On Thin Ice; December 2002; Scientific American Magazine; by Robert A. Bindschadler and Charles R. Bentley; 8 Page(s)

Twelve thousand years ago, as the earth emerged from the last ice age, vast armadas of Titanic-size icebergs invaded the North Atlantic. Purged vigorously from the enormous ice sheets that smothered half of North America and Europe at the time, those icebergs displaced enough water to raise global sea level more than a meter a year for decades.

As the frozen north melted, the ice gripping the planet's southernmost continent remained essentially intact and now represents 90 percent of the earth's solid water. But dozens of scientific studies conducted over the past 30 years have warned that the ice blanketing West Antarctica-the part lying mainly in the Western Hemisphere-could repeat the dramatic acts of its northern cousins. Holding more than three million cubic kilometers of freshwater in its frozen clutches, this ice sheet would raise global sea level five meters (about 16 feet) if it were to disintegrate completely, swamping myriad coastal lowlands and forcing many of their two billion inhabitants to retreat inland.