Three million years ago, the atmosphere’s carbon-dioxide levels weren’t so different from those of today, but sea levels were dozens of meters higher. Looking that far back presents a foreboding peek into the future, as satellite records show that melting Antarctic ice sheets are on their way to bulking up this epoch’s oceans, too. The puzzle for scientists is that the climate models they create can’t seem to match what they see with their own eyes. “Lots of people have been scratching their heads trying to figure out what is missing from our ice sheet models,” said Alex Bradley, an ice dynamics researcher at the British Antarctic Survey, part of the United Kingdom’s Natural Environment Research Council.This week, two new papers in the journal Nature added to the growing pile of evidence that scientists’ models aren’t capturing a complete picture of Antarctica’s rapid deterioration. One study, published on Thursday, found that more than twice as much meltwater could be weighing on the surface of ice shelves, extensions of glaciers that float on the sea, than scientists previously thought. The study published on Tuesday identified a new... Read more
