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  1. Indeed. I started to read the article with the usual trepidation afforded to “newspaper science”. I was very happily surprised by the quality and depth. I became convinced some time ago that we have already passed the point of ruin – but I keep hoping I’m wrong and that we still have time to change course. Hopefully, more stuff like this will get folks motivated to talk reasonably with their neighbors and get a sufficient majority moving in the right direction.

    Comment by Robin D Johnson — 15 Nov 2010 @ 5:27 PM

  2. Thanks for calling my attention to that interesting piece which I would have otherwise missed. The article focused on the threat to the US that a 3′ rise in sea level would bring. What would such a rise mean for China? It seems likely it would displace at least 100 million Chinese? ?

    Comment by John E. Pearson — 15 Nov 2010 @ 5:32 PM

  3. I read this yesterday after someone forwarded it to me…I was quite pleased and surprised. This sets a useful standard for quality scientific journalism

    Comment by Chris Colose — 15 Nov 2010 @ 6:11 PM

  4. Very much all about what I have been reading lately, but I am disappointed they did not mention Galveston’s aging seawall and the damages inflicted on the city by Hurricane Ike.

    Waves visiting the memorial, located on top of the 1904 (plus later additions) seawall, to victims of the 1900 flood:

    http://viviangrant.files.wordpress.com/2008/09/chron1.jpg

    Comment by JCH — 15 Nov 2010 @ 6:25 PM

  5. Your statement that most experts expect a meter sea level rise is not supported in the article. While Gillis says that many think this could happen, he admits that our understanding of glacier dynamics is too primative to make sound predictions. Gillis also included those, Christi, who contend that the changes in Greenland may not be any different than those observed in the early 20th century. While a very nice scientific article for the NY Times and the general public, it did not provide any new data or research.

    [Response: Perhaps you would care to tell us what 'new data or research' that Christy has brought to this issue? His contentions, in the light of plenty of evidence to the contrary, do not hold much weight. Check out the retreat of the Jakobshavn glacier for instance. It has retreated tremendously past any points from the 1930s. - gavin]

    Comment by Dan H. — 15 Nov 2010 @ 6:47 PM

  6. While sea level rise is important, it may be food crop destruction that will blindside us.

    Regarding crop destruction by heat, we don’t need much science to see what is happening before our eyes. Russia’s loss of 25% of their wheat crop this year is but one example. Africa has been suffering crop loss from drought and heat for decades. The 2003 heat wave in Europe, while not billed as crop destruction event, did kill 33,000 humans.

    Sea level rise may get more attention because it is something we can calculate with some precision. Crop loss due to extended heat episodes is less subject to prediction.

    But having food shortages, especially increasingly severe ones, could be the event that finally shuts down the Deniers for good and gets humanity focused on what many who have studied global warming have trying to tell us. This is deadly serious.

    Comment by William P — 15 Nov 2010 @ 7:26 PM

  7. Can someone explain to me why it is a virtue that the NYT focuses on the three foot estimate of rise when their graph shows it to be way at the bottom of the range?

    [Response: Because the NYT (and many other papers and commenters) have downplayed 3 - foot rise as a position held only by Stefan! The fact is that his projections are now mainstream, even among those who think that only the 'low end' scenarios are likely (I happen to be one of those, but the 'low end' is now pretty high).--eric]

    Comment by John Atkeison — 15 Nov 2010 @ 7:39 PM

  8. Gavin’s response to 5 was WAY too kind. Post 5 is idiotic in the extreme. The poster complained that there wasn’t new data or research in a newspaper article!!! To the best of my knowledge Christy has no particular expertise in glaciology.

    Comment by John E. Pearson — 15 Nov 2010 @ 7:49 PM

  9. “Can someone explain to me why it is a virtue that the NYT focuses on the three foot estimate of rise when their graph shows it to be way at the bottom of the range? …”

    I think what I read on a scientist’s website is 1.14 meters is most likely: 3′ 9″, which may be what the graphic used.

    Others may have a different opinion.

    Comment by JCH — 15 Nov 2010 @ 8:06 PM

  10. This was an excellent article.

    People like Dan H might prefer to go with Christie because Christie attempts to insert doubt. Going by the remainder of the article, my guess is Gillis was pressured to provide ‘balance’. Not finding an oceanographer or glaciologist to dispute the fact that sea levels will most likely rise a lot (perhaps even if we act more quickly to curb emissions), he had to go to the sole person who reliably sows doubt and is perfectly willing to comment on matters outside his experience and knowledge.

    I really like how Gillis describes the difficulty of and risks entailed in researching changes in the earth’s ice. I suspect some people think scientific research is easy and that it’s all in a book at the library!

    Another major point is that the USA is no longer able to get the necessary funding (or prioritise it) for satellites. With the US economy likely to continue to wane, it is definitely time there was an international effort to fund and send up satellites. This issue affects the whole world. The whole world has to learn to work together on this and stop relying on the USA to do all the biggest jobs. We need joint efforts by the USA, Asia-Pacific and Europe and any other nation who wants to be in on it. Maybe helped along by large corporations and private wealth-holders. This is the whole earth we are talking about.

    (My only very minor gripe is the use of archaic measures only used in the USA. Because NY Times is read by people all around the world, it would be an idea to use international measures, or at the very least, specify that he is using the Fahrenheit scale when referring to temperature.)

    Comment by Sou — 15 Nov 2010 @ 8:11 PM

  11. Now maybe TNYT will do a similar article on a much more (potentially) serious problem:
    \This is very alarming because if the drying is anything resembling Figure 11, a very large population will be severely affected in the coming decades over the whole United States, southern Europe, Southeast Asia, Brazil, Chile, Australia, and most of Africa.\
    http://onlinelibrary.wiley.com/doi/10.1002/wcc.81/full

    No rain, no food.

    Comment by David B. Benson — 15 Nov 2010 @ 8:30 PM

  12. The poster in #5 actually misses the entire point of the analysis: even taking his statement that we don’t completely understand glacial dynamics at face value, the point is that all the data we actually have indicates a very steep rise in sea level. That’s the data we have, we have nothing to the contrary and we must act upon the data we have.

    Yes, the expected sea level rise _might_ be wrong, glaciers _could_ suddenly stop retreating and the temperature rise _could_ suddenly stop. Those are all within the limits of the possible, but there is absolutely no reason whatsoever for anyone to think that any of that _will_ occur. We live in a universe governed by probability. We have to act on what the evidence indicates is the most likely set of events to occur, not wait until we have absolute metaphysical certainty, a certainty that by the way we will never achieve.

    Analogy: You are in the mall shopping when a man comes in holding a semi-automatic pistol and he starts shooting people, seemingly at random. He shoots and shoot and shoots as bodies fall all around him until he gets right up in front of you. He points the gun right at your face. At that moment, the gun _might_ be empty, he _might_ decide not to shoot you after all, an unseen police sniper _might_ take him out for you, but it would be suicide to _expect_ that any of that is going to occur, and you better damn well take some action or your probably going to die.

    Comment by Kent Hundley — 15 Nov 2010 @ 8:38 PM

  13. Re: #2
    You might get some idea of what such a sea level rise means for China from these maps provided by the Univ. of Arizona. The higher resolution maps are for the US and its territories but all are worth a look.

    http://www.geo.arizona.edu/dgesl/research/other/climate_change_and_sea_level/sea_level_rise/sea_level_rise.htm

    Comment by BillS — 15 Nov 2010 @ 8:44 PM

  14. I occasionally post here.I’m an amateur who follows most all global warming news since 1987, in depth.Also graduate from Harvard, 1982, and Boston College Law School. 1987. Good article.My e mail is markfiore50@hotmail.com.I firmly believe that Hansen is correct.Also, see the work of Peter Ward.1000 ppm co2 is probable by year 2100 -2150, or sooner.The sea level rise, with business as usual, is locked in at 100 feet minimum.End of story.

    [Response: Yes, but not on a timescale most of us, even the most forward thinking ones, worry about very much.--eric]

    Comment by Mark J. Fiore — 15 Nov 2010 @ 8:49 PM

  15. It is wise to revise rates of sea level rise. The NYT article lead me to a recent video lecture by Dr. Jerry X. Mitrovica – provided some background, archeology, data measurement that grounded the issue well.
    http://www.youtube.com/watch?v=GdfTUdU9x-k
    And now note the added complexity of predicting regionally.

    Comment by richard pauli — 15 Nov 2010 @ 9:09 PM

  16. all this just confirms what i have been saying here for two years, we will need polar cities for survivors of AGW climate chaos in the future, my timeline is 2500 AD, but others say sooner: agree now? o ye who earlier tried to ban me from posting here?

    http://pcillu101.bloogspot.com

    Comment by dan bloom — 15 Nov 2010 @ 9:39 PM

  17. BillS @13, thanks for the link to the UofA map page. I just looked at the extent of inundation at 1 meter and 2 meter of rise for Bangladesh and the Mekong delta. Also check the coast of Sumatra and Irian Jaya.

    Comment by Jim Eager — 15 Nov 2010 @ 9:54 PM

  18. When I look at http://en.m.wikipedia.org/wiki/File:Post-Glacial_Sea_Level.png, it appears to me that +/- 1 or 2 meters in sea level is within the baseline noise for the past several thousand years. I’ve never understood why recent (i.e. the last 100 years) sea level rise is viewed as significant in light of this.

    Sea level seems pretty flat for the last 6000 years, but there is a fair amount of noise in the graph. What amount of rise/fall would be considered insignificant due to noise?

    Comment by Rob Huber — 15 Nov 2010 @ 10:09 PM

  19. Here is a much more accessible sea level change mapping system to use. Just avoid the stupid ads.

    http://flood.firetree.net/

    Comment by SWDoughty — 15 Nov 2010 @ 10:15 PM

  20. Rob Huber @18 — Not much infrastructure close to sea level until rather recently, what?

    Comment by David B. Benson — 15 Nov 2010 @ 10:27 PM

  21. correction: overactive keyboard re polar cities:

    http://pcillu101.blogspot.com

    that is why they call me “James Lovelock’s Accidental Student

    Comment by dan bloom — 15 Nov 2010 @ 10:35 PM

  22. I’m going to defend Dan H. a bit. When the IPCC report came out there was a lot of discussion here about nonlinear melting. Then there was an article about Rahmstorf 2007, and there was some grumbling about how low that prediction was. The emphasis was that prediction was based upon a linear relationship between the temperature of the atmosphere and melting that replicated past sea level, and was used to make the prediction. The impression I got at the time was nonlinear melting was still unpredictable and unquantifiable and was not used in making the prediction, but some commenters still talked as though they expected a great deal of it; as in, in addition.

    Later Mauri Pelto wrote an article about Greenland ice, and he explained a great deal about how well Greenland can defend its ice inventory, which threw some cold water on expectations of excessively rampant nonlinear melting.

    In 2009 the Rahmstorf estimate was raised, but I think they still referred to their approach as remaining linear.

    So in the article, there appear to be a lot of scientists who are looking at nonlinear melting up close and personal, at least in part, and thinking 3 feet.

    So I know I missing something, because i’m uncertain whether or not we’re talking the exact same 3 feet.

    Comment by JCH — 15 Nov 2010 @ 10:38 PM

  23. What I don;t understand is, if sea level rise is predicetd to be accelerating, why has the rate of rise been reducing over the last 10 years ?

    http://sealevel.colorado.edu/current/sl_noib_global.jpg

    [Response: Those are very short term statistics you are looking at. It can not be shown to be significant or relevant to the long term picture with such a short record.--eric]

    [Response: Just adding to that: the entire satellite record (starting 1993) is just one data point in the analysis of our paper. Variability on time scales shorter than 15 years or so is in my perspective not linked to global climate change but likely just "noise" - the result of various internal variability mechanisms. Let's wait another 15 years for the next data point, then we may see something. -stefan]

    Comment by ImranCan — 15 Nov 2010 @ 10:51 PM

  24. Sou: perhaps you have heard of Envisat, ERS-1&2, Cryosat-2, GOCE, SMOS, GOSAT, ADM-Aeolus and EarthCARE?

    Comment by Didactylos — 15 Nov 2010 @ 10:56 PM

  25. I’m writing an introductory survey on sea level rise and was getting disappointed that it seems to get so little serious attention in mainstream media. Was therefore most happy to see the NYT story!

    Comment by Hunt Janin — 16 Nov 2010 @ 12:35 AM

  26. My comment:

    http://community.nytimes.com/comments/dotearth.blogs.nytimes.com/2010/11/15/lessons-gleaned-from-greenlands-ice/?permid=11#comment11

    My only qualms were a few statements overplaying measurement uncertainty, but overall, a very well-researched thorough science-based article from the mainstream press – a rarity these days.

    Comment by MarkB — 16 Nov 2010 @ 12:54 AM

  27. the article mentions icequakes. do these have a different frequency spectrum from groundquakes? ifso can we look at the last century of seismic records in addition to the last two decades ?

    Comment by sidd — 16 Nov 2010 @ 1:02 AM

  28. > icequakes
    http://scholar.google.com/scholar?q=icequake+distinguished+from+earthquake
    finds among much else, this:
    http://dx.doi.org/10.1016/S0031-9201(99)00005-9

    “The aim of this study was to find a procedure which will effectively discriminate seismic signals from these icequakes …. according to their characteristics: frequency content, duration, azimuth, inclination and magnitude…. this method was capable of distinguishing icequakes and could substantially improve the production of an automated event list.”

    Comment by Hank Roberts — 16 Nov 2010 @ 1:19 AM

  29. Didactylos #24:

    …and don’t forget contributing to GRACE!

    Comment by Martin Vermeer — 16 Nov 2010 @ 3:14 AM

  30. Dear Stefan,

    Re comment in #23:
    “Just adding to that: the entire satellite record (starting 1993) is just one data point in the analysis of our paper. Variability on time scales shorter than 15 years or so is in my perspective not linked to global climate change but likely just “noise” – the result of various internal variability mechanisms. Let’s wait another 15 years for the next data point, then we may see something. -stefan”

    Well, let’s just rephrase the question then . .
    Costal long term measurements and the satellite data point towards a linear trend with about 1foot per century (just extrapolating the black line in the 2nd figure up in the article)
    Cristy points out, that there is no proof, that the acceleration of the melting is ingreasing (scientists cited in the newspaper article seem to say that some glaciers are slowing down again)
    You seem to say yourself, that the data is a bit too sparse for any definite conclusion.
    Can you rule out a change of only about one foot; in other words is it possible, that your non-linear extrapolation shown up there is just a wrong model?

    All the best,
    LoN

    Comment by Laws of Nature — 16 Nov 2010 @ 5:44 AM

  31. Temperatures in Greenland and icemelting

    http://www.dmi.dk/dmi/index/klima/klimaet_indtil_nu/temperaturen_i_groenland.htm

    http://www.dmi.dk/dmi/index/klima/klimaet_indtil_nu/temperaturen_i_groenland.htm

    https://intranet.tudelft.nl/live/pagina.jsp?id=7a6c3d15-1c1e-4869-b378-840a000c6803&lang=en

    Comment by Ibrahim — 16 Nov 2010 @ 6:47 AM

  32. Its about time the subject of sea level rise is back, and yes a good article its was. I’ve done some reading about the meltwater period, 20,000 to 10,000 yrs ago and the rate of sea level rise in the main episodes and 5mtrs per 100 yrs occurred. Even though the amount of ice was larger than today the temperature was half of today and the increase to todays temperature rose very rapidly once the extra surface area of water was here.
    Looking at the loss of the summer sea ice in the arctic and that it might not be here in about 10 yrs and will have gone from a reflection of sunlight to an absorber,now a person could quite easily understand this extra heat will speed up the undercutting of land based ice and so rapid rise of sea level this century is very possible. So more than 1 meter of rise could quite easily be on the lower end of the scale. Once the locking pin holding back the most vulnerable ice lets go i think a domino effect will take place and literally shake the other compromised ice into the sea, hence rapid sea level rise will take place once more and place the earth into another epoch unfortunately.

    Comment by crusty — 16 Nov 2010 @ 6:49 AM

  33. Stefan :”Just adding to that: the entire satellite record (starting 1993) is just one data point in the analysis of our paper. Variability on time scales shorter than 15 years or so is in my perspective not linked to global climate change but likely just “noise” – the result of various internal variability mechanisms. Let’s wait another 15 years for the next data point, then we may see something. -stefan”

    Sorry, Stefan, may be I missed the point, but if the best measurements so far are unable to show any acceleration term, what is the observational evidence for that ? Why do you assume that unknown “internal variability mechanisms” are important at a given (short) timescale, and unimportant at another (long) one? how can you distinguish between a response to a forcing and a spontaneous variability, if you don’t have precise measurements of any of them ?

    [Response: How about you read our paper? It is all described there. -stefan]

    Comment by Gilles — 16 Nov 2010 @ 8:22 AM

  34. @Didactylos #24

    Yes, I’m aware there are and have been satellites. As well as my own (limited) understanding, I was going by the article by Gillis, where he wrote:

    Yet the rise of the sea could turn out to be the single most serious effect. While the United States is among the countries at greatest risk, neither it nor any other wealthy country has made tracking and understanding the changes in the ice a strategic national priority.

    The consequence is that researchers lack elementary information. They have been unable even to measure the water temperature near some of the most important ice on the planet, much less to figure out if that water is warming over time. Vital satellites have not been replaced in a timely way, so that American scientists are losing some of their capability to watch the ice from space.

    The missing information makes it impossible for scientists to be sure how serious the situation is.

    Comment by Sou — 16 Nov 2010 @ 8:35 AM

  35. I strongly suggest that those questioning the sea level rise measurements view the Jerry Mitrovica talk “In Search of Lost Time: Ancient Eclipses, Roman Fish Tanks and the Enigma of Global Sea Level Rise” that Richard Pauli linked to @15:
    http://www.youtube.com/watch?v=GdfTUdU9x-k

    Comment by Jim Eager — 16 Nov 2010 @ 9:57 AM

  36. So Dr. Christy was consulted for his professional opinion about glaciology in the NY Times article….

    I just can’t help but notice what an incredible climate-science “polymath” many journalists seem to think that Dr. Christy is.

    Most mortal climate-scientists have in-depth expertise in very narrow specialties. Glaciologists generally aren’t tree-ring experts; dendrochonologists generally aren’t experts in isotope chemistry, and geochemists are highly unlikely to be atmospheric physics experts. But if you read enough about global-warming in the popular press, you just might get the impression that Dr. Christy is an expert in all of these areas. How does the guy find the time to get any sleep?

    Comment by caerbannog — 16 Nov 2010 @ 11:05 AM

  37. It will be easier to evacuate coastal cities after they have been mostly depopulated by drought-driven famine.

    Comment by SecularAnimist — 16 Nov 2010 @ 11:12 AM

  38. #33–

    The observational evidence for SLR acceleration comes from comparison with the earlier portions of the 20th century, when rates of SLR were considerably lower. Unfortunately, there was no GRACE back then, but the tide-gauge data, though trickier than you might think to work with, are nevertheless useful.

    This post cites many relevant studies, for those (like Gilles) who would like to investigate further. And the long-term graph illustrates accelerating SLR over the 20th century rather nicely.

    http://www.skepticalscience.com/Visual-depictions-of-Sea-Level-Rise.html

    Comment by Kevin McKinney — 16 Nov 2010 @ 11:12 AM

  39. Dan in #5 wrote: “Your statement that most experts expect a meter sea level rise is not supported in the article.”

    Don’t know about the print version, but it’s pretty well-supported, IMO, in the links given in the online version available here. The linked Hanson review alone provides a pretty extensive bibiography.

    The link in plain:

    http://iopscience.iop.org/1748-9326/2/2/024002/fulltext

    Even discounting them, I think the statement is supportable; ice dynamics aren’t the only reason for the higher projection–just the biggest “wild card.”

    Comment by Kevin McKinney — 16 Nov 2010 @ 11:24 AM

  40. Thanks for the info about the NYT article Stefan.

    I made a point of taking some photos and video of the highest tide of the year at Portsmouth, Hampshire, UK this year.
    It was a roughish day and the sea was a bit choppy. I got soaked by spray from a wave and had to stand on a wall to avoid getting my feet wet on the public footpath. I posted them on my blog:

    http://lovelywaterlooville.blogspot.com/2010/09/highest-tide-2010.html

    The video and photos were taken along the main tourist sea front area, which has a lot more money spent on it for sea defences than other locations around Portsea Island (Portsmouth is on an island and has a population of about 300,000).

    Add a metre or two to current levels and the defences will have to be much more substantial/higher. About half of Portsmouth is below 5 metres above sea level.

    Comment by The Ville — 16 Nov 2010 @ 11:46 AM

  41. This article is an excellent example which makes two on Greenland recently. Wow. <a href="http://www.rollingstone.com/politics/news/17390/208775"Rolling Stones article by Ben Wallace-Wells was also excellent. The only downside is that some of the graphics are a few years old in the data they present such as the Helheim terminus.

    Comment by mauri pelto — 16 Nov 2010 @ 12:00 PM

  42. Sou, CryoSat-1 was lost at launch. The replacement was started immediately, but it takes time to build a satellite. ICESat failed in February. CryoSat-2 was launched in April.

    Yes, it’s not ideal, but failures happen. I think Gillis was being a little nationalistic, or did not do his research on this: the other important environmental satellite to be lost recently is NASA’s Orbiting Carbon Observatory (OCE).

    Comment by Didactylos — 16 Nov 2010 @ 12:41 PM

  43. Aside from Christy’s jejune remarks, this was a refreshing effort from the Times. Too bad the author fell into the false balance trap.

    Comment by Adam R. — 16 Nov 2010 @ 1:51 PM

  44. Charles County in Maryland is working on a water resource element to its long term planning. This county is wrapped by the Potomac River and the Brackish/Fresh line is at about the town of Indian Head. From the above graph, we can expect about a foot of sea level rise within the next twenty to twenty five years. How far up river does this shift the brackish/fresh line? Is there software available to calculate this? Already, there are salt water intrusions into fresh aquifers in places in the county ruining existing wells. Who could provide the best information on protecting aquifer flow to keep this from happening further up river? Thanks in advance for the help.

    Comment by Chris Dudley — 16 Nov 2010 @ 2:01 PM

  45. Gavin,
    With regards to “new data,” Ibrahim (#31)posted a link to Greenland temperature measurements and the new GRACE data showing that the glaciers in Greenland are only melting at half the previously expected rate. At the current rate of melting, the contribution from Greenland to the total sea levels by less than 1mm/year.
    Predicting long-term changes base on short-term data is a troubling endeavor engaged in by too many scientists. Yes, sea level could rise by 3 feet by 2100, but the uncertainty in those predictions exceeds the total increase, it is just as likely to be 6 feet as 0.

    [Response: Sorry, but the uncertainty is all on the up-side. - gavin]

    This is similar to Maslowksi projecting the Arctic to be ice-free by 2013 based on short-term measurements.

    Comment by Dan H. — 16 Nov 2010 @ 2:19 PM

  46. Lets look at some hard facts…

    There are several problems with this article. First, a quick google of “rising sea level” would take anyone really interested in facts to a Wiki page which shows that, based on 20+ global tide guages, the sea has been rising at a steady rate of 1.8MM/yr since 1900 (less than 8 inches a century). Between 1900 and 1940, only 5% of the total CO2 burned in the past hundreds years was burned. However the rate the seal level has been rising has not changed. In fact, the sea has been rising at this rate for thousands of years. Second, 85% of all glacial ice and 70% of the world’s fresh water is stored (frozen solid and been so for 6 million yeaers) in Antarctica (the south pole). The mean temperature of Antarctica is -56Deg F. A 3 deg change in global temp would actually result in an increase in snow pack in Antarctica because the air coming off the ocean to the land would contain slightly more water vapor. In the past six million years, the Ice Sheet in Antartica has endured at least 50 complete global warming/cooling cycles which come every 100,000 years or so. For Antarctica to melt, global warming would have to be in the range of 10+ Deg C for thousands of years. Also, according to Greenland temp. data, the temp in Greenland is still much cooler than it was when the Vikings arrived there in the 10 century.. http://www.junkscience.com/MSU_Temps/Greenland_GISP2.html

    [Response: Very few of your statements are 'hard facts'. Look up the Thwaites or Pine Island glaciers and then tell me that you can't get ice sheet changes without +10 deg C temperatures... - gavin]

    [Response: I'm always a little surprised by lay people making sweeping statements like: "In fact, the sea has been rising at this rate for thousands of years." Think about it: this would mean in the Middle Ages sea level should have been about 1.8 meters lower, in Roman times about 3.6 meters lower... Which clearly contradicts the archeological evidence, as discussed e.g. by IPCC. -stefan]

    Comment by beegdawg007 — 16 Nov 2010 @ 2:31 PM

  47. #23 ImranCan

    Just some perspective. Take another look at the chart. There is indicated a rate change in the last 4 years, not 10 years. Natural variability factors can be tied to the many oscillations and ocean heat content overturn occurring in the climate system, and these attributions are not fully understood, but the picture is getting more interesting.

    One idea might be that if the rate change is not noise and is in fact signal, it may be a result of lag inertia coming down from the peak of solar cycle 23 and the extended solar minimum, as that lower intensity feeds through the oscillations? Just how do the Schwabe cycles affect natural variation? Interesting questions.

    My point is it’s pretty darn complex stuff. I only wish I have the view and understanding that others here have.

    Economics: Balancing Economies
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    Comment by John P. Reisman (OSS Foundation) — 16 Nov 2010 @ 3:24 PM

  48. It seems to me that sea levels are currently at historic lows. Melting sea ice actually displacing more volume as ice than water. Increasing hungry populations will require more potable water in this same time frame, either by capturing and storing rain or by desalinzation. The latest Chinese water project will create a new man made body of water by diverting 19.5 billion cubic meters of water, that will not contribute to rising sea levels. Right here in Arizona a second aqueduct may deliver water to central Arizona from the Colorado River.

    EL

    Comment by Emanuele Lombardi — 16 Nov 2010 @ 4:06 PM

  49. I have been debating these very topics, i.e. sea level rise & the melting of Land ice, particularly Greenland on another obscure political website with, I assume, an AGW denier.
    To support my case, I found the NASA website :-
    http://climate.nasa.gov/

    However, this still only suggests about 24 Cu miles / year of Greenland ice melt, yet other estimates, say from Wiki, now suggest nearly 6 times that.

    Am I interpeting this correctly? If so, should NASA re-evaluate their website suggestions?

    Comment by Clippo — 16 Nov 2010 @ 4:12 PM

  50. I have reached the point where finding ‘experts’ who have no expertise in the subject, being quoted in an article as the de rigueur balance to the actual experts I move on to something more reality based. Christy is one such. Thus I never read the article. Perhaps in a few days my disgust will die down so I might return to the article. I’m sure I missed a whole lotta revelations by not reading the letters section too.

    Comment by w kensit — 16 Nov 2010 @ 4:30 PM

  51. It’s good to see at least some quality reporting. Here in Australia, journalists get fired for fact checking. I went last night to a talk by Naomi Oreskes, based on her Merchants of Doubt book. What I find remarkable about all this is that exactly the same tactics have been used in defence of tobacco and a slew of other industries against science, and journalists still don’t get it.

    You can argue cognitive dissonance in the case of tobacco (many journalists, at least when this was an issue, smoked). To me the most bizarre case of misreporting is the way Bjorn Lomborg was fêted by The Economist for a book he wrote when the only other thing he’d published was an obscure theoretical political science paper. Either the magazine had reporters skilled enough in the science to understand his material, or asked competent scientists to evaluate it, you would think, since they couldn’t accept his views on reputation alone. But there’s no evidence of that. Meanwhile Lomborg has almost completely reversed himself and now writes how the most logical thing is to invest in clean energy rather than whatever else he imagines we are all talking about, and he still gets space in The Australian. To quote Homer Simpson: “D’oh”.

    There’s no logical explanation for any of this. It makes me wonder if I should set myself up as an expert in the Chinese economy and start writing for the popular media. I know nothing about that, but, hey, that’s never been an obstacle.

    Anyone up for a psycho-sociological study of journalism?

    Comment by Philip Machanick — 16 Nov 2010 @ 5:04 PM

  52. Still a fair few people posting here as if RC and the NYT were talking complete nonsense. I know that in some peoples eyes RC is a pro ACC site but in reality it is a pro science site and if 100 ppmv of climate forcing along with others (other GHGs, land use changes etc) are the likely culprits to be leading to this glacial behaviour then I do not see an issue with it as long as its the scientific best answer rather than some mere denial based on nothing scientific as some posters appear to be stating here.

    The quote from John Cristy is unfortunate perhaps but its more than compromised by all of the other quotes. Pro ACC people should not feel they need to comment on him being quoted when many more are too on the science side too.

    Comment by pete best — 16 Nov 2010 @ 5:25 PM

  53. 46. beegdawg007 says:

    First, a quick google of “rising sea level” would take anyone really interested in facts to a Wiki page which shows that, based on 20+ global tide guages, the sea has been rising at a steady rate of 1.8MM/yr since 1900 (less than 8 inches a century).

    It always has to be quote mining with you lot, doesn’t it? Because if you take even whole sentences from the original article, let alone paragraphs, then you can’t put your disingenuous spin on it. Let’s see what the entire first sentence said (even though I know you lifted part of what you said from the accompanying diagramme to make a nice contrarian mash-up out of it):

    Wikipedia: Current sea level rise

    Current sea level rise has occurred at a mean rate of 1.8 mm per year for the past century,[1][2] and more recently, during the satellite era of sea level measurement, at rates estimated near 2.8 ± 0.4[3] to 3.1 ± 0.7[4] mm per year (1993–2003).

    Oh… so the *rate* of sea level rise has *increased significantly* recently? Why did you omit that important piece of information?

    Comment by Steve Metzler — 16 Nov 2010 @ 5:44 PM

  54. Chris Dudley @ 44: Here in southern California we’ve been building barrier wells for some time now to prevent / reverse salt water intrusion into our vital coastal groundwater basins. There’s actually a pretty rich literature on the topic. Essentially you need to create high pressure zones within aquitards to keep the ocean out.

    Comment by Francis — 16 Nov 2010 @ 9:08 PM

  55. Sure has gone suddenly quiet here. Either the mods have taken a well-deserved break, or could it be that everyone is busy reading this:

    Replication and due diligence, Wegman style

    Comment by Steve Metzler — 16 Nov 2010 @ 9:16 PM

  56. beegdawg @46: However the rate the seal level has been rising has not changed. In fact, the sea has been rising at this rate for thousands of years.

    I’ll take it you didn’t watch the Mitrovica talk on sea level rise, did you?
    Pitty, you would have saved yourself the embarrassment of having relied of true junk science.

    Comment by Jim Eager — 16 Nov 2010 @ 10:22 PM

  57. Dan (#45), don’t be too sure that Maslowski was wrong, either–particularly since he didn’t “project the Arctic to be ice-free by 2013,” he said it “could be”–and by 2016, +/- 3 years, not “by 2013.” (Yes, of course 2013 is included at the edge of the uncertainty, but it wasn’t his best estimate.)

    You should also note the definition: “By “ice-free,” Maslowski. . . means more than an 80% drop from the 1979-2000 summer volume baseline of ~200,00 km^3.”

    Having watched the ice melt very closely indeed this year, I for one am convinced we’re in a quite different regime than we have ever seen. It may very well be what a “death spiral” actually looks like.

    Details on what Maslowski actually said are here:

    http://climateprogress.org/2010/06/06/arctic-death-spiral-maslowski-ice-free-arctic-watts-goddard-wattsupwiththat/

    Comment by Kevin McKinney — 16 Nov 2010 @ 10:48 PM

  58. Francis (#54),

    Thanks, that is interesting.

    Comment by Chris Dudley — 16 Nov 2010 @ 11:49 PM

  59. 54. Francis on water: Your comment is a good example of why I read right through the comments on RC as much as I can. Good stuff.

    And for anyone interested, Boston had a Sea Level Rise Forum last Tuesday that I was able to attend. A real eye opener – hign mucky-mucks from real estate and developers paying attention, and Rahmsdorf quoted (Partners Health Care taking future into account in developin sites). Good stuff!

    Did anyone see the creative exhibit “Rising Currents” at MOMA, or Venice Biennale? Creativity working at its best. I liked the idea of walking under a glass (plastic?) ceiling at sea level. They promised the material would be on the web soon; you can read about the meeting, and find some of it at MOMA, but I think it will be more complete later.
    http://www.tbha.org/

    Just took a look, and Kairos Shen (what a name!) summation included mention of: (a) being sent to Climate Change boot camp with reps from 15 other cities, and (b) metaphor with WWIII – if climate change were that, we’d find the resources.

    Couple more citations from my notes (time for me to take a closer look and get sorted on this, sorry for sloppy refs):
    Antonio di Mambro, Boston Visions, plan for harbor barrier from 1988 (!)
    and
    Dutch Delta Commission Report mentioned as being very thorough (pour cause)

    Comment by Susan Anderson — 17 Nov 2010 @ 2:19 AM

  60. sorry, Rahmstorf, won’t misspell it again!

    Comment by Susan Anderson — 17 Nov 2010 @ 2:22 AM

  61. Interesting that mainstream is now publishing this info.

    It always strikes me how the sea rise predictions assume a steady increase .. but anyone who defrosted any kind of container can easily see that after a slow initial melting phase a catastrofic slide of ice and water ALWAYS happens. I bet Greenland will be not different.

    The past record of melting in North America shows clear proof of catastrofic mega-floods. What was the timescale of these floods? I am not sure, but I bet it was days, not years. Once the floodgate opens, it gets wider quickly as the water and remaining ice escavate.

    What is the status of the greenland ice sheet? how close is it to produce a mega-flood event? How much liquid water is contained in lakes below the ice sheet? How much is added every year? I hope we do know this information, and I hope someone is planning to measure this stuff in some reliable way. There is already an interesting paper that says that water leaking into the ice sheet makes the thermal impulse response go down to a few years.

    If a megaflood happens, we will have 3-5 feet of sea level increase + the megaflood. This does not comfort me very much: how much did the seawater suddently raise as a consequence of the North American mega-flood?

    A megaflood is also likely to happen in autumn, right before refreezing starts: an enormous quantity of meltwater would then go into the ocean, decreasing salinity, suddently stopping the thermoaline circulation and raising the seawater surface freezing temperature. A very sudden and extensive refreezing of sea surface would be likely to follow in the winter, causing a sudden increase in albedo which would compound the stopping of the circulation.

    I hope someone here can answer me and hopefully say that the above is totally unlikely to happen soon . Thanks!

    Comment by noniono — 17 Nov 2010 @ 5:03 AM

  62. I disagree with Eric’s response to #14, 1-2 centuries is not an unusually long time to ponder for major civil engineering projects such as dams, large bridges, sewerage systems, etc. Reducing our emissions is definitely a major civil engineering project, so whoever is going to do it does need to think past their own lifetime.

    Comment by Alan of Oz — 17 Nov 2010 @ 5:44 AM

  63. Here is an EPA chapter on salt water intrusion barrier wells describing what Francis pointed out: http://www.epa.gov/ogwdw/uic/class5/pdf/study_uic-class5_classvstudy_volume20-salineintrusionbarrier.pdf

    It strikes me that Southern California is using out-of-watershed water from the Colorado River to inject while the Potomac is an estuary. If fresh water is taken from up stream to inject along the newly brackish part, then fresh flow is reduced which would then shift the brackish/fresh line further upstream so you would then need some extra injection wells perhaps in Prince George’s County. Perhaps the effect would be less if we stopped using wells and just took the Upper Potomac water for drinking, something that the DC water district has been trying to sell us for some time. But that would encourage completely unrestricted development and the destruction of Mattawoman Creek and other surface water resources needed for the health of the Chesapeake Bay.

    Hum… Sea level rise just makes things worse and worse.

    Comment by Chris Dudley — 17 Nov 2010 @ 8:22 AM

  64. A few people have been complaining about the false balance provided by the brief inclusion of Christy’s position. I actually liked that part, and I think it served a subtle and valuable purpose. It’s a good example of how to do the narrative correctly.

    It was only two short paragraphs on the second page, sandwiched between more specific, detailed and reasoned comments and descriptions by and about “real” scientists in that specific field of expertise. In comparison, Christy’s nature and position seemed vague, with general statements that stand in sharp contrast to the detailed science discussed to that point, and after.

    I think to any reasonable person (unreasonable people having stopped reading before the end of the first page), it reflects poorly on the entire skeptical position, but without setting off alarms by actually making it seem like that is the position of the author. It leaves the skeptic position as looking like dismissive hand waving lacking in substance.

    That sort of non-argumentative tactic, I think, is better than either ignoring the deniers, or trying to directly refute them (and so giving weight to their arguments by making enlarging the conflict within the story).

    I only wish that the article had mentioned the GRACE measurements, either immediately before or after Christy’s paragraphs, perhaps with the subtle comment that even the low end Wu 2010 figures exceed the most recent IPCC estimates, which means that the melt rate is at best only worse than we thought, and quite possibly (probably) much, much worse.

    I suppose I also wish that they’d explicitly stated Christy’s specialty and role within climatology, rather than merely labeling him as a climatologist (with the false implication that merely being a climatologist qualifies you to authoritatively comment on anything to do with climate, on a par of any other climatologist, regardless of specialty, track record, or standing among your peers).

    Then again, as I said, this position was rather subtly worked into the article merely by what wasn’t said about or by Christy, rather than what was said.

    Comment by Sphaerica (Bob) — 17 Nov 2010 @ 9:45 AM

  65. I agree with Alan of Oz at #62: we need to think ahead 1, 2 even 3 centuries. If 1 meter of SLR at 2100 seems probable and 2 meters cannot be excluded, what does this mean for SLR and its potential speed at 2200 or 2300? As Jim Hansen and others ask: how is civilization going to adapt to an average SLR of 3 meters (or even more) per century for centuries? Once this process gets going, after a slow start-up, we’re not likely at stopping or slwoing it any time soon.

    It seems we cannot exclude a SLR of 10 meters by 2300 once we have about 3 degrees C of global warming. During the Eemian about 120.000 years ago it was only about 1-2 degrees warmer than now, but SL was on average about 5 meters higher with highs up to 6-9 meters higher. The speed of SLR seems to possibly have been as high as almost 3 meters in 50 years (Blanchon et al) with an average of 1-2 meters per century. But back then the initial forcing was the small and slow orbital change of earth’s position toward the sun, with the ‘slow’ CO2/GHG and albedo feedbacks as the big amplifiers. Now we have a much faster and bigger initial forcing: our CO2/GHG emissions over the past two centuries and probably at least the coming half century.

    So how slow or fast will the CO2/GHG and albedo feedbacks kick in this time? Will it take centuries, or only decades? The ice sheets are starting to melt now, it seems. With more warming and feedbacks in the pipeline this melting will accelerate. But how fast we do not know. We seem to know too little from the past and present to be able to predict with high confidence future melting and SLR. But as Hansen and others stress, on the little we do know it seems we cannot exclude SLR of several meters/century over the coming centuries, with maybe a max of about 10 meters by 2300. And, if we mitigate too little and too late, possibly up to 75 meters over the coming two millennia (the ice free planet).

    These seem too be the risks we’re deciding about in the coming years and decades. So we better think carefully how much risk we’re willing to take on behalf of the generations after us and how much mitigation we need to realise to minimize these risks. The more mitigation the sooner, the better it seems to me. As Stefan said: in 15 years or so we may know some more about the current possible acceleration of SLR and that may give us some more certainty about the potential future SLR. But if we wait with serious mitigation until then our chances to do something about it will be significantly smaller than now.

    Comment by Lennart van der Linde — 17 Nov 2010 @ 10:33 AM

  66. Southern California is hydrologically connected both to northern California via the State Water Project and the Colorado River via the Colorado River Aqueduct. There’s also a surprising amount of water in our local watershed. But the biggest new source of water for the barrier system is treated sewage.

    The larger point is that coastal communities around the world are going to end up following in our footsteps and creating complex (and expensive) conjunctive use systems. It’s still cheaper than desalinating groundwater gone brackish from seawater intrusion.

    Comment by Francis — 17 Nov 2010 @ 11:32 AM

  67. Kevin (#57) I have been watching the Arctic sea ice for quite some time also. Temperatures have been slightly below average during the summer months for the last several years, but above average during the rest of the year. 2010 was similar, except that the deviation from the average was less than in previous years. This resulted in a maximum ice extent which was the greatest since 2002, infact, it has been increasing every year since the low recorded in 2006. The minimum this year was similar (although slightly lower) than 2009, it was higher than either 2008 or 2007, and lower than 2005 and 2006. The sea ice has been increasing over the past few years.
    Yes, these are short-term trends, and that is my point. Maslowski made his calculations based on short-term data trends. If we were truly in a “death spiral,” then I would not expect the sea ice to be increasing as measured in the past few years.
    http://ocean.dmi.dk/arctic/icecover.uk.php

    Analysis of the NOAA tide gauge data yield a median SLR of 1.1 mm/yr with no acceleration observed during the 20th century.
    http://www.burtonsys.com/climate/MSL_global_trendtable1.html

    [Response: This link is a good example of why there is professional science, published in peer-reviewed journals. Burton has simply forgotten to correct the station data for glacial isostatic uplift - quite a few stations are subject to land uplift resulting from the melting of the ice sheets of the last Ice Age, which is often bigger than the sea level trend (e.g. in Finland uplift can be over 9 mm/year). This is completely standard with sea level experts. -stefan]

    Comment by Dan H. — 17 Nov 2010 @ 2:39 PM

  68. hello there

    Sorry if this is the wrong place to post this but I was wondering if any leading experts really have any solid process of not only reducing further damage but of also reducing the effects? it seems to me that either way we are in for some major changes that can’t really be stopped other then trying to change our habits. Again I apologize if this is the wrong place to ask. Thanks in advance.

    Comment by Crystal — 17 Nov 2010 @ 2:45 PM

  69. Dan H #67 Look at the graph of minimum sea ice on Jim Hansen’s web site. http://www.columbia.edu/~mhs119/SeaIce/
    If you draw a trend line from 1980 to 1996 and one from 1996 to 2010, the trend is definitely steeper 1996 to 2010. Deniers like to talk about the increase since 2007, but you can’t look at the graph and make much of that increase.

    Comment by Sir — 17 Nov 2010 @ 3:36 PM

  70. > Dan H.
    > Burtonsys
    unpublished; looks similar to this rather old published work:
    http://www.springerlink.com/content/p364381652174757/

    Don’t fail to read the last sentences of the Abstract at least, then look at the citing papers to bring yourself up to date.

    Ask yourself, why isn’t something so revolutionary publishable?
    Vast conspiracy? Outdated analysis of data? Fails to consider satellite work?
    Many explanations. YMMV.

    Comment by Hank Roberts — 17 Nov 2010 @ 3:40 PM

  71. Dan H wrote @67: “The minimum this year was similar (although slightly lower) than 2009, it was higher than either 2008 or 2007, and lower than 2005 and 2006.”

    Dan must have misplaced the adjectives “lower,” “similar” and “slightly.” He should have written:
    The minimum this year was lower than 2009, higher than 2007 by a similar amount, and slightly higher than 2008.

    Next Dan wishfully wrote: “The sea ice has been increasing over the past few years.”

    Oh really? http://nsidc.org/images/arcticseaicenews/20101004_Figure3.png

    Dan then goes on to admonish Maslowski for using short term data to predict a trend.

    I’ll give Dan H this: he certainly has chutzpah.

    Comment by Jim Eager — 17 Nov 2010 @ 3:48 PM

  72. #67 Dan H.

    Take a look at my Arctic monitoring page:

    http://www.ossfoundation.us/projects/environment/global-warming/current-climate-conditions/arctic

    Please point out the recovery you are speaking of? Ah yes, you recognize short term is natural variation. But you are referring to ice extent, not ice mass or ice volume. If you really want to understand this concentrate on the volume not extent.

    The death spiral is in the loos of ice volume. Around 10% per year. That’s truly a lot of ice loss.

    Take a look at the video here:

    http://www.ossfoundation.us/projects/environment/global-warming/arctic-ice-melt

    We are losing the Arctic ice and no amount of wishful thinking is going to change that.

    Economics: Balancing Economies
    October Leading Edge: The Cuccinelli ‘Witch Hunt”

    Fee & Dividend: Our best chanceLearn the IssueSign the Petition
    A Climate Minute: Natural CycleGreenhouse EffectClimate Science HistoryArctic Ice Melt

    Comment by John P. Reisman (OSS Foundation) — 17 Nov 2010 @ 4:52 PM

  73. #68 Crystal

    Check out the Fee and Dividend solution.

    http://www.climatelobby.com/

    http://www.climatelobby.com/fee-and-dividend/

    I understand it is difficult for people to get their heads around policy, but this is a really good (and very simple) idea.

    We need a price on carbon. This provides a revenue neutral progressive solution to help move us faster towards a clean energy future.

    Economics: Balancing Economies
    October Leading Edge: The Cuccinelli ‘Witch Hunt”

    Fee & Dividend: Our best chanceLearn the IssueSign the Petition
    A Climate Minute: Natural CycleGreenhouse EffectClimate Science HistoryArctic Ice Melt

    Comment by John P. Reisman (OSS Foundation) — 17 Nov 2010 @ 4:56 PM

  74. Dan #67 say
    Temperatures have been slightly below average during the summer months for the last several years, but above average during the rest of the year. http://ocean.dmi.dk/arctic/icecover.uk.php

    These temperatures graphs are model outputs, with big changes in source data over time. Even the models have changed, so they cannot be used as a year to year comparison, just a relative idea of the “average” temperature in the arctic.
    As for the tide gauge analysis, I don’t see where they corrected for isostatic crustal movement.

    Comment by Jathanon — 17 Nov 2010 @ 5:09 PM

  75. Dan H thinks the ice is recovering because 2010 had a higher extent than 2008, and the last years had a higher minimum extent than the record shattering 2008.

    Dan, you need to understand that 2010 set lots of records for the rate at which ice melted, and for how much actually melted out. Hint, 2010 started from a higher extent than 2007 did….

    “extent” is a horrible measure for the amount of ice we have. “extent” is the amount of sea that has at least 15% ice in it. Winds can blow and compact it into a smaller area and ‘poof’ the extent goes way down. Conversely, the winds can scatter the ice and X square km of ice at 50% concentration becomes 2X square km of 25% ice and extent has doubled.

    Area is a better measure than extent. You can find arctic ice area here figures. They’re not terribly different in the ranking: 2007 had an area minimum of 2.9615631 million sq km, 2008 had 3.0035558, and 2010 had 3.0721295. That’s only 65% of the mean for that date, but it’s OK because it’s 2% higher than the area minimum for 2008?

    Volume is the best measure of the health of arctic ice, however, and one can see very clearly from this graph that the ice is not anything like recovering. Citing a 70K sq km increase in area over 2008 while the volume has decreased by several thousand cubic kilometers seems misleading at best.

    Comment by David Miller — 17 Nov 2010 @ 5:10 PM

  76. Re: Crystal @ 17 November 2010 at 2:45 PM (currently comment 68):

    Welcome to the party. You must have taken the Red Pill. :)

    While I don’t think your question is on-topic, it’s too important to go un-answered. I would suggest going over to this post at Skeptical Science where many informed individuals seek to answer that very question.

    Hope that helps!

    The Yooper

    Comment by Daniel Bailey — 17 Nov 2010 @ 6:03 PM

  77. 73 (John P. Reisman),

    I’d actually like to propose a “fee or wager (and dividend)” system.

    It works just like fee and dividend, except that carbon producers also have the option of entering a wager instead of a fee. If they choose to pay the fee, that’s it, that’s what they pay (per unit of carbon). If they choose to wager, however, that wager (per unit of carbon) goes into the books. The amount to be paid will be annual, based on some combination of measurable factors (global temperature and precipitation anomalies, sea level rise, summer Arctic ice extent, etc.) which are exceeded in any particular year, and substantially larger than the flat fee — potentially much larger, depending on the final, total effects on the climate, and how long those effects last. It would be great if this fee could be further supplemented by direct measures of economic impacts (costs of levees and dikes, lost agriculture, displaced businesses and populations, etc.).

    Basically, they get to either admit there’s a problem now, and pay an appropriate fee, or else they get to wager that there is no problem, but if there is, they will pay through the nose (i.e. something to completely offset the expense that their FF profits are costing the rest of us, plus a penalty for playing games with the world, and all of our lives).

    I’m willing to bet that, as loud as the chorus is claiming that climate change isn’t happening and isn’t possible and couldn’t be, none of the big FF corporations would choose the wager instead of the fee.

    Comment by Sphaerica (Bob) — 17 Nov 2010 @ 6:39 PM

  78. Jathanon, the tide gauges analysis does not correct for isostatic crustal movement. That is only necessary for the satellite measurements. The tide gauges are the measure of the sea level at particular coastal sites. This is ultimately the main concern for sea level rise. Only 19 stations had recorded sea level rise above 3 mm/yr during the measurement period, while 14 had drops in sea level of greater than 3 mm/yr. The average rate of sea level rise was only 0.6 mm/yr. This is the concern, after all, that the ocean will rise above its current level and inundate low lying areas.
    Several people seemed to miss my point about using short-term data trends. Extrapolating them into the future is a fool’s venture.

    Comment by Dan H. — 17 Nov 2010 @ 7:10 PM

  79. David A Burton has done an analysis of global mean sea level(cmsl) trend that includes distance weighted averaging. It seems to indicate no increase of sea level in more recent times. Whats up with that?

    Comment by adrian smits — 17 Nov 2010 @ 7:57 PM

  80. I can’t seem to find a scientific paper by David A. Burton on sea level rise on Scholar or anywhere, for that matter, can you give me a link to it please?

    Thanks in advance.

    Comment by Thomas Lee Elifritz — 17 Nov 2010 @ 8:56 PM

  81. Its reassuring to see that the MSM recognises the reality of the primitive degree of understanding in the science of glaciology.

    “Climate scientists readily admit that the three-foot estimate could be wrong. Their understanding of the changes going on in the world’s land ice is still primitive. But, they say, it could just as easily be an underestimate as an overestimate.”

    Comment by Pete50 — 17 Nov 2010 @ 9:07 PM

  82. > Burton
    copypaste delight; Dan H. beat you to it. See above. It’s an old method known to fail, done using new data, almost as though he wanted it to fail.

    Comment by Hank Roberts — 17 Nov 2010 @ 9:22 PM

  83. # 79

    An Admiral testified before congress today. I think he would have mentioned it if somebody had pulled a scam on the United States Navy.

    This is good:

    http://www.icess.ucsb.edu/~davey/Geog163/Readings/annurev-marine-120308-081105.pdf

    Comment by JCH — 17 Nov 2010 @ 9:30 PM

  84. To beegdawg007 at #46, in addition to Steve Metzler’s reveal of your quote mining at #53, it appears that your sins include graph chopping as well. In your link to junkscience.com (at http://www.junkscience.com/MSU_Temps/Greenland_GISP2.html), the data plotted shows that the temperature 95 years ago in Central Greenland was ~1.0 C cooler than during the Medieval Climate Optimum. Strangely, recent data doesn’t appear in this analysis. Looking at the Upernavik data from West Greenland at the Danish Meteorological Institute site, http://www.dmi.dk/dmi/index/klima/klimaet_indtil_nu/temperaturen_i_groenland.htm, you can see that the smoothed mean temperature has moved from -8.5 C 125 years ago to -6.5 C in 2005. That’s a rise of 2.0 C, or 200% of the gain between preindustrial Greenland and the Medieval Optimum, and would actually be off the top end of chart presented at junkscience.com. Might want to check the recent data as well as your allies’ before posting. :)

    Comment by Wikisteff — 17 Nov 2010 @ 9:41 PM

  85. Thomas Lee Elifrit @80 – Maybe you don’t find Dave Burton on Scholar because .. he’s not

    Comment by flxible — 17 Nov 2010 @ 11:13 PM

  86. #62, #65:

    Just the question I wanted to ask. The cutoff at 100 years from now hides the really long-term effects. This is a very interesting question. Do or don’t we care about the consequences of our actions that lie 200, 300 years into the future? A small discount factor reduces the present value of nearly any events that far away from now to practically zero. Therefore, some of the greatest future damages from climate change are hidden away in economic models with discounting to calculate the economic value of climate damage (such as Nordhaus). From a moral point of view, this presents an interesting dilemma.

    Comment by Vincent van der Goes — 18 Nov 2010 @ 4:50 AM

  87. #83 JCH

    I have links to all the Witness statements in the Nov. Leading Edge:

    http://www.ossfoundation.us/projects/environment/global-warming/summary-docs/leading-edge/2010/nov-the-leading-edge

    Economics: Balancing Economies
    October Leading Edge: The Cuccinelli ‘Witch Hunt”

    Fee & Dividend: Our best chanceLearn the IssueSign the Petition
    A Climate Minute: Natural CycleGreenhouse EffectClimate Science HistoryArctic Ice Melt

    Comment by John P. Reisman (OSS Foundation) — 18 Nov 2010 @ 4:58 AM

  88. The Judith Curry Testimony Highlight Reel

    In a rational discussion of climate change, the question needs to be asked as to whether the framing of the problem and the early articulation of a preferred policy option by the UNFCCC has marginalized research on broader issues surrounding climate change, and resulted is an overconfident assessment of the importance of greenhouse gases in future climate change, and stifled the development of a broader range of policy options.

    The IPCC/UNFCCC have provided an important service to global society by alerting us to a global threat that is potentially catastrophic. The UNFCCC/IPCC has made an ambitious attempt to put a simplified frame around the problem of climate change and its solution in terms of anthropogenic forcing and CO2 stabilization polices. However, the result of this simplified framing of a wicked problem is that we lack the kinds of information to more broadly understand climate change and societal vulnerability.

    I figured Curry would raise the uncertainty flag and wave it around the room. This I’m sure pleased the Republicans. She also spent some energy on defending herself and her position as well as saying that

    “My own experience in publicly discussing concerns about how uncertainty is characterized by the IPCC has resulted in my being labeled as a “climate heretic”6 that has turned against my colleagues.”

    Nice narrative for/from her.

    The she goes into the benefits of climate change!!!! And shows off how much she has no clue about:

    “A view of the climate change problem as irreducibly global fails to recognize that some regions may actually benefit from a warmer and/or wetter climate. Areas of the world that currently cannot adequately support populations and agricultural efforts may become more desirable in future climate regimes.”

    Then she talks about water resources. hmmm. . . maybe she should get together with Lomborg, they might make a good obfuscation team as they dance between the pluses and minuses as ‘they’ interpret them to be true. . . still of course lacking expertise in the subjects to which they claim to be advantageous.

    On page 3 she focuses on the Himalaya IPCC mistake and the states:

    “The lack of veracity of the statement about the melting Himalayan glaciers has been widely discussed, and the mistake has been acknowledged by the IPCC. However, both of these statements seem inconsistent with the information in Table 10.2 of the IPCC AR4 WG II and the statement: . . .”

    So not she has found an inconsistency between AR4 and AR2.

    Page 5:

    “Climate scientists have made a forceful argument for a looming future threat from anthropogenic climate change. Based upon the background knowledge that we have, the threat does not seem to be an existential one on the time scale of the 21st century, even in its most alarming incarnation.”

    Page 6:

    “At this point, it seems more important to explore the uncertainties associated with future climate change rather than to attempt to reduce the uncertainties in a consensus-based approach.”

    And finally:

    And finally, climate scientists and the institutions that support them need to acknowledge and engage with ever-growing groups of citizen scientists, auditors, and extended peer communities that have become increasingly well organized by the blogosphere. The more sophisticated of these groups are challenging our conventional notions of expertise and are bringing much needed scrutiny particularly into issues surrounding historical and paleoclimate data records. These groups reflect a growing public interest in climate science and a growing concern about possible impacts of climate change and climate change policies. The acrimony that has developed between some climate scientists and blogospheric skeptics was amply evident in the sorry mess that is known as Climategate. Climategate illuminated the fundamental need for improved and transparent historical and paleoclimate data sets and improved information systems so that these data are easily accessed and interpreted.

    Blogospheric communities can potentially be important in identifying and securing the common interest at these disparate scales in the solution space of the energy, climate and ocean acidification problems. A diversity of views on interpreting the scientific evidence and a broad range of ideas on how to address these challenges doesn’t hinder the implementation of diverse megaton and kiloton solutions at local and regional scales. Securing the common interest on local and regional scales provides a basis for the successful implementation of climate adaptation strategies. Successes on the local and regional scale and then national scales make it much more likely that global issues can be confronted in an effective way.

    Economics: Balancing Economies
    October Leading Edge: The Cuccinelli ‘Witch Hunt”

    Fee & Dividend: Our best chanceLearn the IssueSign the Petition
    A Climate Minute: Natural CycleGreenhouse EffectClimate Science HistoryArctic Ice Melt

    Comment by John P. Reisman (OSS Foundation) — 18 Nov 2010 @ 6:33 AM

  89. Wikisteff,
    You are correct. Nice graph. But did you notice that the temperature in 1940 is the same as today? It is well known that the Arctic had a large warmup in the early part of the 20th century culminating around 1950. Since then, the temperatures dropped almost 1C until bottomming in the 1980s, before rising to the levels of today. Ironically, the satellite data starts near the bottom.

    Comment by Dan H. — 18 Nov 2010 @ 7:15 AM

  90. 79 (adrian smits),

    In a quick perusal, I can find any number of flaws with Burton’s analysis.

    Before going anywhere, however, I find it disingenuous for someone to present something like that, in the form of a peer reviewed paper, when it clearly is not.

    Beyond this, because it has not been peer reviewed, and is not on any professional’s radar to refute, no reputable scientist is going to waste their time going through it looking for the flaws. It’s far too easy with this stuff for anyone with a modicum of mathematical training and writing and organizational skills to put together something that looks reasonable and authoritative and conclusive, when there are either glaring or subtle problems which make the entire thing invalid.

    Personally, I have reached a point where I discount things like this out of hand, because so many of them have proven to be fool’s gold. I don’t have time to look into every such claim. I used to, until so many of them turned out to be painfully flawed or maliciously misleading fluff.

    If this were true, don’t you think there’s a scientist or grad student out there that would love to make a name for himself by proving the rest of the field to be wrong? Do you really think it’s this easy?

    To start with, however, to take the most basic approach: Burton uses a set of 159 data points which he himself questions, and then declares to be “representative”:

    Or, first off, is it possible that the IPCC is right? For instance, is it possible that the GLOSS-LTT list of 159 locations is so unrepresentative of the world as a whole, that it drastically understates 20th century global average MSL rise?”

    That seems very unlikely. The 45 NOAA-maintained stations and 114 PSMSL-provided stations represent what appears to be a pretty good geographic distribution (though Africa is noticeably underrepresented), and the best available data on sea level trends.

    A comparison of his map to the map of sea level rise in Figure 3, page 150, of the Cazenave and Llovel review, however, shows that there is a severe dysfunction in that distribution. Specifically:

    1) Europe and North America (particularly the Atlantic) are grossly over represented in the dataset.
    2) All measurements are coastal, and almost all are continental, with only a handful coming from Pacific islands.

    A quick “eyeballing” of the two factors, particularly making use of Cazenave/Llovel Figure 3b, which shows relative anomalies, demonstrates that North America and Europe, and coasts in general, fall on the very low range of sea level changes, so his data set is clearly not representative. It uses low end measurements, and mostly misses those areas with the greatest sea level rise.

    Of course, it probably would come as a shock to him that something as complex as massive, heterogeneous bodies of water covering a moving, heterogeneous sphere, with varying motions, currents, temperatures and gravitational pulls throughout, would not expand anywhere near evenly over space and time.

    Which is why I trust scientists, and not random Internet scientist-wannabees.

    Comment by Sphaerica (Bob) — 18 Nov 2010 @ 8:14 AM

  91. DanH wants somebody to notice:”It is well known that the Arctic had a large warmup in the early part of the 20th century culminating around 1950. Since then, the temperatures dropped almost 1C until bottomming in the 1980s, before rising to the levels of today. Ironically, the satellite data starts near the bottom.”

    It is also well known that this was a regional effect due to AMO, whereas today’s global warming is due primarily to CO2.

    Comment by t_p_hamilton — 18 Nov 2010 @ 9:09 AM

  92. The internet is full of these claims about seal level either declining right now, or rising at just over 1 mm per year. People like link to a University of Colorado data site on sea level.

    The paper I linked to is pretty current on the subject:

    http://www.icess.ucsb.edu/~davey/Geog163/Readings/annurev-marine-120308-081105.pdf

    “We show that for the 1993–2007 time span, the sum of climate-related contributions (2.85 ± 0.35 mm year−1) is only slightly less than altimetry-based sea level rise (3.3 ± 0.4 mm year−1): ∼30% of the observed rate of rise is due to ocean thermal expansion and ∼55% results from land ice melt. Recent acceleration in glacier melting and ice mass loss from the ice sheets increases the latter contribution up to 80% for the past five years. …”

    Not declining. Not a harmless 1.2 mm per year (which is not harmless, but they like to imply it is.)

    Comment by JCH — 18 Nov 2010 @ 9:43 AM

  93. > DanH
    > “It is well known …”

    Dan H. gives assertions of belief rather than citations. C’mon, Dan.
    Look these up for yourself. It’s pointless to copypaste stuff from other blogs without understanding why it’s bogus, it just makes you look like you’re being duped.

    Try to check the claims you read, rather than just copying and pasting, eh?

    Comment by Hank Roberts — 18 Nov 2010 @ 9:51 AM

  94. For example, for Dan: a reminder to look beyond simple answers — see articles citing Bengtsson: The early twentieth-century warming in the Arctic-A possible mechanism; Bengtsson wrote: “NAO cannot explain why the Arctic rapidly started to warm up from 1920″
    http://scholar.google.com/scholar?hl=en&lr=&cites=10787045184131990918

    Cautionary — see references to Arctic amplification of warming.

    Comment by Hank Roberts — 18 Nov 2010 @ 10:00 AM

  95. Dan H 89: But did you notice that the temperature in 1940 is the same as today?

    BPL: So bleeding what? One year doesn’t make a trend, does it?

    Comment by Barton Paul Levenson — 18 Nov 2010 @ 10:39 AM

  96. More great narrative… there’s a new game out, which apparently pits a player against climate change and its impact on the world. Watts, in his eagerness to insult anything that does not parrot his own world view, is effectively advertising it on his site.

    I haven’t looked at this in detail, so I can say nothing about either the quality or intent of the execution (it could just as easily be done by deniers, to make adaptation look not only feasible but better than mitigation in the context of the game) but IMO this is in theory a great way to approach the narrative. Something like this will give people a much greater and more intimate feel for the complexities and implications of climate change, and how important delay is in the entire process (i.e. no matter what you do, if you wait too long to act, things get out of control).

    Games serve a wonderful teaching role throughout our lives, and the idea of teaching climate through games should have come up much sooner than this (and I’m rather disappointed in myself that I did not have the idea first, since I have a lifelong passion for games myself).

    I’m just reading the reviews that you can find through the Review link on their web site. Looks interesting, although the trailer makes it look a tad too complex for most folks.

    Comment by Sphaerica (Bob) — 18 Nov 2010 @ 10:45 AM

  97. I’d like to return to JCH’s #22. It’s important to get that right and I’d like people to point out any misunderstandings on my part.
    My understanding is that the 3 feet emerging consensus the article talks about does not include the “nonlinear melting”, precisely because it’s “unpredictable”. My understanding is that this 3 feet figure is not based on any agreed-upon temperature scenario (much less aerosol scenario, GHG scenario and so on) and is therefore fanciful given the uncertainties in future emissions, feedbacks and policies.
    The 3 feet guesstimate about the most likely SLR outcome by 2100 is not the figure we need. As outlined in the article, governments and communities need to plan for less likely outcomes as well. And here’s where the “nonlinear melting” matters. So far as I know, no earnest and comprehensive assessment of the low-probability, high-risk SLR outcomes has been published. There was a report prepared for the relevant comission in the Netherlands but, the way I read it, it assumed away many uncertainties. It may be appropriate if you want a figure for a project which is supposed to be able to weather 80% or 90% of possible outcomes but not the >99% of outcomes that we would prefer to be protected against (and that is mandated by law in some places).

    Vincent (#86),
    If you use appropriate valuation methods, distant future events can not be discounted to zero impact (or close). The method you seem to have in mind assumes that “bankruptcy” is OK. It’s appropriate for a business that’s not “too big to fail” but not for the high-impact climate risks. It’s not appropriate to assume an impact-independent discount rates anyway. I don’t know what Nordhaus publication you’re talking about but the one which comes #1 in Google claims it’s going to look at high-impact outcomes but then proceeds to ignore them entierly.

    Bob (#77),
    This wager proposal is not appropriate as long as bankruptcy and limited liability aren’t abolished. Even then, the risks are too high to play these kinds of games. You also need to consider the interaction between your scheme and potential lawsuits in case the wager turns bad.

    Comment by Anonymous Coward — 18 Nov 2010 @ 11:15 AM

  98. JCH @92 – A minor thing, but the paper you cite has Rahmstorf at ~0.5 to 1.2 m rise by 2100. Going to look at the Rahmstorf paper, the abstract says:

    \A semi-empirical relation is presented that connects global sea-level rise to global mean surface temperature. It is proposed that, for time scales relevant to anthropogenic warming, the rate of sea-level rise is roughly proportional to the magnitude of warming above the temperatures of the pre–Industrial Age. This holds to good approximation for temperature and sea-level changes during the 20th century, with a proportionality constant of 3.4 millimeters/year per °C. When applied to future warming scenarios of the Intergovernmental Panel on Climate Change, this relationship results in a projected sea-level rise in 2100 of 0.5 to 1.4 meters above the 1990 level.\

    So, the top end of the estimate is 0.2 m higher for this source.

    Captcha has a sense of humor: seaby measure

    Comment by Maya — 18 Nov 2010 @ 11:51 AM

  99. From just a rough scan of this post it seems one can quote almost any extent, volume, trend of Arctic ice they want, other than in the broadest sense. Maybe this has something to do with the difficulty of making precise measurements as mentioned in an earlier RC post. Though I see David Miller’s source can measure extent with 8 significant figures to the nearest 1/10 of a mile; impressive.

    Comment by Rod B — 18 Nov 2010 @ 12:12 PM

  100. 97 (Anonymous Coward),

    …the risks are too high to play these kinds of games…

    The proposal was mostly tongue in cheek. The point was more that the fossil fuel companies themselves know better, and if faced with a flat, definable fee to go towards mitigation now, versus an unquantifiable but certainly larger, later penalty that they must pay themselves, in proportion to the damage done and the cost of late mitigation plus adaptation, then they would undoubtedly choose the fee… effectively admitting to the truth of the current situation.

    Well, all except for a few, who would probably figure that they could get away with paying nothing for a while, then simply dissolve their companies before the payment on the wager comes due and business is therefore no longer profitable.

    But the main difficulty in the problem is that those who stand to gain the most from ignoring the problem (the FF producing companies and countries) are also those who will suffer the least (or not at all) as a result of CO2 emissions. Any solution (cap and trade, fee and dividend, tax and spend, whatever) is an aim to balance that equation and to shift the burden from the victims to the profiteers.

    A “wager” system (not that it would work) would not only shift the burden to the profiteers, but also shift the decision of how much risk to assume to that same party, in effect forcing them to choose their own poison (rather than requiring a divided global populace to find the unity and strength needed to choose their poison for them).

    Comment by Sphaerica (Bob) — 18 Nov 2010 @ 12:48 PM

  101. Rod, Rod, if you’d just cite — ah, but that would ruin your fun.

    Rod refers at 18 November 2010 at 12:12 PM vaguely to “David Miller’s source … 8 significant figures to the nearest 1/10 of a mile” — it sounds impossible, doesn’t it?

    David Miller at 17 November 2010 at 5:10 PM linked to the UCAR data set. It’s just numbers; Rod tells you what he thinks they are.

    Or, you can look it up.
    Back up from that data set to the main page:
    http://arctic.atmos.uiuc.edu/cryosphere/

    Follow the link there for the data — this page includes an explanation:

    http://www.cgd.ucar.edu/cas/guide/Data/walsh.html

    Was Rod was telling the truth about the data?

    Comment by Hank Roberts — 18 Nov 2010 @ 1:19 PM

  102. Maya, I actually found that paper by when I read the Vermeer-Rahmstorf paper:

    http://www.pik-potsdam.de/~stefan/Publications/Journals/vermeer_rahmstorf_2009.pdf

    I was looking for something that had to do with the most recent mm per year as that is what is being commonly attacked with claims of 1.x mm per year, of which there are a lot of out on the internet.

    Because you can’t get to “three feet” by 2100 at that rate.

    A few weeks ago I asked what the number of mm of rise per year would be in 2100, and I accept Anonymous Coward’s helpful explanation for why I’m not going to get an answer for that question until, I guess, the end of 2100.

    Comment by JCH — 18 Nov 2010 @ 1:27 PM

  103. Bob: what did you make of this?:

    The trap for n00bs (basically, humanity) is that carbon dioxide has a limiting effect on precipitation, while warming of course increases the amount of water vapour in the air. Since temperature change lags carbon ppm (parts per million) change, the air will stay relatively highly water-logged for awhile after the carbon is scrubbed out. Suddenly removing that carbon allows precipitation (rain) to potentially spike way, way, way above normal, or even totally torrential, levels.

    Comment by Didactylos — 18 Nov 2010 @ 1:58 PM

  104. Francis (#66),

    I think you may be right that this sort of approach might be used more widely. Someone in USGS sent me this link http://www.chesapeakeadaptation.org/ which suggests that application here may be complex. While there is a mix of responses to sea level rise, abandoning homes and infrastructure seems to be prevalent.

    Comment by Chris Dudley — 18 Nov 2010 @ 2:19 PM

  105. John P. Reisman (OSS Foundation) (88), while she might have expounded on it a little, isn’t Curry’s comments on uncertainty – which you belittle – pretty much along the same lines of the Inter Academy Council report recently discussed in RC?

    A minor curiosity: would you say that there are NO (that’s zero) regions that might actually benefit from a warmer and/or wetter climate?

    Comment by Rod B — 18 Nov 2010 @ 2:27 PM

  106. JCH,
    We are not going to reach 3 feet by 2100 at the current rate of ~2.5 mm/yr. That number will be obtained only by some significant melting of the Greenland ice sheet. Hence, much research has circulated around the melt rates and stability of the ice fields.
    Barton, are you saying we should ignore the recent data also? Or are you incapable of recognizing a trend line on a graph?
    Rod, nice post. I did not realize they were so precise.
    Hank, do you think it is a coincidence that Chuck & White and Holgate found an acceleration in the sea level rise occurring simultaneously with rising Greenland temperatures?

    http://www.agu.org/journals/ABS/2006/2005GL024826.shtmlhttps://www.e-education.psu.edu/files/earth540/file/2006GL028492.pdf

    Comment by Dan H. — 18 Nov 2010 @ 2:28 PM

  107. BPL, likewise I would assume you accept that the temperature drop from 1950 to 1980+ is a bona fide trend….

    Comment by Rod B — 18 Nov 2010 @ 3:03 PM

  108. Hank, David’s post said, “2007 had an area minimum of 2.9615631 million sq km….” I pointed out that is a number with 8 significant figures to the 1/10 of a mile. Now, I am being untruthful here because why, exactly??? I suggest you look closely at the referred number. Count the digits, etc…..

    Comment by Rod B — 18 Nov 2010 @ 3:16 PM

  109. 105 (Rod B),

    My opinion…

    Curry was way overselling the uncertainty aspect, to the point of “why bother doing anything about anything, we’re all going to die eventually.” It’s one thing to be honest about uncertainties, and another to use them as an excuse to claim, or at least strongly imply, that the problem is therefore insurmountable.

    As far as whether warming will be beneficial to someone, somewhere… someone benefits if you personally die of cancer (the doctor and nurses that get to treat you, the beneficiaries of your will, the person who’s then able to move into your home or apartment). Someone would benefit if an Andromeda Syndrome style illness killed every living person in the U.S.A. Someone benefits from everything, no matter how calamitous or evil an event may be. What we’re interested in is net effect, and justice, and the net is decidedly, predominantly, and unequivocally bad and unjust.

    Comment by Sphaerica (Bob) — 18 Nov 2010 @ 3:28 PM

  110. 103 (Didactylos),

    As I said, I did not vouch for the quality of the game, or the truth of the lessons behind it, just that it’s a clever way to promote the narrative.

    Unfortunately, because it involves such far future events, it is both a difficult situation to model, and difficult to question any assumptions they make (i.e. who’s to say when they are right or wrong?).

    On a separate note, I only just realized that you chose your nom de plume from Diskworld, along with some of the hidden meanings behind it. Touché.

    Comment by Sphaerica (Bob) — 18 Nov 2010 @ 4:11 PM

  111. Dan H #78, what Stefan said. The less said about the burtonsys analysis, the better.

    Jathanon, the tide gauges analysis does not correct for isostatic crustal movement. That is only necessary for the satellite measurements. The tide gauges are the measure of the sea level at particular coastal sites. This is ultimately the main concern for sea level rise.

    In fact, precisely the opposite. The satellites directly observe the absolute location of sea level in space relative to the geocenter from known locations in orbit. No correction for crustal motion is needed — the Earth crust is nowhere involved in the measurement process.

    Tide gauges OTOH are part of the Earth crust by construction — if you want to derive a precise value for global sea level rise, you must remove the local motion for each individual tide gauge. This becomes especially important as tide gauges are very unequally distributed geographically, with lots of them surrounding the Baltic sea (something that makes me particularly happy!). You have to apply a spatial averaging that takes this into account and does not over-weight the areas of dense coverage.

    Then, and only then, if you want to study the effect of global sea level rise on a particular location, do you account for the vertical crustal motion in that location. That’s what we do in Fennoscandia where a sites like Kemi and Furuögrund may move up (relative to the geocentre) by as much as 10 mm/yr. This nicely cancels out part of sea level rise up here; but most parts of the world are not as lucky.

    Comment by Martin Vermeer — 18 Nov 2010 @ 4:12 PM

  112. Rod, surely you can understand people being skeptical about your tone and nit-picking?

    Yes, I’d guess that their precision exceeds the accuracy in those numbers.

    Ignoring the clear decline in ice (down over a third from its mean) while picking at some silly nit is to miss the forest for the trees.

    I’m sure people here feel like you’re trying to direct attention away from the fact that 1/3 of the ice is missing onto something – anything – else. Given your posting history, I certainly feel that way.

    Comment by David Miller — 18 Nov 2010 @ 4:25 PM

  113. JCH, I’m glad I’m not the only one who has had trouble sorting out the sea level rise rate! I hadn’t found this more recent paper; the projections there are even higher. Thank you for that; I will read it. Obviously we aren’t at 1+ mm anymore…

    Comment by Maya — 18 Nov 2010 @ 4:35 PM

  114. Sphaerica (Bob) wrote: “Someone benefits from everything, no matter how calamitous or evil an event may be.”

    I suppose that’s true. Just as humans eventually benefited from the extinction of the dinosaurs, someday other species that eventually evolve over millions of years after we destroy the Earth’s biosphere will benefit from AGW.

    Comment by SecularAnimist — 18 Nov 2010 @ 4:39 PM

  115. Dan H. – in response to your post at 67:

    74 Jathanon says:
    17 November 2010 at 5:09 PM

    As for the tide gauge analysis, I don’t see where they corrected for isostatic crustal movement.

    Your response back:

    78 Dan H. says:
    17 November 2010 at 7:10 PM

    Jathanon, the tide gauges analysis does not correct for isostatic crustal movement. That is only necessary for the satellite measurements. The tide gauges are the measure of the sea level at particular coastal sites. This is ultimately the main concern for sea level rise. Only 19 stations had recorded sea level rise above 3 mm/yr during the measurement period, while 14 had drops in sea level of greater than 3 mm/yr. The average rate of sea level rise was only 0.6 mm/yr. This is the concern, after all, that the ocean will rise above its current level and inundate low lying areas.
    Several people seemed to miss my point about using short-term data trends. Extrapolating them into the future is a fool’s venture.

    This is the pertinent part of your post at 67:

    67 Dan H. says:
    17 November 2010 at 2:39 PM

    Analysis of the NOAA tide gauge data yield a median SLR of 1.1 mm/yr with no acceleration observed during the 20th century.
    http://www.burtonsys.com/climate/MSL_global_trendtable1.html

    To which came this response from a scientist:

    [Response: This link is a good example of why there is professional science, published in peer-reviewed journals. Burton has simply forgotten to correct the station data for glacial isostatic uplift - quite a few stations are subject to land uplift resulting from the melting of the ice sheets of the last Ice Age, which is often bigger than the sea level trend (e.g. in Finland uplift can be over 9 mm/year). This is completely standard with sea level experts. -stefan]

    Are you disputing the above?

    What is your source for your claim of a rate of 2.5 mm per year?

    Comment by JCH — 18 Nov 2010 @ 4:58 PM

  116. Dan H 106: Barton, are you saying we should ignore the recent data also? Or are you incapable of recognizing a trend line on a graph?

    BPL: Not only am I capable of understanding a trend, I’m capable of defining one, which you apparently are not. A “trend” is not any jog in a series. For something to be a “trend” as the word is used by statisticians, it has to be statistically significant–not just in the direction that pleases you. Adequate sample size is a core concept of statistical analysis. I’d advise you to crack a book on the subject.

    Comment by Barton Paul Levenson — 18 Nov 2010 @ 6:12 PM

  117. > the sea level at particular coastal sites. This is
    > ultimately the main concern for sea level rise.

    Do you think all sea level cities are somehow rising fast enough to stay ahead of the rising ocean? How would that be happening?

    Is this the “expanding Earth” notion?

    Comment by Hank Roberts — 18 Nov 2010 @ 7:01 PM

  118. Rod B.@107, It’s actually several trends:

    http://rabett.blogspot.com/2010/11/anti-watts-effect.html

    Comment by Ray Ladbury — 18 Nov 2010 @ 8:50 PM

  119. #77 Sphaerica (Bob)

    Interesting idea. But when I roll it over I see a few issues. It seems idealistic. It’s hard to quantify the wager and it would be even harder to get people to buy into. In other words it may be difficult to estimate the ‘appropriate fee’ through quantification as the costs will roll and accelerate exponentially through time, eventually becoming unaffordable, thus rendering the wager moot.

    We need a price on carbon that does the least damage and is the most efficient in achieving meaningful success sooner rather than later. It should, as best as possible, eliminate the risks of inefficient spending as we need expenditures to be both efficient and effective.

    Comment by John P. Reisman (OSS Foundation) — 19 Nov 2010 @ 2:53 AM

  120. #105 Rod W. Brick

    Scientists already concentrate on certainty. The IAC pointed out that the uncertainties need to be understood properly. Curry was not only overselling the uncertainty, she was making statements outside of her expertise. I do think she was overselling her opinion and this is similar to the Pielke Sr. Problem and the Svensmark problem. When scientists state opinions that reach beyond what the research indicates, and in these cases, in the opposite direction, and that gets in the way of needed policy, then we all have a problem.

    I am not saying scientists should not have opinions, but those opinions need to be reasonable in the light of the evidence. John Christy is in the same boat. I can state right now that a 1 or 2 C rise is not outside the range of natural variability for the planet. But when I say that’s no big deal, then I am ignoring a whole host of issues that I may not be aware of that will be impacted and cause other dominoes to fall. Look at what is happening in America, it still has growth but unemployment is pushing the edges and I think now one out of seven Americans are getting food stamps. That is not a small number. The system does not seem to be as resilient as some would like to think. And such lack also has costs.

    Let us not forget, it’s all about the economy.

    As far as benefits from global warming. That is a more complex question than you might think. Let’s say you live in Norway, and Norway’s climate becomes nicer. That sounds like a benefit. But then let’s say everyone wants to live in Norway because their countries are becoming less habitable? How nice will it be in Norway? And let’s not forget that what you might call a benefit, will likely produce some rather inconvenient snow storms in that region due to increased precipitation.

    BTW – Admiral Titley, Chief Oceanographer for the United States Navy, stated in his testimony yesterday that “September ice volume was the lowest recorded in 2010 at 78 percent below its 1979 maximum and 70 percent below the mean for the 1979-2009 period.”

    http://science.house.gov/publications/Testimony.aspx?TID=15561

    Interested in signing the petition yet?

    Economics: Balancing Economies
    October Leading Edge: The Cuccinelli ‘Witch Hunt”

    Fee & Dividend: Our best chanceLearn the IssueSign the Petition
    A Climate Minute: Natural CycleGreenhouse EffectClimate Science HistoryArctic Ice Melt

    Comment by John P. Reisman (OSS Foundation) — 19 Nov 2010 @ 2:54 AM

  121. Oops

    “Scientists already concentrate on certainty.”

    should be

    Scientists already concentrate on uncertainty.

    of course they try to derive certainty by elimination or reducing uncertainty :)

    Comment by John P. Reisman (OSS Foundation) — 19 Nov 2010 @ 5:57 AM

  122. In addition to the rest of the kudos the article deserves, let’s savor the lead for a moment:

    “With a tense pilot gripping the stick, the helicopter hovered above the water, a red speck of machinery lost in a wilderness of rock and ice.”

    In other words, climate scientists are heroic, daring men (and women) of action who risk their lives in desolate places to find the truth.

    Nice to have a counter-narrative to: scientists are aloof, socially-challenged cranks manipulating data, running computer models and carefully orchestrating a worldwide hoax by sending cranky emails.

    If you want to win this war, it’s all in how you craft the lead. Gillis hit it out of the park.

    Comment by Steve Runge — 19 Nov 2010 @ 8:23 AM

  123. Barton,
    Before you saw something foolish again about trends, you might want to view the graphs to which Wikisteff linked (#84). Several of the temperature profiles show a large increase from 1890-1940. I think that would qualify as a “trend.” Wikisteff selected Upernavik as an example. The smoothed trend line showed an increase of 2-2.5C over those 50 years, even though the annual values show much larger fluctuations. The trend over the next 50 years was a decrease of about ~1C. While the graphs did not show the statistical analysis, they look fairly convincing (even to you). The others stations show similar trends. The current increase has only occurred during the past 10 years.
    Maybe you should check the data again before making any more snide comments.

    Comment by Dan H. — 19 Nov 2010 @ 8:26 AM

  124. 119 (John),

    Interesting idea. But when I roll it over I see a few issues. It seems idealistic.

    For a previous statement of this, reference my previous post here.

    But in a nutshell, I wasn’t really serious about the wager idea, and the main point of it was that if the FF companies were put in a position to choose between a relatively small, set fee now (i.e. the cost of mitigation) versus an undefined, probably huge, ongoing and debilitating payout later (i.e. the cost of late mitigation plus adaptation plus damages), then the FF companies would right now admit that there is a problem and pay the small, set fee.

    They only balk and lobby for inaction because (from a purely profit point of view) they have everything to lose and nothing to gain otherwise. It is in their interests to milk every dollar out of FF that they can, while at the same time trying to position themselves to dominate the energy market of the future (and the longer they delay, the more likely they are to be the dominant players in that market).

    More to the point, all schemes currently focus on trying to attach a fee to FF use (the hidden cost of climate change), in an effort to restrict it’s use and level the playing field for new technologies and behaviors which, in the present, are not competitive with FF unless that hidden future cost is taken into account.

    Fee and dividend aims to do this in the simplest possible way, by attaching the fee up front to the producers, rather than individually to each consumer in a long chain, and by simply giving a bit of the dividend to everyone, rather than trying to control how and where the money is spent on new technologies and behaviors.

    A “wager” scheme (as unworkable as it certainly is) would aim at saddling FF producers with not only the cost, but the decision of whether or not to take the risk. Don’t just make them pay, but make them choose between business-as-usual-with-future-risk versus acceptable-action-now (and in so choosing admit to the truth of the matter).

    Part of the need for a “narrative” today is because there are different parties with different objectives (FF companies, FF countries, developing countries, etc.). One way to win the “narrative game” is to take away those conflicting objectives and to get everyone on the same side, and one (impossible) way to do that is to say: “Okay, you think there’s no climate change? Then put your money where your mouth is. Keep your profits, but also accept the lion’s share of the risk.”

    Comment by Sphaerica (Bob) — 19 Nov 2010 @ 10:00 AM

  125. #122–

    Yes, I agree. And examples of this are not hard to find; one of the most misrepresented facets of modern climate science is that it’s all modelers working in ivory towers. While modelers work hard and do indispensible things, it’s also true that there’s a whole bunch of folks going to lengths that do merit the term “heroic” in order to get the data that’s needed.

    I tried to emphasize that part of the narrative pictorially in this book review:

    http://hubpages.com/hub/Climate-change-resources–Fixing-Climate–A-review

    Actually, that would make a great topic for a stand-alone article. If anyone would like to suggest examples, links, sources or anecdotes of such, please feel free to share them–either below (with the moderators’ approval) or offline via my website. (Click on my name to access. It has a direct email contact button on the home page.)

    There’s history there, too–I’m thinking of De Saussure’s Alpine data, some of which was used by Fourier; Tyndall actually wrote a paper with (I think) Thomas Huxley on glaciers–that’s where he really caught the “Alpine bug”–and (a bit less “heroic” but still noteworthy) Samuel Langley’s Lunar light observations, used by Arrhenius. Those all got a mention in my historical articles on those worthies–linked here repeatedly, and well-supported (thank you!) by RC readers, so I won’t link them again today!–but could perhaps receive a little more focus in themselves.

    Comment by Kevin McKinney — 19 Nov 2010 @ 10:15 AM

  126. 123 (Dan H.),

    I’ll one-up your trend game. Look at this graph here.

    Notice how, about 20,000 years ago, the planet started to warm? Yeah, it seems to have leveled off in the last couple thousand years, but there’s a clear 20,000 year trend. The most recent few thousand years just isn’t long enough to measure a trend when we’re talking about things of this scale.

    So it is painfully obvious to anyone that current warming is merely part of an ongoing, tens-of-thousands-of-years long trend, and we have to wait at least five or ten thousand more years to be able to say whether or not the trend is continuing.

    To put it another way: playing games with numbers or trends without understanding of or attention to the mechanisms behind them (much like Rod B. and his ice extent accuracy/precision silliness) is just that, playing games. That’s what’s so annoying about deniers, because it’s so very easy for anyone to cherry pick facts and numbers and play game after game after tiring, endless game.

    Comment by Sphaerica (Bob) — 19 Nov 2010 @ 10:15 AM

  127. 122 (Steve),
    125 (Kevin),

    Good points, all. In fact, I think there would be huge value in a book/movie/TV show/series of articles/web site which chronicles the work and lifestyles of a wide variety of climate scientists. A demonstration of the broad nature of the work, and the fields of expertise, and the sacrifice and sense of adventure involved, would be an excellent narrative to tell. It would be educational, entertaining, and expose the silent lie being propagated by the deniers, by putting a face (an admirable face) to the thousands in the trenches doing the important (and currently thankless) work.

    That would be a compelling narrative, and a backdoor to climate education and respect.

    It would also be an important counterbalance to the fantasy caricature that has been created by the denialosphere, the one of a handful of grant-grubbing old men who drive to work in their Lexus SUVs, where they spend a few hours a day fabricating computer programs that massage the data and use falsify model outcomes to earn them even more lucrative grants (the money for which can be mindlessly spent on any luxurious trinket they have their eye on)…

    …That is, when they aren’t jetting around the globe for all expenses paid climate conference vacations, or soaking up the limelight on all of those late night talk shows that are so eager to host them, and pay them for their time, because we all know the climate scientists are in it for both money and fame (not to mention the chicks… don’t forget the chicks! — being a climate scientist today is a huge, huge chick magnet).

    [Response: Good point--the chick factor is commonly left out of the calculus. Opposing polarity magnets perhaps, but magnets none the less. OK, back to counting the ol' grant money...--Jim]

    Fox News is a particularly gullible media outlet for rewarding the sinister climate scientists for their foul deeds.

    That is the sort of thing Revkin et al should be doing regularly (the climate scientist profiles, not the denial-fantasy image, I mean), and perhaps should have been doing for some time.

    Perhaps RC could engage a good journalist (or several), someone who is good at writing the sort of thing Justin Gillis produced, to post climate scientist profiles here on a regular basis.

    Comment by Sphaerica (Bob) — 19 Nov 2010 @ 11:07 AM

  128. #78 Dan H.
    I noticed a similar pattern with the tidal gauges, on their relative measurements. While satellites give a better measurement wrt the earth’s geocenter, they do not have a long data record. In addition, it would be interesting to wonder what the sea floor is doing.

    Swing over to http://www.rimfrost.no/
    it shows the Arctica ave. temps almost back to the 1950 levels.

    Comment by J. Bob — 19 Nov 2010 @ 11:14 AM

  129. In case anyone is interested.

    I embedded all the panel videos from the Hearing in the Nov. Leading Edge Report

    http://www.ossfoundation.us/projects/environment/global-warming/summary-docs/leading-edge/2010/nov-the-leading-edge

    Comment by John P. Reisman (OSS Foundation) — 19 Nov 2010 @ 11:16 AM

  130. 124 Bob

    If there were a simple way to quantify, it would be a good idea though, but only if we did not crash the economy and that in iteself is still a bet.

    Sorry I did not get the joke; sometimes my humor factor drops after a certain amount of months in Switzerland.

    I still try to tell jokes over here once in a while and I still get those polite looks and then a curious pause as people try to determine if they should be laughing or not?

    Comment by John P. Reisman (OSS Foundation) — 19 Nov 2010 @ 11:21 AM

  131. Martin Vermeer (111), helpful comment. But won’t the satellites miss the crustal effect (if any) while measuring the absolute level correctly? It seems almost the same analytical problem of tidal gages that do account for crust movement but then get the absolute measurement wrong.

    Comment by Rod B — 19 Nov 2010 @ 12:37 PM

  132. I particularly enjoy Bob (Sphaerica)’s writing here; thank you. The idea of highlighting what scientists do is terrific. Last night I was fossicking around in links from the A Train article and found myself dazzled (along with slowing down my computer) by the material. In particular, the levels of heat anomaly and CO2 values of 297 and 298 on the spot over western Greenland and near the air trail from northern Europe to northeast US rather fascinating. (I don’t know enough to say anything except that as a silly amateur I couldn’t help thinking of watching those maps of where the plane is going and finding those numbers just there!)
    http://www.youtube.com/user/NASAexplorer

    NASA is doing a good job with their site on the presentation side. I’m failing to find what I’m looking for, but the A train early comments have a few good links. This for now:
    http://climatesignals.org/

    However, as usual I am asking anyone who’s interested to weigh in early on Andy Revkin’s recent post (it’s early enough that comments will show up quickly) on the anniversary of “climategate”.
    http://dotearth.blogs.nytimes.com/2010/11/19/reviewing-the-bidding-on-the-climate-files/

    I know it’s unrewarding, but the truth needs to maintain a toehold. The penultimate article is also slightly misleading though I understand the point Andy is trying to make. Personally, I think we need more spectacle to get people’s attention (though in the face of Russia, Pakistan, Haiti, and events closer to home it’s hard to know what will get through).

    Comment by Susan Anderson — 19 Nov 2010 @ 12:58 PM

  133. David Miller (112), your’s is a fair criticism – much of my questions and assertions are over seemingly trivial stuff. None-the-less, pointing out inaccuracies that are blatant, even if nit-piky, might be helpful in a scientific forum. You’re in essence telling me of course I shouldn’t believe the proclaimed figures because they are clearly and egregiously wrong. Why then should I be expected to believe the other stuff that’s said?

    If you are trying to win the hearts and minds (and actions), spouting self-evident crap, however trivial by itself, is not a good tactic.

    Comment by Rod B — 19 Nov 2010 @ 1:59 PM

  134. Sphaerica (Bob), an interesting exercise. One clarification: in this type of scenario a business will always take the certain over the uncertain, and the inherent “truth” in either will have nothing to do with it. Re the prevalence of paying a settlement explicitly without admitting wrong-doing.

    Comment by Rod B — 19 Nov 2010 @ 2:20 PM

  135. 132 (Susan),

    I particularly enjoy Bob (Sphaerica)’s writing here; thank you.

    Thank you, and you are welcome (and now I can go to sleep tonight knowing that there’s at least one person on the planet whom I am not annoying).

    Comment by Sphaerica (Bob) — 19 Nov 2010 @ 3:39 PM

  136. 134 (Rod B),

    One clarification: in this type of scenario a business will always take the certain over the uncertain…

    The recent adventures with credit default swaps would seem to contradict this statement. In fact, the ability to win by taking the right risks is the hallmark of successful entrepreneurs and corporations throughout history.

    The fact is, regardless of your reasoning as to why, a refusal of the wager would be an admission that the negative outcomes are tangibly possible, and so would put to bed the great number of inane outliers who are currently considered mainstream (Watts, Nova, Goddard, and others). The discussion would move to the center, where it belongs, and we’d be expending energy more usefully talking about how much, how soon, and what to do when and how, rather than endless discussing tripe like the Medieval Wish Period, the Urban Heat Ignorance effect, the Pathetic Decadal Oscillation, and Clamorgate.

    Comment by Sphaerica (Bob) — 19 Nov 2010 @ 3:52 PM

  137. Rod B, I see you’re still trying to misdirect things.

    You’re still ignoring the fact that we have 1/3 less ice {area|extent} than the mean and focusing on the improbable precision of a piece of data.

    Me, I look at 4.12345678 million sq km as the output of a program that analyzes the satellite data. Said model undoubtedly breaks said data into much smaller chunks, analyzes it for ice content, and comes up with a number for extent or area, and the number spit out for the date is the sum of the smaller chunks.

    It’s not hard to imagine that said model is storing data in floating point format, and the final output is simply formatted with a few extra digits.

    The fact that you seize on the number of digits printed out thusly:

    “You’re in essence telling me of course I shouldn’t believe the proclaimed figures because they are clearly and egregiously wrong. Why then should I be expected to believe the other stuff that’s said?”

    Think about that Rod. Are you really trying to say you can’t believe the ice is down 1/3 because someone printed 8 digits instead of 4? Because that declares very loudly that you’re not interested in what climate change is doing to the world, you’re only interested in sowing doubt.

    Thanks for clearing that up. I didn’t doubt it, but others may have.

    Comment by David Miller — 19 Nov 2010 @ 4:20 PM

  138. Dan H 123: Maybe you should check the data again before making any more snide comments.

    BPL: I am intimately familiar with the data, thank you. I also know how to use it, which you apparently do not. As to a downward trend 1950-1980–what was the slope and what was the t-statistic on the coefficient? And how did you pick your endpoints? And why use 40 years when 169 years of data are available? And, BTW, do you accept evolution and an old Earth? Just wondering…

    Comment by Barton Paul Levenson — 19 Nov 2010 @ 4:28 PM

  139. Bob: the Medieval Wish Period, the Urban Heat Ignorance effect, the Pathetic Decadal Oscillation, and Clamorgate.

    BPL: ROFLMAO!!! I love it.

    Comment by Barton Paul Levenson — 19 Nov 2010 @ 4:31 PM

  140. J. Bob,
    Thanks.

    Comment by Dan H. — 19 Nov 2010 @ 5:54 PM

  141. Judith Curry said “In a rational discussion of climate change, the question needs to be asked as to whether the framing of the problem and the early articulation of a preferred policy option by the UNFCCC has marginalized research on broader issues surrounding climate change, and resulted in an overconfident assessment of the importance of greenhouse gases in future climate change, and stifled the development of a broader range of policy options.”
    This is a rather ridiculous comment on a number of fronts. What is the “early articulation of a preferred policy option by the UNFCCC?” Is it the reduction of CO2 output? What are the other policy options she would like to have considered? What are the “broader issues surrounding climate change” she would like to have considered?

    The earth exists as it does today because of the heat input from the sun, the atmospheric greenhouse effects, the reflective effect of the surface and the interplay of various systems. The primary forcing that is changing is human emissions of CO2. All of the work and modeling is trying to figure out how the planetary systems will react and what the temperature impact will be over time. Where is the research lacking , and why doesn’t she undertake it or at least propose it so someone else could undertake it?

    Overall, I find her pronouncements to be very vague and not very scientific.

    Comment by Sir — 19 Nov 2010 @ 6:38 PM

  142. Rod B. says, “None-the-less, pointing out inaccuracies that are blatant, even if nit-piky, might be helpful in a scientific forum.”

    Excellent idea! When do you plan to start?

    Comment by Ray Ladbury — 19 Nov 2010 @ 6:40 PM

  143. I don’t know. When I scan an article, I tend to be sensitive to certain kinds of bumpy parts.

    “…Strictly speaking, scientists have not proved that human-induced global warming is the cause of the changes. They are mindful that the climate in the Arctic undergoes big natural variations. In the 1920s and ’30s, for instance, a warm spell caused many glaciers to retreat.

    John R. Christy, a climatologist at the University of Alabama in Huntsville who is often critical of mainstream climate science, said he suspected that the changes in Greenland were linked to this natural variability, and added that he doubted that the pace would accelerate as much as his colleagues feared…

    …The satellite difficulties are one symptom of a broader problem: because no scientifically advanced country has made a strategic priority of studying land ice, scientists lack elementary information that they need to make sense of what is happening…

    …Certain measurements are so spotty for Antarctica that scientists have not been able to figure out whether the continent is losing or gaining ice…”

    An interesting article from a glaciology perspective and descriptive of possibilities, but is it strong from the perspective of climatology and cause and effect of AGW? At least perhaps, psychology being what it is, the downside as a consequence of uncertainty should given more explicit stress in the context of time running out.

    “Uncertainty is not your friend.” — R.L.
    Is there a parable/allegory/whatever that fits that narrative?

    BTW about context, also in the NYT, the brain is a weird thing:

    “Subjects either did or didn’t read an article about the health risks of airborne bacteria. All then read a history article that used imagery of a nation as a living organism with statements like, “Following the Civil War, the United States underwent a growth spurt.” Those who read about scary bacteria before thinking about the U.S. as an organism were then more likely to express negative views about immigration.”

    This Is Your Brain on Metaphors about how the brain confuses the literal and metaphorical.

    Comment by Radge Havers — 19 Nov 2010 @ 8:27 PM

  144. Sphaerica (Bob) (136), true, but your example, betting on uncertainty to make profit through their own efforts, is a whole different scenario/context.

    Comment by Rod B — 19 Nov 2010 @ 11:06 PM

  145. David Miller, that’s nonsense. One tells me “fact A,” “fact B,” “fact C,” and “fact D.” Facts A, B, and C are obvious hogwash to which the explainer readily agrees. But then says, “Yeah, but D is true,” and I’m the silly one if I don’t readily accept his “D” fact??!!?

    Of course one makes precise measurements to the level of the instrument. But the instrument reading does not determine the accuracy of the results. What should I do with an assertion that the Arctic ice extent is measured to be 2,961,563.1 sq.km. +/- 0.1 sq.km. It seems you’re saying I should ignore it because the guy is evidently either just showing off, or has no concept of how to aggregate measurements with a computer working with 8 significant digits in scientific notation, or some such. Then you further imply that I should none-the-less blindly fully accept his next assertion. Other than that his next assertion seems along the party dogma, why else should I be expected to do that?

    Comment by Rod B — 19 Nov 2010 @ 11:31 PM

  146. Ray (142), I think I just did — which is what the fuss is all about…..

    Comment by Rod B — 19 Nov 2010 @ 11:35 PM

  147. Barton,
    Since you think you know everything. Since you seem to have a problem with the analysis by DMI, what is your take on the Greenland temperature data to which Wikisteff linked. You already proved that you are poor with basic arithmetic (#138), but how are you with actual data? Or is your whole purpose here to ridicule others without presenting any productive responses of your own?

    Comment by Dan H. — 19 Nov 2010 @ 11:52 PM

  148. Good grief.

    Rod B, get over yourself.

    We are taught in primary school not to infer precision from numbers that can’t be justified from the original measurements.

    We are also taught not to lose precision mid-calculation. Round off at the end. Or, if you are providing a dataset for further manipulation – don’t round off at all.

    So, David Miller: perhaps you could apologise for failing to predigest everything for people like Rod B.

    And Rod B, perhaps you could apologise for failing to do what is expected of you, namely ignoring precision which you know is irrelevant, and for wasting everyone’s time with pointless argument.

    Then maybe we can get back to important subjects.

    Coda: rounding off to a suitable number of significant figures is no substitute for a proper treatment of the uncertainty. In ice measurements, the absolute error is very large. However, the relative error is much smaller, meaning that we can compare numbers from the same data series with very high precision.

    Comment by Didactylos — 20 Nov 2010 @ 3:15 AM

  149. Dan H–chill. . . . (If that’s not too ironic a suggestion in this context.)

    I doubt that Barton \has a problem with the analysis by DMI.\ (Though clearly he is well able to speak for himself, and perhaps will on this score.) What I would have a problem with, is using this data–or actually, a subset of it, the Upernavik graph–to obfuscate the obvious truth, which is that Greenland is clearly experiencing the same warming trend seen just about everywhere else on the planet.

    It’s curious that Upernavik was selected; it \just happens\ to exhibit the steepest decline from 1940. I suppose it’s true that the other station trends are \similar,\ but it’s also misleading: an unwary reader would tend to think that Upernavik was actually a representative example. It’s important that a writer play fair in such cases.

    A contrary example would be to seize upon the data for Illulissat, where the smoothed trend line is clearly well above the peak from the 30s.

    Looking at the *all* the information, you can see that:

    1) Every place shown has been warming recently; and
    2) The 30s were much warmer in Greenland, relative to today’s temperatures, than was Denmark.

    None of which exactly rocks my world.

    [Response: It's worth asking why the DMI analysis is suddenly gaining favour (well, actually that is obvious - easy to find and gives the 'right' answer). More interesting perhaps is what it actually consists of - it uses the ERA40 reanalysis from 1958-2002 (which is ok, but long term trends can be affected by instrument changes, and the onset of satellite data in 1979), combined with a different NWP model from 2002-2006, and then a newer model since then. Since different NWP models give different results even with the same input, the comparison of the current analysis with the ERA40 climatology is prone to having artifacts. Thus I would not recommend using DMI for trends at all. You would be much better using a consistent up-to-date reanalysis like ERA-Interim or newer. - gavin]

    Comment by Kevin McKinney — 20 Nov 2010 @ 7:13 AM

  150. #140 Dan H.
    Your welcome. Here are a few other points with the problem of accurate seal level readings:
    How accurate are the tidal gauges and satellite measurements?
    One problem with the satellite measurements is the constant motion of gravitational effects on the satellite (due to shifting of the earth’s center of gravity, or local gravitational anomalies). While they may be small, we are dealing in mm’s. If one looks at the best current GPS accuracy, it’s about 1.5 m vertically.

    In addition, if the land area is moving or “uplifting”, what is the sea floor doing?

    P.S. What did you think of the http://www.rimfrost.no/
    Arctica average?

    Comment by J. Bob — 20 Nov 2010 @ 10:32 AM

  151. I saw a good example on how not to do the narrative last night, on the Weather Channel. It was a documentary from 2009 titled “Future World,” clearly crafted to be sensationally alarmist, in a time frame (2025) that would impact people alive today, but far enough in the future that people wouldn’t naturally think “that can’t happen.”

    First, it purported to show possible calamities that could happen by 2025. While each of them might be likely to happen eventually (100 years?) somewhere to some degree, and improbably could happen to the extremes presented, and could in very remote circumstances happen by 2025… the idea that any of them would happen, as portrayed, by 2025, is really stretching it.

    The scenarios included a dust storm that inundates Las Vegas, a desert locust plague that devastates Italy and France, a firestorm that destroys Los Angeles, and flood waters that engulf Washington, D.C.

    They didn’t include the simple, obvious, and I think more likely scenario of reduced food production in the U.S. Midwest, with accompanying economic pressures and impacts on ordinary daily lives (although I don’t know that 2025 is a valid time frame for this scenario either, and I suspect it’s nowhere near it).

    On top of this, the eye candy did not come close to coinciding with their comments, instead going above and beyond, to visually portray something ridiculous. For example, when talking about rising sea levels, they showed huge waves (several stories high) flooding in and swamping city blocks. They showed a map of the world with the shorelines advancing and encroaching on fully one third of the African and South American continents.

    Then, to put the icing on the cake, they finished with a case of a Texas farmer involved in seeding clouds to make rain in a drought stricken area, with a voice over that implies that scientists are working hard and will come up with technology to save us from all of these events, so sorry if we scared you, you can just go back to bed now, trust in science, all is well.

    Sheesh! This is exactly the sort of garbage that the deniers (rightfully) crow about. It was complete nonsense, and only serves to confuse people, and to give weight to the “They’re alarmists! Don’t listen to them!” cries of the denial crowd.

    [[[
    On a side note, the idea of the desert locusts extending their range into a dryer, warmer Mediterranean was interesting. In the 2004 locust outbreak, swarms reached Israel, Crete and Portugal. The danger of an impact on France/Italy was clearly exaggerated to make it feel like it was affecting Western civilization (after all, who really cares about Africa?*), but when merely considering the impact in both human lives and dollars of increased locust activity in Africa and the Middle East, it is still very frightening, and one more potential outcome of global warming that I'd never considered.

    I'm unsure, however, if global warming is more likely to help (extreme rain events, warmer winters) or harm (reduced precipitation overall) desert locusts. I'll have to do more research.

    * Before anyone freaks out, "who really cares" comment was sarcasm.
    ]]]

    Comment by Sphaerica (Bob) — 20 Nov 2010 @ 11:02 AM

  152. Interesting random desert locust fact, pertaining only to a swarm of some unknown size (not necessarily one that could strip a European country bare, mind you) reaching Italy or France:

    In the past there have been some spectacular and very long distance swarm migrations, for example from North-West Africa to the British Isles in 1954 and from West Africa to the Caribbean, a distance of 5,000 km in about ten days in 1988.

    Comment by Sphaerica (Bob) — 20 Nov 2010 @ 11:21 AM

  153. As I suspected (just to clarify, then no more about desert locusts, I promise):

    Even more impressive is the evidence of an actual recorded flight of locusts from the Canary Islands to the British Isles in 1954, a distance of 1600 miles, although only a small proportion of those that set out completed the whole flight.

    Comment by Sphaerica (Bob) — 20 Nov 2010 @ 11:24 AM

  154. Re Gavin’s point about DMI being based on a couple of reanalyses–I’ve pointed out to some of my “usual suspects” that if they truly think that modeling is bereft of any credibility, they really shouldn’t (for consistency) be citing DMI just because they like the answer. The only answer I’ve received so far is a protestation that (basically) they’ve heard somewhere that DMI has the best Arctic temperature data, because, well. . . just because.

    Which tells me quite a lot, in a “meta” topical sort of way.

    Comment by Kevin McKinney — 20 Nov 2010 @ 1:26 PM

  155. Rod B #131, huh?

    J. Bob #150, don’t you feel a moral obligation to read up on a subject, especially a scientific one, before trying to pretend you know what you’re talking about?

    If one looks at the best current GPS accuracy, it’s about 1.5 m vertically.

    Eh, not even close. You could start by finding out how on-board geodetic carrier-phase GPS is actually being used for satellite tracking, and how precise it is. You know, some of us have studied this stuff and applied it successfully. Just stringing together sciencey-looking words into syntactically well-formed English sentences and hoping nobody notices doesn’t make you look good.

    Comment by Martin Vermeer — 20 Nov 2010 @ 3:38 PM

  156. Martin Vermeer, J. Bob …

    In about 30 seconds of google searching and reading an abstract in which the author’s talk about using GPS to pin down satellite location to within 0.07m, which would appear to be a smaller number than the 1.5m proclaimed by J Bob.

    Couldn’t post the link, RC sez it’s spam.

    Comment by dhogaza — 20 Nov 2010 @ 4:28 PM

  157. “I found an abstract” (deleted too much trying to get around the spam catcher).

    Comment by dhogaza — 20 Nov 2010 @ 4:29 PM

  158. #155 Martin says

    “J. Bob #150, don’t you feel a moral obligation to read up on a subject, especially a scientific one, before trying to pretend you know what you’re talking about?”.

    OK, Martin, here’s my reference, where’s yours?

    http://www.maps-gps-info.com/gps-accuracy.html

    Comment by J. Bob — 20 Nov 2010 @ 5:32 PM

  159. Dan H. — BPL has a long hisotry of doing useful work regarding climate. Try these:
    http://bartonpaullevenson.com/Greenhouse101.html
    http://bartonpaullevenson.com/NewPlanetTemps.html

    Comment by David B. Benson — 20 Nov 2010 @ 5:51 PM

  160. JBob – It seems a bit strange to be citing the accuracy of your “personal navigation devices” on a science site: “the bottom line is that GPS accuracy depends on the GPS technology in use.”

    Don’t you think there might be a bit better technology available to science and the folks who designed, implemneted and maintain the satellite system? Investigate Relative Kinematic Positioning a bit.

    Comment by flxible — 20 Nov 2010 @ 7:02 PM

  161. Thanks, David.

    Comment by Barton Paul Levenson — 21 Nov 2010 @ 5:40 AM

  162. dhogaza, BPL… thanks. The 0.07 m is conservative.

    J. Bob, for a challenge, let’s restrict this to papers where 1) I am one of the authors, and 2) there is a free copy on the Internet — like this one. Or this one. Or this one. There are more.

    Enjoy!

    Comment by Martin Vermeer — 21 Nov 2010 @ 11:12 AM

  163. #155 Mark & #156 thank you, for more up to date info on GPS measurement accuracy. You say it’s 0.07m or less. Now am I to assume it’s horizontal accuracy? If that’s the case, vertical accuracy would be about 3-5 times less then the horizontal. So the resulting best GPS vertical measurements are accurate to about 0.21m, or 210mm.

    #160 flxible says use RKP (0.3m), but that’s worse then carrier phase.
    http://en.wikipedia.org/wiki/Global_Positioning_System#Accuracy_enhancement_and_surveying

    It appears that we are talking about geological uplifting measurements in the 2mm/yr range, and the inaccuracy of the measurements is almost 100 times that. Even if the error were reduced by a factor of 10, the error would still be in the 20mm range. When I did a stint in test engineering, for orbital projects, there was a rule of thumb for measurement accuracy. That is, the measuring device had to be about 10 more accurate then what you are trying to measure. This was to reduce the RMS test error. Here we seem to have a case where the measuring instrument has an error of 10 times, or more, then the signal one is trying to measure.

    Then there is the issue of past records. That is ,what was the accuracy of those GPS or Survey, measurements 5,10,20 years ago?

    So unless one can have better methods of measuring “uplift”, that contribution sea level effects may have to be off the table.

    Comment by J. Bob — 21 Nov 2010 @ 11:34 AM

  164. J. Bob #150, don’t you feel a moral obligation to read up on a subject, especially a scientific one, before trying to pretend you know what you’re talking about?

    J. Bob, thank you for your very clear, disappointing, but expected answer.

    Comment by Martin Vermeer — 21 Nov 2010 @ 12:40 PM

  165. Re: 151, sphaerica bob

    How does climate science reach newspapers?

    One of the weak links is university media relations; that’s often the office which crafts press releases of recent studies. I can’t profess to know the process (I’m a lowly writing instructor), but it seems to me that if the news release about Dr. So & So’s recent study doesn’t craft a gripping lead and a good story that can accurately communicate the information, then it will just sink into the swamp of information. If you want to see these releases, just visit EurekAlert.org, sciencedaily.com, or nsf.gov/news. Many of them communicate science to other scientists reasonably effectively, but the leads often miss the boat on relevance to the average, educated person. Here’s an example:

    http://manoa.hawaii.edu/news/article.php?aId=4012

    Here’s the lead:

    Scientists have long known that atmospheric convection in the form of hurricanes and tropical ocean thunderstorms tends to occur when sea surface temperature rises above a threshold. So how do rising ocean temperatures with global warming affect this threshold?  If the threshold does not rise, it could mean more frequent hurricanes.

    Several rules broken. One, the lead spans three sentences. It should be one. Two, the verbs are static: have known, affect, does (not) rise. Three, the logic is too convoluted and vocabulary too polysyllabic for the average person reading quickly. Basically, this isn’t lead material. This isn’t the main story. Sure, those were the findings, but the story is rarely the findings themselves: the story is the significance of findings, the implications, or perhaps the process of discovery. The real story is buried near the end of the article:

    …the tropical atmosphere is warming at a rate that is consistent with climate model simulations…

    Better lead: Researchers in Hawaii have found that changes in the way hurricanes form confirm climate models that predict global warming.

    Would it have run in major papers? Probably not. But at least journalists trolling for stories might have been able to glean its significance in the time it takes to read one sentence.

    Comment by Steve Runge — 22 Nov 2010 @ 10:05 AM

  166. J. Bob,
    I finally had time to look through the Arctic data. For those stations which had long data records, high temperatures were observed in the 1930s and 1940s, and then again in the last two decades. Low were observed from the 1960s-1980s. For the four Greenland stations, two had the highest recorded temperature for the last century in 1947, the other two in 2003, while all four recorded the lowest in 1983-4.

    Many people have asked about the recent change in sea level increase. The change occurred at about the same time that measurements switched from TOPEX to Jason in 2003.
    http://i90.photobucket.com/albums/k247/dhm1353/Climate%20Change/CU2.png

    Comment by Dan H. — 22 Nov 2010 @ 12:04 PM

  167. Dear Stefan,

    in post #30 I asked you:
    “Can you rule out a change of only about one foot; in other words is it possible, that your non-linear extrapolation shown up there is just a wrong model?”
    In post #23 you answered
    “Just adding to that: the entire satellite record (starting 1993) is just one data point in the analysis of our paper. Variability on time scales shorter than 15 years or so is in my perspective not linked to global climate change but likely just “noise” – the result of various internal variability mechanisms. Let’s wait another 15 years for the next data point, then we may see something.”
    This indicates, that in your own opinion there is little knowledge about the trends.

    Your answer in Re #46
    ” I’m always a little surprised by lay people making sweeping statements like: “In fact, the sea has been rising at this rate for thousands of years.” Think about it: this would mean in the Middle Ages sea level should have been about 1.8 meters lower, in Roman times about 3.6 meters lower… Which clearly contradicts the archeological evidence, as discussed e.g. by IPCC.”
    seems to indicate, that you are not willing to attribute any of the recent sea level rise to possible natural cause like the end of the little Ice Age (LIA). Probably I missunderstood this and it’s some kind of German humor..
    But I would really hope, if you could comment/answer on my question.
    After all the sea level rise seems to be the most important concern for humans for the global warming and your statment about the reliability for the data seems the contradict your error bars in the extrapolation.

    Comment by Laws of Nature — 23 Nov 2010 @ 5:17 AM

  168. #166 Dan H. & J. Bob

    While you two are busy fondling each others notions, and romanticizing about short term variability while drinking the elixir of narrowly scoped (cherry picked) data points, the world of physics and reality is sailing away without you.

    Instead, you should be looking at long term trends with attribution and the basic physics. The predictions for 1m by 2100 are looking pretty solid now. There a good chance we may have locked in 2 meters, and there is uncertainly, even a potential for SLR to be higher than 1-2m by 2100?

    After the candles burn down and your dinner by the beach on the island of denial, watching the sunset of reason fade over the horizon of wishful thinking, you will find fantasy eventually replaced by the hard warm facts. What will you say then?

    Economics: Balancing Economies
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    Comment by John P. Reisman (OSS Foundation) — 23 Nov 2010 @ 8:28 AM

  169. John P. Reisman,
    Think maybe we could take up a collection to rent J. Bob and Dan H. a room?

    Maybe Max could join them for a Fun-with-Fourrier three-way.

    Comment by Ray Ladbury — 23 Nov 2010 @ 8:41 AM

  170. 166 Dan H. You have temperatures for the Arctic for a certain period.

    Do you have Sea Surface Temperatures for the same period? Sea ice doesn’t just melt from the top down you know.

    Comment by adelady — 23 Nov 2010 @ 9:59 AM

  171. #169 Ray Ladbury

    ROFLMAO

    Comment by John P. Reisman (OSS Foundation) — 23 Nov 2010 @ 10:56 AM

  172. [edit - try and be constructive]

    Adelady,
    Do you know anyone who has sea surface temperatures for the Arctic going back to 1900? I would like to see them. I do know the US Navy took some measurements back in the 1950s in the open water over the North Pole.

    [Response: Easy, around the North Pole, it will be pretty much a constant -1.8 degC (and it will stay that way until the Arctic is seasonally ice free). - gavin]

    Comment by Dan H. — 23 Nov 2010 @ 12:50 PM

  173. J. Bob:

    #155 Mark & #156 thank you, for more up to date info on GPS measurement accuracy. You say it’s 0.07m or less. Now am I to assume it’s horizontal accuracy?

    No, you’re not to assume so, but obviously you did, and the reason why you did is obvious.

    (it was accuracy in absolute terms, i.e. three dimensions, so the error in the vertical would be <= 0.07m, not greater as you claim.)

    Comment by dhogaza — 23 Nov 2010 @ 1:32 PM

  174. Thank you all for the most helpful info on GPS accuracy.

    However I called professional surveyor. His info was that using Survey grade GPS equipment, there is an vertical error between 3 & 7 mm. This was confirmed from the Canadian government site:
    http://www.geod.nrcan.gc.ca/products-produits/ppp_acc_e.php

    So it looks like the error is about 3-5 times the resolution one is working with. Not the best situation for factoring “uplift” into sea levels.

    Anyway looking at sea level data, around the US Gulf coast (no plate boundaries or glacier effects), there seems to be a fair amount of sea level changes in the early 1900′s. Wasn’t that before high levels of CO2 were around?

    Comment by J. Bob — 23 Nov 2010 @ 8:48 PM

  175. J Bob,
    You should know that whether a 3-7 mm error is significant depends on whether it is random or systematic–and there are ways of dealing with both to achieve better resolution.

    Comment by Ray Ladbury — 23 Nov 2010 @ 10:06 PM

  176. JBob@150: “If one looks at the best current GPS accuracy, it’s about 1.5 m vertically.”
    JBob@158: References a link that discusses consumer recreational GPS units supporting his assertion above.

    MartinVermeer@162 Links various actual studies of crustal deformation and sea level using scientific level GPS methods achieving decimal millimetre precision.

    JBob@163, Apparently ignoring Martins actual science, claims “It appears that we are talking about geological uplifting measurements in the 2mm/yr range, and the inaccuracy of the measurements is almost 100 times that. Even if the error were reduced by a factor of 10, the error would still be in the 20mm range.” Therefor concluding “So unless one can have better methods of measuring “uplift”, that contribution (sic) sea level effects may have to be off the table.”
    So with a hand wave, sweeps Martin off the table.

    And @174, JBob prefers instead to phone a “professional surveyor”, and now believes “using Survey grade GPS equipment” (sounds important!!), there is an vertical error between 3 & 7 mm.” Which in turn he supports with a link to a Canadian Govt site that points out Precise Point Positioning with Dual-Frequency receivers achieves an accuracy of 1cm [10mm], possibly sub-cm, and his mapping-grade receivers [survey grade?] achieved no more than 20cm accuracy, and showing the information he relied on at the beginning was obviously the recreational receiver hardly capable of 1m accuracy.

    So we’ve progressed from 1,500mm @150 and 158, to “the 20mm range” @163 to 3-7mm @174 with anecdotal evidence.

    I’ll take Martin Vermeers science over JBobs musings any day.

    Comment by flxible — 23 Nov 2010 @ 10:46 PM

  177. #175 Ray, if a “error” is correctable, it’s not generally considered a “error”. Most of the “errors” or inaccuracies in the GPS system are corrected, or compensated for. These 3-7mm are the accuracy specs., and are assumed random errors.

    Comment by J. Bob — 23 Nov 2010 @ 11:00 PM

  178. #169–

    I “doubt” it–oh, never mind.

    Comment by Kevin McKinney — 23 Nov 2010 @ 11:05 PM

  179. Sigh. So, lay out a hundred thermometers each accurate to half a degree. How accurately can you determine temperature change in the area using all of them daily?

    Now take a thousand GPS measurements of the same area, each known accurate within 5 mm. How accurately can you determine elevation change in the area using all of the measurements?

    I’m making the numbers up. But I think there’s an issue of measurement accuracy with multiple observations being missed here.

    Comment by Hank Roberts — 24 Nov 2010 @ 1:03 AM

  180. For fans of learning how accurate geodetic dual frequency GPS can be, maybe take a look at the UNAVCO website (Unavco.org), or some of the current polar deployments (Polenet.org). The precision of the GPS is typically 1-2 mm in *position* in the vertical – but over three years or so of continuous data you get a better precision on the *trend* of any vertical motion.

    Comment by Mike W — 24 Nov 2010 @ 3:34 AM

  181. Re: J.Bob getting seven shades beaten out of him…

    The ref’s got to stop this one surely…?!

    Comment by Joe Cushley — 24 Nov 2010 @ 9:04 AM

  182. #181 Joe, I may have lost 7 shades, but there are still a lot more left.

    #162 Martin, while your co-authored papers are interesting, they do not
    answer what I was looking for. That is, how accurate are the “uplift” measurements relating to sea level, not only now, but in the past. While one may measure “uplift”, to mm’s accuracy now, how good was it 10, 20, or 50+ plus years ago when a significant amount of sea level data was being taken?

    Prior to the current GPS system, and older laser ranging, accurate elevation measurements were hard to come by. At least on relatively flat surfaces, one could triangulate with chain, transit or even theodolites for better horizontal accuracy. Elevation in flat coastal areas was another matter. One of the best theodolites we used was the Wild Leitz T-4. That was good for measuring relative elevation just under 1 sec. of arc., in the field. So that gives one an idea of how “good” elevations were measured only ~50 years ago, when tidal data was being accumulated.

    Hence, one might give greater weight to tidal measurements, where geological effects would be minimal.

    Comment by J. Bob — 28 Nov 2010 @ 11:32 AM

  183. Considering that the greatest concern is the sea level rise around the coastal areas, tidal measurements would be of greater importance. A global average will not really tell us much, as many areas will experience much more and others much less. Scandinavian sea level has decreased significantly in the past century (some areas >7 mm/year), whereas many areas along the eastern coast of the U.S. have experienced the largest rise (4 mm/yr). The sea level along the eastern shore of the Pacific Ocean has risen from Southern California down to Colombia, and decreased northward up to Alaska and southward to the tip of South America.

    Comment by Dan H. — 29 Nov 2010 @ 11:01 AM

  184. Dan, the inline response to your previous attempt at this notion should make clear why you’re not making sense here.
    http://www.realclimate.org/index.php/archives/2010/11/sea-level-rise-the-new-york-times-got-the-story/comment-page-2/#comment-191123

    Yes, tide gauges at places experiencing rebound from the last ice age say as long as the land keeps rising faster than the ocean they won’t be in trouble. But most places around the world where people live did not have any glaciers during the last ice age, and don’t have that temporary protection.

    You know this. You looked at the map showing where the tide gauges are when you tried this assertion earlier.

    There’s far more going on here than whether individual cities get wet; sea level rise doesn’t _stop_ conveniently after a short time and doesn’t reverse within millenia. It’s a one-way change for a long time all around the world.

    Look at that map again. You know how to find it.

    Comment by Hank Roberts — 29 Nov 2010 @ 12:18 PM

  185. Dan H #183: “A global average will not really tell us much…”

    While no one should expect a global average to tell everything, it is the starting point and principal reference for the whole discussion. For example, if a blog comment happens to mention sea level decreases of 7mm somewhere and increases of 4 mm elsewhere, the global average of of 3 mm/yr will tell you not to be misled by false balance, and show you that the 7 mm decrease is not to be expected in most places, whereas the 4 mm increase is quite typical. While readers here (most of them!) can be expected to know that context, we find false balance injected into less learned public discussions constantly, with malevolent intent and baleful result.

    Comment by Ric Merritt — 29 Nov 2010 @ 12:20 PM

  186. > J. Bob says …
    > While one may measure “uplift”, to mm’s accuracy now, how good
    > was it 10, 20, or 50+ plus years ago when a significant amount
    > of sea level data was being taken?

    Good enough. The error bars are always wider as you look at older data.

    Look what’s done adding new high-precision data to the older observations–this is a very good, image-rich poster illustrating 300 years of French sea level data and how it has been incorporated into current science:
    http://wcrp.ipsl.jussieu.fr/Workshops/SeaLevel/Posters/1_6_Woppelmann.pdf

    Want denial sites? those rank high in the first page on ordinary Google:
    http://www.google.com/search?q=sea+level+historical+record

    Want the science? more science sites show up if you use Scholar:
    http://scholar.google.com/scholar?q=sea+level+historical+record

    Comment by Hank Roberts — 29 Nov 2010 @ 12:40 PM

  187. Hank,
    It appears that the GRACE data and tidal guage data are more in-line than previously thought. We are both indicating about 1mm.yr sea level rise.
    http://www.insidescience.org/research/satellites_reveal_differences_in_sea_level_rises
    http://www.agu.org/pubs/crossref/2010/2010GL044770.shtml

    [Response: You are confusing the component of SLR from total water mass changes (rough 1 mm/yr from the GRL paper) with the total SLR (which includes a thermal expansion component and a small difference from residual glacial rebound) which is closer to 3mm/yr. -gavin]

    Comment by Dan H. — 29 Nov 2010 @ 1:30 PM

  188. #186 Hank, the link to Brest is interesting, but I have looked at it, and there are breaks in the data. However the data in the mid 1800’s to mid 1900’s is interesting. It ties into my looking at long term central & western European temperatures. These are from 14 stations that started recording priot to 1800. Included are Central England, Debilt, Berlin, Upsalla, Paris, Prague, etc.
    http://www.imagenerd.com/uploads/lt-temp-1800-2008-14-9ZSv8.gif
    While it’s not perfect, it’s pretty much what one has to work with, for direct temperature measurements, in those early years.
    Sea level is interesting, in that it offeres a possible connection to global temperature. But sea level can be influenced by geological changes, hence the “discussion” on “uplift”, GPS accuracy, error bands and such. Anyway, in order to get away from geological & glacial changes (such as Brest), the south & east coast of the US, seemed to be a good place to start. Urban “sinking” is another issue, but off the table for now. Below are some of the longer sea level graphs from this area:
    http://www.imagenerd.com/uploads/n_amer_s_e_composite_4-har7A.jpg
    which I selected for analysis in the near future. That is, to see if there is any connection to global temperatures. Hopefully to form a more comprehensive view if this whole thing is another natural cycle or man’s influence.

    With respect to the “denial” & “science” sites. It’s not a bad idea to go to sites, opposite one’s opinion. If your not careful, you just might learn something .

    Comment by J. Bob — 29 Nov 2010 @ 10:29 PM

  189. With respect to the “denial” & “science” sites. It’s not a bad idea to go to sites, opposite one’s opinion. If your not careful, you just might learn something .

    This is why I go to \Answers in Genesis\, every day …

    Because I want to learn about evolutionary biology …

    Comment by dhogaza — 30 Nov 2010 @ 12:54 AM

  190. JBob: “With respect to the “denial” & “science” sites. It’s not a bad idea to go to sites, opposite one’s opinion.”

    I can honestly say that denialist sites have never taught me a thing about climate science, just as creationist sites have never taught me anything about evolution. Such sites are an amazing (and scary) lesson in human psychology, though.

    Comment by Ray Ladbury — 30 Nov 2010 @ 5:05 AM

  191. Hello there,

    well it seems, that Dr. Rahmsdorf is not willing to comment my question if the non-linear extrapolations is the only possible model. A pity . .

    In the meantime Austrian-climatologists opened a new blog, where they try to bring climate facts closer to a mainstream audience. So far it is only available in German, but here is a translation of a closing sentence of the “future sea level”-chapter:

    http://www.zamg.ac.at/klima/Klimawandel/Klimafolgen/Meeresspiegel/Zukunft/index.php
    “Recent publications of measurement data and corresponding model calculations give regarding the risk of catastrophic “Eisausbrüchen” [..= calving..] on Greenland, or a sudden “float” of the West Antarctic ice sheet is seated below the sea surface a conservative all-clear.”

    Can you comment on this oppinion? After all we are talking on probably the most scary prediction for the global warming ..

    LoN

    Comment by Laws of Nature — 30 Nov 2010 @ 6:43 AM

  192. LoN – The final sentence refers to “catastrophic” calving in Greenland and a “sudden” float of WAIS. I looked at your reference, but Google translate was a bit clumsy. From what I read the bulk of the item was about the large range of uncertainties in the whole field of ice and SLR.

    It may be true that WAIS and Greenland won’t suddenly drop into the ocean. It is certainly true that calving rates and melt rates will increase in a warming world. And _that_ is worth being worried about.

    The final sentence reassuring us that we need not be scared of an instantaneous catastrophic sea level rise is not very reassuring, it’s focusing on a fairly small risk of large SLR happening all at once. Whereas the much larger and more certain risk is of continuing and increasing rates of SLR.

    Comment by adelady — 30 Nov 2010 @ 8:58 AM

  193. #189, 190–

    I have to say that, contrary to dhoghaza & Ray’s experience, that denialist sites played an important part in my learning what I have managed to pick up about climate science. Without them, I’d have known the very basic “big picture” stuff, but gone no deeper.

    But with the usual memes–so thoroughly catalogued and rebutted now on Skepticalscience–to spur me with the basic question “Can this possibly be true?” I was forced to go deeper. I was forced to find out about forcings vs. feedbacks and that famous 800-year lag between rising temps and rising CO2. I was forced to find out about IR absorption and emission. About statistics. About–well, you get the idea.

    And I found out that almost all denialist discourse was marked by the most elementary scholarly failure of all–the failure to do a proper literature search. (Otherwise, long-answered (originally legitimate) questions wouldn’t be continually resurrected as zombie arguments.) And that most of those arguments shared the further features of 1) internal logical incoherency, and 2) substituting rhetoric for analysis (see for examples Motl, Lord Whatsisname, and G & T.)

    Oh, I learned a lot from those guys.

    But I don’t need continually to repeat the lesson, thank heavens.

    Comment by Kevin McKinney — 30 Nov 2010 @ 9:18 AM

  194. > #162 Martin, while your co-authored papers are interesting, they do not
    > answer what I was looking for.

    That’s okay J. Bob, they weren’t meant for you anyway ;-)

    Comment by Martin Vermeer — 30 Nov 2010 @ 10:33 AM

  195. Yes, adding in the thermal expansion of the upper ocean layer (~0.8 mm/yr) and the deep sea estimate (~0.2 mm/yr), the SLR is about 2.0 mm/yr. Not all that different from the tidal gauge data.
    Unless significant calving starts occurring in Greenland, SLR is likely to reamin in the IPCC AR$ projected range.
    http://www.nature.com/nature/journal/v453/n7198/full/nature07080.html

    [Response: Can I get your guarantee on that? Of course, if you were wrong that would be really bad, but if you can really promise that Greenland isn't going start shedding mass at an increasing rate as it gets warmer against all expectation, I'll be happy never to say anymore about it. Thanks! - gavin]

    Comment by Dan H. — 30 Nov 2010 @ 11:27 AM

  196. Dear Laws of Nature,
    Your question to Rahmstorf was based on false premises:
    1 – All models are wrong. Rahmstorf just happens to have used a model which better matches historical data than your “linear trend with about 1foot per century”.
    2 – Rahmstorf’s model is not a “non-linear extrapolation”. It needs to be fed a temperature scenario in order to produce a rate of SLR. You could use it to produce a “linear trend with about 1foot per century”.

    In case you don’t know what I’m talking about: Laws of Nature was implicitely referring to the dual model featured in Vermeer and Rahmstorf’s PNAS paper.

    Comment by Anonymous Coward — 30 Nov 2010 @ 12:04 PM

  197. #194 Martin
    Nice to hear from you again. Perhaps with you vast knowledge on geological “uplift”, it should be quite easy for you to know, and share, how accurate, “uplift” measurements were in the past 10,20 years, and before GPS systems were available. I’m sure you are well aware how this accuracy would effect station sea level measurements, as well as their long term trend line accuracy.

    Comment by J. Bob — 30 Nov 2010 @ 2:07 PM

  198. Can someone tell me why the GRACE “Gravity Recovery and Climate Experiment” seems to indicate a minimal rise in sea levels. Please explain in layman terms.
    Thanks

    Comment by Allan — 30 Nov 2010 @ 5:55 PM

  199. Can someone explain “GRACE” and its contribution to understanding sea level rise/decline. Lay terms please.

    Comment by Allan — 30 Nov 2010 @ 6:00 PM

  200. J. Bob, thanks for the vote of confidence, but what you are asking for would be covered by a number of courses: time series analysis, geospatial statistics, satellite orbits, GPS positioning technologies and processing techniques, physical geodesy, …

    I don’t want to discourage you, but this is work. You need the background. Then, you could start with Cazenave and colleagues to get up on the altimetric analysis, and perhaps Church and White, and Jevrejeva and colleagues, for the tide gauge stuff.

    I am reminded of the question to Gandhi: “Sir, what do you think of Western civilization?”

    ;-)

    Comment by Martin Vermeer — 1 Dec 2010 @ 2:58 AM

  201. Allan,

    Some background can be found in this well referenced blog post:
    http://www.skepticalscience.com/Are-ice-sheet-losses-overestimated.html

    especially figure 4.

    If your question isn’t answered there, you may try to make it more specific.

    Comment by Bart Verheggen — 1 Dec 2010 @ 5:41 AM

  202. Re 196: “Rahmstorf’s model is not a “non-linear extrapolation”. It needs to be fed a temperature scenario in order to produce a rate of SLR. You could use it to produce a “linear trend with about 1foot per century”.

    is wrong!
    Rahmsdorf uses a Non-Linear Model and extrapolates the data towards 2100.
    He uses something like
    d_level /d_t = a (T – T_0) + b d_T / d_t

    and this is very nonlinear in time t!

    In Re #30 he says himself:
    “Let’s wait another 15 years for the next data point, then we may see something. -stefan”

    So I keep on wondering, why his model should be taken as the most valid one, especially since everone seems to also be comfortable with only a sea level increase of about 1ft until 2100 as a linear extrapolation of the data would indicate.

    Cheers,
    LoN

    Comment by Laws of Nature — 1 Dec 2010 @ 5:58 AM

  203. #200 Martin,
    after reading your papers, I thought you would have that info at your fingertips. I don’t think one has to go through a lot of what you mention, to get elevation accuracy. Surveyors do that every day. Who do you think takes geological positions at the tidal stations? There is something called “Certification”, to make sure survey standards are met.

    Not to belabor the point, geological up “lift” does effect sea level measurements. The point is how much do we really know about the “uplift”, except from more recent, higher accuracy readings. So one must extrapolate backward, where a significant amount of sea level data resides. Hence a 50-100 year trend line could have significant changes (errors), due to “uplift”, which is what I was trying to get at.

    Here’s some info that might help you. One of my surveyor friends has a Trimble R-8. It’s spec’ed to about 3mm elevation initially positioned, BUT subject to atmospheric conditions, as are ALL GPS systems.

    http://trl.trimble.com/docushare/dsweb/Get/Document-140079/022543-079J_TrimbleR8GNSS_DS_1109_LR.pdf

    Thank you for the reference on pressure altimeters, I’ll take a look, but talking to retired pilots, we’re talking elevation accuracy in meters.

    I’m not sure what the comment of Gandhi, has to do with the discussion. It’s kind of like asking what you think of Arjuba & Krishna’s dialog, on science, in the Bhagavad Gita. I think a better question would be, what caused the Renaissance and intellectual explosion that occurred. While at the same time, the Eastern, and Middle Eastern areas seemed to go into a stagnation period?

    Comment by J. Bob — 1 Dec 2010 @ 11:23 AM

  204. #203 J. Bob

    I have a funny feeling that if Martin Vermeer actually told you the conclusion, you would then just say. Well, how did you come to that conclusion… in which case I suggest you refer back to his post #200

    http://www.realclimate.org/index.php/archives/2010/11/sea-level-rise-the-new-york-times-got-the-story/comment-page-4/#comment-192618

    Comment by John P. Reisman (OSS Foundation) — 1 Dec 2010 @ 2:23 PM

  205. #204 John, we meet again. While scientific papers are nice to reference, what is the accuracy of the instrumentation in the field? It’s a bit of a walk from the lab to “main street” where data is being taken, instrumentation being calibrated.

    There are however, many things one can do with tidal gauges. The following is a quote from the book “The Measurement of the Power Spectra” 1958, by Blackman & Tukey (co-discover of the FFT).
    “We were able to discover, in the general wave record a very weak low-frequency peak which would have surely escaped our attention without spectral analysis. This peak, it turns out, is almost certainly due to a swell from the Indian Ocean, 10,000 miles distant. Physical dimensions are 1mm high, a kilometer long”

    Comment by J. Bob — 1 Dec 2010 @ 3:35 PM

  206. J.Bob wants a simple answer, and doesn’t like being told this question doesn’t have a simple answer.

    Fig. 4 of the linked skepticalscience page does seem a good answer, though you either trust the scientists or would have to learn their fields to understand exactly why they have come to those conclusions, and why they overlap but aren’t identical.

    Comment by Hank Roberts — 1 Dec 2010 @ 3:57 PM

  207. #205 J. Bob

    Luckily there is more than one thermometer on the planet.

    Ever ask yourself how scientists estimate temperatures on other planets?

    But what does understanding thermal expansion and oceanic cycles have to do with how accurate temperature measurements might be when calibrated, modeled given error bounds and modeled to remove aberrations readings?

    Economics: Balancing Economies
    October Leading Edge: The Cuccinelli ‘Witch Hunt”

    Fee & Dividend: Our best chanceLearn the IssueSign the Petition
    A Climate Minute: Natural CycleGreenhouse EffectClimate Science HistoryArctic Ice Melt

    Comment by John P. Reisman (OSS Foundation) — 1 Dec 2010 @ 4:10 PM

  208. #207 John, I believe this thread is about sea level, and it’s measurement error, not temperature. However in answer to your question, one method of measuring extra terrestrial temperatures is with multiple IR band-pass filters.

    You might go to this site:
    http://wattsupwiththat.com/2010/12/01/sea-level-rise-jumpy-after-last-ice-age/
    They have a discussion on sea levels and combining info from different sensors.

    #206 Hank, no one said, or at least I didn’t, say there is a simple answer. I have said that this problem is a terribly non-linear system. Having dealt with more non-linear problems then I care to think about, Hamlet’s quote comes to mind:
    “There are more things in heaven and earth, Horatio, than are dreamt of in your philosophy”.

    Comment by J. Bob — 1 Dec 2010 @ 10:56 PM

  209. #208 J. Bob Sorry, lack of specificity, i.e. context on the part of others, combined with my chaotic nature can through me off a bit now and then. Plus, I’m working on a lot of different things as usual, so my idiot potential can sometimes be great. At certain times under certain circumstances I have less confidence in my own accuracy regrading target selection. However, in some ways the answer is applicable. Sea level is measured in many ways and of course also accounts now for tectonic shift, uplift and compression which can affect perspective from land.

    As to sea level, what do you think is the easiest way to calculate sea level rise?

    Comment by John P. Reisman (OSS Foundation) — 2 Dec 2010 @ 2:52 AM

  210. #208 J. Bob

    As to your reference to wattsupwiththat

    I don’t read that site. Feel free to call me foolish and ignorant. Feel free to claim that I am ignoring the other side of the debate.

    In reality, ignoring that web site is not ignoring the other side of the debate though. It is ignoring the wannabe and pretend knowitalls that think they have something revolutionairy to talk about when they focus on uncertainty.

    I prefer to listen to uncertainty discussions by experienced scientists working in the field of climate science not the pretenders that love to wave the flag of uncertainty just to get attention but whose arguments when placed in context of the science too often fall outside the outliers of reason and evidence.

    For future reference, if you want me to read something, send me to a peer reviewed paper, or even better the peer response. That is worth my time. For uncertainty questions I like to hear real scientists discussing uncertainty. I will be at the AGU in San Francisco. Will you?

    Comment by John P. Reisman (OSS Foundation) — 2 Dec 2010 @ 3:00 AM

  211. Re. my #210

    Actually,

    “In reality, ignoring that web site is not ignoring the other side of the debate though. It is ignoring the wannabe and pretend knowitalls that think they have something revolutionairy to talk about when they focus on uncertainty.”

    should read

    In reality, ignoring that web site is not ignoring the other side of the debate though. It is ignoring the wannabe and pretend knowitalls that think they have somethingrevolutionarytotalkabout when they focusonuncertainty.

    Comment by John P. Reisman (OSS Foundation) — 2 Dec 2010 @ 10:05 AM

  212. #209-211 Well John, at least your honest with your opinion, which indeed is a gift. And while you don’t like certain sites, that is your prerogative. However, many times it’s not the site itself, but WHAT IT LEADS TO that’s important. In this case, to these sites that have some interesting graphs and references on the topic of old and new sea levels changes:
    http://www.globalwarmingart.com/wiki/File:Recent_Sea_Level_Rise_png

    http://www.globalwarmingart.com/wiki/File:Holocene_Sea_Level_png
    http://www.globalwarmingart.com/wiki/File:Post-Glacial_Sea_Level_png

    In the previous post, I gave you the wrong web site, it should have been ( take a deep breath):
    http://wattsupwiththat.com/2010/12/01/sea-level-rise-and-solar-activity/
    It shows and REFERENCES merging different sensors used to measure sea levels.

    Looking at the first ref. above (file:Recent_Sea Level_Rise_png), it closely follow what I have been looking at, for the past weeks. That is, trying to form a picture as to what really is happening, (between sea levels & global temperatures), to the extent possible, with available sea level & global temp data data.

    P.S. John there is no easy way to measure sea levels to the accuracy we are talking about. But be careful in your comment about only reading peer reviewed material. I’ve seen enough peer reviewed papers not worth the paper their printed on. Now would your criteria, exclude looking in patent offices around the world? You might want to look at history as to how many “classic” papers were NEVER peer reviewed, but spawned an explosion in knowledge.

    Comment by J. Bob — 2 Dec 2010 @ 11:32 AM

  213. J. Bob, wattsup has the same misunderstanding about measurements of sea level as about measurements of temperature.

    > no easy way to measure sea levels to the accuracy we are talking about.

    Yes, actually, there is. It’s what they do as Martin has pointed out to you.

    Combining many measurements gives accuracy far greater than just one instrument used one time can give you. It’s a subtle point hard to understand.

    Comment by Hank Roberts — 2 Dec 2010 @ 1:17 PM

  214. #213 Hank, only if you are measuring the exact same thing, for starters.

    Comment by J. Bob — 2 Dec 2010 @ 2:07 PM

  215. #212 J. Bob

    You are correct, it’s sometimes about what they point to.

    Actually, I’m more interested in peer response and I agree with you that some papers are not worth the paper they are printed on, which is why I like to look at peer response.

    Probably a good example is Ferenc Miskolcz

    http://www.ossfoundation.us/projects/environment/global-warming/myths/ferenc-miskolcz

    In this case, the paper was so bad that it did not even rate a published peer response. It was so bad, no one wanted to waste their time. But that is a good example of a non published peer response.

    Comment by John P. Reisman (OSS Foundation) — 2 Dec 2010 @ 2:24 PM

  216. #213 Hank, sorry, but got called away and didn’t finish. The other assumption is that you have a mean at, or close to, zero. Suppose you are making a batch of thermometers, with a mean error of 0.75 deg., and 3 sigma of .25 deg. If the 3 sigma accuracy tolerance of +-1.0 deg all pass, but the average measurement error is still 0.75 deg., no matter how many thermometers you use.

    #215 John, I can give you a better comment, that Dr. Otto Schmidt said ( he developed the logic gate, the “Schmidt Trigger”) at table. Something like “Out of over 120 papers published in xxxx area, only 5-10 were of any value”.

    Comment by J. Bob — 2 Dec 2010 @ 2:53 PM

  217. > Suppose you are making a batch of thermometers

    It doesn’t happen as you imagine. Try it yourself with ice water or boiling water. Any one thermometer from your batch of cheap ones may read -1 or +213 instead of 0 and 212. Repeat measurements with a single thermometer: you won’t see plus or minus a full degree between repeat measurements. Calibrate, adjust, repeat.

    Yes, GPS from satellites is a bit harder than that to calibrate and repeat, but it’s the same approach — multiple measurements get you better accuracy. You apparently believe the published work can’t be as accurate as the papers say. But you can’t prove it by declaiming it. You’d have to understand it.
    As Martin pointed out, there’s a lot of studying needed.

    Comment by Hank Roberts — 2 Dec 2010 @ 6:49 PM

  218. Laws of Nature (#202),
    These T in the equation represent temperatures. Use different temperatures and you get a different result. You can make the resulting trend as linear as you want by picking the right temperatures.

    You effectively claim that the rate of SLR is independent of temperature. That’s obviously unphysical. That’s why we want a model for the sea level that takes changing temperatures into account.

    Comment by Anonymous Coward — 2 Dec 2010 @ 9:29 PM

  219. and yes, I did mix Fahrenheit and Centigrade in that last example, sigh.
    I suggest waiting for a real scientist to explain why more measurements improves accuracy. It’s been written, all we need is a pointer.

    Comment by Hank Roberts — 2 Dec 2010 @ 9:45 PM

  220. J. Bob,

    about the effect of crustal vertical motion on tide gauge readings, and using GPS:

    here.

    Comment by Martin Vermeer — 3 Dec 2010 @ 3:08 AM

  221. Hank,

    it’s complicated. It’s not just the sheer number of observations that improves the accuracy; there are also some “tricks” that allow you to get rid of some error sources.

    E.g., when you use GPS measurements from networks of permanent, continuously observing reference stations (CORS), you may get the long-term trend much more precisely than the absolute vertical position of any station. Even if the uncertainty in vertical position is several mm, if you take care not to change the station and its immediate environment, the vertical trend can be obtained much more precisely, as errors that are constant over time drop out. Something like 0.5 mm/yr appears well achievable with the current record.

    When using GPS positioning of a satellite by on-board GPS (as has been done from Topex/Poseidon onward, since 1992), the situation is even better. Also there, the “vertical” (radial) positioning accuracy is no better than a few mm, and worse than the “horizontal” (along-track, cross-track) accuracy; but we have the benefit of Kepler’s third law… it allows you to estimate the orbital mean radius — that is, the satellite’s mean height — when you know the orbital period. And more to the point, precisely track changes in it. And the orbital period can be very precisely estimated by just tracking the satellite over many, many periods. Like good wine, it only gets better with time :-)

    Of course you have to analyze the error contributions of the whole processing chain, including the radar altimeter itself and its calibration. See this article for a nicely written overview.

    Comment by Martin Vermeer — 3 Dec 2010 @ 3:45 AM

  222. JB 216: Suppose you are making a batch of thermometers, with a mean error of 0.75 deg., and 3 sigma of .25 deg. If the 3 sigma accuracy tolerance of +-1.0 deg all pass, but the average measurement error is still 0.75 deg., no matter how many thermometers you use.

    BPL: But they could measure CHANGES in the mean a lot more accurately, couldn’t they? And it’s changes in sea level we’re talking about.

    Comment by Barton Paul Levenson — 3 Dec 2010 @ 4:32 AM

  223. Re: #218
    I am glad that we seem to agree on the type of model Rahmstorf used.
    However there is little indication for such a nonlinear behavior of the SLR in the last century, to my untrained eye it looks like a perfect linear trend with 1foot/century and quite contrary to your statement in #218 (“You effectively claim that the rate of SLR is independent of temperature. That’s obviously unphysical.” -I made no such claim) physics as usual would not make a big difference to that value. To reach Rahmstorf-sea levels you need an unparalleled greenland destabilization or something similar.
    This is why I asked how other (harmless) models are dismissed – I cited the poor translation of these Austrian climatologist, they seem to say, that recent data does NOT support a dramatic change in Greenland.

    Comment by Laws of Nature — 3 Dec 2010 @ 6:09 AM

  224. Here a more recent article, unfortunately paywalled.

    http://www.agu.org/pubs/crossref/2009/2009GL038720.shtml

    Comment by Martin Vermeer — 3 Dec 2010 @ 7:32 AM

  225. #220 Martin, thank you , that’s the kind of info I was looking for. It gives one an idea of how to “weight” the various components that make up just sea level measurements, and how to interpret them.

    #222 BPL, my point to Hank, was that using more sensors to measure something does not always automatically improve the “accuracy”. Relative & absolute accuracy requirements are based on the process. For some medical purposes, absolute accuracy is necessary. I agree, in tidal gauges, you are looking at relative changes. But like changing thermometers,where some of the tidal gauges “swapped”, when breaks in the data occur? That’s where measuring relative changes ONLY, breaks down. It reduces the quality of the data. A modern GPS system would have been handy, back then.

    You are now now merging, with recent GPS & radar altimeter “absolute” systems, with older ( and unknown “uplift”) relative tidal data, to form a composite of what is really happening with the sea level. Interesting challenge.

    #217 Hank, you might want to get info on how thermometers are fabricated & calibrated, primarily RTD’s. Omega, Minco or Gordan can supply that info. Omega puts out, or used to, a good catalog on that. There’s a bit more to just “calibrate, adjust, repeat”, or as they say in the “trade”, zero & span it.

    Comment by J. Bob — 3 Dec 2010 @ 12:02 PM

  226. I’ve just attended a geological conference where I got an update on the Holocene geomorphology of the eastern Australian coast. I was surprised to discover there was good evidence for mid-Holocene oscillations in sea level with a magnitude of about a metre. I haven’t seen this issue discussed in Realclimate commentary or even the threads. Can you please comment?

    Here is most of the abstract from a recent paper by Lewis et.al, Mid-late Holocene sea-level variability in eastern Australia (2008)
    http://en.scientificcommons.org/41491766

    “A re-analysis of sea-level data from eastern Australia based on 115 calibrated C-14 ages is used to constrain the origin, timing and magnitude of sea-level change over the last 7000 years. We demonstrate that the Holocene sea-level highstand of +1.0–1.5 m was reached ~7000 cal yr BP and fell to its present position after 2000 yr BP. These findings are in contrast to most previous studies that relied on smaller datasets and did not include the now common conversion of conventional C-14 ages to calendar years. During this ~5000 year period of high sea level, growth hiatuses in oyster beds and tubeworms and lower elevations of coral microatolls are interpreted to represent short-lived oscillations in sea-level of up to 1 m during two intervals, beginning c. 4800 and 3000 cal yr BP. The rates of sea level rise and fall (1–2 mm yr-1) during these centennial-scale oscillations are comparable with current rates of sea-level rise. The origin of the oscillations is enigmatic but most likely the result of oceanographic and climatic changes, including wind strengths, ice ablation, and melt-water contributions of both Greenland and Antarctic ice sheets.”

    With respect to the argument that these oscillations are due to isostatic adjustments, Haworth et.al (2002)write “There is sufficient evidence extending over 20° of latitude to suggest that north–south differences related to hydro-isostatic influence is limited or non-existent”
    http://onlinelibrary.wiley.com/doi/10.1002/jqs.718/abstract

    love your website
    John Ransley

    Comment by John Ransley — 7 Dec 2010 @ 9:42 PM

  227. John Ransley #226: yes, an interesting article. I read the article itself here. Note that I am just an amateur on this, but as you are asking for comment, I will try.

    I must say that I am less than convinced. You mention “good evidence”, but from what I see it is mostly based just two micro-atoll proxies from one location (Figure 4, Torres Strait) which to me look like outliers, and could have local causes. Yes, they also mention two hiatuses in other time series as confirming evidence (Figure 3), but still… note also that the spread among these proxies — the width of the grey band — is already +/- 0.5 m, and quite a bit larger than the drawn error bars.

    What also raises a red flag with me is that these rapid drops and rapid rises in sea level come in pairs. First, sea level drops as much as one meter; then, it immediately rises again by about one meter, back to the level we were at before the drop — and then, the slow descent continues as if nothing had happened.

    I have asked a colleague who is familiar with these things, but no response yet.

    Comment by Martin Vermeer — 9 Dec 2010 @ 3:00 AM

  228. Martin Vermeer 227: Thanks. I will also consult a colleague and get back.

    PS: Correction: that was All of the Lewis et.al abstract.

    Comment by John Ransley — 9 Dec 2010 @ 7:08 AM

  229. Martin Vermeer 227. I am just an amateur on this also, my geology training was not focussed on this field of study. The “good evidence” I referred to has been gathered from multiple locations. There are some dozen or so published refereed papers documenting this. See for example:

    Baker R.G.V, Haworth R J and Flood P.G. (2001b) Intertidal fixed sea level indicators of former Holocene sea-levels in Australia: a summary of sites and a review of methods and models. Quaternary International, 83-85, 257-273.

    http://www.sciencedirect.com/science?_ob=ArticleURL&_udi=B6VGS-43X7KNP-N&_user=10&_coverDate=09%2F11%2F2001&_rdoc=1&_fmt=high&_orig=search&_origin=search&_sort=d&_docanchor=&view=c&_searchStrId=1574568405&_rerunOrigin=google&_acct=C000050221&_version=1&_urlVersion=0&_userid=10&md5=addf9d93988f4f6c572cb01d320838ef&searchtype=a

    The argument has been summarised informally as follows:

    “The Holocene sea-level oscillations match the extensively published glacial advances and retreats over the Holocene so if there is a cryospheric-oceanic exchange as suggested by the IPCC (ie melting glaciers and rising sea-levels or advancing glaciers and falling sea-levels) the problem is not one of science and mechanisms. The published fixed biological indicators, especially tubeworm evidence, is correct to centimetres. The evidence is from northwestern Western Australia through South Australia to Tasmania then up the Australian east coast to Torres Straits. What it shows is higher than present sea level in the mid-Holocene and that the hydro-isostatic warping of the continental shelf around Australia is not—as some researchers claim—sufficient to explain local variations.”

    Here also is the abstract from a recent submitted unpublished article by Peter G Flood and Robert G V Baker titled:

    Fixed Inter-tidal Biological Indicators and Multiple-notched Limestone Cliff Shorelines of Australasia: The Significance for Higher than Present Sea-level Models.

    “Abstract
    Throughout Australasia there exist numerous locations where notches and multiple notches occur on the limestone cliff shorelines. These include: Halong Bay, Vietnam; Langkawi Island, Malaysia; the South China Sea Coast (notches in granites); Palawan Island, Phillipines; Phuket and Phangnga Bay islands in Thailand; and Rottnest Island, Western Australia. These notches occur at heights ranging from about 1m just above present day mid-tide level to approximately 3m above present. In addition, there are even higher notches that appear to have been exposed for a longer period than the lower notches and could be of Late Pleistocene age. The lower notches appear to be of Holocene origin. These notches are consistent with a two-stage Holocene relative sea level statistical polynomial regression model constructed from the fixed inter-tidal biological indicator (FIBI) oyster Saccostrea cucullata. This oyster data set is compiled from sites in Vietnam, the Singapore ‘tin’ islands and Hong Kong. The FIBI and notch distribution suggest rapid sea level change in the order of a metre (within an ~50 year duration) which have occurred prior to the input of anthropogenic GHGs. Indeed, the evidence suggests that sea surface temperatures have been warming since 1400 yr BP when sea-levels began to decline gradually from ~1.0m above present. This is contrary to the simple ‘warming effect and sea-level rise’ conclusion from the current climate change debate and the evidence suggests that there is a far more complex system at work in the ocean conveyor belt than a simple linear response system.”

    Comment by John Ransley — 10 Dec 2010 @ 8:32 AM

  230. John Ransley #228: as I suspected, the colleague also doesn’t believe that the data in Lewis et al. is good enough to draw that kind of conclusions. He also notes the hydro-isostatic issue you refer to.

    I looked at your Haworth et al. link, and note that they actually have no data from the Torres Strait area, where the continental shelf gets very broad and where a key piece of Lewis evidence is from… so even if this paper is right (on which I offer no opinion), is doesn’t seem to be very relevant for Lewis et al.

    Comment by Martin Vermeer — 10 Dec 2010 @ 9:23 AM

  231. References
    Baker, R.G.V., Haworth, R.J. and Flood, P.G., 2001a. Warmer or colder marine Late
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    Palaeography, Palaeoclimatology, Palaeoecology 168, 249-72.
    Baker, R.G.V., Haworth, R.J. and Flood, P.G. 2001b. Intertidal fixed seal-level
    indicators of former Holocene sea-levels in Australia: a summary of sites and a review
    of methods and models. Quaternary International 83-85, 257-73.
    Baker, R.G.V., Haworth, R.J. and Flood, P.G. 2005. An oscillating Holocene sea-level?
    Revisiting Rottnest island, Western Australia and the Fairbridge Eustatic Hypothesis.
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    Comment by peter G Flood — 12 Dec 2010 @ 4:38 AM

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