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- Antarctic ice riddle keeps sea-level secrets
- From NASA's Earth Observatory: Global Temperature ...
- The Shadow on American Democracy by James E. Hanse...
- A Big Drop In Emissions Is Possible With Today's T...
- Science: Climate Change Impact on Antarctica (Inte...
- GISS 2007 Temperature Analysis from NASA
- West Antarctic Ice Sheet (WAIS): Ice loss is accel...
- UGA climatologist studies rate of melt in Greenlan...
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- ▼ January (13)
Thursday, January 31, 2008
TROLL STATION, Antarctica, Jan 31 (Reuters) - A deep freeze holding 90 percent of the world's ice, Antarctica is one of the biggest puzzles in debate on global warming with risks that any thaw could raise sea levels faster than U.N. projections.
Even if a fraction melted, Antarctica could damage nations from Bangladesh to Tuvalu in the Pacific and cities from Shanghai to New York. It has enough ice to raise sea levels by 57 metres (187 ft) if it melted, over thousands of years.
A year after the U.N.'s Intergovernmental Panel on Climate Change (IPCC) projected sea level rises by 2100 of about 20 to 80 cms (8-32 inches), a Reuters poll of 10 of the world's top climatologists showed none think that range is alarmist.
Six experts stuck by the projections, saying the response of ice sheets in Antarctica and Greenland was still unclear, and four other experts, including one of the authors of the IPCC report, projected gains could be 1 or even 2 metres by 2100.
"Most people looking at it are thinking more in terms of a metre," said John Moore of the Arctic Centre at the University of Lapland. "Insurance companies don't know to a factor of 100 where to set their insurance premiums for coastal areas in Florida."
Some island nations, such as the Maldives in the Indian Ocean, are building defences costing millions of dollars and want to know how high to build.
"I think it will be...certainly at the high end of the range," said Kim Holmen, research director of the Norwegian Polar Institute, at the Troll Station 250 km (155 miles) from the coast in Antartica. Set amid jagged mountains like the mythical homes of troll giants, this part of east Antarctica is the world's deep freeze with no sign of a thaw. Temperatures were about minus 15 Celsius (5.00 F) at the height of the Antarctic summer.
"It's my view that more than a metre of sea-level rise can't be ruled out," said Stefan Rahmstorf, of the Potsdam Institute for Climate Impact Research in Germany. He said many experts "think the IPCC range is unfortunately not the full story".
Even so, most experts said it is still impossible to model how the ice will react. Antarctica may accumulate more ice this century because of warming, blamed by the IPCC mainly on human use of fossil fuels, rather than slide faster into the sea.
"The crux of this problem is that we are moving into an era where we are observing changes in the climate system that have never before been seen in human history," said Gerald Meehl, of the U.S. National Center for Atmospheric Research.
"Ice sheets fall into that category. Quite simply, at this time we don't have a good upper-range estimate of 'how much sea- level rise and how fast'," he said. Meehl, a coordinating lead author of the IPCC report, said that gave the best view.
The core prediction for sea-level rise by the IPCC, which shared the 2007 Nobel Peace Prize with former U.S. Vice President Al Gore, is for a gain of 18 to 59 cms (7-23 inches) in the 21st century, after 17 cms in the 20th.
The forecast rate includes faster ice flow from Antarctica and Greenland observed from 1993-2003 but the IPCC said this could increase or decrease in future. If the flow grows in line with temperature rises, it would add a further 10 to 20 cms.
"The IPCC range only takes into account things that can be modelled," said Jonathan Gregory of the University of Reading, who was also among authors who stuck by the conclusions. "There are lots and lots of reasons why you can say there will be large changes. But you can't say it without more evidence," he said.
Among worrying scenarios is the chance Antarctica will slide faster into the sea, perhaps if a ring of sea ice melts away in warmer oceans. Or melt water might flow under the ice sheets of Antarctica and Greenland, and act a lubricant to speed a slide.
But glaciers can slow down as well as speed up.
"We don't know much about changes in the speed of outlet glaciers. Some of these in Antarctica and Greenland tend to speed up -- or slow down. Nobody knows," said Philippe Huybrechts at the Free University of Brussels.
Another factor that could dampen any rise is that warmer air can absorb more moisture -- which may paradoxically bring more snow to Antarctica that would thicken the ice sheet and contribute to lower sea levels this century.
Most of the projected sea-level rise by 2100 will be because water in the oceans expands as it warms, with little being added by the ice sheets. Beyond 2100, the IPCC said sea-level rises are likely to go on for centuries.
"In the long term we are in trouble...Greenland is close to a 'tipping point'," or an irreversible meltdown that would last hundreds of years, Huybrechts said. Greenland has enough ice to raise world sea levels by 7 metres if it all vanished.
One IPCC author said the uncertainties are stacking up towards rising seas. "I firmly believe sea-level estimates are conservative," said Andrew Weaver of the University of Victoria, Canada.
"The lower bound should probably be more like 25 cm and the upper bound closer to a metre if you take everything into consideration now," he said.
Moore at the University of Lapland said a so-far unpublished study by his centre showed seas could rise by 1-2 metres by 2100, based on observational records of sea level in the last 150 years.
Link to this article: http://www.guardian.co.uk/feedarticle?id=7269594
-- For Reuters latest environment blogs click on: http://blogs.reuters.com/environment/ (Editing by Sara Ledwith)
Tuesday, January 29, 2008
In 2007, a moderately strong La Niña event put a chill on the eastern Pacific Ocean, and the Sun was near the low spot in its 11-year cycle of variability. Nevertheless, global average surface temperature in 2007 was still tied for the second warmest year in the instrumental record compiled by scientists at NASA’s Goddard Institute for Space Studies, which goes back to 1880. The record warmest year was 2005, with 1998—now tied with 2007—in second place. The global average temperature anomaly for 2007 was 0.57 degrees Celsius (about 1 degree Fahrenheit) above the 1950-1980 baseline.
This image shows the spatial patterns of temperature anomalies across the planet in 2007. Warm anomalies (compared to the baseline) are red, places where temperatures were the same as the baseline are white, and cold anomalies are blue. The cold anomaly in the Pacific Ocean shows the impact of La Niña, which was particularly strong in the second half of 2007. During La Niña events, the trade winds that blow steadily westward across the Pacific near the equator get stronger. These strong winds drag the sun-warmed surface water into the Western Pacific. Cold water from deep in the ocean wells up off the coast of South America and spreads westward along the equator. The cold anomaly over part of Antarctica is also linked to La Niña through a regional climate phenomenon called the Antarctic Oscillation.
A single year of data on its own can’t be used to either prove or disprove a trend like global warming. However, as the NASA GISS scientists point out in their summary for 2007, the temperature anomaly of 2007 “continues the strong warming trend of the past thirty years that has been confidently attributed to the effect of increasing human-made greenhouse gases. The eight warmest years in the GISS record have all occurred since 1998, and the 14 warmest years in the record have all occurred since 1990.”
- NASA Goddard Institute for Space Studies. (2007). Global Temperature Trends: 2007 Summation. Accessed January 22, 2007.
NASA image created by Jesse Allen, using data provided courtesy of GISS Surface Temperature Analysis team. Caption by Rebecca Lindsey.http://earthobservatory.nasa.gov/Newsroom/NewImages/images.php3?img_id=17902
Saturday, January 26, 2008
Congressional testimony. Do you know that before a government scientist testifies to Congress his/her testimony is typically reviewed and edited by the White House Office of Management and Budget? When I asked for a justification, I was told that a government scientist’s testimony “needs to be consistent with the President’s budget”.
Huh? There have never been any budget numbers in my testimony or in the testimony of most scientists. And OMB’s editing of the scientific content is invariably designed to make the testimony fit better with the position of the political party in power (yes, it is a bi-partisan problem). Where is it stated or implied in the Constitution that the Executive Branch should have such authority? (Actually, does the Constitution not vest control of the purse strings to Congress?) Why does not Congress get incensed about this and fight back?
Offices of Propaganda. The Public Affairs Offices (PAOs) of science agencies have become mouthpieces for the Administration in power. This, too, is a bi-partisan problem. Top people in the Headquarters Offices of Public Affairs can and often are thrown out in a heart-beat when an election changes the party in control of the Executive Branch.
The Executive Branch has learned that the PAOs can be effective political instruments and, with some success, they are attempting to turn them into Offices of Propaganda, masters of double-speak (“clean coal”, “clear skies”, “healthy forests”…) that would make Orwell envious.
Again it is a bi-partisan problem, the control of PAOs being exercised by top political appointees who are replaced rapidly with a change of administration. It is these political appointees that are the problem – the career civil servants at the NASA Centers, e.g., are professionals of high integrity, as are most people at Headquarters.
One may wonder: why doesn’t the media object to this situation? I believe that I learned the reason: it is encapsulated in the phrase “that’s hearsay!”. I heard that phrase over and over again in 2004 after I stated publicly that NASA press releases were being spirited from NASA HQ to the White House for either editing or deep-sixing, when they concerned “sensitive” topics such as global warming. Even NPR did not seem to want to touch that story unless there were multiple pieces of proof on paper.
The phrase “that’s hearsay” seems to make the media folks quake in their boots, doubtless because of the threat of a lawsuit. That probably explains why the New York Times stories about censorship of scientists at NASA that came out in early 2006 became a story about a low-level 24-year-old, who then “resigned”. Reporters, New York Times included, knew that the problem went much higher, but instead of focusing on the threat to democracy, it became too-much an amusing story about a renegade trying to reverse scientific understanding of the “big bang”, etc.
The actual story is made crystal clear in the new book “Censoring Science” by Mark Bowen (author of “On Thin Ice”, a gripping, albeit long, story about Lonnie Thompson’s quest for ice cores from alpine glaciers). Bowen gets insiders at HQ and elsewhere to provide extensive information, most of it “on the record”, about how PAO works to cover its tracks (“Gretchen, don’t e-mail me on this!” There are some heroines in this story, middle level people who refused to comply with orders from political appointees that they recognized as being inappropriate.) By the way, I gave Bowen some long interviews and documentation (and my mug is on the book jacket), but I have no financial interest in the book.
The scary part of this story is that PAO political appointees are learning how to cover their tracks. The picture that Bowen presents is one in which PAO political appointees can communicate directly with the White House. One has to wonder, if the Administrator objected to the PAO political appointee activities, how long would it be before he was on the soup line?
As the tracks are covered better and better, it is as if we have a shadow government organization controlling information that the public receives.
How to fix it? There is an article “Freedom of Speech in Government Science” in the current Issues in Science and Technology, Winter 2008, pages 31-34, by David Resnik. Presumably Resnik is well-intentioned, but I take vehement exception to one of his bottom lines. The article sounds fine for the most part, but keep in mind the common technique of telling you ten things that are true followed by slipping in the whopper, the very questionable point or conclusion concerning the main point of interest. Here is Resnik’s whopper:
“…when a government scientist communicates with the media, the public (or even journalists) may mistakenly assume that the scientist is speaking for the government, when he or she is expressing only a personal opinion. If the scientist expresses an opinion that goes against official policy, this can creates (sic) confusion in the public mind. To minimize confusion and to enable an administration to convey consist (sic) policy messages, it is appropriate to allow public relations officers to review a government scientist’s communications with the media.”
Perhaps I am taking his statement out of context, but he seems to mean review the statement before it is made. This is where we need the Mercedes-driving lawyers (http://www.columbia.edu/~jeh1/distro_Lawlessness_070927.pdf) to help us. What Resnik is saying, which PAO would latch onto in a heartbeat, consists of “prior restraint”, as he suggests review prior to a testimony or statement being made, not correction after the fact by the government. If prior approval for scientific opinions are required, a scientist does not have a snowball’s chance in Hades of providing his unadulterated opinion on a “sensitive” subject.
This is true regardless of which party is in power. The most horrific experience that I ever had with NASA PAO was in 2000 during a Democratic administration when I tried to get a press release through on “Global warming in the twenty-first century: An alternative scenario”, which emphasized the importance of non-CO2 climate forcings. After umpteen iterations, I threw in the towel.
Resnik suggests that the best way to safeguard free speech in government science is for a
scientific organization, such as the American Association for the Advancement for Science (AAAS), to designate a committee or group to focus on these issues. That may do some good, but by itself it will do little.
The presumption of democracy is that the public is informed, honestly informed. Government scientists work for the tax payer and should be allowed to report their research results without political interference. Elected officials can use scientific information as they see fit – they must consider all factors in making policies, not just scientific data. But they should not be allowed to torque the scientific data, or choose what information is allowed to be presented and what information is deep-sixed. Such filtering, which is a recipe for bad decisions and poor management, has never been as intense as in the past several years, in my opinion.
The main problems could be fixed as follows: (1) Public Affairs Offices should be staffed by career professionals protected by civil service rules, not headed by political appointees, (2) the practice of the White House OMB reviewing scientific testimony should be dropped. These changes would be simple to make, they would allow the public to be better informed, the government would have a more complete picture for making decisions, the tax payers would get their money’s worth. So why doesn’t it happen? Because, when a new Administration comes in they say “Hey, now WE can control the Offices of Propaganda (even though they consider them offices of their enlightened truth) and make OUR administration look good!
What is needed is a bi-partisan agreement that these changes would be in the interest of the nation. But it is just not going to happen unless the public gets involved. Politicians do not give up instruments of political power AFTER an election that they have won, unless they made an unambiguous promise before the election. We should be asking the candidates for President “will you make these two specific changes, to take the politics out of scientific reporting?” And then we must check to see that the changes are made when a new administration takes over.
Well, I failed to expound on the relation between the threat to our democracy and the threat to our planet, but I am running out of gas and need to work on a scientific paper. The relation is discussed in (http://www.columbia.edu/~jeh1/worldwatch_nov2006.pdf), and better in Bowen’s “Censoring Science” (Dutton, 2008). Would you believe that the current head of NASA PAO had a senior position in the Southern Company, the second largest holding company of coalburning utilities in the United States? Naw, just kidding. Or am I? Read the book.
Free lunch. At the AAAS meeting in Boston on Saturday February 16, I am receiving their Award for Scientific Freedom and Responsibility. There are still a couple of free seats at my table where I can identify people to take them, so if you are attending AAAS or in the neighborhood and interested, let me know. No guarantees, it might be rubber chicken, but it has become hard to find free lunch these days.
Original article may be downloaded from the following link: http://www.columbia.edu/~jeh1/mailings/20080125_AmericanShadow.pdf
Monday, January 21, 2008
Monday, January 21, 2008; Page A06
You can flip off your widescreen TV with the remote control. Power down your computer to standby. Unplug your cellphone from its charger. But as you leave the room, the "wall warts" -- those small boxes plugged into the wall sockets that power your electronics -- stare with glowing diode eyes in accusation: You are still using power.
In homes and offices everywhere, the power drained by idle electronics adds up to what Andy Williams says is a substantial waste.
Williams is vice president of a company called On Semiconductor. Using more efficient components and design, his company and others make devices that sharply cut the energy appetite of the "wall warts," both on standby and in use. He sees this as a key path to the future that will cut energy use and help curb global warming by ingenious use of technology.
"We're talking about the exact same principle as replacing incandescent light bulbs with compact fluorescent ones," he said from Phoenix. "If our products were built into all consumer electronics -- computers, flat-screen TVs, cellphones -- we could save 800 million pounds of carbon emissions."
His is a vision that dances enticingly in contrast to the doomsday predictions of runaway global warming and the oppressive remedies to fix it. Believers say technology will save us, creating a cleaner, cheaper, less-polluting society that will not require such burdensome changes in how we live.
"I believe with technology pretty much available today or in the very near short term, if we could move those fully into the market, we could get a 30 to 40 percent reduction in greenhouse gases," said Dana Christensen, associate director of engineering sciences at the Oak Ridge National Laboratory in Tennessee, a government-supported research center that studies this question, among others.
The caveat is crucial: if the technology is put to use. That is not as easy as it sounds. And no matter how enthusiastically better technology is adopted, it wouldn't fix the whole problem by itself. But it could go a long way toward the solution, experts say.
Striving for Efficiency
Technological societies are constantly striving to create ways of doing things more efficiently. Advances in efficiency in the past 30 years have led carbon emissions to grow only half as fast as the world's economy, according to Robert Socolow, a Princeton University engineer. But those savings have been offset by the rise in population and consumption.
Still, the potential for energy savings through bright ideas, clever engineering and new inventions is impressive. In Toronto, for example, last year's "Green Living Show" prominently displayed products already on the market to save energy. One company makes old tires into impermeable and energy-efficient roofs for homes. Another demonstrates an invention that duplicates a pen's movements over the Internet -- signing papers remotely without a trip.
On a broader scale, the mundane trappings of our modern life are becoming more efficient. Household appliances, including the thirstiest of them, furnaces and air-conditioners, have steadily diminished their energy consumption in the past three decades. Today's new kitchen refrigerators, for example, use 70 percent less power than those made in the 1970s.
More than one-third of all energy used in the United States goes to heat, cool and power buildings. A little more than half of that is for homes; the rest, for commercial buildings. All can be made to use less power.
Buildings can be made with efficient materials such as old-fashioned straw covered with stucco or new-fashioned polystyrene boards, instead of plywood; with insulation that doubles the energy-savings rating properties; with heat-exchange systems and fewer leaks; with windows that reject heat and admit light; and with designs that make the most of the sun's energy.
In transportation, the technologies to produce more efficient cars have been on the drawing board for years -- and in the case of GM's withdrawn "EV1" car of a decade ago, briefly in production. Foreign automakers have long offered lighter, smaller, more efficient cars, and, pushed by $3-a-gallon gas and by states such as California, U.S. automakers are finally unlocking technology to increase fuel efficiency.
"I don't think there's any doubt we have the existing technologies to double fuel efficiency in vehicles," said Robert Schock, a consultant to the Lawrence Livermore National Laboratory who is also director of studies at the World Energy Council of London, and a lead author of the energy report by the Intergovernmental Panel on Climate Change. "We could significantly reduce the amount of carbon dioxide that goes into the transport sector, which is about 30 percent of the total.
"In buildings here in California, I couldn't get a permit for a remodeled room without screwing in the compact fluorescent light bulbs. And industries already understand the profit motive of doing things more efficiently," Schock said. "With energy efficiency alone, we could cut carbon dioxide emissions at a reasonable cost by probably one-third."
The Problem of Replacement Cost
If the technology exists, what, then, is the problem? The cost of replacing anything, from a power plant to a coffee maker, is the first hurdle. Even if the logic of long-term savings makes it an economical move, individuals and companies often have no money for the initial replacement cost.
In construction, for example, when a builder is trying to make a product that can sell for a lower price and a higher profit, he or she has little incentive to use expensive, energy-efficient techniques and materials.
Even if all new buildings were constructed efficiently, it would take 50 to 75 years or more to substantially replace the existing stock. Unless owners are encouraged -- or required -- to retrofit their buildings with energy-saving materials, the gains from existing and future technology advances will be slow.
In transportation, U.S. automakers have long resisted moves to increase fuel efficiency. Appliance makers argue that cheaper, less efficient, products should be offered as well as more expensive, efficient ones. In industry, tradition, inertia and capital costs slow the adaptation of efficient technologies. Vested interests in old technologies fight to preserve their business. New technologies can be risky and failure disastrous.
Some argue that this is where government should come in. Federal, state and local governments can set standards for more efficient buildings, for example, or more efficient cars or appliances. Lawmakers can require industries to curb greenhouse gas pollution. Subsidies, taxes, incentives and fees can be structured by governments to change the economic equations: to charge big energy users more money per kilowatt rather than less, for example, or to end tax breaks for fossil fuel exploration in favor of subsidies for alternative energy development.
Daniel Sosland, director of the nonprofit group Environment Northeast, did a detailed study in December 2006 of how the northeastern United States and eastern Canada could cut greenhouse emissions. Of the group's five top recommendations, the first three were to improve energy efficiency with what we know how to do already.
"We have built our buildings and roads and transportation around cheap energy. The buildings, appliances have been fairly inefficient," Sosland said. "It's far cheaper to make them efficient" than to do anything else.
"It wouldn't solve the problem," he said. "But it's the cheapest first step. And you have to do it to be on the right path."
Saturday, January 19, 2008
Washington Post Staff Writer and NASA Scientist, respectively
Monday, January 14, 2008; 12:00 PM
Washington Post staff writer Marc Kaufman will be online at Noon ET on Monday, Jan. 14 to discuss the shrinking of the Antarctic ice sheet.
He will be joined by Eric Rignot, who has written a report in the scientific journal, Nature, that shows evidence that climactic changes may be destabilizing vast ice sheets of western Antarctica. Previously, this area of the continent was thought to be relatively protected from the impact of global warming.
As Kaufman, writes of Rignot's report, this raises the prospect of faster sea level rise than current estimates. Read more in Escalating Ice Loss Found in Antarctica (The Post, Jan. 14).
Rignot, a professor of earth system science at University of California, Irvine, is also a senior scientist with NASA's Jet Propulsion Laboratory.
A transcript follows.
Marc Kaufman: Good morning, and thanks for joining us. We also are fortunate to have Eric Rignot, author of the Nature study on Antarctica, on the chat, and he and I will do our best to answer your questions. Eric has studied Antarctica and Greenland for 15 years and is well known for his research. Before we start, a brief correction from me: Mt. Kilimanjaro is not, as I wrote, in Kenya, but in Tanzania.
Clarksville, Md.: The article today referenced Western Antarctica as on land, but also below sea level. Could you please explain this?
Eric Rignot: West Antarctica ice is grounded below sea level. But the top of the ice sheet is of course above sea level. Think about a vast expanse of ice sitting in the middle of the sea and reaching all the way down to the sea floor.
Clarksville, Md.: Using the best scientific common sense with data to date, what is the acceleration trend for the melting that you understand to be happening in Antarctica, and how does that translate into sea level rise by year or decade?
Eric Rignot: The actual trend in Antarctica is a contribution to sea level rise that increased from about 0.3 mm/yr in 1996 to 0.5 mm/yr in 2006. It was certainly lower prior to 1996, and will continue to increase in years to come.
Jefferson, N.C.: Sirs:
I have not seen Dr. Rignot's paper in NATURE, so my question may have already been answered.
For several years, there has been an indication that the temperatures over the Antarctic have cooled, as seen in the satellite data provided by MSU instruments as analyzed by UAH. This same data set was also analyzed by RSS and they chose to exclude any results poleward of 70S because of contamination due to the high elevations of interior Antarctica. Other researchers have reported that there is a warming trend seen in data collected near the coasts of Antarctica. In a paper published in the GRL, I found an apparent flaw in a comparison between sonde data and that produced by the UAH team (2003GL017938), perhaps another indication of surface contamination.
My question is, does the data in the NATURE paper support the claim that the Antarctic is warming and if so, how might that finding be reconciled with the cooling trend found by John Christy et al. at UAH?
R. E. Swanson
Eric Rignot: Good point. Antarctica's interior is cooling. The only air warming is in the Peninsula. But we are seeing at present in the glaciers is not related to atmospheric forcing. We think it is related to thermal forcing from the ocean. Changes in tropospheric circulation and wind patterns have enabled warm sources of water to reach glacier grounding lines and melt them from the bottom. This was the trigger for glacier acceleration in a large section of Antarctica.Melting of the frontal sections reduces the backforce on the glaciers and allows them to flow faster, much like what would happen if you slowly uncork a wine bottle .. or water bottle ..
Bowdoinham, Maine: If the western shelf is largely below sea level, please explain how melting could contribute to sea level rise.
Eric Rignot: The portion of West Antarctica which is below will contribute little to sea level change if it melts in the ocean; only the portion that is sitting above sea level will contribute in full. There is enough ice sitting above sea level however to raise total sea level by 5-6 m if West Antarctica were to melt to sea
Camden, Maine: It seems to me that the experts have consistently (almost) been too conservative in their estimates of coming changes in ice melt and other climatic changes.
Here's my question: Can't they somehow get the bigger picture and therefore predict with more accuracy? There are tons of inputs from all over the planet and taken collectively it would seem that even I, a simple lay person, can project that the future is going to be very, very exciting and challenging. I sometimes get the sense that the scientists are trying to downplay the obvious so as not to be too overbearing. Many did that in pre-Katrina times and look where it got us. I'd prefer to hear the unvarnished truth and have time to adjust and deal with it.
I'm working under the current assumption that climate change is going to be H-U-G-E and dealing with it is going where no man has gone before. Your thoughts?
Eric Rignot: Hello.
Prediction of what is going to happen in the polar regions is difficult. The existing models are not good enough. The first step in the last few years has been to get this accepted by the community, but this was tough. WE are now developing better models.
Scientists do not try to downplay. They have to go by the facts,by what they have, whether it is data or model results. We cannot make things up based on opinion. This is why we may at times sound too conservative.
College Park, Md.: I understand the data and the possible implications. I want to know how we also track our psychological and emotional responses to unprecedented change? What happens to researchers (and all of us) when the facts "enter your system", as Patchauri says?
Eric Rignot: As a scientist, I am trying to do the best research I can do and get objective views on changes in the polar regions. When talking to medias and the press or students about our results, however, I can present a more personal view, but it has to remain within the realms of what I know as a scientist.
New York City: How does the Antarctic ice sheets melt compare to the Greenland ice sheets...are they melting at the same rate?
Eric Rignot: Antarctic ice sheet loss is nearly comparable, though a bit smaller, than Greenland ice sheet loss. The rate of increase in the last ten years is also comparable.
Cary, N.C.: What is the source of the claim from global warming skeptics that Antarctic ice is growing, not shrinking, despite the collapse of the Larsen ice shelves?
Eric Rignot: Climate models have been predicting climate warming would increase precipitation in polar regions (because of enhanced evaporation on the oceans), which has indeed been the case in a few places (e.g. Antarctic Peninsula), but the effect is very modest. Since there is no melt in Antarctica and these models ignored the influence of glaciers, Antarctica could only grow. Reality shows otherwise. Reality shows that glaciers speed up and drive the ice sheet mass budget. This is a major shortcoming of models which we will now try to improve.
Models predicted a loss of Antarctic mass only after a warming of 4-5 degree Celsius. We are obviously there much sooner than expected.
Chantilly, Va.: In your own opinions, what can an average earth citizen do to help to slowdown the glacier melting process?
Eric Rignot: We need to appreciate the seriousness of the situation and the seriousness of climate change. We need to anticipate future changes in the best possible manner. I think that if there is a collective realization that this problem is truly important, we can make a big difference in our every day lives, and elect the right people to make the right decisions.
Toronto, Canada: Skeptics will be looking for holes in the climate change hypothesis. Please evaluate alternative explanations, such as ocean currents/temperature, or prevailing wind direction. Be a severe self-critic!
Eric Rignot: Antarctica has not been warming up. But climate change is complex and impacts many aspects of the climate system besides air temperatures. In the Antarctic, we believe that the main agent of change is the ocean and fluctuations in the sources of heat around the continent.
Fairfax County, Va.: Many of us, including me, base our knowledge of this issue on the movie An Inconvenient Truth, which was helpful to me because it offered a broad survey of the whole subject in lay terms. Do you think that movie gives an accurate picture (for a lay audience) of the scientific consensus on this subject? If it does, how does this new finding change what I learned from that film? Thank you for your work on this subject.
Eric Rignot: Inconvenient truth was an excellent movie because it was entirely based on scientific facts. I do not thin our new finding change much of what this film is showing, except that loss of antarctic ice is larger than thought at the time the movie was made.
New York, N.Y.: How similar or different on what is being observed in Antarctica being observed at the North Polar region?
Marc Kaufman: As I understand it, the sea ice of the Arctic is melting quickly in some areas, while until recently that was true only for the Antarctic peninsula. But a major difference is also that the sea ice in the Arctic typically does melt in the summer--with 5.8 million square miles winter sea ice that exist during winter shrinking on average to 2.7 sq miles in summer -- while that has not been the case typically in Antarctica. Also, much of the Arctic ice covers an ocean, while much of the Antarctic ice is on land in the form of glaciers, snow and ice sheets. Finally, most of the ice in the world is in the Antarctic.
Ojai, Calif.: When I saw Richard Alley at the AGU this December, he was quite concerned about global warming, but nonetheless said that the ice sheets would melt over the course of centuries, not decades. Does this study suggest otherwise?
Eric Rignot: ICe sheets will NOT melt in the course of decades, it will take centuries, there is no doubt about that. Yet some models have predicted it would take 1,000 years. What we are seeing today says it would happen over time scales of centuries. If sea level rises 1-2m in the next 100 years because of ice sheet melting, it would have a major impact on coastal populations.
Bowling Green, Ohio: A friend of mine says that "Global Warming" is occurring on other planets, specifically there is ice melt and that all the hoopla being caused by man is false. Any truth to this statement? Is global warming a cosmic occurrence that we have no control over?
Marc Kaufman: Climate changes are indeed common on other planets, and they have been on the Earth as well. But those natural warming processes occur over long time periods and seem to have different characteristics. But here are some factors that climate specialists--such as those in the Intergovernmental Panel on Climate Change--point to when they this is different. 1/ The build-up of carbon dioxide in the air has been dramatic and unprecedented. 2/ We now have glaciers in retreat not only in polar regions, but also in the high tropics -- the Andes, the Himalayas, and Mt. Kilimanjaro. 3/ Global average temperatures are quickly going up. Put it all together and you have a pretty dramatic picture. The scientists of the IPPC said that human activity was the primary cause, and they said it with a confidence level of 90 percent or so.
Silver Spring, Md.: A question for Eric or Marc...In the Post article this morning, "Rignot said there has been evidence of ice loss going back as far as 40 years", I assume you mean net ice loss? If so, what is the specific evidence?
Eric Rignot: Ice has been lost in the Antarctica Peninsula for several decades as a result of sustained climate warming. Climate warming in the Peninsula has been proceeding at 5 times the global average. But this is an anomaly, most of the rest of Antarctica remains cool. In the main area of Antarctica that is losing mass at present, however, we believe that warm pools of water are able to reach the glaciers as a result of changes in wind patterns. Some of these changes are traced back to the 1970s, but the mass loss numbers get smaller as we go back to the 1970s, so I think the change in ocean forcing started around that time. It turns out to be a time when observations suggest a shift in antarctic oscillation took place. But then the story becomes a bit too technical ...
Washington, D.C.: Could the wind pattern changes that are bringing more warm water to shore, and causing increased erosion of the glaciers and the ice sheets, be a result of the weather changes that are being caused by global dimming?
Eric Rignot: The change in wind patterns is related to global climate change. This is not my area of expertise, however, so I wont dwell into the details.
Climate models have (all) shown that climate change - while influenced by solar variability of course, as it always did in the past and will always do - was very strongly influence by greenhouse gases emissions. Climate models simply cannot match observations of climate change if they do not include human influence. This was a major conclusion of the last report from IPCC.
Raleigh, N.C.: Almost every day brings another article/more evidence about the damage human beings continue to inflict on the environment and the earth, and my despair and sadness deepens. Is there anything an "average" person can do to help in any significant way?
Marc Kaufman: Experts say that we can address the issue on both individual and societal levels. Individually we can try to reduce our use of gasoline, home heating oil and electricity, and try to learn more about how much energy goes into producing the products (including food) that we purchase. Based on that information, we can make more or less energy-efficient choices.
On a larger societal level, it is clear that many states and quite a few businesses have embraced reducing greenhouse gas emissions as a priority. Others have not, and perhaps they could be convinced over time. The big issue, of course, is the role of the federal government, with many saying the Bush administration has been missing in action. Bush officials say that is unfair, but whatever is the case, I think it's clear that his successor will have to do more. On this issue, I think that public pressure has shown itself to make a difference. The next step will be how to translate a desire to reduce global warming to an actual plan. For now, it certainly wouldn't hurt to plant some trees (which take up CO2.)
Olney, Md.: I'm curious about the theory that the "ice melt" or "ice recession" in Antarctica is being caused by warmer underwater currents. Has there been testing of the currents and have actual temperatures been measured? You didn't mention specific data in your story. How much warmer is this current? Thanks!
Eric Rignot: Unfortunately, we do not have much data to quantify how warm these currents are. In places where we do, however, the waters are 3 degrees warmer than 'normal' water. This is a very high temperature differential and quite possibly one of the warmest around Antarctica. Unsurprisingly, this also corresponds to the sector that is changing most rapidly at present.
Clarksville, Md.: Given what you know of Antarctic, Greenland, and global climate change, what can U.S. citizenry do to give you scientists better tools through government to develop the scientific evidence? Satellites, onsite monitoring stations, UAV's, etc.?
Eric Rignot: We need to make sure we have appropriate tools to observe ongoing changes. Unfortunately, the number of satellite missions flown to observe the Earth has been decreasing in the last decade, as a result of more efforts placed on the Mars program and the space station. I hope this will change. Studies have shown that if we were able to go back to the situation we were in the early 1990s, we would be ok.
Perhaps more important, we need better numerical models with the realization that existing ones have major shortcomings. Fortunately this can be solved by giving a job to a lot of smart young scientists interested in doing that.
Milwaukee, Wis.: Am I correct that the melting of ice in Antarctica is a more serious threat than in the Arctic in terms of ocean level rise because this ice is on land, like Greenland?
If you were looking ahead 50 years, would we be seeing by then many of our coastal cities beginning to be submerged, as well as flooded during storms and surges? And if this is the case, when will scientists begin telling the world that we must start planning, and soon to retreat from the coasts? This is going to take decades to prepare, but it seems we will only start dealing with it when we are in crisis mode.
Do scientists have the responsibility to urge these kinds of preparations?
Marc Kaufman: Yes, the loss of ice in Antarctica is the big issue in terms of ocean level rise. Some 90 percent of the world's ice is locked up in Antarctica, and that makes it the 900 pound gorilla. The large eastern section of the continent is on land and is not currently losing much ice -- indeed, some have found an increase in ice levels there. (Rignot's newest data shows a steady-state in terms of snowfall versus ice loss.) So for now, the drama is being played out in West Antarctica and the peninsula. The West Antarctic coast appears to be losing ice because of changed wind patterns and ocean movements that together bring more warm water from the circumpolar current to shore. The result is ice erosion and melting. But on the peninsula, the weather is also changing dramatically -- and is showing increased temperatures that are some of the most dramatic in the world. By the way, West Antarctica has as much ice as Greenland.
Washington, D.C.: Is there a relation between ocean temperature and sea level rise. In other words, how does just temperature change relate to increases in sea levels?
Marc Kaufman: The connection is that an increase in ocean temperatures has the effect of eroding glaciers and ice sheets. When they melt, that increases the volume of water in the oceans and so they rise. This is not an issue so much of sea ice, but rather of ice on land, or glaciers that have displaced ocean (as in West Antarctica.)
Clarksville, Md.: Sir, going back to your Camden, Maine, answer. I have to concur 100% with the questioner, but I also understand that scientifically-established truth has not caught up with the unraveling massive climate events. However, why can't the scientific community in this seemingly dire emergency for civilization, take what data they have, along with te 25-yr. history of scientific underestimates, and provide an un-scientific but extremely valuable "forecast" of where civilization is truly headed...without politicians having any say?
Eric Rignot: Good point. A lot of the changes we are observing today however have virtually no equivalent in the past. In the past, we did not have an outburst of greenhouse gases generated by an inhabitant of the planet. Also, despite all our accumulated knowledge of past climate, we do not know well how fast climate can change. Cores taken in Greenland in the early 1990s said: very fast, perhaps less than decades. New cores taken a few years ago said: even faster, perhaps years. This was unthinkable before these results were obtained.
In terms of ice sheets, we have been relatively data poor. It is hard to get there, get data over large areas, and measurements are difficult. Satellite remote sensing has truly changed our capability to understand what is happening the polar regions. But this only started a few decades ago, and as far as ice sheets are concerned, it really only started in the early 1990s. That's quite a short time to allow us to fully understand what is going and what the implications will be. But we will catch up. In March 2007, the International Polar Year started. There could not have been a better time for it.
Iowa City, Iowa: How many years have the glaciers been melting on Greenland? It would appear the comparison is not valid to the Antarctic regions. Please watch the film 90 Degree's South by Henry Ponting 1910 words added in 1933 to see some of the calving of icebergs 100 years ago. Can you explain Geologic Time against what you call real time today to help us all gain a little more understanding?
Eric Rignot: Greenland glaciers have been melting ever since the end of the last glacial maximum. It is an ongoing story. Except that the rate of melting at present is far larger than what it has been over the last century and there is no sign of it slowing down.
Similarly, Antarctica has been deglaciating since the last glacial maximum. In some parts of it, it is still ongoing, very slowly. In others, the deglaciation process is pretty much over.
Now this is a process over 100,000 years. What we are concerned about right now is the evolution of ice in the next 100 years.
Rockville, Md.: Given the rapid decrease of ice in the polar regions, how much longer are they saying it's going to be before Boston, NYC, other coastal cities are under water? I would think that would force us to do whatever it takes to stop global warming. Is it fair to say also, that if we plant millions of trees, that might help in stopping the warming?
Marc Kaufman: I think was has become clear over the past few years is that the global warming, and the related consequences, are taking place faster than expected. But that said, there are still so many imponderables involved that I don't think anyone has firm predictions about what will happen and when.
As for planting trees, it certainly couldn't hurt. I've seen studies suggesting that even massive tree planting in temperate climates would not make much difference in terms of global warming, but that it could have some effect on localized climates.
Clarksville, Md.: Sir, would you agree that the scientific community, through no fault of their own, have been disadvantaged over the past 25 years in trying to understand global climate change, but in attempting to address it, the scientific community has consistently underestimated the change rate and global dimensions? My understanding is that science cannot grasp the enormously complex and interdependent feedback loops in the warming trend...with new ones being discovered every few months. Your thoughts?
Eric Rignot: Yes, you are correct, but I am a bit more optimistic. I think the scientific community is coming to grasp with the Earth climate system. Slowly but surely. We are not doing very well in terms of predicting the future of ice sheets, but we are now gathering important information which will help improve the next generation of models. Global climate models were not doing very well 30 years ago. They came a long way and are now becoming more reliable. I remain optimistic that in years to come, not decades, we will produce more realistic predictions of the evolution of Greenland and Antarctica. We are learning tremendously right now about the dynamics of these systems. An unfortunate byproduct of changing the climate of the Earth so rapidly ...
Silver Spring, Md.: If Antarctic ice loss is accelerating - particularly in West Antarctica - as your work shows ... what do you think odds are it will collapse this century?
Eric Rignot: That is a very difficult question. I think a collapse of West Antarctica in the next 100-200 yr is now a concept that is back on the table; it was not on the table anymore 10 years ago; it was first put on the table in the early 1970s. But even if the ice sheet does not collapse, a loss of a significant portion of Antarctica and Greenland could raise sea level 1-2 m in the next century, and I think this is already something to worry about.
Milwaukee: Just want to reiterate the question: given how long a timeline would be needed, shouldn't scientists begin recommending development of a long-term plan for retreating from the coasts? Shouldn't there be some policy recommendations around the whole issue of coastal development that would be informed by this science -- not just here in the US, but also internationally? When does science interact with politics and economics -- neither or which is anywhere near catching up to the new alarms about melting ice sheets.
Marc Kaufman: I'm not sure it's up to scientists to come up with a long-term plan for pulling back from coastal areas -- that's far more a political, social and economic issue. The grim truth is that a huge proportion of human activity occurs within 100 miles of a coastline, and a large percentage of humans live in that region. So my guess is that nobody will do much until we are forced to by a number of tragedies like Katrina. There is just too much human and economic capital invested along coasts, and not enough certitude about the nature of the risk. But this said, it certainly seems to me that it's time for government to look seriously at limiting new development along coastal areas, and to do more about restoring coastal wetlands.
Normal trends versus altered trends: Just for the sake of clarity, can you explain briefly the difference between the normal global warming/cooling that we know has taken place from time to time and the influence of external factors including man-made issues that may increase or decrease these trends? I'm thinking in particular of things like magnetic polar shift as a normal trend compared to greenhouse gases that are clearly influenced by humanity.
Eric Rignot: This is a climate question. I am a glaciologist. From looking at ice melting, I cannot trace the origin of the change. I can only say: air temperatures have been getting warmer, or the ocean has been getting warmer, and the glacier changes we are observing are quite large compared to the background noise.
Ice sheets have growing and shrinking over time, over geologic times, over 100,000 year cycle. My view is that what we are witnessing right now is of a different nature. Ice sheets are responding to a spike in climate change created by us, and we are not well prepared to predict what may happen next. The only thing I can add to that is that this is serious problem. The way ice sheets are changing today, the rate at which they change worries me.
Clarksville, Md.: To Marc,
You & the Washington Post have done an excellent job of reporting global warming news over the past several years. I commend you! I hope that even as the Post has played a key role in national politics in the past in the name of truth, on the topic of awakening people everywhere to the coming global warming crises, the Post will take this subject where scientists cannot by their required discipline. As Dr. Rignot cited, there are not past parallel events to reference where we are. His dedication and that of his colleagues will be cited years hence as having saved many from disaster. Thank you!
Marc Kaufman: Many thanks for your comment. My colleagues Juliet Eilperin and Doug Struck have also written many stories on the subject, which clearly the paper sees as very important.
We thank you all for your questions, which have been most interesting and stimulating.
Editor's Note: washingtonpost.com moderators retain editorial control over Discussions and choose the most relevant questions for guests and hosts; guests and hosts can decline to answer questions. washingtonpost.com is not responsible for any content posted by third parties.
Wednesday, January 16, 2008
Let me summarize it this way: 2007 was very hot, and it would have been hotter had it not been for the effects of the La Nina/Southern Oscillation and the solar minimum.
PARIS: Global warming has caused annual ice loss from the Antarctic ice sheet to surge by 75 per cent in a decade, according to the most detailed survey ever made of the white continent's coastal glaciers.
In 2006, accelerating glaciers spewed an estimated 192 billion tonnes of Antarctic ice into the sea, scientists calculate.
The West Antarctica ice sheet lost some 132 billion tonnes, while the Antarctic Peninsula, the tongue of land that juts up towards South America, lost around 60 million tonnes.
But there was a "near-zero" loss in East Antarctica, the world's biggest icesheet, the paper says.
Investigators from five countries, led by Eric Rignot of NASA's fabled Jet Propulsion Laboratory (JPL), used interferometry radar from four satellites to build a picture of the periphery of Antarctica.
They sought to measure the velocities of glaciers that shift ice to the coast from the massive sheets that cover Antarctica's bedrock.
They built up a picture of around 85 per cent of Antarctica's coastline thanks to the data supplied by the European Space Agency's two Earth Remoting Sensing (ERS) satellites, the Canadian Radarsat-1 and Japan's Advanced Land Observing satellites.
"Over the time period of our survey, the ice sheet as a whole was certainly losing mass, and the mass loss increased by 75 percent in 10 years," according to the study, published online by the specialist journal Nature Geoscience.
"Most of the mass loss is from the Pine Island Bay sector of West Antarctica and the northern tip of the Peninsula, where it is driven by ongoing, pronounced glacier acceleration.
"In East Antarctica, the loss is near zero, but the thinning of its potentially unstable, but the thinning of its potentially unstable marine sectors calls for attention."
The loss of 192 billion tonnes is more than twice the annual flow of the River Nile when it reaches the sea, according to a calculation by news agency.
Seen by another yardstick, it is equivalent to an annual rise in global sea levels of about 0.5 mm (0.02 of an inch), if factors such as evaporation and effects on precipitation are not factored in.
By comparison, sea levels rose by between 10-20 centimetres (four to eight inches) from 1900 to 2006, the Nobel-winning Intergovernmental Panel on Climate Change (IPCC) reported last year.
It forecast a rise of at least 18 cms (17.2 inches) by 2100, mainly as a result of thermal expansion, for water expands when it warms. The IPCC declined to set an upper figure to this estimate specifically because of uncertainty about icemelt from Antarctica and Greenland.
The new study says glaciers are likely to determine whether these vast stores of frozen water remain stable or leak.
From 1980-2004, snowfall over Antarctica was unchanged or was even above normal in the regions where there was the biggest ice loss, it notes.
Previous research has found two big factors that can cause a glacier to build up speed.
One is the loss of ice shelves, on the coast. These act rather like corks, bottling up the movement of the glacier. When the shelf breaks up as a result of warmer seas, the glacier can flow into the sea unimpeded.
Another factor is water from melted snow that penetrates the glacier through cracks and shafts known as moulins. The water then acts as lubricant beneath the glacier, enabling it to move faster.
David Vaughan, a professor at the British Antarctic Survey (BAS), said a consensus was emerging, after several years of doubt and debate, that Antarctica was contributing to sea-level rise.
"For the future, we will need more of this type of study quantifying the change, and more studies out on the ice, to determine why the changes are occurring, so we can predict whether they will increase in future."
Around 70 per cent of the world's fresh water is stored in Antarctica. The loss of either of the continent's icesheets or of Greenland would drive up ocean levels by many metres (feet), drowning highly-populated delta regions and low-lying states and amplifying dangerous storm surges.
But that is a doomsday scenario which does not feature in any of the IPCC's projections.
Loss of water from ice sheets on land adds to sea levels, whereas loss of sea ice does not. Ice that floats on the ocean -- such as at the North Pole -- displaces its own volume.
Link to original article: http://timesofindia.indiatimes.com/Opinion/Planet_SOS/Global_Warming/Ice_loss_is_accelerating/articleshow/2699841.cms
Monday, January 14, 2008
by Lee Shearer (email@example.com)
Story updated at 11:11 p.m., on Sunday, January 13, 2008A University of Georgia scientist's research has revealed a dramatic rise in the rate of melt in the vast ice sheet of Greenland -- 60 percent higher last year than ever before recorded.
UGA climatologist Thomas Mote didn't use a big bucket to measure the water coming off the ice -- enough ice covers Greenland, the world's largest island, to fill the Gulf of Mexico.
Instead of actually trying to measure the vast amounts of ice that melts in spring and summer, Mote used a nearly 40-year record of satellite data.
"What we found was quite remarkable," said Mote, a professor in UGA's department of geography and director of its Climatology Research Lab.
Satellites have been recording microwave radiation coming off the ice sheet since 1973, Mote explained.
When ice begins to melt, it begins to radiate a lot more microwave radiation than solid ice, Mote said.
"It looks a lot hotter where it's melting than where it isn't," Mote said.
The melting ice reflects less sunlight and absorbs more energy than unmelted ice.
So while it's not possible to measure the exact amount of water coming off the world's largest island, Mote was able to use the satellite data to measure how long the ice melted in a given year and over how big an area.
Mote's analysis showed the rate of melt for the past decade is sharply higher than the previous 25 years -- and that 2007's rate of melt was 60 percent higher than the previous high in 1998.
Scientists have been keeping an increasingly close eye on Greenland as worries over the effects of global warming have mounted in recent years.
Mote's research helps confirm other scientists' conclusions that the loss of ice from Greenland and the globe's other titanic ice masses has speeded up.
Satellite data has shown a decrease in sea ice across the Northern Hemisphere since 2000.
But all of Greenland's ice won't melt any time soon -- a good thing, since that much melted ice could raise the sea level by about 21 feet, Mote said.
"The ice sheet has been there thousands of years. We're looking at a very small slice of time," he said.
But the research lends weight to other researchers' conclusions that the extent of global ice is shrinking, and that the shrinkage stems from man-made climate changes that are melting the ice.
Some scientists believe we could see a sea level rise of 3 feet over the next century. Other scientists think the rise could be even more, as much as 7 feet.
Another concern is what the increasing melt could do to a vast ocean current system called the North Atlantic Deep Water formation, which affects global climate, particularly in Northern Europe.
"It keeps Northern Europe quite warm," at least compared to other areas that far north on the globe, Mote said.
Mote plans to shift his focus slightly in the next few months on a Fulbright Scholar grant, which will allow him to spend three months at the University of Rio Grande do Sul in Porto Alegre, Brazil, from March to July -- fall and winter in the Southern Hemisphere.
In Porto Alegre, Mote hopes to set up a research collaboration to study how the changes in Antarctic ice are influencing the climate of South America.
He and his colleagues also will be trying to understand questions such as exactly how the giant masses of cold air coming out of the Antarctic influence the climate, and how the continuing deforestation of the Amazon River basin is influencing the South American climate, he said.
Mote also will expand his Northern Hemisphere research, working with four other scientists, he said.
The five-member team, from NASA and four U.S. universities, recently learned they will get a five-year, $1.13 million grant from the space agency, Mote said.
"We will be assembling an integrated look at changes in snow and ice over the Northern Hemisphere," Mote said.
Published in the Athens Banner-Herald on 011408Link to article: http://www.onlineathens.com/stories/011408/news_20080114036.shtml
Sunday, January 13, 2008
Thursday, January 10, 2008
BY JOEL WARNER
From the Boise Weekly, December 12, 2007
In the middle of a table in Konrad Steffen's office at the University of Colorado in Boulder sits a strikingly beautiful globe composed of hand-carved gemstones. Steffen, a geography professor, knows very well that sooner or later the globe will have to be revised. The coastline will shift, swallowing the Nile River megadelta, flooding low-lying expanses of Bangladesh, encroaching onto the Florida panhandle.
On the globe, the changes will be a difference of millimeters, but on a worldwide scale, they could mean the displacement of tens of millions of people. One of the main reasons: The Greenland ice sheet, a gargantuan expanse of ice roughly the size of the Gulf of Mexico, is melting—and it's doing so faster than anyone imagined.
Over the past few years, the ice sheet spewed 250 gigatons of ice into the ocean, or "two-and-a-half times all the ice in the Alps," Steffen said, turning the globe and planting his finger in the center of Europe.
In October, former Vice President Al Gore and the U.N. Intergovernmental Panel on Climate Change won the Nobel Peace Prize for drawing attention to global warming. Earlier this year, the U.N. panel published a report concluding that human influences likely were to blame for planet-wide climate change. It warned that as glaciers and ice sheets melted and caused the oceans to swell through thermal expansion, sea levels would rise between 18 and 59 centimeters by 2100.
But Steffen, known to everyone as Koni, believes the Greenland ice sheet is deteriorating faster than predicted by these models. By the end of the century, he said, the oceans could rise by roughly 3 feet.
And when he makes predictions like this, powerful people listen. Steffen is a worldwide authority on Greenland's ice sheet and the director of the Cooperative Institute for Research in Environmental Sciences. The joint institution of CU and Boulder's National Oceanic and Atmospheric Administration is the largest research unit at the university, with a $50 million budget and a staff of 550.
In early October, just before winning the Nobel Prize, Gore visited Boulder to meet with its many celebrated climate scientists. Steffen wasn't there—he was at a conference in Sydney—so Gore made sure they talked by phone. "He had follow-up questions at least as good or better than my graduate students," the professor said.
Steffen's recent research on Greenland's ice sheet wasn't included in the U.N. panel's study because it had yet to be fully understood and peer-reviewed. But it will appear in a report he is preparing for the Bush administration. It's an issue he hammered home several weeks ago during a presentation to Congress, at which he was asked to explain how much of Greenland's ice was melting each year. Enough to make a column of water encompassing the entirety of the District of Columbia and stretching nearly a mile into the sky, he replied. "That got some attention," he said in a thick Swiss accent.
It started in 1975, when Steffen, a grad student from Zurich, spent the summer studying the Arctic climate on an island 400 miles from the North Pole. Every summer and two entire winters since, he's traveled to the Arctic Circle, and from 1990 onward, he's focused much of his attention on Greenland.
"We knew more about the backside of the moon than we did about Greenland, data-wise," he said.
Summer on the ice sheet is a relative term. During the seven weeks Steffen and his team of grad students and scientists spend there each year, nighttime temps usually drop to 24 degrees below zero. "I seem to like the extremes," he said. "I am not afraid of cold."
In 1990, Steffen built a research station on the Greenland ice sheet, and by 1995, his team began having problems of a different sort: The station itself was coming apart. The living areas had been flooded with meltwater, monitoring towers sunk deep into the ice were toppling over.
This wasn't expected to happen, since the station was located on the ice sheet's "equilibrium line," the point where winter snowfall was supposed to cancel out summer melt. But the melt had been outpacing snowfall, and the equilibrium line was moving. Although he had gone to Greenland to study the climate, he ended up studying climate change.
Over the next decade, they watched the average winter temperature on the ice sheet increase by 6 degrees, an amount so improbable that their colleagues at first didn't believe them.
The ice, it seemed, was moving toward the sea faster than could be explained by rising temperatures alone. The researchers concluded that meltwater was making its way through the ice and lubricating the bedrock below. This allowed the ice to spread out faster and made it more susceptible to melting—which is why Steffen believes the U.N. panel's sea-level predictions are significantly understated.
"This is something some glaciologists thought would not happen, and it had major implications about how fast climate changes could affect the ice flow, cause changes in ice mass and sea-level rise," said Jay Zwally, a NASA glaciologist who tracked the speed of the ice.
Some scientists say the Earth could be entering a phase that in hundreds or thousands of years will lead to the dissolution of the Greenland ice sheet and raise the sea level by 21 feet. Worse yet, Steffen recently led a study showing that an area of ice the size of California had melted in west Antarctica, a region thought to be largely undisturbed by global warming.
But making people care is a challenge.
Climate "is never local," he said. "Greenland shows the environment can change quite fast. We could see similar change here in Colorado."
This summer, House Speaker Nancy Pelosi visited Steffen's research station. Both on the ice sheet and in Boulder, Steffen is participating in a research campaign called the International Polar Year, in which 5,000 scientist from 60 nations are focusing on what is causing—and what can be done about—the dramatic changes in Arctic and Antarctic regions.
"You always ask yourself, 'There is uncertainty. What happens if I send out the wrong message?'" he said. "But that was five years ago. Now there is no question the sea level is rising. I am starting to worry that my kids are going to have quite a different world from the one I grew up in."
Link to this article: http://www.boiseweekly.com/gyrobase/Content?oid=oid%3A309554
Monday, January 7, 2008
The Age of Consequences: The Foreign Policy and National Security Implications of Global Climate Change
The short quote below is from the report. Anyone who has paid attention and looked at the old IPCC graphs from 2004 must have noted that in almost all cases, what actually occurred by 2006 or 2007 was the worst case scenario. And, remember, the scientists who went out on a limb and published their simulations with the worst case scenarios were for the most part ridiculed. Unfortunately, it turns out that they were right.
"Our group found that, generally speaking, most scientific predictions in the overall arena of climate change over the last two decades, when compared with ultimate outcomes, have been consistently below what has actually transpired."
I am borrowing from the RealClimate blog without prior permission in the belief that dissemination of this report is important.
Here are some words by the RealClimate blogger about what this report contains:
"The group imagined three potential scenarios, labeled expected, severe, and catastrophic. These are not forecasts exactly, since forecasting society is even harder than forecasting climate, which is itself pretty dicey on a regional spatial scale, but rather a fleshing out of plausible possibilities, a story-telling, visualization-type exercise.
The “expected” scenario calls for 1.3 °C of warming globally above 1990 levels, by the year 2040. Changes in precipitation and sea level prompt migration at a scale sufficient to challenge the cohesion of nations. The potential responses to this scenario are broken down into specific regions with their particular historical and political settings. Just to pick a region at random, Nigeria in West Africa will suffer accelerated desertification with climate change, prompting intensified migration into the megacity of Lagos, which is itself threatened by sea level rise. Compounding Nigeria’s misfortune, there is oil in the Niger Delta, and as global oil supplies dwindle, the strife and corruption that oil brings a weak nation will only intensify.
In the “severe” scenario, the globe warms by 2.6 °C by 2040 and sea level rises about a half a meter. Scientists in 2040 conclude that the eventual collapse of Greenland and the West Antarctic ice sheets has become inevitable in the centuries that follow. Agricultural production declines in the arid subtropics and in increasingly flooded river deltas. Again to pick a random example from the report: the river systems in the American Southwest collapse, leading to impoverishment of Northern Mexico and increased migration pressure in the U.S. Resource stress in Latin American leads to a tendency toward populist, Chavez-type governments, and more extensive regions of de facto anarchy such as found today in parts of Colombia.
The “catastrophic” scenario assumes positive feedbacks in the carbon cycle to warm the planet by 5.6 °C by the year 2100, and sea level has risen by 2 meters. I feel compelled to note that if this is supposed to be a worst-case scenario, I personally can imagine worse in terms of sea level rise. In the social realm the crystal ball gets murkier as the report progresses from expected to severe to catastrophic, but one important ingredient in the prognosis for the catastrophic scenario is the migration of millions of people, a scale unprecedented in human history, potentially enough to undermine the stability of civilized governance. One participant recommended that we check out the movie Mad Max, only imagine it hotter."Read the complete post at the RealClimate blog at this link:
The ancient frozen dome cloaking Greenland is so vast that pilots have crashed into what they thought was a cloud bank spanning the horizon. Flying over it, you can scarcely imagine that this ice could erode fast enough to dangerously raise sea levels any time soon.
Along the flanks in spring and summer, however, the picture is very different. For a lengthening string of warm years, a lacework of blue lakes and rivulets of meltwater have been spreading ever higher on the ice cap. The melting surface darkens, absorbing up to four times as much energy from the sun as unmelted snow, which reflects sunlight. Natural drainpipes called moulins carry water from the surface into the depths, in some places reaching bedrock. The process slightly, but measurably, lubricates and accelerates the grinding passage of ice toward the sea.
Most important, many glaciologists say, is the breakup of huge semisubmerged clots of ice where some large Greenland glaciers, particularly along the west coast, squeeze through fjords as they meet the warming ocean. As these passages have cleared, this has sharply accelerated the flow of many of these creeping, corrugated, frozen rivers.
All of these changes have many glaciologists “a little nervous these days — shell-shocked,” said Ted Scambos, the lead scientist at the National Snow and Ice Data Center in Boulder, Colo., and a veteran of both Greenland and Antarctic studies.
Some fear that the rise in seas in a warming world could be much greater than the upper estimate of about two feet in this century made by the Intergovernmental Panel on Climate Change last year. (Seas rose less than a foot in the 20th century.) The panel’s assessment did not include factors known to contribute to ice flows but not understood well enough to estimate with confidence. All the panel could say was, “Larger values cannot be excluded.”
The Arctic Council, representing countries with Arctic territory, has commissioned a report on Greenland’s environmental trends, to be completed before the 2009 climate-treaty talks in Copenhagen, at which the world’s nations have pledged to settle on a long-term plan for limiting human-caused global warming.
Konrad Steffen, a University of Colorado glaciologist who has camped on the shoulders of Greenland’s ice sheet each year since 1990, is the lead author of the chapter in the report on Greenland’s climate. Last August, he and a team focusing on the ways meltwater might affect ice movement dropped a camera 330 feet down a water-filled moulin to explore whether the plumbing system can be mapped.
Research on alpine glaciers shows that as more water flows through such apertures, ice can shift more quickly. But eventually large sewerlike conduits form, limiting the lubrication effect. The camera drop was only an initial test.
Alberto Behar, a NASA engineer who designed the camera, said some unconventional methods were being considered to chart the flow of such water. “We had ideas to send rubber ducks down and see if they pop out in the ocean,” he said. “They’d have a little note saying, ‘Please call this number if you find me.’”
The changes seen in Greenland may turn out to be self-limiting in the short run; surging glaciers can flatten out and slow, for instance. Or they may be a sign that the island’s ice — holding about the same volume of water as the Gulf of Mexico — is poised for a rapid discharge. Scientists are divided on that question, and on whether there is a near-term risk from a Texas-size portion of West Antarctica’s ice sheet that is also showing signs of instability. This split divides those foreseeing a rise in the sea level of a couple of feet this century from water added by Greenland, West Antarctica and mountain glaciers, and a few experts who speak of a couple of yards in that time.
Those holding a more conservative view of Greenland’s near-term fate include Richard Alley of Pennsylvania State University, who noted that ice cores and tests of organic material from beneath the ice implied that the main mass of the Greenland ice sheet clearly endured thousands of years of warming in the past without vanishing.
“It’s basically a big lump of ice sitting on this bedrock,” Dr. Alley said in describing Greenland’s behavior in warm conditions. “What it tries to do is snow more in the middle and melt more on the edges. If it pulls its edges back, then there’s less area to melt, and that helps it survive. That’s why you can have a stable ice sheet in a warmer climate.”
But there is no significant debate on the long-term picture anymore. Should greenhouse-gas emissions follow anything close to a “business as usual” rise, the resulting warming and ice loss at both ends of the earth would cause coasts to retreat for centuries. While it was circumspect about near-term changes, the intergovernmental panel was confident about that long view.
The prospect of having no “normal” coastline for the foreseeable future has many scientists deeply concerned.
“What is at stake is the stability we have always taken for granted” both for coasts and climate itself, said Jason E. Box, an associate professor of geography at Ohio State University. Dr. Box presented fresh findings at the American Geophysical Union meeting last month showing that several Greenland glaciers accelerated sharply in direct response to warming, both in a warm spell starting in the 1920s and now.
Eric Rignot, a longtime student of ice sheets at both poles for NASA’s Jet Propulsion Laboratory, said he hoped the public and policymakers did not interpret uncertainty in the 21st-century forecast as reason for complacency on the need to limit risks by cutting emissions.
Dr. Rignot recently proposed that unabated warming could result in three feet of global sea rise just from water flowing off Greenland, three feet from Antarctica and 18 inches as the remaining alpine glaciers shrivel away.
This is similar to projections by the most prominent NASA climate scientist, James E. Hansen, but more than twice the three-foot rise that many glaciologists seem to agree on as an outer bound for what is possible by the end of the century.
“It is too early to reassure that all will stabilize, and similarly there is no way to predict a catastrophic collapse,” Dr. Rignot said. “But things are definitely far more serious than anyone would have thought five years ago.”
This article may be found at the following link: http://www.nytimes.com/2008/01/08/science/earth/08gree.html?ref=science
Wednesday, January 2, 2008
From the Discovery Channel News at: http://dsc.discovery.com/news/2008/01/02/arctic-ice-melt.html
Jan. 2, 2008 -- The dramatic loss of the Arctic ice cap may have been triggered by disruption to the thermal layers of atmosphere stacked over Earth's far north, according to Swedish research to be published Thursday.
The study, published in Nature, offers a new explanation for the rise in the Arctic's surface temperature, which over the past century has been nearly two degrees Celsius (3.6 Fahrenheit), or twice the global average.
Until now, the big suspect in "Arctic amplification" has been reflectivity of sunlight.
When the Sun's rays hit snow or ice, most of that solar energy bounces back into space -- but as those melting surfaces give way to dark-blue sea, the heat is absorbed instead.
This self-reinforcing process, called a feedback, is an established factor in accelerating warming in snow and ice.
But Stockholm University scientists led by Rune Graversen believe a possibly bigger cause for Arctic warming could be changes in heat transport in the middle of the troposphere, an atmospheric band that extends 10 kilometers (seven miles) above Earth's surface.
In polar regions, the layers of relative heat above the surface are usually stable. But Graversen says that over the last two decades or so there have been changes in Arctic atmospheric circulation which have brought in heat and moisture.
The moisture is particularly important, as it helps form persistent low cloud over the Arctic.
Moisture-laden clouds at this altitude tend to absorb heat from the Sun, thus bringing a warming effect close to the surface. In contrast, high-altitude clouds, which mainly comprise icy crystals, reflect heat back into space, and thus cool the surface.
The circulatory shifts have an especially big impact in summer, says Graversen.
In 2007, summer sea ice in the Arctic shrank to about four million square kilometers (2.4 million square miles), a 23 percent decrease from the previous record low of 5.3 million square kilometers in 2005.
A second study, also in Nature, meanwhile, shows that the capacity of vegetation to absorb carbon dioxide (CO2) appears to be ebbing, with potentially serious consequences for global warming.
Currently, about 50 percent of all the CO2 produced by burning fossil fuels is soaked up -- "sequestered" -- by land masses, mainly through forests, and by oceans.
Remarkably, that percentage has remained stable even as the output of man-made greenhouse gases has increased.
Up to now scientists have assumed that longer growing seasons were a silver lining of climate change because the warmer temperatures gave photosynthesising plants more time to remove the most important of these gases -- CO2 -- from the atmosphere.
This view has been bolstered by satellite images showing a clearly visible "greening trend," notably in the northern hemisphere.
But Shilong Piao of France's National Center for Scientific Research (CNRS), found that over the past 20 years the planet's biomass above the 20th parallel released nearly as much CO2 in the fall or autumn as it soaked up during the spring.
"If future autumn warming occurs at a faster rate than in spring, the ability of norther ecosystems to sequester carbon may be diminished earlier than previously suggested," he warns.
While Piao's study draws a clear link between rising temperatures and reduced carbon uptake, projecting future trends is very difficult, cautions John Miller, a expert on carbon cycles at the University of Colorado, in a commentary, also published in Nature.