Environmentalists have worried about Antarctica's fate for decades. As a result, they said, sea levels could rise globally. They fall into two camps. Calif. Another camp, Cooper says, argues that at least parts of the West Antarctic Ice Shelf are highly unstable, and could rapidly fall apart during a major warming. Conceivably, Alley said, the glaciers might be undergoing some very dramatic, but normal, changes that are unrelated to global warming.
Glaciers do odd things sometimes.
The new evidence impresses at least one veteran skeptic, Barclay Kamb, a noted glaciologist at Caltech. But now, he says, the evidence for rapid ice changes is good enough that the worst case scenarios are worth worrying about. You'd produce a lot of these huge 'tabular' icebergs, some as big as the state of Connecticut. Scherer's work impresses John Barron, a USGS-Menlo Park geologist who studies diatoms. What has been lacking is direct evidence.