Published: Fri, June 15, 2018
Science | By Joan Schultz

Antarctica lost an unprecedented amount of ice in the last five years

Antarctica lost an unprecedented amount of ice in the last five years

Shepherd says that actually, their data shows a "a progressive increase in ice loss throughout the whole 25 year time period".

"Since around 2010, 2012, we can see that there's been a sharp increase in the rate of ice loss from Antarctica".

These "tell us about changes in the earth's gravitational attraction over time and that can be related to the mass of the ice sheets overall", Shepherd says, "and they are really powerful measurements because they can add up everything across Antarctica".

Scientists have acknowledged that these sad results surpassed their expectations.

"We should be anxious", Velicogna told the USA Today. "Things are happening faster than we expected", Isabella Velicogna of the University of California and one of the report's authors said.

Researchers found that the ice losses are largely driven by melting of the West Antarctic ice sheet, which is hit hard by warm oceans that melt ice from below.

It's possible that Antarctica alone can add about half a foot (16 centimeters) to sea level rise by the end of the century, Shepherd said. Ice shelf collapse in the Antarctic Peninsula is another major contributor, whereas less certain estimates of East Antarctica's mass change suggest the region may have gained a negligible amount of ice.

Changes in global sea level, from 1992 to 2017, due to contributions from the Antarctic ice sheet.

For the new study, the scientists combined data from three types of satellite measurements to track changes in ice over time, study co-author Andrew Shepherd, a professor of Earth observation with the School of Earth and Environment at the University of Leeds in the United Kingdom, told Live Science.

Antarctica has enough ice to raise seas by 190 feet if it ever all melted, dwarfing frozen stores in places from Greenland to the Himalayas and making its future the biggest uncertainty in understanding global warming and ocean levels.

The pace of change can be seen in how much more ice we're losing now than in the past.

Regardless of the exact rate, these findings emphasize the importance of efforts to combat climate change.

That's because as Antarctica's mass shrinks, the ice sheet's gravitational pull on the ocean relaxes somewhat, and the seas travel back across the globe to pile up far away - with USA coasts being one prime destination.

The researchers relied on samples taken as part of the worldwide ANtarctic geological DRILLing (ANDRILL) project. Antarctica is now causing sea levels to rise at a rate of 0.6mm a year - faster now than at any time in the past 25 years. "The good news is that limited climate change can slow the rate of ice loss, and there are many proven actions that can reduce climate change and be implemented immediately".

Scientists have previously raised fears about a scenario in which ice loss from Antarctica takes on a rate of explosive growth. "But remember for the northern hemisphere, for North America, the fact that the location in West Antarctica is where the action is amplifies that rate of sea level rise by up to an about additional 25 percent in a city like Boston or NY".

"These events and the sea-level rise they've triggered are an indicator of climate change and should be of concern for the governments we trust to protect our coastal cities and communities".

"Unfortunately, we appear to be on a pathway to substantial ice-sheet loss in the decades ahead, with longer-term consequences for enhanced sea-level rise; something that has been predicted in models for some time".

Rising sea levels can have a risky impact on coastal habitats and communities as flooding increases along with higher tides and stronger storm surges.

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