ICE

The Nature, the History, and the Uses

of an Astonishing Substance

By Mariana Gosnell

Knopf. 560 pp. $30

THIN ICE

Unlocking the Secrets of Climate

in the World's Highest Mountains

By Mark Bowen

Henry Holt. 463 pp. $30

Last summer, Arctic sea ice dwindled to its smallest coverage in a century of record-keeping. Montana's Glacier National Park will soon be glacier-free. Alaska's permafrost is thawing and buckling. Polar bears are getting skinnier and scarcer as their icy habitat shrinks. With ice beating a hasty retreat just about everywhere on earth (except, apparently, the Antarctic), the timing of Mariana Gosnell's Ice and Mark Bowen's Thin Ice could not be better. Ice, or rather its precipitous decline, is a hot topic these days -- and these two books go a long way toward explaining what's happening and why.

Maybe too long a way. At a combined heft of nearly 1,000 pages, there's a lot about ice here to crunch through. But despite some overlap and overweight, the two volumes are different enough and worthy enough that the ice-minded reader would do well to tackle both.

I'd recommend starting with Gosnell, for she has cast the wider net. A former science writer at Newsweek, Gosnell is a "pagophile" -- lover of ice and frost -- who has packed her book with everything she has ever read, heard, seen, felt, tasted or slid over related to her favorite subject. She has chased down Alaskan natives to find out how many words Eskimos really do use for ice and snow (closer to a dozen for snow than the alleged 200). She has unearthed the statistics on an Antarctic iceberg so big that its melted water would supply everyone in the world with two glasses of fresh water every day for the next 1,977 years. To Gosnell, ice, "this solid phase of life's essential liquid," is "changeable, idiosyncratic, complex," a "strange, beautiful substance in our midst." She's obsessed with it, and she has no doubt that any curious reader will find her obsession irresistible.

I certainly did, up to a point. Gosnell is an engaging writer, as adept at spinning a simile (the "sealant" of ice on rocks is cloudy "like skim milk, or a blind man's eye") as at elucidating exactly how ice crystals bond and why they float. And she elegantly organizes her mass of frozen facts into neat categories -- ice in lakes, rivers, glaciers, bergs, plants, animals, air and space. There's a lot of good hard science here, from the nucleation process by which water "learns" how to freeze to the temperature at which ice crystals form in human tissue (not 32 degrees but between 24 and 20 degrees), and a lot of gripping human-interest stuff about ice fishermen cracking through Minnesota lakes and explorers' ships crushed in polar sea ice. But, at heart, this is a cabinet of curiosities related to all things icy -- an immense freezer of facts. Without a driving narrative or a unifying concept aside from Gosnell's own inextinguishable sense of wonder, Ice ends up feeling like a dozen nights of Discovery Channel: fascinating, but finally just too much.

One of Gosnell's five chapters on glaciers describes the remarkable discoveries made by Ohio State University climatologist Lonnie Thompson while drilling ice cores in the most unlikely of places -- tropical and subtropical mountain ranges. Mark Bowen has seized on Thompson's discoveries and their implications for global climate change and made them the subject of Thin Ice. Bowen first encountered Thompson in 1997 at the 21,500-foot summit of Nevado Sajama, Bolivia's highest peak -- "a hooded figure in a quilted red parka" with "a gray beard and sky-blue eyes" standing against a backdrop of tents, drilling gear and "solitary mountains [that] hovered above the horizon like clouds of carved crystal." It's typical of Bowen to drop details about Thompson's eye color and the awe-inspiring scenery he works in before telling us what exactly that work is about and why it's important. Bowen, a climber and a magazine writer, practices the kind of smell-the-sweat journalism familiar from the pages of Outside magazine and Men's Journal: If you don't risk your life, it's not worth writing about.

This approach has its pluses and minuses when it comes to reporting on climate research. On the one hand, Thompson has made a distinguished career of risking life and limb to bring back ice-core samples from some of the most beautiful and dangerous places on earth. And Bowen captures both the thrill and the torture of living and drilling for weeks in the high-altitude "death zone" of the mountains of Peru, China, Tibet and Kenya. On the other hand, even a science-savvy reader may have a hard time teasing out just what Thompson has found and what it all means from Bowen's breathless, you-are-there narrative.

With help from Gosnell's crystal-clear summary, I was able to piece it together. Over the past two decades, Thompson has reconstructed thousands of years of changing weather patterns by analyzing the chemistry, structure and impurities frozen in tropical and subtropical ice, along with the dust compressed between annual ice layers. His precision dating of ancient droughts, El Nino events and volcanic eruptions has provided archaeologists and anthropologists with invaluable clues to the rise and fall of pre-Incan South American civilizations.

Before Thompson, notes Bowen, the "polar mafia" of climatologists dismissed tropical ice as marginal or irrelevant. No longer. Thompson has turned the field on its head with his provocative theory relating Earth's precession (the wobble of the axis of rotation exhibited by spinning objects like tops, gyroscopes and planets) to the track of summer storms that feed moisture into tropical glaciers. His new paradigm, which Bowen says he and Thompson christened the "asynchrony theory" while driving together down a rough Tanzanian road on their way to Mount Kilimanjaro, enabled him to predict accurately, even before he drilled a single core, that the Kilimanjaro glaciers were born some 11,000 years ago. "As usual with him," writes Bowen, "science and adventure were turning out to be essentially the same thing."

Science and adventure do not always fuse so neatly in Bowen's narrative, though his muscular approach does give punch and urgency to warnings about global warming. Thompson's research confirms that the Earth's climate has changed abruptly and disastrously in the past -- and his treks into the tropical death zone provide ample evidence that it's changing again right now. Glaciers are dying everywhere on Earth, but nowhere as quickly as in the tropics and subtropics. Thompson's outdoor laboratory is literally melting before his eyes. In 15 years, maybe 10, the snows of Kilimanjaro will be gone, and with them will go an 11,000-year-old climate archive. Though Bowen the alpinist and Gosnell the pagophile bring markedly different agendas to their tomes on frozen water, they agree that, at the rate things are going, some of our planet's most elemental mysteries will melt before they can be understood. *

David Laskin is the author of "The Children's Blizzard," just released in paperback, and "Braving the Elements: The Stormy History of American Weather."

The melting ice atop Mt. Kilimanjaro