Tag: West Antarctic Ice Sheet

Antarctic sea ice meltdown likely in a warming world

New study offers climate clues from most recent interglacial warm period

Antarctic sea ice
Antarctic sea ice is likely to decline dramatically in coming decades, which could lead to amplification of global warming in the southern hemisphere. @bberwyn photo.

By Bob Berwyn

The last time the Earth was as warm as today was about 128,000 years ago — and Antarctic sea ice extent was 65 percent smaller than it is now, according to British scientists who tracked past climate change in the region by studying ice core samples from that era.

That means Antarctic sea ice is on course to shrink dramatically in the decades and centuries ahead, said British Antarctic Survey scientist Max Holloway, who with a team of researchers analyzed oxygen isotopes in ice and air bubbles trapped for 128,000 years in the East Antarctic Ice Sheet. Continue reading “Antarctic sea ice meltdown likely in a warming world”

What’s the tipping point for Antarctica’s ice sheets?

New study suggests rapid meltdown during post-ice age warming

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How long will it take for Antarctica’s ice sheets to melt? @bberwyn photo.

Staff Report

After taking a close look at rocks from West Antarctica’s dramatic Ellsworth Mountains, climate researchers say there’s a chance that ice sheets in the region could melt quickly as the planet warms, potentially causing sea level to rise by  six to eight feet.

The new study, published in Nature Communications, took a close look at Antarctic climate change about 21,000 years ago during a period of warming after the coldest point of the most recent Ice Age. They found that  the West Antarctic Ice Sheet reached a tipping point, after which it thinned relatively quickly, losing 400m of thickness in 3,000 years. Continue reading “What’s the tipping point for Antarctica’s ice sheets?”

Climate study says West Antarctic Ice Sheet could melt quickly

The ice fields of Antarctica
How quickly will the West Antarctic Ice Sheet melt away under global warming? @bberwyn photo.

‘All signs suggest the ice from West Antarctica could disappear relatively quickly …’

Staff Report

An in-depth survey of Antarctica’s rugged Ellsworth Mountains suggests that the West Antarctic Ice Sheet could melt quickly under the influence of global warming, potentially raising global sea level by three meters.

“It is possible that the ice sheet has passed the point of no return and, if so, the big question is how much will go and how much will sea levels rise,” said Professor John Woodward, of the University of Northumbria. Continue reading “Climate study says West Antarctic Ice Sheet could melt quickly”

Antarctic ice susceptible to climate domino effect

New study says melting of small Amundsen Basin likely to trigger a climate tipping point

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The meltdown of West Antarctica’s ice sheets is likely already under way. @berwyn photo.

Staff Report

Just a small shift in the Antarctic climate could have long-lasting consequences on a global scale, according to a new research paper that once again takes a close look at the fate of the West Antarctic Ice Sheet.

Based on the new study, destabilization of the relatively small Amundsen Basin — triggered by a few decades of ocean warming — could trigger a massive ice loss from the West Antarctica Ice Sheet that would raise global sea level by 10 feet. Other recent studies show that this area is already losing stability, making it the first element in the climate system about to tip. Continue reading “Antarctic ice susceptible to climate domino effect”

Climate: Study shows that just a little bit of warming could destabilize West Antarctic ice sheets

Meeting in Uruguay, an Antarctic science committe advocated for the 2012 establishment of marine reserves in the Southern Ocean and the Ross Sea. PHOTO BY BOB BERWYN.
Will the West Antarctic Ice Sheet slip-slide away as the Southern Ocean warms up? bberwyn photo

A delicate balance

Staff Report

FRISCO — West Antarctica ice sheets are delicately anchored in place along a narrow sliver called the grounding zone, and new research shows that even slight increases in regional ocean and air temperatures are likely to destabilize the ice. The grounding zone is a sloping rock bed that lies below sea level.

In the new study, published this month in the Journal of Glaciology, Caltech scientists said future estimates of sea level rise need to take into account that the ice sheets are more sensitive to temperature perturbations driven by climate change than previously thought.

“Our results show that the stability of the whole ice sheet and our ability to predict its future melting is extremely sensitive to what happens in a very small region right at the grounding line. It is crucial to accurately represent the physics here in numerical models,” said study coauthor Andrew Thompson, an assistant professor of environmental science and engineering at Caltech. Continue reading “Climate: Study shows that just a little bit of warming could destabilize West Antarctic ice sheets”

Climate: More signs of an irreversible Antarctic meltdown

It's not clear when the waters around Antarctica will no longer be able to support production of phytoplankton.
New research shows signs of a major meltdown in Antarctica. bberwyn photo.

Ocean temperatures increasing steadily near West Antarctica

Staff Report

FRISCO — Warming seawater around parts of Antarctica is speeding the melting and sliding of glaciers, and that there is no indication that this trend will reverse, according to researchers with  the University of East Anglia.

The study, published in the journal Science, tracked ocean temperatures in the shallow shelf seas of West Antarctica for the last 50 years. The findings also suggest the areas of warmer seawater are spreading, and that other Antarctic areas, which have not yet started to melt, could experience melting for the first time, which would increase the pace of global sea level rise. Continue reading “Climate: More signs of an irreversible Antarctic meltdown”

Study says odds are sea level will rise 3 feet by 2100

Denmark-based research team seeks to pinpoint ice sheet melt factor

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Large parts of the U.S. Gulf Coast could be swamped by rising seas.
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Coastal tidal flooding is already causing transportation problems near Venice, Louisiana, USA. bberwyn photo

Staff Report

FRISCO — Developing accurate projections for sea level rise has been an elusive, high-priority goal for climate scientists. It’s certain that sea level will keep rising for centuries to come. But it’s not clear at what rate and pace that will happen, especially during the next few decades as coastal communities try to prepare.

Some factors, like thermal ocean expansion, can be established with some accuracy but researchers still aren’t sure exactly how the Greenland and Antarctic ice sheets will respond to warming.

In the latest number-crunching, scientists with the Niels Bohr Institute established that there’s little chance sea level will rise more than 1.8 meters (about 6 feet) by 2100. The results are published in the scientific journal Environmental Research Letters. Continue reading “Study says odds are sea level will rise 3 feet by 2100”