Doug Macdougall’s ‘Frozen Earth’ Explains Ice Age, Threat of Global Warming
A few months ago I read The Oceans, by Ellen J. Prager. An introduction to oceanography, the first section is a chronicle of how the earth was formed 4.6 billion years ago, how life began, and the various prehistoric creatures that populated the ever-changing continents and seas of the planet during the various eras until the modern day. As I read this section I kept saying to myself, “How do they know this? How do they know that?” For the author never explained where this knowledge came from, from what proof it was derived. Very occasionally she’d mention ‘the fossil evidence,’ and she dedicates a page to the Burgess Shale, but that was about it, and not enough. Was the reader getting concrete 100%-known facts, or just theories being stated as fact?
I developed this obsession for facts and evidence many years ago, after reading about the dinosaurs created for the Crystal Palace exhibition in 1853. There were only three known at the time, the Iguanodon, the Megalosaurus and the Hylaeosaurus, and they were known only from the briefest of evidence…a single bone here and there. But this didn’t prevent scientist Richard Owen from commissioning three life-sized models of them. His interpretation of what they looked like was completely wrong, but since they were presented with such confidence no one who strolled through the Crystal Palace had a doubt that that’s what they actually looked like.
Since then I’ve taken nothing on faith. I want to be shown the evidence. Is this particular theory based on an extrapolation from only one bone…or from several? (In other words, from a single piece of a particular puzzle, or several interlocking pieces?) Do most people agree with this theory and why do some people, if any, disagree? That’s the information any book designed for the general public should provide. (*The Oceans* is a good book, by the way, and if it were brand new I’d review it here favorably, with the one quibble mentioned above).
This is why I was pleased, for the most part, with Frozen Earth. Doug Macdougall is an author after my own heart. He not only recounts the history of the earth’s ice ages and how the evidence of these ice ages was discovered and interpreted over time – he also shares that evidence with the reader, in simple, easy to understand prose.
“Like most other scientific advances, the realization that the Earth has periodically been gripped in ice ages didn’t come in a single Eureka! moment. Rather, it developed over a period of time and through the efforts of many naturalists and other close observers of the natural landscape.” explains Macdougall.
He continues: “Science progresses…not on a smooth trajectory but in fits and starts and sometimes even with “backward” steps, with long periods of accumulation of evidence and gestation of ideas, a certain amount of serendipity, occasional brilliant flashes of insight, and, especially in more recent times, technological advances.”
Macdougall recounts that progression for us in Frozen Earth. The author of A Short History of Planet Earth (1998), Macdougall knows his subject well. This book is thoroughly researched and well written…though it could have benefited from some judicious editing, as on a couple of occasion the same point is repeated within a couple of paragraphs.
The story of the discovery of the ice ages is the story of dozens of scientists and their theories, based on years of observation. Swiss naturalist Louis Agassiz, who was the first to postulate a global ice age. He published a book outlining his ideas in 1840, entitled Studies on Glaciers.
Other scientists were by no means convinced that he was correct, and years of argument, discussion and further study ensued before it was learned that there had not only been one ice age…but several. (How do they know? Among other things, Macdougall explains the principal of superposition.)
But while Agassiz believed there had been a time when ice covered most of the earth, he never “spent much time thinking about what caused the ice age he proposed.”
Other scientists took up that task, such as French scientist Joseph Adhemar; a self-educated Scotsman, James Croll; and Serbian mathematician Milutin Milankovich.
It’s the human element throughout this book that makes it even more fascinating than just a well-written explanation on the story of why our planet runs hot and cold…and our possible fate as another ice age is due to come. Will it be triggered by today’s global warming…or postponed by it? There is as much discussion about these theories today as there was about Agassiz’ back in the 1840s. (Macdougall devotes his final chapter to this topic.)
Global warming is much in the news these days. There are articles that point out its fears, there are articles that scoff, there are articles recounting efforts to fight it and efforts to ignore it. New theories are being announced, old theories discredited, or brought back into favor. These articles are written by reporters who perhaps have an imperfect understanding of the science they cover – as with the announcement of any scientific discovery the news can be prone to misinterpretation.
The news must be read (or heard) in an informed manner.
This book is an introduction to an important subject, for all that much of it dwells on the past. To help you separate the wheat of fact from the chaff of speculation about global warming, you can’t do better than to start here.
