Scientists Fear Massive Sea Level Rise from “Unstoppable” Melt of West Antarctica Ice Sheet

Two new academic studies released Monday reveal that the crucial West Antarctic ice sheet is now melting, a seemingly unstoppable disaster that could eventually trigger sea levels to rise by more than 14 feet (4.3 metres).

The studies could finally make politicians rethink how climate change is affecting humankind and how society is going to deal with the increasingly expensive cost of mitigating climate change caused by burning fossil fuels overheating our atmosphere.

One of the studies indicates the glaciers in the Amundsen Sea sector of West Antarctica “have passed the point of no return,” according to glaciologist and lead author Eric Rignot, of UC Irvine and NASA’s Jet Propulsion Laboratory in California. The new study has been accepted for publication in the journal Geophysical Research Letters.

NASA says the glaciers already contribute significantly to sea level rise, releasing almost as much ice into the ocean annually as the entire Greenland ice sheet. “They contain enough ice to raise global sea level by four feet (1.2 metres) and are melting faster than most scientists had expected,” according to a press release.

Greenland and Antarctic ice sheets. Image Credit: NASA

“The collapse of this sector of West Antarctica appears to be unstoppable,” Rignot was quoted as saying. “The fact that the retreat is happening simultaneously over a large sector suggests it was triggered by a common cause, such as an increase in the amount of ocean heat beneath the floating sections of the glaciers. At this point, the end of this sector appears to be inevitable.”

Image from NASA's "The Unstable West Antarctic Ice Sheet: A Primer."

The other study, conducted by University of Washington researchers, also shows the collapse of the West Antarctic ice sheet appears to have already begun. “The fast-moving Thwaites Glacier will likely disappear in a matter of centuries, researchers say, raising sea level by nearly two feet,” according to a media release.

“That glacier also acts as a linchpin on the rest of the ice sheet, which contains enough ice to cause another 10 to 13 feet (three to four metres) of global sea level rise. The study is to be published in Science.”  

Lead author Ian Joughin, a glaciologist at the UW’s Applied Physics Laboratory, said scientists looking at ice thinning previously didn’t know how fast the glacier would melt. “In our model simulations it looks like all the feedbacks tend to point toward it actually accelerating over time; there’s no real stabilizing mechanism we can see,” Joughin said.

“All of our simulations show it will retreat at less than a millimeter of sea level rise per year for a couple of hundred years, and then, boom, it just starts to really go,” Joughin said.

The studies suggest the ice sheet won’t totally melt for between 200 and 1,000 years, as they aren’t currently sure of the pace of melting, but they say the accompanying sea level rise is inevitable.

West Antarctica bed topography. Areas colored brown are below sea level. Sea level itself is colored yellow, and green areas are above sea level. Image credit: NASA/GSFC/SVS

And while scientists have been warning about the possibility of the West Antarctic ice sheet melting for years, the studies released Monday suggest that human-induced climate change is indeed redefining our world.

The two studies come just a week after an alarming U.S. National Climate Assessment report noted climate change is already occurring in every region of America and a month after the Intergovernmental Panel on Climate Change said global emissions of greenhouse gases have risen to unprecedented levels.

Together the recent reports could force politicians, engineers, money markets, health planners, military leaders and insurance companies to more aggressively embrace climate change as humankind’s most pressing issue.

Ironically, as sea levels rise, offshore oil exploration platforms and drilling rigs — one of the most high-profile symbols of society’s addiction to fossil fuels — will also have to deal with problems associated with higher seas. But almost certainly the most negatively affected will be the more than a billion people estimated to live along low-lying coastlines, some of which will most likely be abandoned over time.

Image Credit: Thwaites Glacier, NASA