Team Studying ‘Doomsday Glacier’ Offer ‘Grim’ Update

The Thwaites Glacier in West Antarctica is, once again, not doing so hot. A team of scientists known as the International Thwaites Glacier Collaboration met this week in the U.K., and offered what they termed a “grim” summary of their six years of work studying an enormous but troubled keystone section of the Antarctic ice sheet.

“Thwaites has been retreating for more than 80 years, accelerating considerably over the past 30 years, and our findings indicate it is set to retreat further and faster,” said Rob Larter, a marine geophysicist at the British Antarctic Survey. The glacier, the widest in the world and in places over 6,500 feet thick, would add around two feet to global sea levels if it melts entirely. But it also serves as a buttress to a big chunk of the rest of West Antarctica, meaning its contribution to sea level rise would eventually be much higher.

Other experts have said the Thwaites is “the most unstable place in the Antarctic.” A study earlier this year found warm seawater is pumping underneath it, potentially accelerating warming. In general, most new studies about the region bring bad and worse news — though not all, like the study this summer showing one potential bit of instability known as marine ice cliff instability is likely not something to be concerned about just yet.

On the whole though, the glacier is on its way out. The ITGC this week said there is consensus that its retreat will accelerate significantly within a century. “However,” Larter said, “there is also concern that additional processes revealed by recent studies, which are not yet well enough studied to be incorporated into large scale models, could cause retreat to accelerate sooner.”

Ted Scambos, a glaciologist at the University of Colorado and a collaborator with the ITGC, said the widespread collapse of the entire West Antarctic ice sheet is now slated for sometime in the 23rd century, unless those additional processes prove to be unfortunate accelerants. The answer, obviously, is to cut global greenhouse gas emissions as rapidly as possible, and then hope some of the modeling is a bit off. “Immediate and sustained climate intervention will have a positive effect,” Scambos said, “but a delayed one.”