West Antarctic ice sheet collapse unstoppable

2014-05-12 20:53
MV Akademik Shokalskiy still stuck in the ice off East Antarctica, as it waits to be rescued. (Andrew Peacock, AFP)

MV Akademik Shokalskiy still stuck in the ice off East Antarctica, as it waits to be rescued. (Andrew Peacock, AFP)

Multimedia   ·   User Galleries   ·   News in Pictures Send us your pictures  ·  Send us your stories

Washington - Ice is melting in the western Antarctic at an unstoppable pace, scientists said on Monday, warning that the discovery holds major consequences for global sea level rise in the coming decades.

The speedy melting means that prior calculations of sea level rise worldwide made by the Intergovernmental Panel on Climate Change will have to be adjusted upwards, scientists told reporters.

"A large sector of the West Antarctic ice sheet has gone into a state of irreversible retreat. It has passed the point of no return," said Eric Rignot, professor of Earth system science at the University of California Irvine.

"The retreat of ice is unstoppable," he said, noting that surveys have shown there is no large hill at the back of these glaciers that could hold back the melting ice.

"This retreat will have major consequences for sea level rise worldwide," he added, anticipating the melting will take place largely in the next two centuries.

"It will raise sea level by 1.2m or four feet," said Rignot, whose paper appears in the peer-reviewed Geophysical Research Letters, a journal of the American Geophysical Union.

A pair of published studies document observational changes in the Antarctic in recent years, and predict the future behaviour of the melting ice through computer models.

Rignot, a glaciologist at Nasa's Jet Propulsion Laboratory, said his study compiled data from satellites, aircraft, ships and ground surveys in the west Antarctic ice sheet.

Retreat of the Pine Island glacier has slowed in recent years, but scientists said that was likely to due to a very rapid retreat it went through at first.

The nearby Thwaites glacier has been speeding up since 2006.

"From year to year things can change a little bit, so it is really important when looking at this observational evidence to look at the long term trend of these glaciers," Rignot said.

A separate study published in the journal Science on Monday found that Thwaites glacier is melting fast and that its collapse could raise global sea level nearly 61cm.

That study was based largely on computer modelling of the future, in addition to airborne radar measurements of the West Antarctic ice sheet that allowed scientists to map the underlying bedrock.

Study author Ian Joughin, a glaciologist at the University of Washington, said the process is now expected to take between 200 and 1 000 years.

He also found that such a collapse may be inevitable.

"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.

Current projections of sea level rise, agreed upon by international surveys, do not account for the Antarctic ice sheet melting.

Sridhar Anandakrishnan, professor of geosciences at Pennsylvania State University, said that studies like these will cause the United Nations to revisit their projections.

"The number for 2100 will almost certainly be revised and revised upwards, and my guess is toward what is now their upper limit of something like 90cm, close to three feet," said Anandakrishnan, who was not involved in the new reports.

He said that the rise in sea level is widely accepted to be a result of human-caused climate change, driven by the burning of fossil fuels.

"As glaciers and ice sheets flow faster, that water has nowhere to go but in the ocean and once in the ocean this results in a rise in sea level around the globe," he told reporters.

Even though in the past, Greenland has been the source of most melting glaciers, that appears to be changing, with more and more coming from the South Pole.

"Thus far the loss of ice from Antarctica has not been of the same scale. This appears to be changing," he said.

Read more on:    nasa  |  antarctica  |  climate change
NEXT ON NEWS24X
SHARE:

Read News24’s Comments Policy

24.com publishes all comments posted on articles provided that they adhere to our Comments Policy. Should you wish to report a comment for editorial review, please do so by clicking the 'Report Comment' button to the right of each comment.

Comment on this story
65 comments
Add your comment
Comment 0 characters remaining
 

Inside News24

 
/News
 

Joburg hot spots for cocktails, craft beer, tapas and wine!

It’s the season to be jolly – so we’ve rounded up some new Joburg hot spots!

 
 

I love summer.24

13 things you might not know about Disneyland
The craziest deaths of 2014
How to make this a sensual, sexy summer!
This is what South Africans Googled in 2014!

Jobs in Cape Town [change area]

Property [change area]

Travel - Look, Book, Go!

Kalahari.com - shop online today

2DAYS ONLY – 30% off Appliances

Coffee makers, blenders, fans, juicers and more. T&Cs apply. Shop now!

2 DAYS ONLY – 40% off books

Get 40% off when you buy 2 books. For two days only! T&Cs apply. Buy now!

Up to 50% off on outdoor gear

Save on chairs, blankets, cooler bags, umbrellas and more. Shop now!

Save on Samsung

Cameras, mobile phones, TVs, Tablets and more. While stocks last. Shop now!

Grand Theft Auto 5

Now available on PS4, Xbox One and PC from R649. Buy now!

OLX Free Classifieds [change area]

Samsung Galaxy s4

Mobile, Cell Phones in South Africa, Western Cape, Cape Town. Date October 24

Best bargain in big bay

Real Estate, Houses - Apartments for Sale in South Africa, Western Cape, Cape Town. Date October 25

VW Golf 6, 1.6 Trendline (Excellent condition)

Vehicles, Cars in South Africa, Western Cape, Cape Town. Date October 25

Horoscopes
Aquarius
Aquarius

There is so much going on around you and inside your head. You may want to take your ideas to the next level. Romance may be...read more

There are new stories on the homepage. Click here to see them.
 
English
Afrikaans
isiZulu

Hello 

Create Profile

Creating your profile will enable you to submit photos and stories to get published on News24.


Please provide a username for your profile page:

This username must be unique, cannot be edited and will be used in the URL to your profile page across the entire 24.com network.

Settings

Location Settings

News24 allows you to edit the display of certain components based on a location. If you wish to personalise the page based on your preferences, please select a location for each component and click "Submit" in order for the changes to take affect.








Facebook Sign-In

Hi News addict,

Join the News24 Community to be involved in breaking the news.

Log in with Facebook to comment and personalise news, weather and listings.