and thought-provoking read. Highly recommended for public libraries of all sizes and small academic libraries.-Denise Dayton Hamilton, Heritage Christian Sch., Rindge, NH

Copyright 2004 Library Journal, LLC Used with permission.

September 15, 2004
People commonly think the earth's climate is warming, but on a geological time scale, the earth has been cooling for the past 35 million years and is in the midst of a three-million-year ice age--the Pleistocene Ice Age. Earth-sciences professor Macdougall presents the scientific history behind ice ages, emphasizing the roles of four great scientists in the field: Louis Agassiz, James Croll, Milutin Milankovitch, and Harlan Bretz. Each made milestone contributions, and the author interestingly highlights their characters and the resistance to their hypotheses. Their biographies will draw readers into the story of geology's emergence as a science in the nineteenth century. Another hook for readers is the author's discussions of evidence, appearing in landforms and geochemical analysis, which also incorporate the narration of contemporary scientists on the natural history of climate. By grounding general readers in the science of ice ages and by underscoring climate's propensity for abrupt gyrations, Macdougall's account promotes a welcome, reasoning attitude toward ice-age research and its relevance to global warming.(Reprinted with permission of Booklist, copyright 2004, American Library Association.)