Scientists have been concerned for many years that the collapse of a continental glacier on Greenland or the Antarctic could result in a rapid and dangerous rise in sea levels, and now the surprising condition of an Antarctic glacier has seriously increased that concern.

A group of international scientists recently led a two month-long expedition to one of Antarctica’s most remote regions to measure the rate of ice melt under the 50km-long Pine Island Glacier, and the results have concerned glaciologists worldwide. The glacier, which thins out towards the Amundsen Sea at a rate of about 2.5 miles (4 kilometers) each year, has been carefully monitored by scientists because it has been identified as one of the most rapidly melting ice masses in the world.

Climatologists have discovered that West Antarctica is warming TWICE as fast as they previously thought it was.

This unexpectedly big increase adds to fears the ice sheet will thaw, causing the sea level to rise and drown coastal cities all over the world. West Antarctica holds enough ice to raise world sea levels by 11 feet if it ever all melted, although this is a process that would take centuries (allowing us time to prepare?) In addition to offering a more complete picture of warming in West Antarctica, the new study shows for the first time that significant melt is occurring during the summer.

We didn’t really know–until now. The ocean, which has risen an average of 8 inches since 1900, should rise another 3 feet or so by 2100, but without an accurate record of where we started, we can’t know if the melting starts to speed up or (hopefully) slow down.

On the Climate Central website, Michael D. Lemonick quotes researcher Ian Joughin as saying, "There are lots of processes in play and it remains unclear whether the ice loss will level out or slow down or speed up. We thought we understood ice sheets, but it’s clear we don’t. We need a lot more observations and a lot better modeling."

One of the world’s leading ice experts has predicted the final collapse of Arctic sea ice in summer months within four years. That’s earlier than the Earth’s predicted demise in December of 2012, but it could be a major cause of it.

In the September 17th edition of the Guardian, John Vidal quotes climatologist Peter Wadhams as calling it "a global disaster."