CLAIMS OF DRAMATIC MELTING OF ANTARCTIC ICE SHEET UNFOUNDED

From "Comptes Rendus Geosciences"

Antarctica ice sheet mass balance

By: Frederique Remy and Massimo Frezzotti

Abstract

The mass balance of the Antarctica ice sheet is one of the sources of uncertainty about the sea-level rise. However it is not easy to determine the mass balance due to a lack of knowledge of the physical processes affecting both the ice dynamics and the polar climate. Other limitations are the long time lag between a perturbation and its effect, but also the lack of reliable data, the size of the continent and finally the huge range of variability involved. This article examines the results given by three different ways of estimating mass balance, first by measuring the difference between mass input and output, second by monitoring the changing geometry of the continent and third by modelling both the dynamic and climatic evolution of the continent. The concluding synthesis suggests that the East Antarctica ice sheet is more or less in balance, except for a slight signature of Holocene warming, which is still active at the current time. On the contrary, the West Antarctica ice sheet seems to be more sensitive to current warming.

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5. Synthesis and conclusion

Observations of the Antarctica ice sheet suggest that the East Antarctica ice sheet is nowadays more or less in balance, while the West Antarctica ice sheet exhibits some changes likely to be related to climate change and is in negative balance. For the East Antarctica ice sheet, the component survey method indicates a slight positive imbalance of 22 +/- 23km^3 yr^-1 (0.065 mm^-1eq. s.l.), while survey by altimetry gives an upper limit of twice this value and the coffee-can technique indicates steady-state conditions in the surveyed sector of East Antarctica. The model finds a slight negative imbalance for this part due to the actual response of the warming of the Holocene, as the signature of this signal was indeed observed with altimetry analysis. For the western part, the component survey suggests a negative imbalance of 48 +/- 14 km^3 yr^-1 (+0.14mm yr^-1 eq. s.l.) and the altimetry survey a negative imbalance of 59 +/- 60 km^3 yr^-1 (+0.18 mm yr^-1 eq. s.l.), which may be explained by the retreat of ice shelves. These observations, namely a slight increase of the east part and a significant decrease of the western part, have been recently confirmed by the analysis of 2.5 yr of Grace [32].

Modelling of the Antarctica ice sheet [21] suggests that the current response of the Antarctica ice sheet is dominated by the background trend due to the retreat of the grounding line, leading to a sea-level rise of 0.4 mm yr^-1 over the short-time scale (100 yr). This component is again found to be dominant during the following centuries, depending on the climate scenario. Later, the precipitation increase will counterbalance this residual signal, leading to a thickening of the ice sheet and thus a decrease in sea level. Taking into account the low and middle scenarios leads to a decrease in sea level over the next millennium, while the high scenario inverses the trend in 500 years due to the grounding-line retreat. It should be noted that the time when the trend is reversed not only depends on the climatic scenario, but also on the ice shelves modelling, basal melting rate beneath ice shelves being the most critical factor to be estimated.

However, these determinist models do not take into account the stochastic fluctuations of the forcing given the inertia of the ice sheet. For instance, taking random fluctuations of snow accumulation rate into account alone yields a probability of a present-day induced sea level rise of between 0.5 and 1 mm yr^-1 over a 30-year time scale at 10%~10% [40].

Both observations and modelling are still not reliable enough. Let us point out some limitations and problems that should be carefully considered.

The more critical factor is probably the surface mass balance, which varies from location to location due to interaction between precipitation and wind driven by slope along wind direction [9] and [11]. One of the major unexpected discoveries regarding cryosphere/atmosphere interaction was indeed made in the remotest part of the East Antarctic Ice Sheet with the discovery of the megadunes [6] and [9]. Major gaps in our knowledge of the temporal and spatial variability processes and of the exact relation between climate change and precipitation change prevent us from producing a reliable estimate of current surface mass balance and from predicting its future trend.

From the point of view of ice sheet dynamics, observations of the Antarctic Ice Sheet over the last decade have identified recent unexpected changes, which are much more dynamic than previously thought. Thus our idea of a slowly evolving Antarctic ice sheet is radically changing [22]. However, the models lack some of the physical processes that may explain these unexpected changes. For instance, a limitation on predicting the future with respect to actual measurements and knowledge lies in the effect of ice-shelf retreat on upslope glaciers. It may be argued either that ice-shelf retreat has little effect on glaciers or that the breaking up of the ice-shelf will accelerate. Considerable improvements are also needed, in particular for characterizing fast moving outlet glaciers. The first results with ICEsat on the glaciers of the Ross embayment suggest that we can hope a very good precision with a very fine space resolution [46]. Lastly, due to numerical limitations, small-scale features such as fast glaciers are poorly taken into account, so that ice sheet modelling underestimates rates of changes [2].

The ICEsat satellite, launched in 2003, will enable measuring of ice sheet mass balance, but on a small temporal scale, which is insufficient for inferring long-term trends. Grace, launched in 2002, will give access to change in ice mass. By combining this data with the ERS and Envisat series, uncertainty with respect to ice sheet mass balance will be reduced.

In the future, the launch of several satellites dedicated to the study of the ice sheet may further our understanding of the physical processes acting on ice sheet and of its actual state. Unhappily due to a launch failure, the Cryosat satellite, devoted for the survey of polar regions, is postponed. Carisma mission, a P-band radar designed to sound the ice sheet, will provide us with exact ice thickness and volume, and will detect internal ice layering, which will be of great help for ice-sheet modelling.







Saving what from whom?

By Thomas Sowell

When conservationists talk about "saving" this and "protecting" that, a logical question might be: Saving it from whom? Protecting it from whom? And why should the government force what you want on someone else who obviously wants something different, or there would not be an issue in the first place? After all, the Constitution says that all citizens are entitled to the "equal protection of the laws."

Such questions almost never get asked. Nor do evidence or logic play much of a role in most conservation issues. Instead, we hear rhapsodies about "open space," sneers at "urban sprawl" and self-congratulatory phrases like "smart growth." In short, rhetoric has long since replaced reasons on this as on so many other issues.

The latest conservation crusade has been announced in the San Francisco Bay area -- putting an additional one million acres aside as "open space." According to an official of the Peninsula Open Space Trust, the next couple of decades represent "the last chance" to "save" these million acres. The fashionable phrase is: "Once it's paved, it can't be saved."

Just to introduce a few facts into all these rhetorical flourishes, there are four and a half million acres of land in the San Francisco Bay Area. Less than one-sixth of this land has been developed. So we are not talking saving the last few patches of greenery from being paved over. More than a million acres are already legally off-limits to development while less than three-quarters of a million acres are actually developed.

What then is the urgency about making another million acres of land legally off-limits to building anything? Because otherwise, more people will move into the area over time and, since they don't want to live outdoors, they will want to have housing. That bothers the conservationists, who prefer trees to houses. If they can't cut these other people off at the pass by making it illegal to build anything on an additional million acres, they can at least force those people to live in the kinds of housing that conservationists want to restrict them to, rather than the kinds of housing that these people prefer for themselves. That's called "smart growth." What is smart about it is another question.

An international study of 26 urban areas with "severely unaffordable" housing found 23 of those 26 subject to strong "smart growth" policies. What is "smart" about causing skyrocketing housing prices by making it illegal to build anything on vast amounts of land? It is smart if you already own a home and the astronomical costs of buying or renting are going to have to be paid by other people who move into the area. It may be especially smart if restrictions on building cause the value of the home you already own to go up by leaps and bounds.

The San Francisco Bay area already has housing prices about three times the national average. The heavy burden that this places on people is reflected in the fact that two-thirds of the purchases of homes last year were financed with risky "interest-only" loans. That means that the mortgage payments for the first few years do not reduce the amount owed by one cent. Moreover, since these are usually adjustable-rate mortgages, the payments can shoot up as the Federal Reserve raises interest rates.

The connection between severe restrictions on building and skyrocketing housing prices can be seen from evidence around the country and around the world, wherever people have succumbed to rhetoric about "smart growth" and sneers at "urban sprawl." Severe restrictions on building began in the Bay Area back in the 1970s. At the beginning of that decade, housing in this area was as affordable as in other parts of the country. A median income family in the Bay Area could pay off the mortgage on a median-priced house in just 13 years, using just one-fourth of their income. A decade later, it took 40 percent of their income to pay off the mortgage in 30 years. Today it requires 50 percent. Very "smart."

Source








The effects of aerosols

A scientist at the Weizmann Institute of Science and his colleagues caused a storm in the atmospheric community when they suggested a few years back that tiny airborne particles, known as aerosols, may be one of the main culprits causing climate change - having, on a local scale, an even greater impact than the greenhouse gases effect. Attempts to understand how these particles influence clouds have generated many uncertainties. A new paper by Dr. Ilan Koren of the Weizmann Institute Environmental Studies and Energy Research Department and Dr. Yoram Kauffman of the NASA/Goddard Space Flight Center, USA,* published in Science Express online, weaves together two opposing effects of atmospheric aerosols to provide a comprehensive picture of how they may be affecting our climate.

Cloud formation is dependent upon the presence of small amounts of aerosols such as sea salt and desert dust. These tiny particles serve as the seeds around which water vapor in the air condenses, forming tiny water droplets that rise as they release heat. As the small droplets rise, they collide and merge with larger droplets. When the droplets reach a critical size, gravity takes over, causing them to fall from the cloud in the form of rain.

One of the controversies surrounding the extent of aerosol impact on climate change is the duality of their influence. On the one hand, Koren and his colleagues previously found evidence to suggest that the extra seeds planted in the atmosphere by the emission of man-made aerosols (pollution, forest fires, and fuel combustion) lead to more, but smaller-sized, water droplets. The formation of larger water droplets by the collision process is less efficient and, therefore, rainfall is suppressed. The smaller droplets are lifted higher up into the atmosphere, creating larger and taller clouds that will persist longer. Not only does this alter the whole water cycle, but the increased cloud cover reflects more of the sun's radiation back into space, creating a local cooling effect on Earth.

But to complicate matters, Koren, in another study, showed that certain types of aerosols - those containing black carbon - can also decrease cloud cover, ultimately leading to a warming effect. This occurs as black carbon absorbs part of the sun's radiation, warming the surrounding atmosphere and reducing the difference in temperature between the Earth's surface and the upper atmosphere. This combination prevents atmospheric instability - the condition needed to form clouds and rain. A stable atmosphere means fewer clouds; fewer clouds mean less reflection of sunlight; less reflection of sunlight and absorption of radiation lead to warming.

Policy makers have argued that, in the bottom line, the warming effect of the greenhouse gases and the (mainly cooling) aerosol effect may balance each other out so that the net global climate change will be small. Koren argues that it is the local climate change that is problematic: Clouds may persist without releasing their rain over regions where they would normally precipitate, such as rainforests, and move to precipitate over regions where rain is not needed, such as oceans. Or the effect could lead to the warming up of cold and the cooling down of hot regions. These additional effects to the already problematic warming by greenhouse gases could have disastrous repercussions in the long run.

Also controversial is the question of how such tiny localized particles affect weather systems thousands of kilometers away from their sources. There is no doubt that aerosols do play a role, but the skeptics believe it is negligible compared to meteorological key players such as temperature, pressure, the amount of water vapor in the air, and wind strength.

What Koren needed was a way to separate meteorological from aerosol influences - something which was lacking in his previous studies. Together with Kauffman, he used a network of ground sensors (AERONET) to measure the effect of aerosol concentration on cloud cover. Radiation absorption is less affected by meteorology, so if the skeptics are right and meteorology is the main influence, then the correlation between aerosol absorption and cloud cover should have been seen in only a few circumstances. But this was not the case. They observed the duality effect on clouds: As total aerosols increase, cloud cover increases; and as radiation absorption by aerosols increases, cloud cover decreases - for all locations, for all seasons. Backed up with a mathematical analysis, it becomes harder to deny that it is, in fact, aerosols that have the major influence.

"We hope that this study has finally provided closure," says Koren. "Hopefully policy makers will start to tackle the issue of climate change from a different perspective, taking into account not only the global impact of aerosols and greenhouse gases, but local effects too."

Source






A Waste of Energy: Yucca Mountain hangs in nuclear limbo

"As you can see, Yucca Mountain isn't really a mountain," says our guide as we near the end of an hour-long bus ride, about 100 miles north from Las Vegas. "Those of you who know geology will recognize it's only a ridge." The Department of Energy gives monthly tours these days, anxious to prove--after almost 25 years--it still intends to open its Nuclear Waste Repository at Yucca Mountain someday. The trip, however, feels like an expedition into hostile territory. The whole state of Nevada is on the warpath over the project.

"See those buildings off on the left there," says our guide as we pass through the sagebrush. "They're brothels. As you may know, prostitution is legal in certain Nevada counties. The state has no trouble supplying them with water, but for almost a year they wouldn't give us any. We used port-o-potties for quite a long time." As it turns out, though, the brothels have their upside. Anticipating a surge in business from the construction project, they are among the few locals supporting the project.

Right now the Yucca Mountain Repository consists of one five-mile long tunnel dug into the side of the mountain/ridge. In 1994, a locomotive-like device with a 25-foot drill face started burrowing about 185 feet a day. After a mile into the mountain it turned left for three miles, then left again, re-emerging only five feet from its target. A video at the visitors' gallery shows the whirling snout breaking through the cliff face like a diver returning to the surface, as staff members in hardhats stood and cheered. That was 1997. Nothing much has happened since.

The whole project is now tied down in environmental impact statements. The Environmental Protection Agency set a standard that radiation from the site should not exceed 15 millirems a year (about one chest x-ray) for 10,000 years. Environmentalists screamed that wasn't enough. They wanted a million years. A federal court, of course, agreed. So the EPA set a standard of 350 millirems for the next million years (about two-thirds of what people in Denver get from natural sources) and environmentalists are screaming that isn't good enough either. Nobody has suggested how these standards are to be monitored.

Naturally, in trying to make such preposterous forecasts, somebody winged some numbers somewhere and that's what made it into the papers. Now the press and politicians are playing "the government lied to us."

So the bad news is that it's going to be a long, long time--if ever--before Yucca Mountain is completed. If a license is issued, there are seven more years of construction ahead, then another round of federal permits. Meanwhile, Entergy, the country's second-leading operator of nuclear plants, has collected a multimillion-dollar settlement against DOE for failing to take the spent fuel off its hands by 1998, as promised by the Energy Policy Act of 1982. Others will surely follow.

The good news is that all this probably doesn't make much difference. Nuclear power is about to undergo a resurgence in this country--with or without Yucca Mountain. In the first place, the whole idea that there is such a thing as "nuclear waste" is a bit of a misconception. More than 98% of the material in a spent nuclear fuel rod is being recycled in other parts of the world. About 97% of spent fuel is uranium: 2% is fissionable U-235 isotope, the fuel that powers the reactor and the other 95% is good old U-238, the same non-fissionable isotope that comes out of the ground. It can't be used for bombs. Sure, it has a half-life of four billion years (that's why environmentalists think they have to sit and watch it for a million years) but this is the same stuff that's in granite.

No, the isotope everybody really worries about is plutonium-239, which is formed when small amounts of U-238 absorb neutrons during the three-year cycle. It makes up 1% of spent fuel. Separating it and putting it back in a reactor as "mixed oxide fuel" (uranium plus plutonium) is no problem.

Unfortunately, back in 1976, Jimmy Carter decided that if we extracted the plutonium, somebody might run off with it and make a bomb. Therefore he cancelled fuel recycling. That created the problem of "nuclear waste." France recycles all its fuel rods and has never had any plutonium stolen. As for the remaining 2% of the fuel rod--the highly radioactive transuranic elements and fission byproducts--it is all stored in a single room in Le Havre.

The real waste problem in this country is the 10 million tons of carbon dioxide we throw into the atmosphere every day from coal-fired electric boilers. That constitutes almost 15% of the world's carbon dioxide garbage, which environmentalists warn us is causing global warming. It's ironic that these same people are also opposing the only technology that could conceivably replace those coal plants.

No, it's more than ironic--it's dishonest. In "An Inconvenient Truth," Al Gore lifts the "seven-wedge" approach to global warming from Robert Socolow, director of the Carbon Mitigation Initiative at Princeton. Mr. Socolow's main "wedges" are efficiency, conservation, fuel switching, renewables, carbon sequestration, reforestation--and "nuclear fission." Mr. Gore conveniently leaves nuclear out.

Even as Yucca submerges slowly beneath a raft of environmental impact statements, alternatives are emerging. Some utilities are using "dry cask storage," simple upright concrete containers surrounded by a barbed-wire fence. "Dry storage is safe on the order of 50 to 100 years," says Allison Macfarlane, co-editor of "Uncertainty Underground," an anthology on the Yucca situation. "Geological repositories are the ultimate solution but there's no need to rush into one right now." The 221-member Goshute Tribe has signed a $1 million contract to accept nuclear material on its reservation in Utah. A group of Wyoming businessmen want to do the same thing at Owl Creek.

As half a dozen utilities prepare to submit applications for new reactors to the Nuclear Regulatory Commission, perhaps the best role for DOE's effort will be to serve as a distraction. While environmentalists continue their war dance around Yucca Mountain, a revived nuclear industry will be solving their global warming problem for them.

Source

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Many people would like to be kind to others so Leftists exploit that with their nonsense about equality. Most people want a clean, green environment so Greenies exploit that by inventing all sorts of far-fetched threats to the environment. But for both, the real motive is to promote themselves as wiser and better than everyone else, truth regardless.

Global warming has taken the place of Communism as an absurdity that "liberals" will defend to the death regardless of the evidence showing its folly. Evidence never has mattered to real Leftists

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