Frozen Earth: The Once and Future Story of Ice Ages

Hey, I've been reading this kind of material for forty years....ice ages, Milankovitch cycles, loess deposits you name it. This book is a nice synopsis. The truth is in the ice cores and seafloor sediment cores....the truth is that an ice is something that nearly destroyed the human race while it changed it. The truth is that another will happen , in geological terms, VERY soon. The truth is that human caused greenhouse gases may have forestalled the onset of the next ice age already..... This is a very good book and I recommend it for anyone with an open mind about global climate and the so called immenent dangers of global warming. However, being cynical, I'd say that people with minds open to this subject must account for less than one percent of the populace......so great is the global warming juggernaut. Don't read the book if you want to actually KNOW something about ice ages that might shake your confidence in all the hype. Read it if you want to learn. But then, after you've learned, you'll have to keep your mouth shut on the subject since the present orthodoxy ( political correctness ) will brand you as either a fool or enemy of the planet or both if you so much as suggest that there may be more to the story than slick media propaganda teach..... Yah, I know the sea level is going to rise and that the floods will be terrrible. How does a 400 foot drop in sea level for oh, about 100,000 years, sound as an alternative? Hummmmmm? Just how much has the sea level actually risen BTW? It's going to be time to see some real movement in that direction soon if the hypothesis is true that man caused CO2 is raising the global temp etc. My money is on the onset of a new ice age within several thousand years......but then, I don't have to compete for tenure or research grants as a climate 'scientist'.

Doug Macdougall's "Frozen Earth" is clear, easy-to-read popular science for those interested in changes in global climate but without the scientific background to understand the often emotionally-charged discussion in the public media. Macdougall's sub-title. "The Once and Future Story of Ice Ages", emphasizes the longer perspective he takes on how and why climate changes. He begins with the fact that we are likely living in an interglacial period of what has been a series of ice ages recurring at more or less regular intervals of several thousand years. Macdougall gives his story a human aspect by describing how, over the last 300 years, a succession of scientists struggled to make sense of the physical evidence around them indicating that glaciers had once covered much more area than they do at present. The struggle leads to a still growing understanding of ice ages; the details of the story underline just how complex the workings of Planet Earth really are and how incomplete our understanding of these processes still is. Macdougall loops back later in the book to relate how the ice ages interacted with human evolution; specifically, how the stress of environmental change forced both adaptation by early humans and selection of those best able to survive the changes. Macdougall's discussion of the "Little Ice Age" during the period 1600-1800 nicely links climate change to a human era we can still relate to. Macdougall is properly cautious in weaving in the possible effects of mankind on climate change and global warming. The burning of carbon-based fuels clearly has some effect on climate, but Macdougall points out that this is only one of many factors that influence climate. At the same time, he makes clear that timing affects the impact of different factors, and lays out the possibility that the human impact may be altering the natural "schedule" of glacial and interglacial periods on earth. This book is highly recommended to those readers interested in a longer perspective on climate change.

Frozen Earth by Doug Macdougall is a fascinating book and it makes a great summer read as the heat beat downs and one tries to remember that we are in an ice age, albeit an interglacial period. The history of the discovery is told for all its glory and each chapter highlights a different personality related to the realization that the world has been through, and will continue to go through, a series of ice ages. The science is explained very neatly and the story is driven by the series of discoveries, beginning with Louis Agassiz to the very latest scientific discoveries, including alternate theories. The author also brings the story forward. All in all, a fascinating glimpse into our world, past, present, and future. Ice is a nice thing to think about on a hot summer day and this is just the book to get one truly thinking.

This is an absolutely fascinating account of the various ice ages that have periodically taken over the earth. From the ancient "Snowball Earth" (sometimes called "Slushball Earth," 550 to 850 million years ago) in which the entire planet was more or less frozen from pole to pole, to the "Younger Dryas," a cold spell beginning 12,800 years ago and lasting for about 1,200 years, to "Little Ice Age" in Europe (700 to 150 years ago) to the "year without a summer," in 1816, UCSD Professor of Earth Sciences Doug MacDougall chronicles the ebb and flow of glacial advance and retreat in a most interesting and informative manner. Much of this is a historical account of how scientists discovered the past ice ages through geology and the study of cores taken from the Antarctic, the Arctic, from the sea floor, and from still standing glacial ice packs. MacDougall explains how these cores are read to reveal climate changes in the past based on evidence from isotopes, pollen, and bubbles of trapped atmospheric gases. It is really amazing how much information can come from such minute bits of evidence. In the early chapters MacDougall recalls the first scientists who became aware of the earth's climate in previous ages--Louis Agassiz, James Croll, Milutin Milankovitch and others. MacDougall recalls their efforts to get their ideas accepted by the geological establishment. It is fascinating to see how gradually it was realized that great rocks had arrived at various places, having been carried there by ancient glaciers. A particularly interesting story is how the Channeled Scablands of the Columbia Plateau in Washington were created when the glacial Lake Missoula sudden broke through the melting ice and drove an immense wall of water clear to the Pacific Ocean. Part of his concentration is on the glacial and interglacial periods that have characterized the environment during the rise of the genus homo and especially the last 150,000 years or so during which homo sapiens have evolved. Chapter Ten, "Ice Ages, Climate, and Evolution" is devoted to how the advance and retreat of the ice affected the evolution of hominids and other animals and plants. For those of us who might be worried about global warning it is perhaps refreshing to be warned that we are still living in an ice age. MacDougall writes, "We are in a warm period, one of the many interglacial intervals that have occurred throughout the Pleistocene Ice Age [now three million years old]." (p. 233) Near the end of the book MacDougall looks at today's climate and takes into account the warming due to human activities, in particular the burning of fossil fuels. But he is not alarmed. He notes that the atmosphere on the planet Venus (surface temperature 485 degrees Centigrade, more than hot enough to melt lead) is almost all CO2 while that on earth is less than four-tenths of one percent CO2. No runaway greenhouse effect seems likely here any time soon. MacDougall explains the carbon dio

I was sad when I reached the end of this book! I wanted it to be at least twice as long. That's how good it is. The author has the ability to express himself very clearly and concisely but not at all in a boring way. The book covers some history and mini-biographies of key individuals who have given thought to glaciations and ice ages right up to modern methods and current thinking about this subject. There is even a discussion on how ice ages may have influenced human evolution. Written in a style that makes it nearly impossible to put down, this book is a gem that should be read by anyone with even just a passing curiosity about ice ages and glaciations.