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.
"Although not all scientists will agree with Alley's conclusions, [this] engaging book--a brilliant combination of scientific thriller, memoir and environmental science--provides instructive glimpses into our climatic past and global future . . . "--Publisher's Weekly
"Alley's . . . striking finding is that the earth's climate has always been wildly variable and subject to dramatic swings--except during the past 10,000 years. So the period during which humankind has established itself across the globe and made the transition from grubby bands of hunter-gatherers to the dubious majesty of global capitalism corresponds exactly to a freakishly stable period in the earth's climate."--Angus Clarke, The Times of London
"With a highly readable style designed to capture and stimulate the imagination of his students, Alley explains some of the complexities of Earth system science with a minimum of jargon. This book is not just for students: it will be readily accessible to a wide audience that should be aware of its contents."--David Peel, New Scientist
"[A] provocative little book . . . a compelling tale of climate sleuthing . . .[Alley] is authoritative without being dogmatic, concerned without being alarmist."--Robert C. Cowen, Christian Science Monitor
"A fascinating journey into the geologic past and the history of the Earth's climate . . . Alley ends his entertaining book by polishing his crystal ball, envisioning what the future climate will be, and what we might do about it."--J.A. Rial, American Scientist
"A superlative account of a complex topic . . . It is refreshingly straightforward to read, often humorous, yet still deadly serious, complete with anecdotes and understandable explanations of complex processes."--Choice
Table of Contents
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