Antarctica Records Hottest Day Ever, New Study Published in SCIENCE Finds Rapid Acceleration of Ice Melt
The warmest temperature ever recorded on the continent of Antarctica may have occurred on Tuesday, March 24, 2015, when the mercury shot up to 63.5°F (17.5°C) at Argentina’s Esperanza Base on the northern tip of the Antarctic Peninsula. According to weather records researcher Maximiliano Herrera, the previous hottest temperature recorded in Antarctica was 63.3°F (17.4°C) set just one day previously at Argentina’s Marambio Base, on a small islet just off the coast of the Antarctic Peninsula. Prior to this week’s remarkable heat wave, the hottest known temperature in Antarctica was the 62.8°F (17.1°C) recorded at Esperanza Base on April 24, 1961. (The World Meteorological Organization—WMO—has not yet certified that this week’s temperatures are all-time weather records for Antarctica, though the Argentinian weather service has verified that the temperatures measured at Esperanza Base and Marambio Base were the highest ever measured at each site.) A new all-time temperature record for an entire continent is a rare event, and Weather Underground’s weather historian, Christopher C. Burt, has full details in his latest post.
The record heat coincides with the release of a new study from Science that finds “ice shelves in West Antarctica have lost as much as 18 percent of their volume over the last two decades, with rapid acceleration occurring over the last decade. The study found that from 1994 to 2003, the overall loss of ice shelf volume across the continent was negligible, but over the last decade West Antarctic losses increased by 70 percent,” says Think Progress.
The heat wave also coincides with Robert Swan and his 2041 team’s Antarctic Expedition, which wrapped up last week. The point of the trip was to document the firsthand effects of climate change, which was obviously very apparent.
The Antarctic Peninsula is one of the fastest warming spots on Earth. A 2012 Climate Central post by Michael Lemonick documented how while the Earth as a whole warmed up by 1.3°F between 1900 and 2011, the Antarctic Peninsula warmed by 5°, forcing massive ice shelves to disintegrate and penguin colonies to collapse. A 2012 paper in Nature found that the recent warming is faster than 99.7% of any other given 100-year period in the last 2000 years.
In May 2014, a study by researchers at NASA and the University of California, Irvine, found a rapidly melting section of the West Antarctic Ice Sheet to be in an irreversible state of decline, with nothing to stop the glaciers in this area from melting into the sea.
The study presents multiple lines of evidence, incorporating 40 years of observations that indicate the glaciers in the Amundsen Sea sector of West Antarctica “have passed the point of no return,” according to glaciologist and lead author Eric Rignot, of UC Irvine and NASA’s Jet Propulsion Laboratory in Pasadena, California. The new study has been accepted for publication in the journal Geophysical Research Letters.
These glaciers already contribute significantly to sea level rise, releasing almost as much ice into the ocean annually as the entire Greenland Ice Sheet. They contain enough ice to raise global sea level by 4 feet (1.2 meters) and are melting faster than most scientists had expected. Rignot said these findings will require an upward revision to current predictions of sea level rise.
“This sector will be a major contributor to sea level rise in the decades and centuries to come,” Rignot said.
Three major lines of evidence point to the glaciers’ eventual demise: the changes in their flow speeds, how much of each glacier floats on seawater, and the slope of the terrain they are flowing over and its depth below sea level. In a paper in April, Rignot’s research group discussed the steadily increasing flow speeds of these glaciers over the past 40 years. This new study examines the other two lines of evidence.
The glaciers flow out from land to the ocean, with their leading edges afloat on the seawater. The point on a glacier where it first loses contact with land is called the grounding line. Nearly all glacier melt occurs on the underside of the glacier beyond the grounding line, on the section floating on seawater.
Just as a grounded boat can float again on shallow water if it is made lighter, a glacier can float over an area where it used to be grounded if it becomes lighter, which it does by melting or by the thinning effects of the glacier stretching out. The Antarctic glaciers studied by Rignot’s group have thinned so much they are now floating above places where they used to sit solidly on land, which means their grounding lines are retreating inland.
“The grounding line is buried under a thousand or more meters of ice, so it is incredibly challenging for a human observer on the ice sheet surface to figure out exactly where the transition is,” Rignot said. “This analysis is best done using satellite techniques.”
The team used radar observations captured between 1992 and 2011 by the European Earth Remote Sensing (ERS-1 and -2) satellites to map the grounding lines’ retreat inland. The satellites use a technique called radar interferometry, which enables scientists to measure very precisely — within less than a quarter of an inch — how much Earth’s surface is moving. Glaciers move horizontally as they flow downstream, but their floating portions also rise and fall vertically with changes in the tides. Rignot and his team mapped how far inland these vertical motions extend to locate the grounding lines.
The accelerating flow speeds and retreating grounding lines reinforce each other. As glaciers flow faster, they stretch out and thin, which reduces their weight and lifts them farther off the bedrock. As the grounding line retreats and more of the glacier becomes waterborne, there’s less resistance underneath, so the flow accelerates.
Slowing or stopping these changes requires pinning points — bumps or hills rising from the glacier bed that snag the ice from underneath. To locate these points, researchers produced a more accurate map of bed elevation that combines ice velocity data from ERS-1 and -2 and ice thickness data from NASA’s Operation IceBridge mission and other airborne campaigns. The results confirm no pinning points are present upstream of the present grounding lines in five of the six glaciers. Only Haynes Glacier has major bedrock obstructions upstream, but it drains a small sector and is retreating as rapidly as the other glaciers.
The bedrock topography is another key to the fate of the ice in this basin. All the glacier beds slope deeper below sea level as they extend farther inland. As the glaciers retreat, they cannot escape the reach of the ocean, and the warm water will keep melting them even more rapidly.
The accelerating flow rates, lack of pinning points and sloping bedrock all point to one conclusion, Rignot said.
“The collapse of this sector of West Antarctica appears to be unstoppable,” he said. “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 sections of the glaciers. At this point, the end of this sector appears to be inevitable.”
Because of the importance of this part of West Antarctica, NASA’s Operation IceBridge will continue to monitor its evolution closely during this year’s Antarctica deployment, which begins in October. IceBridge uses a specialized fleet of research aircraft carrying the most sophisticated suite of science instruments ever assembled to characterize changes in thickness of glaciers, ice sheets and sea ice.
For additional images and video related to this new finding, visit:
For additional information on the West Antarctic Ice Sheet and its potential contribution to sea level rise, visit:
For more information on Operation IceBridge, visit:
Wisconsin Utilities, Public Service Commission and Governor Walker Being Bad Actors in Leading Fight Against Solar Energy in Wisconsin
Once considered a Midwestern leader in clean energy development, Wisconsin is now referenced as one state where electric utilities with the backing of regulators are putting up financial roadblocks against the solar industry.
A new report in the Washington Post mentions Wisconsin along with New Mexico and Arizona as states where traditional utilities like WE Energies and Madison Gas & Electric are fighting to maintain electric sales in the face of a changing marketplace.
The story quotes from a private meeting three years ago where power company executives were told that as demand for residential solar continued to soar, traditional utilities could soon face serious problems from “declining retail sales” and a “loss of customers” to “potential obsolescence.”
“Industry must prepare an action plan to address the challenges,” warned the Edison Electric Institute, the leading industry trade association. All four of Wisconsin’s investor-owned utilities are members.
The meeting at a resort in Colorado Springs, Colorado, became “a call to arms for electricity providers in nearly every corner of the nation” wrote reporter Joby Warrick.
“Three years later, the industry and its fossil-fuel supporters are waging a determined campaign to stop a home-solar insurgency that is rattling the boardrooms of the country’s government-regulated electric monopolies,” he wrote.
Warrick’s report also makes the link between the electric utilities and the American Legislative Exchange Council, or ALEC, a nonprofit organization with financial ties to billionaire fossil fuel industrialists Charles and David Koch.
In Wisconsin last year, the state Public Service Commission approved major price increases in electric rate structures for state utilities. Utilities argued the changes were needed to cover the cost of maintaining the power plants, poles and wires in the face of slowing electric sales.
For MGE customers, fixed charges for residential electric service went from $10.50 to $19 a month.
MGE customers fought against the changes and eventually got the company to agree to a series of community listening sessions before pursuing additional fixed rate prices hikes going forward. At one point, MGE had talked about raising residential customer fixed charges to nearly $70 a month by 2017.
Meanwhile, the state Public Service Commission (PSC) of Wisconsin is facing a lawsuit from Madison-based Renew Wisconsin and the Alliance for Solar Choice of San Francisco, saying it was guilty of discrimination by passing additional fees on solar customers in the WE Energies 2014 rate case.
Gov. Scott Walker has appointed all three members of the PSC, with the naming in February of former Department of Administration secretary Mike Huebsch to the powerful regulatory agency.
Koch Industries has significant operations in Wisconsin, including Flint Hills Resources, which produces gasoline and asphalt; the C. Reiss Coal Co., which supplies coal throughout the Great Lakes region; and Georgia-Pacific, the packaging and paper firm. Georgia-Pacific’s chemical division is also a producer of proppant resin, a coating for small particles used in hydraulic fracturing.
Another current decision of interest to the utility companies, the PSC, and the governor is American Transmission Company’s (ATC) and Xcel Energy’s proposed Badger-Coulee transmission line project, which stretches from the La Crosse area to Madison in Wisconsin. It is estimated 345-kilovolt, 180-mile line project will cost $580 million.
More than 200 people attended a public hearing in the Town of Holland by the PSC in December. Most of the people who testified in front of the Public Service Commission of Wisconsin voiced their opposition to the project. Some cited health concerns from massive power lines and others questioned whether it’s necessary.
Xcel Energy is one of project partners. A spokesman at the meeting, Tim Carlsgaard, said power lines need a capacity upgrade. Plus, he said, Wisconsin has a 10 percent renewable energy mandate and wind energy is the best option for the Midwest. Carlsgaard said it’s nearly impossible to develop wind energy in Wisconsin.
“Where it’s located is out in the rural areas,” Carlsgaard said. “Out in western Minnesota, southern Minnesota, parts of the Dakotas. The only way to bring that energy to the people is by building transmission lines. There are not existing lines in those areas.”
Dr. Patrice Tronstad, of Prairie View Elementary School, presented PSC administrative law Judge Michael Newmark with a poster signed by students opposing the project. The line could run right next to the Holmen school.
Onalaska Mayor Joe Chilsen said he doesn’t want the Badger-Coulee transmission line to be built at all. But, if the proposed project running from the La Crosse area to Madison is approved, he urged PSC officials not choose the route that could cut through his city. Chilsen said the power line could affect property values and aesthetically damage the city along the Mississippi River.
“This in essence kills all our future economic growth, our business growth in Onalaska,” he said. “I’m absolutely flabbergasted that this is even being considered.”
Chilsen also testified that future expansion plans for Mayo Clinic and other businesses could come to a halt if the Badger-Coulee line comes through the area.
Chilsen was one of the dozens of people who testified before two PSC commissioners: chairman Phil Montgomery and commissioner Ellen Nowak.
Commissioner Eric Callisto didn’t attend because his term is ended in February.
The now 3-person Walker appointed PSC decided last Thursday, March 26, 2015 to allow the construction of the new power line from La Crosse to Madison, over the objections by the public. Discussions and debate over the power line have lasted years, with many opposed citing environmental and aesthetic grievances. The Badger Coulee high-voltage transmission line will be built and it will follow a route from a substation near Holmen, north of La Crosse, to the Madison area, the Wisconsin Public Service Commission (PSC) decided in a unanimous preliminary vote.
Opponent group, Citizens Energy Task Force, said it is “appalled, but not surprised” by the decision, saying there was not enough study of alternatives to building another huge power line. It conceded the construction of the line is “economically driven, with the economic benefits going to utilities while ratepayers being saddled with massive unneeded debt and the health, environmental and quality-of-life consequences that come with these unsightly, unnecessary lines,” the citizen group said. Organizations that have been fighting the proposal said they are considering filing a petition for a rehearing by the PSC or challenging the validity of the PSC’s decision in circuit court.
“More than 90 units of local government tried in vain to understand why these lines are needed,” said Maureen Freedland, La Crosse County Board supervisor. “Our local planning rights have been stripped from us. The decision is a blow to our values and the way of life for our rural Wisconsin neighbors.”
The PSC is expected to issue a final order on the project within four weeks, and Wisconsin-based ATC and Minnesota-based Xcel said they will start contacting property owners on the chosen route yet this year. Construction of the line is expected to begin in 2016 and it is scheduled to go into service in 2018.
Sources: March 11, 2015, report by Mike Ivey of The Capital Times.
Reports aired on Wisconsin Public Radio.
Over Two-thirds of Americans are Cowards When it Comes to Standing Up to the Threats of Global Warming
Over two-thirds of Americans polled answered they were not concerned about global warming and climate change, according to a Gallop poll released last Wednesday and published by The Washington Times. Thirteen percent of Republicans are concerned about global warming and climate problems compared to 52 percent of Democrats polled.
A “coward” is any person who lacks the courage endure dangerous or unpleasant things. Global warming is the most dangerous natural disaster our civilization will have ever had to face and endure, and it is human-caused.
The majority of Americans worry about only one environmental issue, however. Fifty five percent are concerned about the pollution of drinking water. Next in line: 47 percent fret over lake and river pollution, air pollution (36 percent) and the loss of tropical rain forests (33 percent).
In general, Americans are more positive about the environment these days notes Gallup analyst Jeffrey Jones, with negative sentiments now at the “low end” of what the polling group has measured in the last 25 years.
“The nature of the environmental agenda may indirectly be influencing Americans’ concern. The primary focus of the environmental movement has shifted toward long-term threats like global warming – issues about which Americans tend to worry less than about more immediate threats like pollution,” writes Mr. Jones.
“Importantly, even as global warming has received greater attention as an environmental problem from politicians and the media in recent years, Americans’ worry about it is no higher now than when Gallup first asked about it in 1989”, according to Jones.
Source: From an article by Jennifer Harper in The Washington Times, Wednesday, March 25, 2015.
Following are the comments I submitted by email on the governor’s proposed budget for July 1, 2015 to June 30, 2017.
Bad things can happen to good people. It happens all the time, and has occurred all throughout history. So when bad things, or threats, are predicted to occur or seem reasonably likely to occur, it’s best for one to take action, and involve others in removing the oncoming threat, before it gets realized and significant damage to life and our environment occurs.
Governor Walker’s biennial budget plan for Wisconsin for the next two years contains numerous threats to the people of Wisconsin and the state of Wisconsin’s natural resources. Some of those threats could have devastating and harmful impacts if they are allowed to occur without any attempts to prevent or ameliorate them.
Governor Walker’s budget plan as written will cause a great deal of harm for many thousands of Wisconsin’s people and their families. Some people who have worked their entire life at University of Wisconsin or UW-extension will likely lose their jobs, and the public who those people serve will lose out as well. Wisconsin’s elderly and disabled population, and families having children enrolled in Wisconsin’s excellent public school system will also suffer loses. Many hard working and dedicated school teachers and educational assistants serving special needs children will be without a job next fall if this budget is not revamped.
The governor’s budget also hurts those who watch over and protect our precious natural resources, both now and in the coming years, by cutting positions and land stewardship funds.
But really the worst thing about the governor’s budget is not what’s in it but rather what’s NOT IN IT BUT SHOULD IN IT. For example, despite Wisconsin’s aging population and increasing number of people who prefer not to drive, or who can’t drive because of the high cost of owning, maintaining and driving an automobile, the Walker budget proposes nothing new to help with mobility in the state, transit in particular. Rather, it borrows hundreds of millions of dollars to expand an already too large highway system at great environmental harm to the state, and for no good reason.
Numerous observations demonstrate that the climate of the Great Lakes Region, including Wisconsin’s climate, is changing. Average temperatures are getting warmer and extreme heat events are occurring more frequently. Total precipitation is increasing and heavy precipitation events are becoming more common. Winters are getting shorter and the duration of lake ice cover is decreasing over time. As a state, we should already be doing as much as we can to drastically cut back on our burning of fossil fuels but we seem to be doing almost the opposite. This tragedy grows in magnitude the longer it takes for our country and other countries to wean themselves off burning fossil fuels. There are many other unintended consequences of living in a fossil fuel burning dependent society.
But ironically, rather than then increasing substantially the funding of transit systems and the funding of positive financial incentive programs aimed at reducing greenhouse gas emissions and encourage walking and use of nonmotorized travel by state residents and businesses, the governor’s budget promotes more highway expansion. Instead, the state should reward those who drive less (miles), don’t fly, and minimizing their use of fossil fuel derived energy over the year. Use the money that Governor Walker’s budget borrows to fund a bigger highway system and a big new professional basketball arena instead – expenditures that not only subject state taxpayer to great financial risks but also promote adding millions more tons of greenhouse gases to the atmosphere including promoting jet airplanes flying of visiting teams and fans to the games.
Wisconsin Public Radio (part of state’s UW-extension) plans vacationing trips to Scotland and Australia, trips that not only release hundreds of millions of tons of greenhouse gases to the atmosphere but also give nothing back to the state’s own tourism businesses.
Governor Walker’s budgets include more trade promotions with foreign countries despite the fact that shipping products and working with foreign business interests similarly add millions and millions more tons of greenhouse gases to the atmosphere.
My plan would increase Wisconsin families’ and individuals’ annual income for polluting less and reducing the global warming threat, rather than adding to it. It would encourage Wisconsinites and Americans to buy from local entrepreneurs, whenever possible.
Governor Walker’s plan is to require a monthly drug test of food share (too low to begin with) recipients and proof of their having worked at least 80 hours at a place of employment before their receiving the meager food share benefits. It would do nothing to curb the rising income and employment inequalities and racial disparities in the state. The numbers of families and children living in poverty already will not be helped by Governor Walker’s budget. It is a fact that children of families living in poverty start their lives with a handicap because of many reason but the worst is that they do not receive adequate nutrition before and after they enter their school years. The governor’s budget insufficiently funds Wisconsin public schools and the families that live in poverty are disadvantaged in those schools from day one. Yet the governor’s budget does nothing to make up for previous cuts to public schools and add more financial stress for them by requiring them to pay vouchers for children attending private schools.
The budget should also refund the planned parenthood clinics the state had before Scott Walker took office. Certainly we ought not be adding to our human population pressures on the environment if we don’t have to.
Thank for the opportunity to submit my comments on the proposed state budget. For addition background on my concerns expressed here, please visit my blog at: http://www.allthingsenvironmental.com.
A group a mayors living along the Mississippi River has plans to collaborate with international leaders, with an eye toward playing a bigger role in global talks surrounding climate change.
Mayors with the Mississippi River Cities and Towns Initiative will be working more closely with the Netherlands, learning what actions have been taken to protect the Rhine River from climate change.
The group is also initiating discussions with people living along the Amazon, Euphrates, Yellow, Paraná, Danube, Volga, and Ganges rivers.
MRCTI director Colin Wellenkamp said the Mississippi River Valley is the most agriculturally productive zone on the planet and working with those other major food-producing regions is a necessity.
“This is not going to be not just about flooding and water management, it’s going to be about the future of our food supply,” Wellenkamp said. “Climate disruption is a major component of that and so far, that part of the conversation really hasn’t been emphasized.”
Mayors from La Crosse, Onalaska, Prairie du Chien, and Prescott are involved in the initiative, which will send a delegation of mayors to the Conference of the Parties to the United Nations Framework Convention on Climate Change, also known as COP21, later this year.
The MRCTI also recently praised sections of the president’s proposed budget for offering more funding for flooding and disasters.
President Obama proposed funding the Federal Emergency Management Agency’s Pre-Disaster Mitigation Grant program at $200 million, which is a record high.
In La Crosse, this program has been used to flood-proof and remove homes built in the city’s floodplain.
Mayor Tim Kabat and fellow members of the Mississippi River Cities and Towns Initiative met with members of Congress this week, encouraging them to maintain the funding. Kabat said the grants can save money in the long run.
“You do the investment and the project in the front end and prevent a lot of the emergency situations on the back end,” Kabat said.
Kabat said, in the future, these grants could be used to restore the city’s marsh.
The mayors also hope to see funding go up for National Flood Insurance Program Risk Mapping.
There is a difference between a “global warming denier” versus a “global warming skeptic”. The deniers are those who have been conducting brain-washing campaigns to lobby Congress and citizens into believing global warming is either not occurring or, if it is occurring (it most definitely is) that it is not caused by human actions because earth’s climate has always been changing (never as fast before like it is now).
In the new documentary Merchants of Doubt, filmmaker Robert Kenner (of Food, Inc.) shows how professional climate-change deniers like Marc Morano profit by making that desired belief an easy one simply by cultivating uncertainty. “I’m not a scientist, but I play one on TV,” he says in the film, referring to his appearances on cable news shows as a talking head. There he “debates” scientists, often on Fox News, as a form of pandering to viewers who want to believe that legitimate people will tell them what they want to hear. He traffics in doubt, he admits in the film. That is all it takes to lead to legislative inaction: Let everyone keep burning fossil fuels until there is more evidence that this is a bad thing. Even though there is abundant evidence; more than there is for most things we do to protect and preserve our health and general continued existence.
From: “How the Most Important Glacier in East Antarctica Is Melting
New evidence of potentially enormous consequences as rapid ice loss continues”
BY JAMES HAMBLIN MAR 20, 2015 – posted in “The Atlantic.com”.
Merchants of Doubt Official Trailer 1 (2014) – Documentary HD
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We’d heard that the Western Antarctic glacier was rapidly melting. And if it does, it could raise the word’s ocean levels 11 feet.
Now comes news that the Eastern ice sheet may be headed in that direction, too. That would release the same amount of water, giving our grand children a lot of waterfront property where there isn’t any now.
A hundred years from now, humans may remember 2014 as the year that we first learned that we may have irreversibly destabilized the great ice sheet of West Antarctica, and thus set in motion more than 10 feet of sea level rise.
Meanwhile, 2015 could be the year of the double whammy — when we learned the same about one gigantic glacier of East Antarctica, which could set in motion roughly the same amount all over again. Northern Hemisphere residents and Americans in particular should take note — when the bottom of the world loses vast amounts of ice, those of us living closer to its top get more sea level rise than the rest of the planet, thanks to the law of gravity.
The findings about East Antarctica emerge from a new paper just out in Nature Geoscience by an international team of scientists representing the United States, Britain, France and Australia. They flew a number of research flights over the Totten Glacier of East Antarctica — the fastest-thinning sector of the world’s largest ice sheet — and took a variety of measurements to try to figure out the reasons behind its retreat. And the news wasn’t good: It appears that Totten, too, is losing ice because warm ocean water is getting underneath it.
“The idea of warm ocean water eroding the ice in West Antarctica, what we’re finding is that may well be applicable in East Antarctica as well,” says Martin Siegert, a co-author of the study and who is based at the Grantham Institute at Imperial College London.
The floating ice shelf of the Totten Glacier covers an area of 90 miles by 22 miles. It it is losing an amount of ice “equivalent to 100 times the volume of Sydney Harbour every year,” notes the Australian Antarctic Division.
That’s alarming, because the glacier holds back a much more vast catchment of ice that, were its vulnerable parts to flow into the ocean, could produce a sea level rise of more than 11 feet — which is comparable to the impact from a loss of the West Antarctica ice sheet. And that’s “a conservative lower limit,” says lead study author Jamin Greenbaum, a PhD candidate at the University of Texas at Austin.
In its alignment with the land and the sea, the Totten Glacier is similar to the West Antarctic glaciers, which also feature ice shelves that slope out from the vast sheet of ice on land and extend into the water. These ice shelves are a key source of instability, because if ocean waters beneath them warm, they can lose ice rapidly, allowing the ice sheet behind them to flow more quickly into the sea.
The researchers used three separate types of measurements taken during their flights — gravitational measurements, radar and laser altimetry — to get a glimpse of what might be happening beneath the massive glacier, whose ice shelves are more than 1,600 feet thick in places. Using radar, they could measure the ice’s thickness. Meanwhile, by measuring the pull of the Earth’s gravity on the airplane in different places, the scientists were able to determine just how far below that ice the seafloor was.
The result was the discovery of two undersea troughs or valleys beneath the ice shelf — regions where the seafloor slopes downward, allowing a greater depth of water beneath the floating ice. These cavities or subsea valleys, the researchers suggest, may explain the glacier’s retreat — they could allow warmer deep waters to get underneath the ice shelf, accelerating its melting.
In this particular area of Antarctica, Greenbaum says, a warmer layer of ocean water offshore is actually deeper than the colder layers above it, because of the saltwater content of the warm water (which increases its density). And the canyons may allow that warm water access to the glacier base. “What we found here is that there are seafloor valleys deeper than the depth of the maximum temperature measured near the glacier,” Greenbaum says.
One of these canyons is three miles wide, in a region that was previously believed to simply hold ice lying atop solid earth. On the contrary, the new study suggests the ice is instead afloat.
The availability of warm water, and the observed melting, notes the study, “support the idea that the behaviour of Totten Glacier is an East Antarctic analogue to ocean-driven retreat underway in the West Antarctic Ice Sheet (WAIS). The global sea level potential of 3.5 m flowing through Totten Glacier alone is of similar magnitude to the entire probable contribution of the WAIS.”
For Richard Alley, a glaciologist at Penn State University, the new research hints at a possible solution to a question that scientists have long had about the planet’s past — and in particular the Pliocene epoch, beginning 5.3 million years ago, when sea levels were dramatically higher, by as much as 40 meters.
“The sea-level indicators from the Pliocene have suggested that an important amount of ice came out of East Antarctica into the ocean,” says Alley. “Sedimentary records offshore pointed in the same way, and recent modeling…shows the strong potential for this to have happened. This new paper adds to the evidence — the pieces are fitting together.”
One limitation of the study is that the scientists were not able to directly measure the temperature of ocean water that is reaching the glacier itself. While this could be done with robotic underwater vehicles or other methods, that wasn’t part of the study at this time. Thus, the conclusions are more focused on inferring the vulnerability of the glacier based on a number of different pieces of evidence — topped off by the fact that the glacier is, indeed, retreating.
“What we need now is a confirmation of the findings of the paper from oceanographic data, because it is one thing to find potential pathways for warm water to intrude the cavity, it is another to show that this is actually happening,” observes Eric Rignot, an Antarctica expert at the University of California, Irvine. “This paper comes short of the latter, but other research efforts are underway to get critical oceanographic information near Totten.”
For residents of the United States — and indeed, the entire Northern Hemisphere — the impact of major ice loss from Antarctica could be dire. If Antarctica loses volumes of ice that would translate into major contributions to sea level rise, that rise would not be distributed evenly around the globe. The reason is the force of gravity. Antarctica is so massive that it pulls the ocean toward it, but if it loses ice, that gravitational pull will relax, and the ocean will slosh back toward the Northern Hemisphere — which will experience additional sea level rise.
For the United States, the amount of sea level rise could be 25 percent or more than the global average.
[The U.S. has caused more global warming than any other country. Here’s how the Earth will get its revenge.]
Much as with the ocean-abutting glaciers of West Antarctica, just because a retreat has been observed — and because the entirety of the region implies a sea level rise of 11 or more feet were all ice to end up in the ocean — does not mean that we’ll see anything near that much sea level rise in our lifetimes. These processes generally are expected to play out over hundreds of years or more. They would reshape the face of the Earth – but we may never see it.
The problem, then, is more the world we’re leaving to our children and grandchildren — because once such a gigantic geophysical process begins, it’s hard to see how it comes to a halt. “With warming oceans, it’s difficult to see how a process that starts now would be reversed, or reversible, in a warming world,” Siegert says.
Update: This article was updated to correct the size of the Totten Glacier. According to Greenbaum, its floating portion (or ice shelf) is 90 miles by 22 miles in size.
The problem, then, is more the world we’re leaving to our children and grandchildren — because once such a gigantic geophysical process begins, it’s hard to see how it comes to a halt. “With warming oceans, it’s difficult to see how a process that starts now would be reversed, or reversible, in a warming world,” Siegert says.
By Chris Mooney March 16. 2015 in The Washington Post