GLACIAL SPEED: Greenland may get much of the scientific
attention but it is smaller glaciers such as the Columbia Glacier
in Alaska pictured here that are already contributing to sea level
rise--and will continue to do so in future.
Posted on 09/28/2008 6:44:06 AM PDT by yankeedame
News - September 5, 2008
Some say high, some say low, some say fast, some say slow
By David Biello
GLACIAL SPEED: Greenland may get much of the scientific
attention but it is smaller glaciers such as the Columbia Glacier
in Alaska pictured here that are already contributing to sea level
rise--and will continue to do so in future.
Greenland, the world's largest island, holds enough ice to raise global sea levels by 23 feet (seven meters). Add the ice sheets of Antarctica and the oceans would deepen more than 200 feet (60 meters). Satellite measurements from space and speed measurements on land confirm that Greenland's glaciers are melting and on the move. And although the picture is less clear in Antarctica, the global warming seems to be having an impact there, too.
So the question is: How much—and how soon—will sea level rise?
New research from glaciologist Tad Pfeffer of the University of Colorado at Boulder and colleagues published in Science attempts to better estimate the possible sea level rise over the next century by measuring the speed at which the world's glaciers—in Greenland and Antarctica but also the many mountain ice sheets throughout the globe—are actually speeding to the sea as well as how swiftly they may melt.
"What would the flow velocities of the ocean-ending outlet glaciers have to be," if Greenland alone was to raise sea level by just six feet (two meters)? "The answer turned out to be huge: about 49 kilometers [30 miles] per year, 70 times faster than those glaciers move today," Pfeffer says, "and three times faster than we've ever observed an outlet glacier to move."
Given that Greenland's glaciers are not presently moving anywhere close to that pace—Kangerdlugssuaq Glacier, the fastest, reached speeds above nine miles (14 kilometers) per year in 2005—the researchers also looked at ice that could contribute from the rest of the world. Assuming that the largest remaining ice shelves in East Antarctica—Filchner-Ronne and Ross—will remain intact, sea level rise from all other melting ice and the expansion of seawater as the weather gets warmer over the next century would be somewhere between 2.6 feet (0.8 meter) and six feet (two meters)—or nearly twice as much as projected last year by the U.N. Intergovernmental Panel on Climate Change (IPCC).
This does not take into account how much sea level might swell from the metldown of the numerous small glaciers in Alaska, Argentina, Canada and Russia, which already contribute 60 percent of sea level rise from glacial melt. (In fact, Pfeffer notes that they are melting faster and therefore adding to sea levels more rapidly than Greenland and Antarctica combined currently do.) Nor is it clear whether something might suddenly occur to change that upper estimate. "If those two big ice shelves [in Antarctica] go out, then it's an entirely different situation," Pfeffer says. "But there's no good evidence that that's going to happen over the next century."
Ancient melting events suggest that glaciers can disappear in a hurry, however, and raise sea levels by more than half an inch a year.
The Laurentide ice sheet that stretched as far south as New York State and Ohio some 20,000 years ago had retreated to eastern Canada, just across the water from Greenland, by roughly 11,000 years ago thanks to increased sunlight (due to the periodic wobble in Earth's axis known as precession). It then completely disappeared by 6,800 years ago in two geologically rapid bursts, shedding enough ice to raise sea levels by as much as four feet (1.3 meters) per century, according to research published this week in Nature Geoscience.
"The inspiration came from the IPCC report stating that we don't know how fast ice sheets will retreat and raise sea level in the future," says Anders Carlson, a paleoclimatologist at the University of Wisconsin–Madison and lead author of that study. "Well, we do have past records of ice sheet retreat under climates warmer than present so we decided to determine what those rates of retreat were."
At the same time, Greenland's glaciers were also smaller, though they persisted because of snowfall generated from the ocean. "More snow can partially offset the greater melting, helping the Greenland Ice Sheet to survive this interval," Carlson says. "But note it did retreat and this is what we are predicting for the future."
Based on this historical record and the fact that the Laurentide melted away under summertime temperatures similar to those expected in Greenland by the end of this century, Carlson and his colleagues forecast glacial melting that contributes somewhere between 2.8 inches (seven centimeters) and 5.1 inches (13 centimeters) of sea level rise per year, or as much as a 4.3-foot (1.3-meter) increase by 2100. Current rates are just 0.1 inch (3 millimeter) per year—and Greenland is contributing roughly 0.02 inches (0.4 millimeters) of that rise annually.
Pfeffer notes that the Laurentide and other ice sheets that disappeared in the past had an easier path to the sea than the glaciers in Greenland or Antarctica. "The analogies between those past climates and today aren't strong enough to say anything specific about the rate of sea level rise in the next century," he says.
The bottom line: sea levels will rise much more than predicted by the IPCC, based on both present understanding of current glacial melt as well as evidence from the geologic record. "The IPCC noted that their estimates should be seen as minimum estimates," Carlson notes, "and they are right."
ahhhhhhhhhhhhhhhhh. None.
ABSTRACT:
"Carbon dioxide in the atmosphere is the product of oceanic respiration due to the well-known but under-appreciated solubility pump. Carbon dioxide rises out of warm ocean waters where it is added to the atmosphere. There it is mixed with residual and accidental CO2, and circulated, to be absorbed into the sink of the cold ocean waters. Next the thermohaline circulation carries the CO2-rich sea water deep into the ocean. A millennium later it appears at the surface in warm waters, saturated by lower pressure and higher temperature, to be exhausted back into the atmosphere. Throughout the past 420 millennia, comprising four interglacial periods, the Vostok record of atmospheric carbon dioxide concentration is imprinted with, and fully characterized by, the physics of the solubility of CO2 in water, along with the lag in the deep ocean circulation.
Notwithstanding that carbon dioxide is a greenhouse gas, atmospheric carbon dioxide has neither caused nor amplified global temperature increases. Increased carbon dioxide has been an effect of global warming, not a cause. Technically, carbon dioxide is a lagging proxy for ocean temperatures. When global temperature, and along with it, ocean temperature rises, the physics of solubility causes atmospheric CO2 to increase.
If increases in carbon dioxide, or any other greenhouse gas, could have in turn raised global temperatures, the positive feedback would have been catastrophic. While the conditions for such a catastrophe were present in the Vostok record from natural causes, the runaway event did not occur. Carbon dioxide does not accumulate in the atmosphere."
http://www.rocketscientistsjournal.com/2006/10/co2_acquittal.html
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The graph above represents temperature and CO2 levels over the past 400,000 years. It is the same exact data Al Gore and the rest of the man-made global warmers refer to. The blue line is temps, the red CO2 levels. The deep valleys represent 4 separate glaciation periods. Now look very carefully at the relationship between temps and CO2 levels (the present is on the right hand side of the graph) and keep in mind that Gore claims this data is the 'proof' that CO2 has warmed the earth in the past. But does the data indeed show this? Nope. In fact, rising CO2 levels all throughout this 400,000-year period actually lagged behind temperature increases ...by an average of 800 years! So it couldn't have been CO2 that got Earth out of these past glaciations. Yet Gore dishonestly and continually claims otherwise. Furthermore, the subsequent CO2 level increases due to dissolved CO2 being released from warming oceans, never did lead to additional warming, the so-called "run-away greenhouse effect" that Al Gore and his friends keep warning us about. In short, there is little if any evidence that CO2 had once led to increased warming during the past 400,000 years. -ETL
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"The above chart shows the range of global temperature through the last 500 million years. There is no statistical correlation between the level of carbon dioxide in the atmosphere through the last 500 million years and the temperature record in this interval. In fact, one of the highest levels of carbon dioxide concentration occurred during a major ice age that occurred about 450 million years ago [Myr]. Carbon dioxide concentrations at that time were about 15 times higher than at present." [also see 180 million years ago, same thing happened]:
http://www.tcsdaily.com/article.aspx?id=010405M
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So, greenhouse [effect] is all about carbon dioxide, right?
Wrong. The most important players on the greenhouse stage are water vapor and clouds. Carbon dioxide has been increased to about 0.038% of the atmosphere (possibly from about 0.028% pre-Industrial Revolution) while water in its various forms ranges from 0% to 4% of the atmosphere and its properties vary by what form it is in and even at what altitude it is found in the atmosphere.
In simple terms the bulk of Earth's greenhouse effect is due to water vapor by virtue of its abundance. Water accounts for about 90% of the Earth's greenhouse effect -- perhaps 70% is due to water vapor and about 20% due to clouds (mostly water droplets), some estimates put water as high as 95% of Earth's total tropospheric greenhouse effect (e.g., Freidenreich and Ramaswamy, 'Solar Radiation Absorption by Carbon Dioxide, Overlap with Water, and a Parameterization for General Circulation Models,' Journal of Geophysical Research 98 (1993):7255-7264).
The remaining portion comes from carbon dioxide, nitrous oxide, methane, ozone and miscellaneous other 'minor greenhouse gases.' As an example of the relative importance of water it should be noted that changes in the relative humidity on the order of 1.3-4% are equivalent to the effect of doubling CO2.
http://www.junkscience.com/Greenhouse/
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Water Vapor Rules the Greenhouse System
Water vapor constitutes Earth's most significant greenhouse gas, accounting for about 95% of Earth's greenhouse effect (4). Interestingly, many 'facts and figures' regarding global warming completely ignore the powerful effects of water vapor in the greenhouse system, carelessly (perhaps, deliberately) overstating human impacts as much as 20-fold.
Water vapor is 99.999% of natural origin. Other atmospheric greenhouse gases, carbon dioxide (CO2), methane (CH4), nitrous oxide (N2O), and miscellaneous other gases (CFC's, etc.), are also mostly of natural origin (except for the latter, which is mostly anthropogenic).
Human activities contribute slightly to greenhouse gas concentrations through farming, manufacturing, power generation, and transportation. However, these emissions are so dwarfed in comparison to emissions from natural sources we can do nothing about, that even the most costly efforts to limit human emissions would have a very small-- perhaps undetectable-- effect on global climate.
From BBC News [yr: 2004]:
"A new [2004] analysis shows that the Sun is more active now than it has been at anytime in the previous 1,000 years. Scientists based at the Institute for Astronomy in Zurich used ice cores from Greenland to construct a picture of our star's activity in the past. They say that over the last century the number of sunspots rose at the same time that the Earth's climate became steadily warmer."..."In particular, it has been noted that between about 1645 and 1715, few sunspots were seen on the Sun's surface. This period is called the Maunder Minimum after the English astronomer who studied it. It coincided with a spell of prolonged cold weather often referred to as the "Little Ice Age". Solar scientists strongly suspect there is a link between the two events - but the exact mechanism remains elusive."
http://news.bbc.co.uk/1/hi/sci/tech/3869753.stm
It's really hard to imagine how this little ball of fire could have any impact on our climate at all.
But the main arguments being made for a solar-climate connection is not so much to do with the heat of the Sun but rather with its magnetic cycles. When the Sun is more magnetically active (typically around the peak of the 11 year sunspot cycle --we are a few yrs away at the moment), the Sun's magnetic field is better able to deflect away incoming galactic cosmic rays (highly energetic charged particles coming from outside the solar system). The GCRs are thought to help in the formation of low-level cumulus clouds -the type of clouds that BLOCK sunlight and help cool the Earth. So when the Sun's MF is acting up (not like now -the next sunspot max is expected in about 2012), less GCRs reach the Earth's atmosphere, less low level sunlight-blocking clouds form, and more sunlight gets through to warm the Earth's surface...naturally. Clouds are basically made up of tiny water droplets. When minute particles in the atmosphere become ionized by incoming GCRs they become very 'attractive' to water molecules, in a purely chemical sense of the word. The process by which the Sun's increased magnetic field would deflect incoming cosmic rays is very similar to the way magnetic fields steer electrons in a cathode ray tube or electrons and other charged particles around the ring of a subatomic particle accelerator.-ETL
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There's a relatively new book out on the subject titled The Chilling Stars. It's written by one of the top scientists advancing the theory (Henrik Svensmark).
And here is the website for the place where he does his research:
2008: "The Center for Sun-Climate Research at the DNSC investigates the connection between variations in the intensity of cosmic rays and climatic changes on Earth. This field of research has been given the name 'cosmoclimatology'"..."Cosmic ray intensities – and therefore cloudiness – keep changing because the Sun's magnetic field varies in its ability to repel cosmic rays coming from the Galaxy, before they can reach the Earth." :
http://www.spacecenter.dk/research/sun-climate
100,000-Year Climate Pattern Linked To Sun's Magnetic Cycles:
ScienceDaily (Jun. 7, 2002) HANOVER, N.H.
Thanks to new calculations by a Dartmouth geochemist, scientists are now looking at the earth's climate history in a new light. Mukul Sharma, Assistant Professor of Earth Sciences at Dartmouth, examined existing sets of geophysical data and noticed something remarkable: the sun's magnetic activity is varying in 100,000-year cycles, a much longer time span than previously thought, and this solar activity, in turn, may likely cause the 100,000-year climate cycles on earth. This research helps scientists understand past climate trends and prepare for future ones.
http://www.sciencedaily.com/releases/2002/06/020607073439.htm
From a well-referenced wikipedia.com column (see wiki link for ref 14):
"Sunspot numbers over the past 11,400 years have been reconstructed using dendrochronologically dated radiocarbon concentrations. The level of solar activity during the past 70 years is exceptional — the last period of similar magnitude occurred over 8,000 years ago. The Sun was at a similarly high level of magnetic activity for only ~10% of the past 11,400 years, and almost all of the earlier high-activity periods were shorter than the present episode.[14]"
[14] ^Solanki, Sami K.; Usoskin, Ilya G.; Kromer, Bernd; Schüssler, Manfred & Beer, Jürg (2004), “Unusual activity of the Sun during recent decades compared to the previous 11,000 years”, Nature 431: 1084–1087, doi:10.1038/nature02995, . Retrieved on 17 April 2007 , "11,000 Year Sunspot Number Reconstruction". Global Change Master Directory. Retrieved on 2005-03-11.
"Reconstruction of solar activity over 11,400 years. Period of equally high activity over 8,000 years ago marked.
Present period is on [the right]. Values since 1900 not shown."
http://en.wikipedia.org/wiki/Solar_variation
Depends if they are over land are water?? But the Arctic cap is is getting bigger I think..
The wild rice crop in N. Minnesota failed this year. Too cold.
“The Laurentide ice sheet that stretched as far south as New York State and Ohio some 20,000 years ago had retreated to eastern Canada, just across the water from Greenland, by roughly 11,000 years ago thanks to increased sunlight (due to the periodic wobble in Earth’s axis known as precession).”
False. Everybody knows that global warming is Man’s Fault.
“Water Vapor rules” is important to understand. More of a glacier evaporates into the atmosphere than melts and runs down into the sea.
The rate at which both solid and liquid water evaporate into the atmosphere is controled by the amount of water already in the atmosphere and the remaining capacity for more water in the atmosphere. if the temperature rises, the air has the capacity to hold more vapor. Thus, if a glacier is disappearing due to rising temperature a large portion of that water goes into the atmosphere and not running down into the ocean.
Of course, the increased water in the atmosphere means more precipitation (rain and snow) on both land and sea. It means more cloud cover during both the day and night.
I was watching an old movie last night, a lot of the shots were along the cliffs on the California coastline. I was shocked at what I was seeing gelogically, which I guarantee were ancient shorlines and water levels etched in the cliff face (you see the same sorts of things here in Nevada along dried up ancient lake beds).
The point is, I don’t think what we are seeing is abnormal at all, if we are indeed seeing any global warming.
How much water in a glass rises when the ice melts? Zero.
Unfortunately, none of this science will have ANY effect on them whatsoever.
Their attitude and belief system isn’t based on relevant facts. Therefore, all the REAL SCIENCE in the world won’t matter.
Their life is based on nothing more than “anti-human” emotion.
Their reasoning ability is no more advanced than a average teenage girl.
Excellent links. Thanks.
ML/NJ
"I believe this idea has a strong connection with reality. I don't think we have much time. Fidel Castro said in one of his speeches I read not so long ago, 'tomorrow could be too late, let's do now what we need to do'."
"I believe it is time that we take up with courage and clarity a political, social, collective and ideological offensive across the world — a real offensive that permits us to move progressively, over the next years, the next decades, leaving behind the perverse, destructive, destroyer, capitalist model and go forward in constructing the socialist model to avoid barbarism and beyond that the annihilation of life on this planet."
--Hugo Chavez, at the 16th World Festival of Youth and Students, held in Caracas on August 8-15, 2005
http://www.greenleft.org.au/back/2005/640/640p16.htm
“How much water in a glass rises when the ice melts? Zero.”
The concern is about ice on land, such as Antarctica or Greenland, which WOULD raise sea levels if it melted.
March 5, 2004: Global warming could plunge North America and Western Europe into a deep freeze, possibly within only a few decades.
That's the paradoxical scenario gaining credibility among many climate scientists. The thawing of sea ice covering the Arctic could disturb or even halt large currents in the Atlantic Ocean. Without the vast heat that these ocean currents deliver--comparable to the power generation of a million nuclear power plants--Europe's average temperature would likely drop 5 to 10°C (9 to 18°F), and parts of eastern North America would be chilled somewhat less. Such a dip in temperature would be similar to global average temperatures toward the end of the last ice age roughly 20,000 years ago. ..."
http://science.nasa.gov/headlines/y2004/05mar_arctic.htm?list1101254
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