East Antarctica melt could cause a global coastal destruction

Parts of the vast ice sheet of East Antarctica – which collectively holds enough water to raise global sea levels by 53 metres – could begin an irreversible slide into the sea this century, causing an unstoppable process of global coastal destruction, scientists have warned.

East Antarctica is widely considered to be more stable than the West Antarctic ice sheet but a study suggests that a large region of the eastern ice sheet is in danger of becoming irreversibly unstable once a relatively thin section of retaining ice on its coast is lost, the researchers said.

A slab of coastal ice is all that is stopping the giant Wilkes Basin ice sheet from slipping into the sea. Once this process begins it will relentlessly continue to pour vast amounts of water into the oceans for centuries to come, raising global sea levels by between three and four metres, they said.

“East Antarctica’s Wilkes Basin is like a bottle on a slant and once uncorked it empties out,” said Matthias Mengel of the Potsdam Institute for Climate Research in Germany, and lead author of the study published in the journal Nature Climate Change.

The ice sheet of Antarctica holds enough water to raise global sea levels by more than 50m The ice sheet of Antarctica holds enough water to raise global sea levels by more than 50m (AP)

“The East Antarctic ice sheet has long been considered to be stable even under a warmer climate, in contrast to its West Antarctic counterpart. We have now shown that this may not be true,” Mr Mengel said.

“This implies that the future sea-level contribution of the East Antarctic ice sheet may be significantly higher than previously estimated. This is important for the millions of people who live on the coasts. Every centimetre of sea level rise on top of what is already expected is going to be even more difficult to adapt to,” he said.

“By emitting more and more greenhouse gases we might trigger responses now that we may not be able to stop in the future,” he added.

East Antarctica holds about 10 times the volume of ice than is smaller West Antarctic cousin. Much of the ice in the east lies at high altitude and is kept well below freezing point, but a large proportion of it – enough to raise sea levels by 19 metres – lies on bedrock that is below sea level, such as the Wilkes Basin.

Scientists had considered even this low-lying part of the East Antarctic ice sheet – the so-called marine ice sheet – to be more stable and less likely of disintegrating in a warmer climate than the marine ice sheet of the West Antarctic.

However, the analysis the underlying bedrock on which the marine ice sheet of Wilkes Basin stands suggests this is not the case. The scientists found that the rock, which is below sea level and therefore more vulnerable to climate change, becomes a raised ridge at the coast which allows the ice to form a protective plug between the ocean and the ice sheet on the land behind it.

Computer modelling shows that if the local ocean temperatures around the East Antarctic rise as a result of global warming, the ice plug will continue to melt to a point where the “bottle” of ice held within the Wilkes Basin becomes “uncorked”.

“Once started, it becomes unstoppable. At the moment it’s still stable but if it melts then the ice plug alone will result in a global sea-level rise of between 5 and 8 centimetres, but the ice that it will release is going to cause 80 times that amount of sea-level rise,” said Professor Anders Levermann of the Potsdam Institute.

“The bottle is so much bigger than the cork and these plugs of ice on the coast are so much smaller than the ice that they are keeping in place,” Professor Levermann said.

The Intergovernmental Panel on Climate Change (IPCC) said that estimating future sea-level rise was one of the most difficult areas to predict, partly because of the unknown effects in the Antarctic. In its last report, published in March, the IPCC said that Antarctica’s total sea level contribution would be up to 16cm this century, but if half of this ice loss occurred in the ice-cork region, the irreversible discharge of Wilkes Basin ice into the sea will begin, Professor Levermann said.

“Unfortunately we don’t know whether we’ve initiated this process yet. It’s fair to say that if we continue unmitigated climate change and global warming then we’ll destabilise parts of Antarctica and trigger a discharge of ice that will not stop for centuries,” he said.

“It may not be an imminent threat but it will change the planet and will have an impact on global culture because of the huge loss of the cultural heritage of the people living near the coasts,” he added.

“We have probably overestimated the stability of East Antarctica so far….Until recently, only West Antarctica was considered unstable, but now we know that its ten-times-bigger counterpart in the East might also be at risk,” Professor Levermann said.

Start your day with The Independent, sign up for daily news emails
Arts and Entertainment
The Doctor and Clara have their first real heart to heart since he regenerated in 'Deep Breath'
TV
Life and Style
Apple showed no sign of losing its talent for product launches with the new, slightly larger iPhone 6 making headlines
techSecurity breaches and overhyped start-ups dominated a year in which very little changed (save the size of your phone)
Arts and Entertainment
Jamie Oliver
filmTV chef Jamie Oliver turned down role in The Hobbit
News
The official police photograph of Dustin Diamond taken after he was arrested in Wisconsin
peopleDownfall of the TV star charged with bar stabbing
PROMOTED VIDEO
Arts and Entertainment
Jeremy Clarkson, left, and Richard Hammond upset the locals in South America
tvReview: Top Gear team flee Patagonia as Christmas special reaches its climax in the style of Butch and Sundance
News
people
Sport
Ashley Barnes of Burnley scores their second goal
footballMan City vs Burnley match report
Arts and Entertainment
Peter Mayhew as Chewbacca alongside Harrison Ford's Han Solo in 'Star Wars'
film
News
i100
Arts and Entertainment
Man of action: Christian Bale stars in Exodus: Gods and Kings
film
ebooks
ebooksA year of political gossip, levity and intrigue from the sharpest pen in Westminster
Arts and Entertainment
Tracy Emin's 1998 piece 'My Bed' on display at Christie's
artOne expert claims she did not
News
Ernesto Che Guevara and Fidel Castro, right, met at Havana Golf Club in 1962 to mock the game
newsFidel Castro ridiculed the game – but now investment in leisure resort projects is welcome
News
Hackers revealed Oscar-winning actress Lawrence was paid less than her male co-stars in American Hustle
people
Arts and Entertainment
Clueless? Locked-door mysteries are the ultimate manifestation of the cerebral detective story
booksAs a new collection of the genre’s best is published, its editor explains the rules of engagement
Sport
Robin van Persie is blocked by Hugo Lloris
footballTottenham vs Manchester United match report
Latest stories from i100
Have you tried new the Independent Digital Edition apps?
Independent Dating
and  

By clicking 'Search' you
are agreeing to our
Terms of Use.

iJobs Job Widget
iJobs General

Recruitment Genius: Business Manager

£32000 - £40000 per annum: Recruitment Genius: A Business Manager is required ...

Recruitment Genius: Operations Manager

£45000 - £55000 per annum: Recruitment Genius: This is an exciting opportunity...

Recruitment Genius: Panel & Cabinet Wireman

£20000 per annum: Recruitment Genius: Panel Wireman required for small electro...

Recruitment Genius: Electronics Test Engineer

£25000 - £27000 per annum: Recruitment Genius: An SME based in East Cheshire, ...

Day In a Page

A timely reminder of the bloody anniversary we all forgot

A timely reminder of the bloody anniversary we all forgot

Who remembers that this week we enter the 150th anniversary year of the end of the American Civil War, asks Robert Fisk
Homeless Veterans appeal: Former soldiers pay their respects to a friend who also served

Homeless Veterans appeal

Former soldiers pay their respects to a friend who also served
Downfall of Dustin 'Screech' Diamond, the 'Saved By The Bell' star charged with bar stabbing

Scarred by the bell

The downfall of the TV star charged with bar stabbing
Why 2014 was a year of technological let-downs

Why 2014 was a year of technological let-downs

Security breaches and overhyped start-ups dominated a year in which very little changed (save the size of your phone)
Cuba's golf revolution: But will the revolutionary nation take 'bourgeois' game to its heart?

Will revolutionary Cuba take 'bourgeois' golf to its heart?

Fidel Castro ridiculed the game – but now investment in leisure resort projects is welcome
The Locked Room Mysteries: As a new collection of the genre’s best is published, its editor Otto Penzler explains the rules of engagement

The Locked Room Mysteries

As a new collection of the genre’s best is published, its editor explains the rules of engagement
Amy Adams on playing painter Margaret Keane in Tim Burton's Big Eyes

How I made myself Keane

Amy Adams hadn’t wanted to take the role of artist Margaret Keane, because she’d had enough of playing victims. But then she had a daughter, and saw the painter in a new light
Ed Richards: Parting view of Ofcom chief. . . we hate jokes on the disabled

Parting view of Ofcom chief... we hate jokes on the disabled

Bad language once got TV viewers irate, inciting calls to broadcasting switchboards. But now there is a worse offender, says retiring head of the media watchdog, Ed Richards
A look back at fashion in 2014: Wear in review

Wear in review

A look back at fashion in 2014
Ian Herbert: My 10 hopes for sport in 2015. Might just one of them happen?

Ian Herbert: My 10 hopes for sport in 2015

Might just one of them happen?
War with Isis: The West needs more than a White Knight

The West needs more than a White Knight

Despite billions spent on weapons, the US has not been able to counter Isis's gruesome tactics, says Patrick Cockburn
Return to Helmand: Private Davey Graham recalls the day he was shot by the Taliban

'The day I was shot by the Taliban'

Private Davey Graham was shot five times during an ambush in 2007 - it was the first, controversial photograph to show the dangers our soldiers faced in Helmand province
Revealed: the best and worst airlines for delays

Revealed: the best and worst airlines for delays

Many flyers are failing to claim compensation to which they are entitled, a new survey has found
The stories that defined 2014: From the Scottish independence referendum to the Ice Bucket Challenge, our writers voice their opinions

The stories that defined 2014

From the Scottish independence referendum to the Ice Bucket Challenge, our writers voice their opinions
Stoke-on-Trent becomes first British city to be classified as 'disaster resilient' by the United Nations

Disaster looming? Now you know where to head...

Which British city has become the first to be awarded special 'resilience' status by the UN?