For half a century, climate scientists have seen the West Antarctic ice sheet, a remnant of the last ice age, as a sword of Damocles hanging over human civilization.
The great ice sheet, larger than Mexico, is thought to be potentially vulnerable to disintegration from a relatively small amount of global warming, and capable of raising the sea level by 12 feet or more should it break up. But researchers long assumed the worst effects would take hundreds — if not thousands — of years to occur.
Now, new research suggests the disaster scenario could play out much sooner.
"You could think of all sorts of ways that we might duck this one. I’m hopeful that will happen. But given what we know, I don’t think we can tell people that we’re confident of that.”
Dr. Alley was not an author of the new paper, though it is based in part on his ideas about the stability of glacial ice. Several other scientists not involved in the paper described it as significant, with some of them characterizing it as a milestone.
But those same scientists emphasized that it was a single paper, and unlikely to be the last word on the fate of West Antarctica. The effort to include the newly recognized factors imperiling the ice is still crude, with years of work likely needed to improve the models.