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Richard Alley, one of the world's leading climate researchers, tells the fascinating history of global climate changes as revealed by reading the annual rings of ice from cores drilled in Greenland. In the 1990s he and his colleagues made headlines with the discovery that the last ice age came to an abrupt end over a period of only three years. Here Alley offers the first popular account of the wildly fluctuating climate that characterized most of prehistory--long deep freezes alternating briefly with mild conditions--and explains that we humans have experienced an unusually temperate climate. But, he warns, our comfortable environment could come to an end in a matter of years.

The Two-Mile Time Machine begins with the story behind the extensive research in Greenland in the early 1990s, when scientists were beginning to discover ancient ice as an archive of critical information about the climate. Drilling down two miles into the ice, they found atmospheric chemicals and dust that enabled them to construct a record of such phenomena as wind patterns and precipitation over the past 110,000 years. The record suggests that "switches" as well as "dials" control the earth's climate, affecting, for example, hot ocean currents that today enable roses to grow in Europe farther north than polar bears grow in Canada. Throughout most of history, these currents switched on and off repeatedly (due partly to collapsing ice sheets), throwing much of the world from hot to icy and back again in as little as a few years.

Alley explains the discovery process in terms the general reader can understand, while laying out the issues that require further study: What are the mechanisms that turn these dials and flip these switches? Is the earth due for another drastic change, one that will reconfigure coastlines or send certain regions into severe drought? Will global warming combine with natural variations in Earth's orbit to flip the North Atlantic switch again? Predicting the long-term climate is one of the greatest challenges facing scientists in the twenty-first century, and Alley tells us what we need to know in order to understand and perhaps overcome climate changes in the future.

Average Customer Rating:

Informative, but not a great read.

Customer Rating:

The author, a scientist, actually did of OK job of keeping me interested in the book. The thing is... the discussion wasn't technical enough to warrant considering on that level. And perhaps it's just me, but it the author didn't provide any strong opinions or speculation of what may have happened and what may happen... just "layman" (weak) facts about how the tests were performed and what it probably means. I think it would have been much better if the author would have included an extra couple chapters in the end with just some interesting ideas in a story form of "what happened and what's going to happen." As it is, if it wanted to be a technical book, it's not technical enough. For entertainment, it's not entertainment enough. In the middle without any strong points in either direction is a bad place to be.

A perfect example of why you need a good editor

Customer Rating:

I found this book unreadable. I don't often say that about a book. I can slog through the Code of Federal Regulations with the best of them. I've edited fiction for publication, and scientific reports. Alley's prose is some of the worst I have ever read. After 41 pages, I gave up. I was nauseated. Technically, Alley makes some good points. His knowlege is first hand and primary observations. However, his prose is stilted and right out of the 17th Century. I got the impression he tried to make a travel memoir out of his scientific investigations. If he really wanted to make a true memoir, he should have split the scientific from the experiential, either as discrete sections or entire books. The down side to that, he would have be more sophisticated with his writing methods, possibly including other people's observations and dialog in his memoirs and less preachy in his science. No such prose appears in this book. Barf! This book is a waste of my time and good paper. Shame on Richard Alley, Princeton Press, and most of all his editors! Um, well if had any editors, that is . . .

Takes You Way Back

Customer Rating:

The Two-Mile Time Machine is a fascinating look into one of the most important scientific endeavors in recent history, the extraction of a two-mile ice core in Greenland that gives us clues to the past earth climate, with some startling revelations on how climate has changed abruptly in the past, and could do so in the near future. Very well-written first-hand account that's easy to read, steering clear of dense technical jargon that has hampered similar books. If you are interested in learning more about global warming and climate change, this book is valuable background information on some of the science behind why scientists have made the recent global warming predictions that give concern about abrupt climate change, tipping points, and positive feedback cycles. This book, however, steers clear of making any bold predictions. It's a very even, balanced look at the results of the Greenland ice core analysis.

Richard Alley is a great storyteller.	Customer Rating:
Alley really knows how to write. This book is about the ice core record of past climate, the adventure of collecting the ice cores in Greenland, what drives climate change, and a bit about global warming. He makes analogies to everyday situations that humorously and clearly explain the science. A fun read.

From Greenland's Icy Mountains

Customer Rating:

An excellent book in many ways, I'll mark the author down because he didn't answer questions he raised in my mind. For example, on page four he says that the climate in Greenland became fifteen degrees warmer in one decade 11,500 years ago! But he doesn't develop the point. I want to know what happens when the climate suddenly becomes that much warmer. We're worried about the extinction of the polar bear because the climate has gotten 5 degrees warmer over the last century. How did the polar bear survive a 15 degree jump in temperature? Secondly, the author makes the point that, for the last 10,000 years the world has been in a warm period of little climate change. His chart on page 9 shows that the average temperature on the Greenland icecap Geenland during this period has been about 25 F below zero, whereas the "normal" temperature during the last 100,000 years has been much more variable and usually between 35-75 F below zero (page 119). The fact that we are now -- and have been since before civilization began -- in an "abnormal" climatic period seems to me to call for more speculation as to why and as to what the world was like when Greenland was so cold. Those criticisms aside, the book is excellent in describing the author's work coring ice in Greenland to discover climatic changes. In the last few chapters he broadens the subject to consider why those changes may have taken place, notably through a lucid examination of the "North Atlantic Conveyor Belt." Smallchief