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.

PROMOTED VIDEO
Life and Style
fashionHealth concerns and 'pornified' perceptions have made women more conscious at the beach
Arts and Entertainment
tv
Sport
Ojo Onaolapo celebrates winning the bronze medal
commonwealth games
Arts and Entertainment
Rock band Led Zeppelin in the early 1970s
musicLed Zeppelin to release alternative Stairway To Heaven after 43 years
Arts and Entertainment
High-flyer: Chris Pratt in 'Guardians of the Galaxy'
filmHe was homeless in Hawaii when he got his big break. Now the comic actor Chris Pratt is Hollywood's new favourite action star
Sport
Van Gaal said that his challenge in taking over Bobby Robson's Barcelona team in 1993 has been easier than the task of resurrecting the current United side
footballA colourful discussion on tactics, the merits of the English footballer and rebuilding Manchester United
Life and Style
Sainsbury's could roll the lorries out across its whole fleet if they are successful
tech
News
ebookA unique anthology of reporting and analysis of a crucial period of history
Travel
The shipping news: a typical Snoozebox construction
travelSpending the night in a shipping container doesn't sound appealing, but mobile crash pads are popping up at the summer's biggest events
Arts and Entertainment
'Old Fashioned' will be a different kind of love story to '50 Shades'
film
Arts and Entertainment
Tracey Emin's 'My Bed' is returning to the Tate more than 15 years after it first caused shockwaves at the gallery
artTracey Emin's bed returns to the Tate after record sale
Arts and Entertainment
Smart mover: Peter Bazalgette
filmHow live cinema screenings can boost arts audiences
Environment
Neil Young performing at Hyde Park, London, earlier this month
environment
Independent
Travel Shop
the manor
Up to 70% off luxury travel
on city breaks Find out more
santorini
Up to 70% off luxury travel
on chic beach resorts Find out more
sardina foodie
Up to 70% off luxury travel
on country retreats Find out more
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

Project Coordinator

Competitive: The Green Recruitment Company: The Organisation: The Green Recrui...

Project Manager (HR)- Bristol - Upto £400 p/day

£350 - £400 per annum + competitive: Orgtel: Project Manager (specializing in ...

Embedded Linux Engineer

£40000 - £50000 per annum + competitive: Progressive Recruitment: Embedded Sof...

Senior Hardware Design Engineer - Broadcast

£50000 - £65000 per annum + Benefits: Progressive Recruitment: Working for a m...

Day In a Page

Save the tiger: The animals bred for bones on China’s tiger farms

The animals bred for bones on China’s tiger farms

The big cats kept in captivity to perform for paying audiences and then, when dead, their bodies used to fortify wine
A former custard factory, a Midlands bog and a Leeds cemetery all included in top 50 hidden spots in the UK

A former custard factory, a Midlands bog and a Leeds cemetery

Introducing the top 50 hidden spots in Britain
Ebola epidemic: Plagued by fear

Ebola epidemic: Plagued by fear

How a disease that has claimed fewer than 2,000 victims in its history has earned a place in the darkest corner of the public's imagination
Chris Pratt: From 'Parks and Recreation' to 'Guardians of the Galaxy'

From 'Parks and Recreation' to 'Guardians of the Galaxy'

He was homeless in Hawaii when he got his big break. Now the comic actor Chris Pratt is Hollywood's new favourite action star
How live cinema screenings can boost arts audiences

How live cinema screenings can boost arts audiences

Broadcasting plays and exhibitions to cinemas is a sure-fire box office smash
Shipping container hotels: Pop-up hotels filling a niche

Pop-up hotels filling a niche

Spending the night in a shipping container doesn't sound appealing, but these mobile crash pads are popping up at the summer's biggest events
Native American headdresses are not fashion accessories

Feather dust-up

A Canadian festival has banned Native American headwear. Haven't we been here before?
Boris Johnson's war on diesel

Boris Johnson's war on diesel

11m cars here run on diesel. It's seen as a greener alternative to unleaded petrol. So why is London's mayor on a crusade against the black pump?
5 best waterproof cameras

Splash and flash: 5 best waterproof cameras

Don't let water stop you taking snaps with one of these machines that will take you from the sand to meters deep
Louis van Gaal interview: Manchester United manager discusses tactics and rebuilding after the David Moyes era

Louis van Gaal interview

Manchester United manager discusses tactics and rebuilding after the David Moyes era
Will Gore: The goodwill shown by fans towards Alastair Cook will evaporate rapidly if India win the series

Will Gore: Outside Edge

The goodwill shown by fans towards Alastair Cook will evaporate rapidly if India win the series
The children were playing in the street with toy guns. The air strikes were tragically real

The air strikes were tragically real

The children were playing in the street with toy guns
Boozy, ignorant, intolerant, but very polite – The British, as others see us

Britain as others see us

Boozy, ignorant, intolerant, but very polite
How did our legends really begin?

How did our legends really begin?

Applying the theory of evolution to the world's many mythologies
Watch out: Lambrusco is back on the menu

Lambrusco is back on the menu

Naff Seventies corner-shop staple is this year's Aperol Spritz