The maximum global sea-level rise from the collapse of the rapidly warming West Antarctic ice sheet may be 3.2 meters—not five meters or more as predicted in the past. The revision comes from a new model suggesting that only parts of the ice sheet will collapse—namely, those that are grounded below sea level or sloping downward. Areas of the sheet grounded above sea level or on upward-sloping bedrock would remain in place. The results, in the May 15 Science, say nothing about disappearing ice sheets elsewhere, however. Greenland, for instance, holds enough ice to raise sea levels by seven meters.
@dbiello Biello is the award-winning senior reporter for environment and energy at Scientific American. He has also written on subjects ranging from astronomy to zoology for both the Web site and magazine. He has been reporting on the environment and energy since 1999--long enough to be cynical but not long enough to be depressed. He is a contributor to the Instant Egghead video series, 60-Second Science podcasts, and host of "Beyond the Light Switch" as well as a forthcoming documentary on ethanol for PBS. He is the author of a children's book on bullet trains and is currently working on a book for grown-ups about whether the Earth has entered a new geologic epoch thanks to people's impacts and what should be done about this Anthropocene.