In Antarctica, proof that action on climate change is more urgent than ever
Fears that global sea levels this century may rise faster and further than expected are supported by a study showing that 300 glaciers in Antarctica have begun to move more quickly into the ocean.
Scientists believe that the accelerated movement of glaciers in the Antarctic Peninsula indicates a dramatic shift in the way melting ice around the world contributes to overall increases in global sea levels.
Instead of simply adding huge volumes of meltwater to the sea, scientists have found rising temperatures are causing glaciers as far apart as Alaska, Greenland and now Antarctica to break up and slip into the ocean at a faster rate than expected.
The findings will raise concerns within the UN's Intergovernmental Panel on Climate Change (IPCC) which, earlier this year, downplayed the so-called "dynamic" nature of melting glaciers - when rising temperatures cause them to break up quickly rather than simply melt slowly.
Using radar images taken between 1993 and 2003, scientists at the British Antarctic Survey in Cambridge mapped a 12 per cent increase in the average rate of movement of more than 300 glaciers in the Antarctic Peninsula over the period.
The scientists believe that their findings are among the first to suggest that as glaciers being to melt they experience a physical transformation that causes an acceleration in their movement into the sea.
"We're only just now getting to grips with just how big these dynamic processes may be. There are still a lot of surprises out there," said David Vaughan, a glaciologist at the British Antarctic Survey and a co-author of the study.
"It is yet another example of how subpolar glaciers are responding very quickly to climate change because they are close to the temperature transition from ice to water," Dr Vaughan said.
"Scientists want to know why these things are happening because that's the route to the prediction of future sea levels."
In its fourth report published in February, the IPCC said sea levels this century could rise by between 20 cms and 43cms but it accepted that this could be a serious underestimate if ice sheets and glaciers undergo the sort of dynamic changes that existing computer models do not take fully into account.
Hamish Pritchard, a co-author of the study published in the Journal of Geophysical Research, said the findings demonstrated how melting glaciers can change in a way that speeds up their eventual disappearance into the sea.
The study showed that rising temperatures cause glaciers to become thinner, which makes them more buoyant when resting on submerged bedrock, so allowing them to slip faster into the ocean, Dr Pritchard said.
"The Antarctic Peninsula has experienced some of the fastest warming on Earth, nearly 3C over the past half-century. Eighty-seven per cent of its glaciers have been retreating during that period and now we see these glaciers are also speeding up," Dr Pritchard said.
"They are speeding up in a steady, progressive way. Warming causes widespread thinning, which causes widespread acceleration due to an increase in buoyancy. They speed up and the fronts of the glaciers break off and float away."
Chris Rapley, director of the British Antarctic Survey, said: "Without doubt we are seeing a striking global picture of ice on the retreat."
Sales of the tablet are set to fall again, say analysts
Met Police confirm that there was a 'minor disturbance'
Trend which requires crisps, a fork and a strong stomach is sweeping Mexico's streets
George Lucas criticises the major Hollywood film studios
Does Chris Grayling realise what a vague concept he is dealing with?
Parties threaten resort's image as a family destination
I Am Bread could actually be a challenging and nuanced title
'Victory for bees' as European Union bans neonicotinoid pesticides blamed for destroying bee population
The last charge as western black rhino is declared extinct
Brazilian wandering spider: Where are they from and how deadly are they?
Cannibal harlequin ladybirds now threaten native species with STDs
Dredging can make flooding worse, say activists
- 1 Jack the Ripper: Scientist who claims to have identified notorious killer has 'made serious DNA error'
- 2 Banksy arrest hoax: Internet duped by fake report claiming the street artist's identity has been revealed
- 3 Are you ready for Crazy Doritos, the red-hot snack food craze sweeping Mexico’s streets?
- 4 Drink alcohol and eat meat to improve male fertility - but cut down on coffee, studies suggest
- 5 Former East 17 frontman Brian Harvey turns up at Downing Street and 'demands to speak to Prime Minister'
Cameron is warned 'no possibility' of UK reducing immigration and that bid to bring in quota on migrant workers would be illegal
Residents should throw a street party and mix with immigrant neighbours, councils told
London bus driver 'kicks gay couple off for kissing'
Russell Brand threatened with arrest after filming outside Fox News headquarters
Amal Alamuddin calls for the return of the Elgin Marbles from Britain: 'Injustice has persisted for too long'
Lord Freud: Tory welfare minister apologises after saying disabled people are 'not worth’ the minimum wage
£21500 - £40000 per annum: Randstad Education Plymouth: ***KS1 & KS2 Teachers ...
£80 - £140 per day: Randstad Education Leeds: Year 5 Teacher KS2 teaching job...
£35000 - £45000 Per Annum Pensions Scheme After 6 Months: Clearwater People So...
£35000 - £37000 per annum + Benefits: Ashdown Group: Systems Analyst / Busines...