Posted on March 11, 2015 by Bob Berwyn
Will the West Antarctic Ice Sheet slip-slide away as the Southern Ocean warms up? bberwyn photo
A delicate balance
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
Filed under: Antarctica, climate and weather, Environment, global warming | Tagged: climate change, glaciology, global warming, sea level rise, West Antarctic Ice Sheet | Leave a comment »
Posted on December 5, 2014 by Bob Berwyn
New research shows signs of a major meltdown in Antarctica. bberwyn photo.
Ocean temperatures increasing steadily near West Antarctica
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
Filed under: Antarctica, climate and weather, Environment, global warming | Tagged: climate change, global warming, sea level, Southern Ocean warming, University of East Anglia, West Antarctic Ice Sheet | 1 Comment »
Posted on October 15, 2014 by Bob Berwyn
Denmark-based research team seeks to pinpoint ice sheet melt factor
Large parts of the U.S. Gulf Coast could be swamped by rising seas.
Coastal tidal flooding is already causing transportation problems near Venice, Louisiana, USA. bberwyn photo
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
Filed under: climate and weather, global warming | Tagged: climate, Environment, global sea level rise, Greenland ice sheet, IPCC, West Antarctic Ice Sheet | 1 Comment »
Posted on August 20, 2014 by Bob Berwyn
Loss of ice volume doubles in just 5 years
Arctic and Antarctic ice sheets are losing volume at a record pace. bberwyn photo.
By Bob Berwyn
FRISCO —Detailed new data from satellites and other sources show the world’s major ice sheets losing volume at a record pace, faster than at any time since satellite measurements started about 20 years ago.
Since 2009, the rate of volume loss from the Greenland Ice Sheet has doubled, and the rate of volume loss from the West Antarctic Ice Sheet has tripled, according to the new findings from the Alfred Wegener Institute, Helmholtz Centre for Polar and Marine Research. Continue reading
Filed under: Antarctica, climate and weather, Environment, global warming, Greenland | Tagged: climate change, global warming, Greenland ice sheet, sea level, West Antarctic Ice Sheet | 2 Comments »
Posted on August 16, 2014 by Bob Berwyn
‘Official’ IPCC sea level estimates may be too low
Antarctica ice is becoming a bigger factor in global sea level rise. bberwyn photo.
By Bob Berwyn
FRISCO — Although Antarctica’s vast ice sheets are only a small factor in global sea level rise right now, that’s likely to change in coming decades, scientists said after a new analysis of ocean temperatures around the frozen continent.
“If greenhouse gases continue to rise as before, ice discharge from Antarctica could raise the global ocean by an additional 1 to 37 centimeters in this century already,” says lead author Anders Levermann, with the Potsdam Institute for Climate Impact Research. “Now this is a big range – which is exactly why we call it a risk: Science needs to be clear about the uncertainty, so that decision makers at the coast and in coastal megacities like Shanghai or New York can consider the potential implications in their planning processes,” says Levermann.
The scientists analyzed how rising global mean temperatures resulted in a warming of the ocean around Antarctica, thus influencing the melting of the Antarctic ice shelves. The marine ice sheets in West Antarctica alone have the potential to elevate sea level by several meters – over several centuries. Continue reading
Filed under: Antarctica, climate and weather, Environment | Tagged: Antarctica, climate change, global warming, sea level, West Antarctic Ice Sheet | Leave a comment »
Posted on May 13, 2014 by Bob Berwyn
Thwaites Glacier, Photo courtesy NASA.
New data means sea level may rise more — and sooner — than expected
FRISCO — Antarctica’s massive, fast-moving Thwaites Glacier is probably going to be history in a couple of centuries, leading to a two-foot rise in global sea level, according to a new study funded by the National Science Foundation.
The glacier is a key piece in the global sea level puzzle, acting as an ice dam, stabilizing and regulating movement toward the sea of the massive West Antarctic Ice Sheet. The ice sheet contains enough ice to cause another 3 to 4 meters (10 to 13 feet) of global sea level rise. Continue reading
Filed under: climate and weather, global warming | Tagged: Antarctica, Thwaites Glacier, West Antarctic Ice Sheet | 1 Comment »
Posted on May 13, 2014 by Bob Berwyn
Meltdown is inevitable …
New findings require upward revision of sea level rise estimates. bberwyn photo.
By Summit Voice
FRISCO — Scientists say it’s only a matter of time before a huge chunk of the West Antarctic Ice Sheet melts into the ocean, potentially raising sea level around the world by several feet.
“The collapse of this sector of West Antarctica appears to be unstoppable,” said glaciologist Eric Rignot, a UC Irvine Earth system science professor who is also with NASA’s Jet Propulsion Laboratory. “The fact that the retreat is happening simultaneously over a large sector suggests it was triggered by a common cause, such as an increase in the amount of ocean heat beneath the floating parts of the glaciers. At this point, the end appears to be inevitable.” Continue reading
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