Get Ready for 7 Foot Sea Level Rise by 2100 + Antarctic Glacier Past Tipping Point


British Antarctic Survey camp on Pine Island Glacier. Photo: Wikipedia.

A quick update on the state of sea level rise projections. As you can tell from the title, it's not so good. Basically, by 2100 coastal areas should being prepared for about 7 feet (2.13 meters), that's what scientists from Western Carolina and Duke universities are saying. And, according to new research done at the universities of Oxford and Cambridge, the Pine Island Glacier in Antarctica has reached a melting tipping point, which alone will eventually contribute about 9 inches (24 centimeters) of water to the world's oceans. Glacier Ground Line Steadily Retreating
The word on the Pine Island Glacier comes via work published in the Proceedings of the Royal Society A which shows how changes in the 'grounding line' of an ice sheet--where it floats free from its base of rock or sediment--can lead to its disintegration.

Oxford University's Dr. Richard Katz says that the model his team developed shows "how instability in the grounding line, caused by gradual climatic changes, has the potential to reach a tipping point where disintegration of the ice sheet could occur."

Pine Island Glacier Melting Accelerating
The leap to that tipping point being reached comes in New Scientist's write up of the research. They explain that the grounding line for the PIG passed over a crucial crest on the Antarctic sea bed back in 1996, readying the glacier for accelerated shrinking. In fact PIG is four times faster than ten years ago.

Dr. Katz's model shows that within 100 years, the grounding line of the glacier will have retreated about 125 miles (200 km) and by the time it comes to rest the glacier will have lost about 50% of its ice, contributing the aforementioned 9 inches to global sea level rise.

If the entirety of the Pine Island Glacier disappears, which could occur if another glacier nearby, Thwaite's Glacier, also retreats, it would contribute about 18 inches to the oceans. If the entire West Antarctic Ice Sheet collapses it would mean at least 11 feet of additional sea level rise.

More: Search for ice sheet 'tipping point' - University of Oxford

Which leads us to the big question of how much sea level rise should we realistically be preparing ourselves for over the next century?


Saving Mississippi Delta communities is virtually impossible... photo: Natalie Maynor via flickr.
7 Feet Not Only Possible, But Likely
It's been widely acknowledged that the IPCC estimates from 2007 are too conservative when it comes to sea level rise. Unofficial updates to that research, publicized in March 2009 at the Copenhagen Climate Congress, said at minimum the world is likely to see half a meter, with more than a meter well within the realm of possibility. A new piece in Yale Environment 360 goes beyond that.

Authors Rob Young (Western Carolina University) and Orrin Pilkey (Duke University) argue persuasively that "governments and coastal managers should assume the inevitability of a seven-foot rise in sea level. This number is not a prediction...a number of academic studies examining recent ice sheet dynamics have suggested that an increase of seven feet or more is not only possibly, but likely. Certainly, no one should be expecting less than a three-foot rise in sea level this century."

Most TreeHugger readers are probably aware of the devastation that this increase in sea level would cause in Bangladesh, Egypt, Southeast Asia, but when it comes to things more close to home, check this out:

Preserving Mississippi Delta Communities 'Doomed to Failure'

The Mississippi Delta is unique because it lies within a country with the financial resources to fight land loss. Nevertheless, we believe multibillion-dollar engineering and restoration efforts designed to preserve communities on the Mississippi Delta are doomed to failure, given the magnitude of relative sea level rise expected. Former Secretary of the Interior Bruce Babbitt said in 2008 that it was an "ineluctable fact" that within the lifespan of some people alive today, "the vast majority of that land will be underwater." He also faulted federal officials for not developing migration plans for area residents and for not having the "honesty and compassion" to tell Louisiana residents the "truth": Someday, they will have to leave the delta. The city of New Orleans can probably be protected into the next century, but only at great expense and with little guarantee that future storms like hurricane Katrina will not inundate the city again.

Read more: How HIgh Will Seas Rise? Get Ready for Seven Feet
Antarctica
Antarctica's Pine Island Glacier Melting Four Time Faster Than 10 Years Ago
West Antarctic Glacier Disintegrating Rapidly: First Hand Account
TreeHugger Goes to Antarctica, Meets Penguins, Seals, and More
Sea Level Rise
Two Meter Sea Level Rise Now Inevitable, But How Fast Will It Happen?
Sea Level Rise Best Case Scenario: 50cm Rise, 10% of World Population Hit

Tags: Antarctica | Global Climate Change | Global Warming Effects | United States

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