Epic Antarctic ice sheet melt speeding up sea level rise

Adjust Comment Print

The speed of Antarctica's melting has begun to gather pace.

Researchers fear that if the thaw continues to increase at this rate, low-lying communities and coastal cities from NY to Shanghai could be under water by 2100.

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.

The rate at which Antarctica is losing its ice has dramatically accelerated in recent years, according to new research from a team of scientists.

Forget yesterday's news. Get what you need today in this early-morning email.

As part of IMBIE, Professor Shepherd coordinated with 83 other scientists, from 44 global organizations, to combine the data from two dozen different satellite surveys for this comprehensive look at the changes in Antarctica's ice mass balance.

"We can not count on East Antarctica to be the quiet player, and we start to observe change there in some sectors that have potential, and they're vulnerable", co-author Isabella Velicogna, a researcher from University of California, told told the Post.

"The sharp increase ... is a big surprise", professor Andrew Shepherd, of the University of Leeds in England, told Reuters.

"The detailed record shows an acceleration, starting around 2002, " said Beata Csatho, one of the study authors and a glaciologist at the State University of NY at Buffalo, in an email. Forty percent of that loss has occurred in just the last 5 years, again underscoring the increase in losses recently.

Crevasses form on Pine Island Glacier in Antarctica, near the part of the glacier where it leaves land and extends over the ocean. Antarctica is, on balance, losing its ice sheets and raising the world's sea levels. He noted that climate change is the only plausible cause of this increased ice melt. Both numbers are higher than the annual losses for any other glacier anywhere in the world.

"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". 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.

Most of this ice loss has come from West Antarctica. The rapid increase in Antarctic ice loss and consequent sea level rise we have measured over the past 25 years are a clear indicator of climate change.

The research shows that Antarctica has lost nearly 3 trillion tons of ice since 1992.

A separate study - also published in Nature this week - found that global sea levels could be 3 feet higher by 2070 if nothing is done to curb the ice loss in the next few years.

In total, sea levels have risen about 8cm since 1992.

Granted, there's no proof the current rate of change in Antarctica will continue.

"I don't know if it's going to keep exactly tripling, but I think it has a lot of potential to keep significantly increasing, " said Velicogna.

The researchers relied on samples taken as part of the global ANtarctic geological DRILLing (ANDRILL) project. And they found that it's melting faster than they thought.

We're nowhere near that point yet.

From 1992 to 2012, sea levels were said to be rising at an average of 0.2mm each year due to ice loss.

This new knowledge will help us better predict sea level rise in the future. To put that into perspective, the massive iceberg that broke off from Antarctica's Larsen C ice shelf in July 2017 - one of the largest icebergs in recorded history - weighed over 1 trillion tons, and was roughly the size of the state of Delaware.