Posted on 02/16/2006 9:27:29 PM PST by quantim
Sea levels are rising quicker than previously thought because the amount of water Greenland's glaciers are dumping into the Atlantic Ocean has almost doubled in five years, according to research to be published today.
Scientists who carried out the first comprehensive analysis of changing speeds of the glaciers on the world's largest island were shocked to discover that many have doubled in speed within the past decade.
Warmer temperatures are "lubricating" the glaciers and have driven a 150 per cent increase in the amount of ice they are delivering to the ocean between 1996 and last year. The latitude at which this is happening is moving north.
The researchers fear that as a result current estimates that sea levels will rise by up to 90cms during the 21st century could underestimate the problem.
While there have been previous isolated reports of particular glaciers speeding up, the research presented yesterday at the American Association for the Advancement of Science conference in St Louis is the first detailed study showing the effect is widespread across Greenland.
Eric Rignot, of Nasa's Jet Propulsion Laboratory at the California Institute of Technology in Pasadena, the leading author of the study, said: "Climate change can work in different ways, but generally speaking, if you warm up the ice sheet, the glacier will flow faster.
"The southern half of Greenland is reacting to what we think is climate warming. The northern half is waiting but I don't think it is going to take long. If more glaciers accelerate farther north, especially along the west coast, the mass loss from Greenland will continue to increase well above predictions."
The Intergovernmental Panel on Climate Change has estimated that global sea levels will increase by 10-90cms over the next century. Last century they rose by 10-20cm. Previously models of the melting of the Greenland ice sheet have been based mainly on airborne laser altimetry and have suggested that while the interior is reasonably stable, the periphery was thinning, especially in areas where glaciers meet the sea.
Dr Rignot and colleagues set out to obtain accurate measurements to help to build a clearer picture of Greenland's current and future contribution to rising sea levels. They collected satellite data on the speeds of 27 glaciers and made estimates for two others.
The velocities of several large glaciers had doubled in recent years to 12km per year, making them among the fastest flowing in the world.
The scientists found that warmer air temperatures have increased the overall shrinkage of the Greenland ice sheet from 91 cubic km per year in 1996 to 138 cubic km per year in 2000 and to 224 cubic km per year in 2005.
About two-thirds of this was caused by the dumping of ice in the Atlantic by glaciers and so the ice loss attributable to glacier flow grew by 150 per cent from 60 cubic km a decade ago to 150 cubic km last year.
On this basis Dr Rignot, whose work is published in Science, concluded that Greenland's contribution to rising global sea levels increased from around 0.23mm per year in 1996 to around 0.57mm per year in 2005.
The Greenland ice sheet is 1.7 million sq km - a little smaller than Mexico - and three kilometres thick. If it melted completely sea levels would rise by seven metres
It apparently is received wisdom on this forum that global warming isn't really happening, and that it's all some grand conspiracy perpetrated by tens of thousands of researchers world wide. However, it is apparent the Earth is warming (it does so on occasion). The only thing in contention is the cause. The best evidence I've heard to date is that this is cyclical, and simply a natural phenomenon.
Tens of thousands? Climate experts?
Bad analogy. If ice is melting in the deep freezer, then it is warming in there. If not, it isn't.
Actually, a more accuarrate analogy would be if you had a cup of ice on one side of the room, and a bathtub full of ice on the other end of the room. If the cup of ice is melting, and the tub of ice is accumulating more ice, you could not accurately conclude that the room is getting warmer, and then blame it on human breathing.
This is what is going on on earth. A tiny portion of the earth's glaciers are melting, while 90% of the earth's glaciers are GROWING.
A vast majority of the ports and marinas with tide gages are in the Atlantic Basin. The shores of the Atlantic Basin are largely riding atop crust this is subsiding. (Contrast this with the lesser ported Pacific shore's overall uplift). I rest my case.
So, when we moved from a wood burning, horse and human powered world, to the one we are in now, were there any things the went away or were lessened? Do land use patterns play any role in either carbon fixing or the H20 cycle? Does the virtual explosion in technology and ubiquitousness of electrical and eletronic gear, and RF excitation of the atmosphere that has happened over the past 100 years need to be taken into account in any way? These are only a few of the questions that must be answered in order to resolve the impasse honestly.
Not just "climate experts." There are geologists, vulcanologists, folks who study glaciers, oceanographers, whatnot contributing to the study of global warming.
Politics are involved when there is focus put on the tiny portion of glaciers which may be melting, and the overwhelming mass of ice worldwide (which is growing) is ignored. The Amen Chorus of researchers then know that the key to research grants is to chant "The sky is falling!!!!".
To anyone will a clear head, Global Warming is one big Kohoutek.
Glaciologists often point out that glaciers are sensitive indicators of climate. This paradigm should not be applied to calving glaciers. During most of the calving glacier cycle, the slow advances and relatively rapid retreats are not very sensitive to climate. For example, the calving glaciers that are currently growing and advancing in the face of global warming, were retreating throughout the little ice age. Calving glaciers become sensitive to climate only late in the advancing phase, when the mass flux out of the accumulation area approaches the mass lost by melting in the ablation area and losses due to calving can no longer be replaced. No reasonable change in climate will change this imbalance and stop the advances of these few glaciers.
Please provide links that support your contention the mass of ice on Earth is increasing. I'm not arguing your point, I simply want something other than an offhand contention.
"However, it is APPARENT the Earth is warming"
Apparently, like beauty, global warming is in the eye of the beholder.
I haven't seen any incontrovertible evidence that:
1. Temperatures are rising all over the globe(in fact there have been reports that "global warming" may actually result in a new ice age)
2. That it is caused by man's activities
3. That even if it were real, the net effect would be negative
4. That we could do anything to stop it (Kyoto would reduce the temp by at most half a degree)
5. That we couldn't adapt - humans are not exactly the spotted owl.
6. That it's even remotely close to being the imminent disaster that the hysterical reports make it out to be. It just doesn't keep me up at night!
But I agree with you on one point - if it is happening, I would look for natural causes first. Isn't it interesting how little research is being done (as far as I'm aware) on this possibility. The reason in my view is because it doesn't serve the purpose of the people behind this scam.
I can't wait for your explanation about the glaciers as far south as Illinois managing to retreat completely over the past 10,000 years.
Global warming has been going on for centuries. Mankind's contribution is probably non-existent.
That temperatures are rising is incontrovertible. That man has anything to do with it is not. That man can do anything to change it is also up in the air.
"That temperatures are rising is incontrovertible."
Must be a function of what you read...
http://www.freerepublic.com/focus/f-news/1567567/posts
http://www.freerepublic.com/focus/f-news/1570241/posts
And finally, may I suggest this site to balance what you get from the MSM.
http://www.co2science.org/scripts/CO2ScienceB2C/Index.jsp
OK, so what does this have to do with CO2, campfires, plate tectonics, sunspots, rotation and wobble of Earth's axis, and water seeking its own level?
Mind if I steal that for a hit-and-run post tagline?
Sure.
No problem. It might take a day or two to track down, but they're real.
Greenland was once warm enough to sustain Viking settlements for quite some time. Then it cooled off again and they were forced out.
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