Republished with permission by Knowhere News
According to a paper published in Nature Wednesday by a team of 84 scientists representing 44 scientific institutions around the planet, the Antarctic is not only losing ice, but the loss is speeding up, fast. The assessment is based on 24 different satellite-based measurements, making it among the most comprehensive such studies to date. The jump in ice loss is focused in West Antarctica, where losses increased from 53 billion metric tons in 1992 to 159 billion in 2017.
“The sharp increase … is a big surprise,” said Professor Andrew Shepherd at the University of Leeds, one of the report’s lead authors. Shepherd said Antarctica is on track to raise global sea levels about 15 cm by 2100, just in terms of its own contribution, faster than most previous estimates. Such a rise may sound small to some but would cause more damaging coastal floods during storms at high tides, said Shepard. According to Shepard, sea level rise threatens low lying coastal cities and nations all over the world.
“There are no other plausible signals to be driving this other than climate change,” said Shepard. However, Shepherd cautioned that this paper does not formally determine that any climate events are human-caused.
Nevertheless, Shepard implied that such a conclusion is strongly suggested by the acceleration of ice loss.“Under natural conditions, we don’t expect the ice sheet to lose ice at all,” Shepherd said.
Antarctica lost ice between 1992 and 1997 at an average speed of 49 billion metric tons per year. Ten years later, between 2002 and 2007, that increased to 73 billion metric tons. And between 2012 and 2017, it was 219 billion tons per year. In other words, Antarctica is definitely melting more quickly by the year.
Overall, global sea levels have risen about 20 cm over the past century, mainly due to a natural expansion of the oceans as they get warmer, along with glaciers melting from the Andes to the Alps. A major UN study in 2014 said seas could rise between about 30 cm and a meter by the end of this century.
In Antarctica, it’s mostly a warmer ocean causing the melt. The water eats away at the edges of ice sheets from below. Forces “that are driving these changes are not going to get any better in a warming climate,” said University of Colorado scientist Waleed Abdalati, a former chief NASA chief who was not part of Shepard’s study.