From the “you really should get your stories straight” department.
OK, here is press release #1 from the UNIVERSITY OF SOUTH FLORIDA (USF HEALTH)
Melting of east Antarctic ice sheet could cripple major US cities
TAMPA, Fla (December 13, 2017)- The world’s largest ice sheet may be less stable than previously thought, posing an even greater threat to Florida’s coastline.
The first ever marine geologic survey of East Antarctica’s Sabrina Coast, published this week in Nature, concludes that some regions of the massive East Antarctic Ice Sheet have been sensitive to climate change for millions of years. Much like the West Antarctic Ice Sheet, this region of the East Antarctic Ice Sheet is grounded below sea level and local glaciers are experiencing ice mass loss due to ocean warming.
“Antarctica may seem far away from Florida, but all Floridians should care about what is happening in Antarctica,” said co-lead author Dr. Amelia Shevenell, Associate Professor, University of South Florida, Tampa. “As ice melts, global sea levels rise. Most of Florida is at or several feet above sea level. We are already seeing the effects of rising seas caused by melting ice sheets and ocean warming. There is enough ice in our study region alone to raise global sea level by as much as 15 feet. This, in isolation, would be catastrophic to Florida.”
Dr. Shevenell, co-author Sean Gulick, PhD, Research Professor, University of Texas at Austin, and their collaborators used marine seismic technology and ocean sediments to reconstruct the evolution of the East Antarctic Ice Sheet in the Sabrina Coast region over the past 50 million years. Their research found that during past warm climates, when atmospheric temperatures and carbon dioxide concentrations were similar to or slightly higher than today, the East Antarctic Ice Sheet was much wetter and more unstable than it has been in the more recent past, when global climates were generally cooler.
“Today, a majority of Antarctica’s ice mass loss occurs when warm ocean waters melt ice shelves and glaciers from below. Our records of surface-meltwater production during past warm climates indicate that in the future, Antarctica will also experience ice melt from above, as air temperatures warm and carbon dioxide increases,” said Dr. Shevenell. “Thus, we might expect regional glaciers to become more unstable as atmosphere and ocean temperatures warm. This observation suggests that existing climate and ice sheet models likely underestimate East Antarctica’s contribution to global sea level rise.”
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And, here is press release #2 from the UNIVERSITY OF MASSACHUSETTS AT AMHERST
Instability of antarctic ice makes projecting future sea-level rise difficult
UMass Amherst, Rutgers climate scientists say it will take time for events to unfold
AMHERST, Mass. – Authors of a new study that combine a well-established sea-level rise projection framework plus a model of Antarctic ice-sheet instability suggest in a paper released today that scientists won’t be able to determine until the 2060s which of two different sea-level rise scenarios is most likely to occur.
Coastal communities should therefore have flexible contingency plans for a range of outcomes by the year 2100, say lead author Robert Kopp at Rutgers University and co-author Robert DeConto at the University of Massachusetts Amherst.
The authors say that one of the mechanisms they modeled, marine ice sheet instability, has been studied for decades, but another, marine ice cliff instability, has only recently been considered as an important contributor to future sea level change.
They point out that based on measuring large-scale phenomena like global sea level and Antarctic mass changes, it is not yet clear which of two scenarios will eventually unfold. The authors believe their study, which appears today in the journal Earth’s Future, is the first to link global and local sea-level rise projections with simulations of two major mechanisms by which climate change can affect the vast Antarctic ice sheet.
DeConto, who with David Pollard at Penn State developed the ice sheet computer model used in the study, says, “The widespread loss of Antarctic ice shelves, driven by a warming ocean or warming atmosphere, could spell disaster for our coastlines, and there is sound geological evidence that supports what the models are telling us.”
It’s possible, they add, that a process called hydrofracturing, which may have helped to break up the Larsen B ice shelf on the Antarctic Peninsula in 2002, could leave much of the Antarctic coast with 300-foot cliffs of ice exposed to the open ocean and subject to collapse. The interaction between hydrofracturing and ice-cliff collapse could drive global sea level much higher than projected in the Intergovernmental Panel on Climate Change (IPCC)’s 2013 assessment report and in a 2014 study led by Kopp.
DeConto says, “We’re making progress, but we still don’t know exactly when these processes might kick in, and how fast sea level might rise if they do. The ice shelves are the key. They hold back the flow of Antarctic ice toward the ocean, so we don’t want to lose them. The problem is, they don’t last very long when they are sitting in warm water or if they are covered with summer meltwater, so keeping global temperatures in check is critical.”
The Earth faces a range of possible outcomes with climate change. At the less severe end, 2 feet of global-average sea-level rise by 2100 would submerge land that’s currently home to about 100 million people. Toward the high end, 6 feet of rise would swamp the current homes of more than 150 million. Either scenario would have drastic effects in New England and on other coastal states.
Kopp says, “There’s a lot of ambiguity in post-2050 projections of sea-level rise and we may have to live with that for a while. We could end up with 8 feet of sea level-rise in 2100, but we’re not likely to have clear evidence for that by 2050.”
He and DeConto say that lower sea-level rise would be much more likely if the world meets the 2015 Paris Agreement goal of zero net greenhouse gas emissions in the next 50 years, the study shows. They also say cientists may also become able to distinguish between different scenarios sooner by studying the physics of local ice-sheet changes and refining reconstructions of changes during warm periods in geological history.
Kopp notes, “You should plan for 2050, while also considering what options to follow under more extreme scenarios after 2050. If we end up in a world with 2 or 2.5 meters (6.6 to 8 feet) of global sea level rise in 2100, that’s a lot to adapt to. That necessitates taking a flexible approach, where possible: building for the half foot to 1.3 feet of sea-level rise that are likely by 2050, while plotting out options that will depend on what we learn in the next few decades and how sea level rises beyond that.”
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Gosh, who to believe?
Oh, wait, here’s another one out today, from RUTGERS UNIVERSITY
Sea-level rise projections made hazy by Antarctic instability
Scientists should have a much better understanding in a few decades how high the sea level could rise, Rutgers-led study says
It may take until the 2060s to know how much the sea level will rise by the end of this century, according to a new Rutgers University-New Brunswick-led analysis. The study is the first to link global and local sea-level rise projections with simulations of two major mechanisms by which climate change can affect the vast Antarctic ice sheet.
The Earth faces a broad range of possible outcomes with climate change. At the less severe end, 2 feet of global-average sea-level rise by 2100 would submerge land that’s currently home to about 100 million people. Toward the high end, 6 feet of rise would swamp the current homes of more than 150 million. Either scenario would have drastic impacts in New Jersey and other coastal states.
But the study, published today in Earth’s Future, finds that scientists won’t be able to determine, based on measurements of large-scale phenomena like global sea level and Antarctic mass changes, which scenario the planet faces until the 2060s. So coastal communities should have flexible contingency plans for a broad range of outcomes by 2100 and beyond, the study concludes.
“There’s a lot of ambiguity in post-2050 projections of sea-level rise and we may have to live with that for a while,” said Robert E. Kopp, the study’s lead author and a professor in the Department of Earth and Planetary Sciences at Rutgers. “We could end up with 8 feet of sea level-rise in 2100, but we’re not likely to have clear evidence for that by 2050.”
The world can make lower sea-level rise outcomes much more likely by meeting the 2015 Paris Agreement goal of bringing net greenhouse gas emissions to zero in the second half of this century, the study shows. Scientists may also become able to distinguish between different scenarios sooner by studying the physics of local ice-sheet changes and refining reconstructions of changes during warm periods in geological history.
Sea-level rise poses a potentially existential risk to Earth’s low-lying cities and coastal areas, so any projected increase needs to be taken seriously by planners, environmental officials, property owners and others, said Kopp, director of Rutgers’ Institute of Earth, Ocean, and Atmospheric Sciences. In addition to permanently submerging coastal land, sea-level rise will make the flood damage from hurricanes and nor’easters worse in the future, he said.
“You should plan for 2050, while also considering what options to follow under more extreme scenarios after 2050,” said Kopp, who also co-directs Rutgers’ Coastal Climate Risk & Resilience (C2R2) initiative.
This study combines a well-established sea-level rise projection framework with an Antarctic ice sheet model that simulates two pathways that can lead to ice-sheet instability. The first of these pathways, marine ice sheet instability, has been studied for decades, but the second, marine ice cliff instability, has only recently been considered as an important contributor to future sea level change.
Might a process called “hydrofracturing,” implicated in the 2002 breakup of the Larsen B ice shelf on the Antarctic Peninsula, leave broad swaths of the Antarctic coast with 300-foot tall cliffs of ice exposed to the open ocean and subject to collapse under their own weight? If so, the interaction between hydrofracturing and ice-cliff collapse could drive global sea level much higher than projected in the Intergovernmental Panel on Climate Change (IPCC)’s 2013 assessment report and in a 2014 study led by Kopp.
“The widespread loss of Antarctic ice shelves, driven by a warming ocean or warming atmosphere, could spell disaster for our coastlines – and there is sound geological evidence that supports what the models are telling us,” said Robert M. DeConto of the University of Massachusetts Amherst, a co-author of the study and one of the developers of the ice-sheet model used.
“We’re making progress, but we still don’t know exactly when these processes might kick in, and how fast sea level might rise if they do. The ice shelves are the key. They hold back the flow of Antarctic ice toward the ocean, so we don’t want to lose them. The problem is, they don’t last very long when they are sitting in warm water or if they are covered with summer meltwater, so keeping global temperatures in check is critical,” DeConto added.
“Our previous study, like the IPCC, found that global sea-level rise in a high-emissions future would likely be between 2 and 3.5 feet by 2100. Linking in the physical model with marine ice-cliff instability raises that range to 4 to 7 feet,” Kopp said. “By contrast, marine ice-cliff instability doesn’t have much effect if we meet the Paris Agreement emissions goal. That keeps the likely global rise to about 1 to 3 feet.”
“If we end up in a world with 2 or 2.5 meters (6.6 to 8 feet) of global sea level rise in 2100, that’s a lot to adapt to,” Kopp added. “That necessitates taking a flexible approach, where possible: building for the half foot to 1.3 feet of sea-level rise that are likely by 2050, while plotting out options that will depend on what we learn in the next few decades and how sea level rises beyond that.”
Kopp is also a co-author of another study, led by Tufts University researcher Klaus Bittermann and published today in Environmental Research Letters, assessing the sea-level rise benefits of achieving the Paris Agreement’s more ambitious 1.5 degrees Celsius (2.7 degrees Fahrenheit) temperature target rather than its headline 2 degrees Celsius (3.6 degrees Fahrenheit) target. That study found that a 1.5 degrees Celsius world would reach a peak rate of sea-level rise about 0.7 inches per decade less than in a 2 degrees Celsius world – a potentially life-saving reduction for some vulnerable coastal ecosystems.
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But wait, there’s MORE!
From the UNIVERSITY OF TEXAS AT AUSTIN
East Antarctic Ice Sheet has history of instability
The East Antarctic Ice Sheet locks away enough water to raise sea level an estimated 53 meters (174 feet), more than any other ice sheet on the planet. It’s also thought to be among the most stable, not gaining or losing mass even as ice sheets in West Antarctica and Greenland shrink.
New research published on Dec. 14 in Nature and led by The University of Texas at Austin and the University of South Florida found that the East Antarctic Ice Sheet may not be as stable as it seems. In fact, the ice sheet has a long history of expanding and shrinking — a finding that indicates the ice sheet may contribute substantially to global sea level rise as Earth’s climate warms. The new results came from geophysical and geological data collected during the first-ever oceanographic survey of East Antarctica’s Sabrina Coast. The glaciers in this region may be particularly susceptible to climate change because they flow from the Aurora Basin, a region of East Antarctica that mostly lies below sea level.
Co-lead author Sean Gulick, a research professor at the University of Texas Institute for Geophysics (UTIG) and the UT Department of Geological Sciences (DGS), said the study found that glaciers from the Aurora Basin have been stable only for the past few million years.
“It turns out that for much of the East Antarctic Ice Sheet’s history, it was not the commonly perceived large stable ice sheet with only minor changes in size over millions of years,” he said. “Rather, we have evidence for a very dynamic ice sheet that grew and shrank significantly between glacial and interglacial periods. There were also often long intervals of open water along the Sabrina Coast, with limited glacial influence.”
UTIG and DGS are units of the UT Jackson School of Geosciences.
Collaborators include researchers at Louisiana State University, the University of Southampton, Florida State University and Colgate University.
Using marine seismic technology deployed from an icebreaker, researchers were able to reconstruct how glaciers on the Sabrina Coast have advanced and retreated during the past 50 million years. The team also took core samples of mud from 1 to 2 meters below the seafloor and analyzed ancient pollen to determine the age of the samples. The analysis was conducted at Louisiana State University’s Center for Excellence in Palynology.
The Sabrina Coast, and nearby Aurora Basin, are particularly important because regional glaciers are presently thinning and retreating as nearby ocean waters warm. If the ice sheet in the Aurora Basin melted, global sea levels would rise more than 3-5 meters (10-15 feet).
According to the team’s data, ice advanced from the Aurora Basin and retreated back again at least 11 times during the first 20 million years of the ice sheet’s history. Researchers also found that the young ice sheet was much wetter than it is today, with meltwater from the surface flowing into a network of channels beneath the ice. These channels were eroded into the rock below the ice, leaving distinctive formations known as “tunnel valleys.” This dynamic time for East Antarctic glaciers occurred when atmospheric temperatures and atmospheric CO2 levels were similar to or higher than present day.
“We shouldn’t view this as one ice sheet that suddenly grew to its present size, but rather one that was a transient ice sheet that expanded every couple million years or so,” Gulick said.
Around 6 million years ago, the East Antarctic Ice Sheet expanded, stabilized and ceased producing large volumes of meltwater. However, as climate change raises global air temperatures, it is possible that East Antarctic glaciers could start melting, a change that could make the ice sheet shift back into unstable territory.
The warm ocean water presently melting Totten Glacier — East Antarctica’s largest glacier, which flows from the Aurora Basin — could be an early warning sign, said co-lead author Amelia Shevenell, an associate professor in the University of South Florida College of Marine Science.
“A lot of what we are seeing right now in the coastal regions is that warming ocean waters are melting Antarctica’s glaciers and ice shelves, but this process may just be the beginning,” Shevenell said. “Once you have that combination of ocean heat and atmospheric heat — which are related — that’s when the ice sheet could really experience dramatic ice mass loss.”
The National Science Foundation (NSF) manages the United States Antarctic Program and provided the funding and logistical support that made field research to the Sabrina Coast possible.
“The past behavior and dynamics of the Antarctic ice sheets are among the most important open questions in the scientific understanding of how the polar regions help to regulate global climate,” said Jennifer Burns, director of the NSF Antarctic Integrated Science System Program. “This research provides an important piece to help solve that massive puzzle.”
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All of these press releases appeared within a couple of hours of each other on EurekAlert, which is a Science PR clearing house. They will all inevitably get turned into stories by the media. Who could blame the public for being confused when we have such certainty/uncertainty battles like this going on in climate science?
It seems Yogi Berra was right.
It’s tough to make predictions, especially about the future.
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[QUOTE]”It’s possible, they add, that a process called hydrofracturing, which may have helped to break up the Larsen B ice shelf on the Antarctic Peninsula in 2002, could leave much of the Antarctic coast with 300-foot cliffs of ice exposed to the open ocean and subject to collapse.”
This should be classified as an apples-to-kumquats comparison. The Antarctic Peninsula is relatively narrow, and projects northward toward the southern tip of South America, where it is buffeted by waves driven by westerly winds circling the pole over mostly open water. These waves crashing into the ice broadside during spring and summer could cause some of the ice to fracture and fall into the sea.
But the coastline of East Antarctica runs nearly due east and west along the Antarctic circle. Westerly winds would be nearly parallel to the coast, and not bring waves into the ice. Moreover, there would not be a “sea breeze” effect that occurs during daylight hours in temperate and tropical climates, because the air over the ice is colder than that over the ocean, so that warmer air rising over the ocean would be replaced by cold air blowing off the ice, which would tend to push waves away from the coast.
Any “hydrofracturing” effect from waves would be much weaker along the East Antarctica coast than along the west coast of the Antarctic Peninsula, which is exposed to strong waves hitting the ice broadside.
Well Steve you forgot that earth rotates on its axis once in 24hours during which time, the south Atlantic ocean and the South Pacific Oceans swap places twice a day through that narrow gap of the Horn.
All of that tidal bulge flows UNDER those ice shelves, and Ice has about the same tensile strength as concrete, so it breaks when you bend it upwards twice a day.
G
This “hydrofracturing” they describe happens to be physically impossible. “Hydrofracturing” is something that only happens for shelf-ice which is floating (otherwise there is no “hydro” to do the fracturing). Shelf-ice is typically about 200 meters thick, which means that the “ice-cliff” is about 20 meters high. A “300 feet high ice cliff” means that the ice must be about 900 meters thick, and the sea at least 800 meters deep at the ice-front. Otherwise it won’t float. This simply does not happen in the real world.
This is because ice-cliffs higher than about 50 meters are mechanically unstable and calve, and this means that a grounded glacier cannot be stable at depths greater than about 500 meters. It will either collapse or float off as (thinned-out) shelf-ice. This is a well-documented fact, supported by geological studies in both the Arctic and Antarctic oceans. Grounded ice never expands any further than the upper continental slope.
Hmmm… Too bad NASA announced on October 30, 2015 that Antarctic Land Ice Mass has been INCREASING by around 100 BILLION tons/yr since 1992, despite saying for decades it was DECREASING by over 120 Billion tons/yr based on faulty GRACE data:
https://www.nasa.gov/feature/goddard/nasa-study-mass-gains-of-antarctic-ice-sheet-greater-than-losses
This year, Greenland’s land mass will also INCREASE by 44 billion tons:
https://www.climate.gov/news-features/understanding-climate/greenland-ice-sheets-2017-weigh-suggests-small-increase-ice-mass
With both the AMO and PDO being in the their respective 30-year cool cycles from early 2020’s, both poles will soon consistently show land ice mass increase…
Moreover, the early stages of 50~70 year Grand Solar Minimum starts from 2021, which will likely add to polar ice mass increases..
CAGW is so screwed…
“Melting of east Antarctic ice sheet could cripple major US cities”
I bet all your funding this never happens during your working life time and I would bet the same if we could live for 1000 years.
“However, as climate change raises global air temperatures, it is possible that East Antarctic glaciers could start melting, a change that could make the ice sheet shift back into unstable territory.”
There is no chance because climate change/global warming has not warmed here at all at least during the satellite era and requires such a huge rise in temperature it not possible in any scenario.
Over millions of years continental drift was in action and the position of the them are different and change the climate depending where they are. In the current continental positions there is no chance of it melting ever, unless something extremely unlikely occurs like natural disasters.
More chance of Death valley recording snow in summer. The East Antarctic ice sheet is the coldest and driest place on Earth, where summer temperatures rarely get above -25 c away from coasts. Unless a comet/asteroid or volcanic activity melts it temporary, how on earth is it going to melt at all any time over the next two hundreds years?
Think of this scenario.
If the temperature were to rise to 1 c above the freezing point for one day in a year, how many days would it take to melt even 1% of it?
These type of articles on Antarctica are cringworthy how ridiculous they always are with current climate change agenda.
https://www.the-cryosphere.net/7/303/2013/tc-7-303-2013.pdf
It’s yet another example of “settled science”.
It would not take much work to see where the ‘new’ and very valuable beachfront will be in Florida should sea level rise 10 ft. This currently inland property is relatively cheap compared to current beachfront – very cheap in fact. When I see these ‘scientists’ start to buy a lot of properties inland, then I will know they are serious. Right now the are just collecting and spending my tax dollars.
Don’t forget, “the science is settled” (TM)
Entirely devoid of self-awareness – do they not realise that hardly anyone is listening?
Obviously not even their own peers inside Climate Science
Otherwise they’d realise they have a theory that explains everything and hence, explains precisely nothing
Good job we’re rich enough to afford this nonsense…………
If alleged global warming were to raise the average summer (D\J) temperature at McMurdo Sound one degree C, then it would just reach freezing from its present -1 degree C.
It is summer there now of course taking the warmest months into account, yet over the last few days it has only reached briefly -1.4 c. The majority of the time it has been below -3 c. No higher than -4.3 c on the 14th December, so with those very low dew points an increase of 2 c would make very little difference to any thaw at all right on the coast.
http://www.bom.gov.au/products/IDT60803/IDT60803.89664.shtml
I apologize if someone else already noted this, but the four press releases are for only two papers. If you read the author names, universities involved, and methods used, that becomes clear. I just wanted to point that out.
As always, the obligatory plea for control of the planetary environment. What hubris!
““Antarctica may seem far away from Florida, but all Floridians should care about what is happening in Antarctica,” said co-lead author Dr. Amelia Shevenell, Associate Professor, University of South Florida, Tampa. “As ice melts, global sea levels rise.”
No duh. This sounds like the type of “science” one might find in grade school. When snow melts, streams and rivers rise. And now let’s talk about Wally the Beaver.
The usual drivel, ginned up to make it look like there is a planetary emergency, caused by our evil CO2.
What has happened to science? Bruce Cobb”
Mr. Cobb I am also a non believer in AGM but you are wrong on this point
Look at the link
http://smithplanet.com/stuff/iceandwater.htm