Antarctica’s ice sheet is melting 3 times faster than before

We have found that since 1992 Antarctica has lost 2,720 billion tonnes of ice, raising global sea levels by 7.6mm.

This latest IMBIE is the most complete assessment of Antarctic ice mass changes to date, combining 24 satellite surveys of Antarctica and involving 80 scientists from 42 global organizations. Most of the airborne data used were gathered as part of the UTIG-led International Collaboration for Exploration of the Cryosphere through Aerogeophysical Profiling (ICECAP) project with support from the UK’s Natural Environment Research Council, the US National Science Foundation, the Australian Antarctic Division, NASA’s Operation IceBridge, the G. Unger Vetlesen Foundation, and the University of Texas at Austin’s Jackson School of Geosciences, and the NSF-supported GIMBLE (Geophysical Investigations of Marie Byrd Land Lithospheric Evolution) project.

In its Fifth Assessment Report, the Intergovernmental Panel on Climate Change suggested that average sea level rose by 7.5 inches between 1901 and 2010.

Scientists have long believed the last glacial period, famously known as the Ice Age, ended with a period of continued warming which resulted in the shrinking of ice sheets and an increase in sea levels for thousands of years.

In April, a team of United Kingdom researchers released a report saying that underwater glaciers in Antarctica are melting at an “alarming rate”.

Most ice was being lost from West Antarctica and the Antarctic Peninsula, where warmer ocean water is melting floating ice shelves at the end of glaciers, allowing ice pent up on land to slide faster toward the sea, the study said.

“It’s a hard one for us to answer because the time series is still pretty short”, he said.

Experts monitoring the ice levels have revealed that Antarctica is losing 200 billion tonnes a year of ice.

“This does not mean that at current atmospheric carbon dioxide levels Antarctica won’t contribute to sea level rise”.

This new knowledge will help us better predict sea level rise in the future.

Reduced sea ice coverage since the late 1980s has led to increased exposure of ice shelves on the Antarctic Peninsula to ocean swells, causing them to flex and break.

Another way the Ice Continent could be melting is due to a mantle plume beneath Antarctica. “There are no other plausible signals to be driving this other than climate change”. Global sea levels would then only rise by around half a metre due to effects that have been irreversible since 2010. But what concerns scientists is the balance of how much snow and ice accumulates in a given year versus the amount that is lost. “To do this, we need to keep watching the ice sheet closely, but we also need to look back in time and try to understand how the ice sheet responded to past climate change”. You can see ice loss in that area over time in the video above.

“If we aren’t already alert to the dangers posed by climate change, this should be an enormous wake-up call”, said Martin Siegert, of the Grantham Institute at Imperial College London, and one of the authors. The rate at which ice losses from Antarctica will increase in response to a warming world remains uncertain.

“The data from GRACE’s twin satellites show us not only that a problem exists, but that it is growing in severity with each passing year”.

“The datasets from IMBIE are extremely valuable for the ice sheet modeling community”, said study co-author Sophie Nowicki of NASA’s Goddard Space Flight Center.

The planet’s largest ice sheet is now losing more than 240 billion tons of ice every year ― a threefold increase from less than a decade ago.

This assessment, conducted by 84 scientists from 44 worldwide organizations, is known as the Ice Sheet Mass Balance Inter-comparison Exercise (IMBIE).

Earlier studies of the East Antarctic Ice Sheet indicated that some marine-based portions of the ice sheet and its neighboring West Antarctic Ice Sheet retreated during the Pliocene.