"This does not mean that at current atmospheric carbon dioxide levels Antarctica won't contribute to sea level rise".
An accelerating thaw of Antarctica has pushed up world sea levels by nearly a centimeter since the early 1990s in a risk for coasts from Pacific islands to Florida, an global team of scientists said on Thursday. Most of this came from the acceleration of the huge Pine Island and Thwaites Glaciers.
If the land-based East Antarctic Ice Sheet was stable during the Pliocene, as Shakun and colleagues suggest, the Pliocene total could have been at most 30 meters.
"We have long suspected that changes in Earth's climate will affect the polar ice sheets", said Professor Shepherd.
The study appears in the journal Nature. The rate at which Antarctica is losing ice has more than doubled since 2012, according to the latest available data.
In contrast, the global consequences set out under the high emissions narrative include dramatic loss of major ice shelves, sea warming, sea ice retreat and ocean acidification, and degradation of the environment caused by unrestricted growth in human use of Antarctica and introduced invasive pests.
A trillion-tonne iceberg, one of the biggest on record and twice the size of the ACT, snapped off the Larsen C West Antarctic ice shelf in July a year ago. This information, along with the previous assessment done in 2012, is key to understanding how climate change is affecting the most remote part of the planet, and in understanding the effects of the changes in the Antarctic ice sheet and the rise in sea levels.
A University of Waterloo study published in Science Advances discovered a mechanism that could further accelerate Antarctic ice loss.
Antarctica is covered by ice sheets that get channelled into the oceans through a network of ice streams and glaciers and the continent has seen a reduction in the extent of floating ice shelves.
Sea level will rise to 5 mm in one year, and it will flood cities on the coasts, causing economic losses of $1 trillion per year.
The researchers measured isotopes produced by the interaction between cosmic rays and the nucleus of an atom, called cosmogenic nuclides, in glacial sediment from Antarctic's largest ice shelf.
A team of researchers on the German research icebreaker Polarstern have successfully mapped an area of the seafloor previously covered by ice. Sea ice typically forms a thin and highly-dynamic veneer up to a few metres thick that covers between about 3 million square kilometres (in winter) to 19-20 million square kilometres (in summer) of the Southern Ocean surrounding Antarctica.
"The next piece of the puzzle is to understand the processes driving this change".
Coastal flooding during storms at high tides will be more damaging and a threat to cities, from NY to Shanghai as well as low-lying nations from the Pacific Ocean to the Netherlands.
Whether Antarctic mass loss keeps worsening depends on choices made today, argues DeConto, who co-authored a separate paper in this week's Nature outlining two different visions for Antarctica's future in the year 2070. However, since then there has been a sharp, threefold increase.