Antarctica’s Ice Loss Has Reached 250 Billion Tons Per Year

Over the past four decades, Antarctic ice loss has accelerated at an astounding rate. From 1979 through 1990, the frozen continent was shedding ice at a rate of 40 billion tons per year. A new analysis, however, found that from 2009 onward, that number rose to 252 billion tons per year—six times higher than the previous rate.

The findings, published in the Proceedings of the National Academy of Sciences, represent the “longest-ever” assessment of Antarctica’s ice mass. As Matthew Taub reports for Atlas Obscura, a team of researchers from the University of California, Irvine, and the Netherlands’ Utrecht University drew on satellite and aerial imagery dating back to 1979 to examine 18 Antarctic regions constituting 176 basins and several surrounding islands.

The comprehensive survey paints a stark portrait of Antarctica’s future. The 40-year jump in ice loss is worrying enough, but as the scientists point out, this figure will only rise in the future, sending melted ice into the world’s oceans and triggering sea-level rise with potentially devastating consequences. Writing for the Washington Post, Chris Mooney and Brady Dennis explain that escalating seas promise to threaten island communities, wildlife habitats and even potable water supply.

Global sea levels have risen by seven to eight inches since 1990, but again, researchers say this number will only increase in the coming decades. In fact, a 2013 report predicted a jump of nearly three feet by 2100 if no action is taken to significantly curb carbon output. In total, Antarctica’s ice holds a potential 187.66 feet of sea-level rise.

Under normal circumstances, Antarctic ice loss is offset by snowfall accumulation that keeps the world’s oceans relatively stable. Thanks to rising temperatures linked with global warming, however, the continent is experiencing what Brandon Miller of CNN terms an “imbalance between melting ice and replenishing snowfall.”

The latest analysis also attributes significant ice loss to East Antarctica, which was previously thought to be relatively safe from warming waters because its base is mostly above sea level, reports Alex Fox for Science magazine. In all, Maddie Stone writes for Earther, the team found that East Antarctica has contributed 4.4 millimeters to Earth’s global sea level in the last 40 years, while West Antarctica has contributed 6.9 millimeters.

The eastern ice sheet may not be melting as quickly as its western neighbor, but the Washington Post’s Mooney and Dennis point out that East Antarctica holds the majority of the continent’s ice, accounting for about 90 percent of Antarctica’s total potential sea-level rise.

Antarctic ice loss is nothing new, but as lead author Eric Rignot of the University of California, Irvine, tells the Post, East Antarctica’s contributions to this phenomenon warrant further study.

“The traditional view from many decades ago is that nothing much is happening in East Antarctica,” Rignot says. “It’s a little bit like wishful thinking.”

Continuing this line of thought in a press release, he concludes, “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."

Meilan Solly | | READ MORE

Meilan Solly is Smithsonian magazine's associate digital editor, history.