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The Amundsen Sea has long been thought to be the weakest ice sheet in the West Antarctic.

Now, a new US study suggests the barren region is haemorrhaging ice at a rate triple that of a decade ago.

Researchers believe that the melting of glaciers in West Antarctica, which contain enough water to raise sea levels by at least a metre, may be irreversible.

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The Amundsen Sea (pictured) has long been thought to be the weakest ice sheet in the West Antarctic. Now, a new US study suggests the barren region is haemorrhaging ice at a rate triple that of a decade ago

The findings of the 21-year study by Nasa and the University of California, Irvine claim to provide the most accurate estimates yet of just how fast glaciers are melting in the Amundsen Sea Embayment. 

Scientists found the rate by taking radar, laser and satellite measurements of the glaciers' mass between 1992 and 2013.

They found they lost an average 83 gigatons per year (91.5 billion U.S. tons), or the equivalent of losing the water weight of Mount Everest every two years.

'The mass loss of these glaciers is increasing at an amazing rate,' said scientist Isabella Velicogna, jointly of the University of California, Irvine and Nasa's Jet Propulsion Laboratory.

'Previous studies had suggested that this region is starting to change very dramatically since the 1990s, and we wanted to see how all the different techniques compared,' added lead author Tyler Utterley of UCI.

NASA animation shows Antarctic ice sheet melting

The study found they lost an average 83 gigatons per year (91.5 billion U.S. tons), or the equivalent of losing the water weight of Mount Everest (pictured) every two years

'The remarkable agreement among the techniques gave us confidence that we are getting this right.'

The researchers reconciled measurements of the mass balance of glaciers flowing into the Amundsen Sea Embayment.

Mass balance is a measure of how much ice the glaciers gain and lose over time from accumulating or melting snow, discharges of ice as icebergs, and other causes.

Measurements from all four techniques were available from 2003 to 2009. Combined, the four data sets span the years 1992 to 2013.

The glaciers in the embayment lost mass throughout the entire period. The researchers calculated two separate quantities: the total amount of loss, and the changes in the rate of loss.

IT TAKES JUST TEN YEARS FOR CO2 TO DAMAGE THE CLIMATE, SAYS STUDY 

It takes just 10 years for a single emission of carbon dioxide (CO2) to have its maximum warming effects on the Earth, according to a new study by the Carnegie Institute for Science. Pictured is the average global surface temperatures in 2013. Red and dark orange show warmer-than-average temperatures

Many scientists believe it takes several decades for the effects of global warming to be felt on Earth.

But in fact, it takes just 10 years for a single emission of carbon dioxide (CO2) to have its maximum warming effects on the planet.

This is according to Washington-based researchers who claim to have dispelled a common misconception that the damaging effects from a CO2 emission will only be felt by future generations.

The results suggest that warming can persist for more than a century and that the benefits from emission reductions will be felt by those who have worked to curb the emissions.

Some of these benefits would be the avoidance of extreme weather events, such as droughts, heatwaves and flooding, according to scientists at the Carnegie Institute for Science.

However, some of the bigger climate impacts from warming, such as sea-level rise, melting ice sheets and long-lasting damage to ecosystems, may not occur for hundreds or thousands of years later, they claim. 

'A lot of climate scientists may have an intuition about how long it takes to feel the warming from a particular emission of CO2, but that intuition might be a little bit out of sync with our best estimates from today's climate and carbon cycle models,' said lead author of the study Dr Katharine Ricke.

The rate of loss accelerated an average of 6.1 gigatons (6.7 billion U.S. tons) per year since 1992.

From 2003 to 2009, when all four observational techniques overlapped, the melt rate increased an average of 16.3 gigatons per year - almost three times the rate of increase for the full 21-year period. The total amount of loss was close to the average at 84 gigatons.

The scientists said that glacier and ice sheet behavior worldwide is by far the greatest uncertainty in predicting future sea level.

'We have an excellent observing network now. It's critical that we maintain this network to continue monitoring the changes,' Ms Velicogna said, 'because the changes are proceeding very fast.'

The results were released as a global warming conference has begun in Peru. Those talks are seen as critical to reaching a multilateral accord next year in Paris

The Amundsen Sea is an arm of the Southern Ocean off Marie Byrd Land in western Antarctica. The sea is mostly ice-covered, and the Thwaites Ice Tongue protrudes into it