Greenland Hype Meltdown

stevengoddard says:
July 13, 2010 at 4:18 pm
R. Gates
The polar ice sheets have been losing mass since the end of the last ice age, and sea level has been increasing since the end of the last ice age.
Even if Congress had passed cap and trade 16,000 years ago, Chicago would not still be buried under a mile of ice.
Hansen claims five plus metres this century, and so far is only off by a factor of 15.
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http://climateprogress.org/2007/05/25/yet-another-must-read-by-james-hansen/
I suggest that a “scientific reticence” is inhibiting the communication of a threat of a potentially large sea level rise. Delay is dangerous because of system inertias that could create a situation with future sea level changes out of our control. I argue for calling together a panel of scientific leaders to hear evidence and issue a prompt plain-written report on current understanding of the sea level change issue.
Hansen is especially concerned that sea level rise is nonlinear:
Rahmstorf (2007) has noted that if one uses the observed sea level rise of the past century to calibrate a linear projection of future sea level, BAU warming will lead to a sea level rise of the order of one meter in the present century. This is a useful observation, as it indicates that the sea level change would be substantial even without the nonlinear collapse of an ice sheet. However, this approach cannot be taken as a realistic way of projecting the likely sea level rise under BAU forcing. The linear approximation fits the past sea level change well for the past century only because the two terms contributing significantly to sea level rise were (1) thermal expansion of ocean water and (2) melting of alpine glaciers.
Under BAU [business as usual] forcing in the 21st century, the sea level rise surely will be dominated by a third term: (3) ice sheet disintegration. This third term was small until the past few years, but it is has at least doubled in the past decade and is now close to 1 mm/year, based on the gravity satellite measurements discussed above. As a quantitative example, let us say that the ice sheet contribution is 1 cm for the decade 2005–15 and that it doubles each decade until the West Antarctic ice sheet is largely depleted. That time constant yields a sea level rise of the order of 5 m this century. Of course I cannot prove that my choice of a ten-year doubling time for nonlinear response is accurate, but I am confident that it provides a far better estimate than a linear response for the ice sheet component of sea level rise under BAU forcing.
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I am not going to take you at your word that you believe Hansen officially claims 5 meters. Hansen in his papers has projections of 5 to 6 feet.
WHat you may be referring to is if the melting of earth’s ice is nonlinear. It’s just showing a thought possibility if ice melt doubled every decade

stevengoddard says:
July 13, 2010 at 7:19 pm
Chris Noble
Nonsense.
The lack of upwards change in slope is all that is need to prove my point.
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You have set your standard of what your win is. You have claimed that the melting ice is this flow of disinformation. You have not proven that. If anything you have been the
disinformation. As long as there is an upward trend in co2 there will be an upward trend in ice melt.

Jeff Green: I have read enough papers and blogs that to create a list for you would take far more time than I care to invest. This is what I have learned:
1. There is very little (both in time and geography) hard (non-proxy) data available on the global climate that comes from measurement sources with high degrees of accuracy and precision.
2. There are many “corrections” applied to the data that are not well documented enough such that they can be independently reproduced and confirmed by others.
3. Many of the measurement stations are clearly poorly sited (e.g. at airports surrounded by asphalt, etc.), and the corrections applied seem to make no sense.
4. There is a lot of “selective use” of measuring stations, both for temperature and, for example, for sea level measurements.
5. There is an awful lot of inappropriate and/or lack of use of statistics. For example, the random drawing of “trend lines” between arbitrarily selected endpoints. But also, use of the wrong types of tests for significance, correlation, error estimation, etc.
6. Regardless of the quality of the data, the time frame, even if the data were “perfect”, is not nearly long enough for any reasonable conclusions to be drawn.
7. The major source of “proof” of a link between CO2 and climate is computer models that have been calibrated with a combination of hard and soft (proxy) data. As a former computer modeler myself, I am well aware of how difficult it is to build an accurate model of a complex system, even when one can run experiments to help build/confirm the model. In the absence of being able to run experiments, it is foolish, at best, to have a high level of confidence in these models until they can predict the climate accurately for years.
8. The behavior of those on the pro-AGW side of the argument do not behave like scientists. They behave, instead, like a clique. They do not put their data, their methods, etc. in the open so that others can reproduce them.
I could go on, but you get the point. I’m an engineer, (PhD in Chemical Engineering). I know good science when I see it. The good science I see is on the skeptical side of the fence.
A final note: there is a terrific, recent post on this site of a speech Michael Crichton gave at Caltech detailing the history of major scientific debates. If you haven’t read it, I urge you to read it. The best quote is this:
“Finally, I would remind you to notice where the claim of consensus is invoked. Consensus is invoked only in situations where the science is not solid enough.
Nobody says the consensus of scientists agrees that E=mc2. Nobody says the consensus is that the sun is 93 million miles away. It would never occur to anyone to speak that way.”
Why is it that the pro-AGW crowd continues to crow about consensus? History, as Mr. Crichton reminded us, tells us that consensus is what people cry when the science isn’t on their side.
Peace.

http://pubs.giss.nasa.gov/docs/2007/2007_Hansen_2.pdf
Runaway collapse
The current rate of sea level change is not
without consequences. However, the primary
issue is whether global warming will reach a
level such that ice sheets begin to disintegrate
in a rapid, non-linear fashion on West
Antarctica, Greenland or both. Once well
under way, such a collapse might be impossible
to stop, because there are multiple positive
feedbacks. In that event, a sea level rise of
several metres at least would be expected.
As an example, let us say that ice sheet
melting adds 1 centimetre to sea level for
the decade 2005 to 2015, and that this doubles
each decade until the West Antarctic ice sheet
is largely depleted. This would yield a rise
in sea level of more than 5 metres by 2095.
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You are either dishonest because you really know what Hansen is talking about or you haven’t really done your homework. I will assume the latter. This is an example of 1cm per year doubling every ten years. He is talking about the disintegration of the West Antartic Ice Sheet. Your objectivity is a little skewed here.

(Snip. Sockpuppet. -mod)

The lack of upwards change in slope is all that is need to prove my point.

Nonsense! The largest contribution to sea level rise is the thermal expansion of water. You need to come back with some actual numbers to prove your point.
Your refusal to do so just makes you look silly.

Robert Lund
Given that Godthab temperatures are more than 1C cooler now than the were in the 1930s and 1940s, we must be on a very, very steep long term warming trend.
And I have never been more confident in World Cup referees.

“The Greenland ice sheet is all but doomed to melt away to nothing, according to a new modelling study.”
Uh huh… well that settles it then, the *cough* science *cough* is now set in concrete.
(palm, forehead)

Sea level has increased by about 300 feet in the last 20,000 years. According to your theory, the oceans must be about 400F to produce such a large rise.

I really have trouble deciding whether you are being deliberately obtuse or whether you just don’t get it.
Currently the largest contribution to sea level change is the thermal expansion of water. If the mass loss from Greenland and Antarctica continues to accelerate then very soon this will be the dominant factor.
You presumably know this but for some reason want to play silly games.

Chris Noble
Glad that you agree with me that melt from Greenland and Antarctica has been negligible. So what are you arguing about?

Interesting paper from 2008, which indicates that the Greenland ice sheet is more resilient to the effects or warming that previously thought, and that mechanisms exist to slow the movement of the sheet towards the sea.
“Recent studies have shown these natural drainpipes, called moulins, can speed up the slow seaward march of the grinding ice by lubricating the interface with bedrock below. The faster that ice flows, the faster seas rise. A Dutch study of 17 years of satellite measurements of ice movement in western Greenland concludes that the speed-up of the ice is a transient summertime phenomenon, with the overall yearly movement of the grinding glaciers not changing, and actually dropping slightly in some places, when measured over longer time spans. ”
Abstract:
Large and Rapid Melt-Induced Velocity Changes in the Ablation Zone of the Greenland Ice Sheet
R. S. W. van de Wal,* W. Boot, M. R. van den Broeke, C. J. P. P. Smeets, C. H. Reijmer, J. J. A. Donker, J. Oerlemans
Institute for Marine and Atmospheric research Utrecht, Utrecht University, Netherlands.
Continuous Global Positioning System observations reveal rapid and large ice velocity fluctuations in the western ablation zone of the Greenland Ice Sheet. Within days, ice velocity reacts to increased meltwater production and increases by a factor of 4. Such a response is much stronger and much faster than previously reported. Over a longer period of 17 years, annual ice velocities have decreased slightly, which suggests that the englacial hydraulic system adjusts constantly to the variable meltwater input, which results in a more or less constant ice flux over the years. The positive-feedback mechanism between melt rate and ice velocity appears to be a seasonal process that may have only a limited effect on the response of the ice sheet to climate warming over the next decades.
Full paper behind a pay wall – link here:
http://www.sciencemag.org/cgi/content/abstract/sci;321/5885/111?maxtoshow=&hits=10&RESULTFORMAT=&fulltext=Roderik+S.+W.+van+de+Wal&searchid=1&FIRSTINDEX=0&resourcetype=HWCIT
Reality is never as simple as the CAGW brigade and their adherents would have us believe.

kuhnkat says:
July 13, 2010 at 8:31 pm
Jeff Green,
” As long as there is an upward trend in co2 there will be an upward trend in ice melt.”
You funny big guy. Did Tamino tell you that, or was it James Hansen, or Nick Stokes or those excellent Modellers??
To show you how dumb that statement is, if there were an upward trend of 1ppm per 10000 years, exactly how much melting could you attribute to that??
Then there is the issue that there is NO melting that has been conclusively attributed to the Current CO2 trend. You really need to read the caveats in all those most excellent Climate papers!!
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CO2 is a greenhouse gas. There’s no getting around it. Global warming theory is coming true. Night time minimum temperatures are rising. The number of record highs are now double the number of record lows. About 30 40 years ago it was about even. It goes on and on and on.