Antarctica's melt quickens, risks metres of sea level rise


Scientists are urging for a reduction in emissions after a new study found the tilt of the Earth could exacerbate the melting of the Antarctic ice sheets.

"In the decades to come, it is likely that sea level rise from Antarctica will originate from the same general areas", researchers noted, resulting in feet of sea level rise if climate change isn't combated.

Antarctic glaciers lost around 40 billion tons of ice melt each year from 1979 to 1989.

The PNAS study estimated that Antarctica lost 169 billion tonnes of ice from 1992-2017, above the 109 billion tonnes in the same period estimated a year ago by a large global team of researchers. The impact of unchecked ice sheet melt on our future societies would be extremely challenging.

Co-authors of this study are Jeremie Mouginot, UCI associate researcher in Earth system science; Bernd Scheuchl, UCI associate project scientist in Earth system science; Mathieu Morlighem, UCI associate professor of Earth system science; and Michiel van den Broeke and Jan M. "Melchior" van Wessem of the Netherlands' Utrecht University. But this study finds a vast quarter of eastern Antarctica is now becoming a bigger player and "is a great concern as well".

The most striking finding in Monday's study is the assertion that East Antarctica, which contains by far the continent's most ice - a vast sheet capable of almost 170 feet of potential sea-level rise - is also experiencing serious melting.

The Associated Press Health & Science Department receives support from the Howard Hughes Medical Institute's Department of Science Education. In fact, a major analysis published last June - which most of the new study's authors participated in - concluded that on the whole, East Antarctica hasn't been losing ice at all.

"Ice-sheet models link Pine Island glacier absence to full WAIS collapse into ice caps on mountains", the study's abstract read.

They said the East Antarctic ice sheet is thawing at the fringes and adding to rising seas, unlike many past reports which have concluded that the eastern sheet has so far resisted a melt seen on the western side.

"In order for us to really ensure that we don't lose too much ice, we really need to work hard at getting those emissions - at least keeping them at what they are today but even trying to get them lower than they are today, we certainly can't let them get higher because all the evidence suggests that's just not good for the ice sheets". From 2001 to 2017, the ice melting rate rose by 280 percent to 134 gigatons per year.

"This region is probably more sensitive to climate change than has traditionally been assumed, and that's important to know, because it holds even more ice than West Antarctica and the Antarctic Peninsula together", said Rignot.

"Our expectation would be that the Earth and the ice sheets become much more sensitive again to this obliquity forcing". This massive body of ice flows out into the ocean through a complex array of partially submerged glaciers and thick floating expanses of ice called ice shelves.

The A-68 iceberg separated from the Larsen C ice shelf in July 2017.