Some Ice Cores in NAS – Antarctic

Now that I’ve caught my breath a little, just for fun, I’m parsing through sections of the NAS report on areas not directly involving the MM-MBH battle. In the press conference, I recall Cuffey placing a lot of emphasis on the "regional" MWP, and that it wasn’t in the Antarctic ice core data (although it was in Greenland data.) Maybe someone can give a time and reference for what he said and I’ll edit up. In the summary, the panel stated:

This [additional] evidence [of the unique nature of recent warmth in the context of the last one or two millennia] includes …the fact that ice cores from both Greenland and coastal Antarctica show evidence of 20th century warming (whereas only Greenland shows warming during medieval times).

In the Ice Core chapter (preprint p. 62), they said:

Some coastal sites in Antarctica show 20th century warming but interior sites do not. No Antarctic sites show a warming during medieval times.

Now I don’t claim to be an authority on ice cores, but here’s the Law Dome dO18 series as illustrated in Jones and Mann 2004, which has a very strong maximum at AD1000, exactly the same time of very active Viking exploration in Greenland. It also has minimal 20th century warming. Isn’t this the exact opposite of the situation as summarized?

Figure 4. Jones and Mann 2004.

The NAS panel does not actually illustrate or cite any series with the said property: modern warming and no medieval warming. Elsewhere in the NAS report, the panel says:

"In Greenland, Figure 6-2, and coastal Antarctica, ice isotopic ratio records clearly show 20th century warming, a Little Ice Age and earlier warmth. In Greenland, this earlier warmth is centered at about AD1000, whereas in Antarctica, it is much earlier … As a group, the ice cores from interior Antarctica (Figure 6-2) show nothing anomalous about the 20th century warming".

They don’t cite the series that are considering here. To the extent that the Law Dome series is representative, the high dO18 period is mostly dated prior to AD1000, but the actual peak is at AD1000. (I also wonder how much play there is in the dating, but that’s a different story.)

In their figure, they illustrated Taylor Dome from interior Antarctica: here is the bottom panel of Figure 6-2 showing information from Taylor Dome – curiously they show dD values rather than dO18 (shown for the other sites) , even though dO18 is available for Taylor Dome. Yes, there is no MWP in Taylor Dome series (and presumably other interior sites), but according to the graph of Taylor Dome (and the NAS text), there is no modern warming reflected in this data either.

NAS Figure 6.2 Bottom Panel. Taylor Dome dD

A comment from Fisher about Greenland Summit gives one theory why there might be less variability at some of the coldest, most remote sites. Fisher noted that the dO18 at Greenland summit did not show marked modern warming or MWP and mooted the possibility that some very remote and very, very cold sites might have little response to lesser changes (think of a LIFO inventory management system) . Maybe this hypothesis applies to the Antarctic interior as well. In the literature, there are suggestions that centennial warming tends to be through poleward movement of mid-latitude systems, with strengthening of polar vortices. Thus mid-latitude warming characteristic of centennial changes might not have a strong impact on the coldest and most remote sites in interior Antarctica.

So what’s the basis for the statements in the summary and for Cuffey’s statements at the press conference? Whatever it is, I can’t find it in the details of the report.


92 Comments

  1. Gary
    Posted Jun 24, 2006 at 11:43 AM | Permalink

    Steve,
    Has anyone ever globally mapped every individual temperature proxy record at the same time points (eg, 1900AD, 1800AD, etc.) to see if the spacial patterns look anything like today’s measured temperatures? It seems that anomalous records would stand out pretty clearly, and likewise, regional patterns would show up too. I would expect that this has been done with limited sets of records, but has it been done with all the data publicly available?

  2. tas
    Posted Jun 25, 2006 at 12:55 AM | Permalink

    Hi Steve,

    As I think I indicated to you and most certainly to others who have this preliminary Law Dome isotope series, the direct interpretation of isotope fractionation as temperature proxy should be made with caution. Ice cores only record when snow is falling. Such periods occur in a stochastic fashion, with event sizes and intervals that result in a unique form of environmental record. Averaging very quickly recovers a signal that correlates well with temperature, although the properties of coastal sites with marine cyclonic precipitation differ from those far inland. Not surprisingly, the isotope fraction also responds to other climatic variables – the temperature response is but one manifestation.

    I would caution any readers from a simple mapping of the data you have put up here to mean temperature. When we openly release and publish this data, it will be accompanied by a much more detailed and appropriately reviewed discussion of how it should be calibrated to temperature and of the various other climate signals that are embedded within.

  3. TCO
    Posted Jun 25, 2006 at 5:44 AM | Permalink

    Any efforts to get “limiting stands” for ice cores?

  4. Steve McIntyre
    Posted Jun 25, 2006 at 7:58 AM | Permalink

    OK, Tas, I realize that you have caveats with respect to the Law Dome data. Can you tell me what is the evidence for the following claims of the NAS Panel? I ask this because I cannot locate any evidence in the report itself. (And, if such evidence relies on dO18 at the sites, why is it usable at these sites and not Law Dome?)

    1. “ice cores from both Greenland and coastal Antarctica show evidence of 20th century warming (whereas only Greenland shows warming during medieval times)”
    2. “Some coastal sites in Antarctica show 20th century warming but interior sites do not. No Antarctic sites show a warming during medieval times.”

  5. Paul Linsay
    Posted Jun 25, 2006 at 8:18 AM | Permalink

    #2 tas,

    Not surprisingly, the isotope fraction also responds to other climatic variables – the temperature response is but one manifestation

    This is starting to sound like tree rings which strongly depend on a fair number of variables other than temperature. If what you say is true, and I don’t doubt you one bit, then it is incumbent on you to provide information on what all the other variables are, how they affect the isotope fraction, and what independent measurements you made to disentangle the temperature from the other variables. Otherwise, there could be a Mannian mess in the making and yet another reason to put quotation marks around “climate science.”

  6. Andre
    Posted Jun 25, 2006 at 8:43 AM | Permalink

    Michiel Helsen did research about the noise in water isotopes in Dronning Maud Land Antarctica. See his PhD thesis.

    Of course the factual isotope data in compressed and merged annual snow-ice layers is mainly a function of seasonal temperature and seasonal precipitation. The latter being ignored. Variation in precipitation has probably more impact than variation in temperature.

  7. Greg F
    Posted Jun 25, 2006 at 8:48 AM | Permalink

    #4

    Some coastal sites in Antarctica show 20th century warming but interior sites do not. No Antarctic sites show a warming during medieval times.

    Unstable Climate Oscillations during the Late Holocene in the Eastern Bransfield Basin, Antarctic Peninsula

    The late Holocene records clearly identify Neoglacial events of the Little Ice Age (LIA) and Medieval Warm Period (MWP). Other unexplained climatic events comparable in duration and amplitude to the LIA and MWP events also appear in the MS record, suggesting intrinsically unstable climatic conditions during the late Holocene in the Bransfield Basin of Antarctic Peninsula.

  8. TCO
    Posted Jun 25, 2006 at 9:55 AM | Permalink

    I read the Heilsen paper. It was a bit long and dry. I think based on section 6.5, that he is casting doubt on the current transfer function being posited by others for extracting temp from 018. His remark that the transfer function varies by location and over time seems to imply that the simple fractionation picture is not good enough, that something more complicated is needed to extract the signal from noise, if this is even possible.

  9. TCO
    Posted Jun 25, 2006 at 9:59 AM | Permalink

    #7: that is a sediment core, not an ice core. Perhaps the Panel was only referring to ice cores? Of course, that begs the question of if this is still evidence that needs to be considered. Guess, it would be nice to see a really quality review. What were all the cores, records, papers, considered by the Panel to base their Antarctica claims on.

  10. Lee
    Posted Jun 25, 2006 at 10:40 AM | Permalink

    re 8,

    TCO, what level of resolution error is he talking about?

    Just to offer a simple factual reminder; one of the compelling features of the high-latitude ice cores is that they clearly capture glaciations and interglacials, and they do it from widely separated locations, from diffferent hemispheres. That fact alone places a rigid limit on the real error in the temperature resolution of those records; it must be substantially lower than the temp delta between those temp extremes that we can verify on independent criteria. In other words, one must start from the baseline recognition that the method works pretty damn well.

    And Paul, if you read the report, they cite a fair amount of literature that looks at the other variables (primarily precipitation) and attempts to isolate when and where one or the other might predominate. In fact, when the report refers to tropical glacier isotope records, they are very careful to point out that they cant separate temp and precip effects in that record – but that nonetheless, the “climate” (ie, the integrated temp/precip record) is anomalous for the 20th century.

    You may not be satisfied with the stae of that literature, but to say even that you would have to read and understand the literature – but it simply isnt true to imply that it isnt being paid attention to. And then to criticise tas for pointing out that what he is doing is what you think needs to be done?

  11. TCO
    Posted Jun 25, 2006 at 10:44 AM | Permalink

    Go look at the link yourself, Lee.

  12. Lee
    Posted Jun 25, 2006 at 10:59 AM | Permalink

    TCO,

    The Khim paper (the sediment core) is available only as an abstract at a cost of nearly $60 for the paper. The Heilson thesis is downloading; its 5.3 mb adn the DL is proceeding glacially slowly. You said you read the Heilson “paper”, so I asked you about a relevant and potentially informative factoid from it – it would have been sufficient to say you dont remember.

  13. Steve McIntyre
    Posted Jun 25, 2006 at 11:05 AM | Permalink

    If anyone are interested in the graphic from Khim et al on Bramsfield, ever think of looking at past climateaudit posts? Try http://www.climateaudit.org/?p=105 . When one sees the use of magnetic susceptibility in sediments, note that this is a somewhat similar strategy to the one used for the Venezuela glaciers (which did not exist in the MWP, which supposedly did not exist either).

  14. welikerocks
    Posted Jun 25, 2006 at 11:47 AM | Permalink

    Don’t 018 ratios only give you an idea about how much ice is on the planet at a certain point in time, not what the temperature is?

  15. Lee
    Posted Jun 25, 2006 at 11:49 AM | Permalink

    re 14:

    No.

  16. welikerocks
    Posted Jun 25, 2006 at 12:03 PM | Permalink

    #15 That’s weird.

    It is the O16/O18 (light oxygen/ heavy oxygen) ratios that capture a picture of glaciations and interglacials, and they do it from widely separated locations, from diffferent hemispheres (when they match)

    Then you look a the physical land/terrestrial evidence (like the Sierra Nevadas) and see if those match. If they all come to an agreement you know something happened (glacial or none glacial event on the planet)

  17. Lee
    Posted Jun 25, 2006 at 12:10 PM | Permalink

    welikerocks.

    The O18 ratio captures the endpoint of a complex distillation water vopor process dependent on primarily temperature and precipitation.

    At midlatitudes either temp or precip canpredominate, depending on a lot of variable including as major one, altitude, and distance and precip history between source and snowfall. At high latitudes, temp is the predominant determining variable.

    The amount of ice on the planet is not a relevant variable affecting the ratios.

    So no, the O18 ratio does not “only give you an idea about how much ice is on the planet at a certain point in time.”

  18. welikerocks
    Posted Jun 25, 2006 at 12:21 PM | Permalink

    Lee, you are out arguing yourself.

    Some of the O16/018 ratios we have come from deep sea sediments (ie: all over the planet includes them) and they match glacial evidence from the Eastern Sierras, for example.

    The whole original importance of the o18/o16 ratios is that they were developed to find sea level curves amd how much water was trapped in ice on the planet.

    From there, it leads up to your explaination..

    Each time you use these proxies, you fail to see there are more factors beyond your understanding, you don’t consider them important or valid.

  19. Lee
    Posted Jun 25, 2006 at 12:48 PM | Permalink

    Right. When its cold, there is more ice. When its warm, there is less ice. Coincidence with other measures of whether there is more or less ice, helps to verify that the dO18 ratio is in fact a reasonable proxy for temperature.

    But that is a consequence of the temperature that is being estimated by the dO18, not a cause of the dO18. dO18 is not just a measure of the ice content of the planet, as your original post claimed.

  20. Andre
    Posted Jun 25, 2006 at 2:08 PM | Permalink

    About the role of changing precipitation for instance the Greenland ice cores.

    Here you can see the strong correlation between “temperature” but actually processed isotopes and the snow accummulation.

    It is noted that the initial “warming”, the Bolling-Allerod event started with a dramatic increase in precipitation, when the precipitation stopped the “cold” Younger Dryas began. Note that the B-A event lags the Antarctic warming by some 2400 years. Nevertheless other proxies suggest that the “global” warming started simultaneously. This would weakem the case of the isotopes of Greenland showing temperature considerably, especially when Bjork et al show warm arid summers for the Younger Dryas and cool wet summers for the Bolling Allerod in South Greenland. The odds are two to one now that the abundant B-A event summer precipitation only brought “warm” isotopes, but no warmth, whereas the Younger Dryas (with milder summers) did not bring those isotopes and only appeared to be cooler due to the relativer abundance of “cold” winter snow.

    But I guess we’re not ready yet for a major paradigm shift about ice cores and precipitation and ice ages

  21. Lee
    Posted Jun 25, 2006 at 2:21 PM | Permalink

    re 20: yes, there is a strong known corerlation between warmer temperature and greater snowfall. Are you seriously arguing that the fact that they graph them together means they didnt consider that in arriving at derived temperatures? Or did you miss this:

    “Glaciochemical and particulate data record atmospheric-loading changes with little uncertainty introduced by changes in snow accumulation. Confident paleothermometry is provided by site-specific calibrations using ice-isotopic ratios, borehole temperatures, and gas-isotopic ratios. ”

    Or are you perhaps arguing that the fact that they detect the MWP and LIA means that they arent detecting temperatures?

    Get real.

  22. welikerocks
    Posted Jun 25, 2006 at 2:46 PM | Permalink

    #19, Lee I think you are learning as we go and making up arguments that have been covered in the field of geology for a long time.

    The FACT IS you are arguing about less then one degree and calling it “global warming” when the margin of error using all these proxie thermometers is larger than one degree.

  23. Lee
    Posted Jun 25, 2006 at 2:50 PM | Permalink

    welikerocks:

    Uhhh… and this has what to do with your claim that”018 ratios only give you an idea about how much ice is on the planet at a certain point in time”?

  24. welikerocks
    Posted Jun 25, 2006 at 3:47 PM | Permalink

    Because you are believing in “an idea” of temperatures derived at a point in time but and won’t look at all the margins of error. Like in the Hockey Stick, or in an ice dome, using proxies, over large amounts of time, and with each step back or forward, also has margins of error.

  25. Lee
    Posted Jun 25, 2006 at 3:53 PM | Permalink

    where have I ever said there isnt a “margin of error?”

    welikerocks, I’m sorry, but your point isnt coherent – are you arghing over what O18 rations are a proxy for, or over what teh precision is? It appeasts that you are mixing the points, and not making relevant arguments for either point.

  26. welikerocks
    Posted Jun 25, 2006 at 4:30 PM | Permalink

    Lee, yes I am.

    You say: The O18 ratio captures the endpoint of a complex distillation water vopor process dependent on primarily temperature and precipitation.

    –But it is the isotopic ratio, not temperature that tells us about ice or no ice, warm times on the earth or cold times on the earth.

    From Steve’s starting topic paragragh un the first graph:

    “In Greenland, Figure 6-2, and coastal Antarctica, [bold]ice isotopic ratio[/bold] records clearly show 20th century warming, a Little Ice Age and earlier warmth. In Greenland, this earlier warmth is centered at about AD1000, whereas in Antarctica, it is much earlier … As a group, the ice cores from interior Antarctica (Figure 6-2) show nothing anomalous about the 20th century warming”.

    Read TCO’s #8 and Andre’s #20 again as well.

  27. TCO
    Posted Jun 25, 2006 at 4:38 PM | Permalink

    Lee, [snip - TCO - stop it]. I skimmed it and it was rather hard to get immediate conclusions, assertions out of the paper. You would need to read the 150 pages pretty well and think about what is described to get all the inferences. I admit that I didn’t. Note this was not an issue of technical content. It’s pretty understandable paper for a physical scientist. It’s just that they make you read a loooot of background and buildup before giving the bottom line. Rather then the style I like better which is to make the assertions and then support them. Mind wanders too much with long explication that I’m not sure where it’s going. That said, I skipped ahead to 6.5 and read the conclusions and what I reported was summary of those. Mea culpa that I didn’t do more…but I’m honest about how much I do do. Take it as that. If you wade through the thing, would be glad to get your download. :) Of course, then you will be my…friend!

  28. tas
    Posted Jun 25, 2006 at 6:16 PM | Permalink

    Steve,
    Just picking up a couple of these things briefly:
    It would be unreasonable of me to comment on the NAS remarks without firsthand reading (and I haven’t had time to do this yet), so I will refrain.

    Regarding the ice cores themselves, I felt it important to make the point that the “isotope thermometer” is a complex subject that can easily be misapplied and misunderstood, as many subsequent posts by your readers illustrate. The following website comes highly recommended and assumes no specialist background.

    http://isohis.iaea.org/userupdate/description/1stpage.html

    The isotope thermometer is certainly “usable” both at Law Dome as well as at other sites – I did not suggest that it wasn’t usable at LD, merely that best and wisest use requires us to explore and quantify the fidelity of the “thermometer” properly (as post #5 asks). At LD, we have the ability to do this in somewhat greater detail than most other places because of a very high snow accumulation rate. As noted in my earlier post, these findings will be published with a finalized data set.

    It would be fair to say that we expect different baises and calibrations will apply to the isotope thermometer at sites with very different climatology. Factors like seasonality of precipitation, and changes in this, and the type of precipitation (large episodic cyclonic versus small, frequent clear-sky precipitation, or even a variable mix). For a great example of a leap in understanding, look up the work of Cuffey (of the NAS panel) that compared Greenland borehole temperatures to the isotope record and led to a completely revised calibration of the isotope thermometer there.

  29. Steve McIntyre
    Posted Jun 25, 2006 at 9:24 PM | Permalink

    Tas, without necessarily wading through all 5 pages of the Ice Core section and both paragraphs on Antartica, as an expert on Antarctic ice cores, what is the status of teh following:

    This [additional] evidence [of the unique nature of recent warmth in the context of the last one or two millennia] includes …the fact that ice cores from both Greenland and coastal Antarctica show evidence of 20th century warming (whereas only Greenland shows warming during medieval times).

    Some coastal sites in Antarctica show 20th century warming but interior sites do not. No Antarctic sites show a warming during medieval times.

    I just don’t understand the basis of this.

  30. TCO
    Posted Jun 25, 2006 at 11:08 PM | Permalink

    Well…they also shot from the hip with their anti-bristlecone pine remark. :) Probably, just not careful workers.

  31. andre
    Posted Jun 26, 2006 at 2:03 AM | Permalink

    Lee re #21

    Please try and think out the box for a second. I limit my observation to the Bolling Allerod – Younger Dryas and Preboreal as an supported example that isotopes are not always temperature, which was the topic of the discussion developing. It may help if you click some of my links. Again there is an abundance of evidence that the northern hemisphere got out of the ice age some 2300 years before the “warm” isotope spikes of the Allerod. So it’s not only the Bjork palynologic evidence that puts doubts on the severeness of the Younger Dryas which may or may not have been that much colder than the surrounding periods.

    Now let’s look at Alley’s evidence that would support the isotope thermometer.

    “Glaciochemical and particulate data record atmospheric-loading changes with little uncertainty introduced by changes in snow accumulation.

    But Alley did not have the palynologic proxy evidence also abundantly available in Siberian proxies (Andreev, Schirmeister, Zazula) or Europe (Lucke and Brauer)that there was a shift in seasonal precipitation more than a shift in temperature. I believe it’s lesson two of stable isotope behavior that seasonal precipitation determines the weighted average of the isotopes.

    Confident paleothermometry is provided by site-specific calibrations using ice-isotopic ratios

    but that’s begging the question. It’s not that the seasonal isotope changes are still visible after 10,000 years of compression.

    borehole temperatures,

    the resolution of ice core borehole temperatures is thousands of years and the Younger Dryas is not visible in there, nor is it possible to date warmin events to the nearest 5000 years or so.

    and gas-isotopic ratios.

    That’s the most sophisticated one. Jeffrey Severinghaus spent years to analyze d5N and d40Ar changes due to moleculair and gravitational fractination dependant on temperature. However, empiric evidence of current steady state isotope behavior in Antarctica is used to validate the model, which does not take into account the large changes in all proxies. There is no correction for the sudden change in accumulation rate.

    Moreover when new evidence emerges that tells things were diffirent, it’s very tempting for some odd reasons to declare old assumptions lacking that to be solid evidence that it’s not so. That’s why I was certainly right with:

    But I guess we’re not ready yet for a major paradigm shift about ice cores and precipitation and ice ages

    As the alternative hypothesis of the isotopes not being thrustwhorty paleothermometers strongly opposes the ice age support for global warming it’s the more tragic that even the most sceptic paleoclimatologists don’t even start to consider to give the idea more than a passing thought before closing the mind again and point towards superseded ideas of the evidence.

    Get real? How real can you get.

    References that are never used to validate ice core paleothermometry:

    Andreev A, Siegert C, Klimanov V, Derevyagin A, Shilova G, Melles M, 2002. Late Pleistocene and Holocene Vegetation and Climate on the Taimyr Lowland, Northern Siberia. Quaternary Research 57, pp.138–150.

    Andreev A, Tarasov P,. Klimanov V, Melles, M, Lisitsyna O, Hubberten H, 2004,Vegetation and climate changes around the Lama Lake, Taymyr Peninsula, Russia during the Late Pleistocene and Holocene Quaternary International Volume 122, Issue 1 , pp 69-84

    LàƒÆ’à‚⻣ke, A. and Brauer, A., 2004. Biogeochemical and micro-facial fingerprints of ecosystem response to rapid Late Glacial climatic changes in varved sediments of Meerfelder Maar (Germany). Palaeogeography, Palaeoclimatology, Palaeoecology Volume 211, Issues 1-2 , 19 August.

    Schirrmeister L, Siegert C, Kuznetsova T, Andreev A, Kienast F, Meyer H, Brobov A, 2002. Paleoenvironmental and paleoclimatic records from permafrost deposits in the Arctic region of Nothern Siberia. Quaternary International 89, pp. 97-118

    Zazula, G.D. Schweger C.E, Beaudoin A.B. McCourt G.H., 2006. Macrofossil and pollen evidence for full-glacial steppe within an ecological mosaic along the Bluefish River, eastern Beringia , Quaternary International, January volumes 142-143, pp. 2-19

  32. jae
    Posted Jun 26, 2006 at 10:03 AM | Permalink

    Steve: The Tasmania series: are tree cores used all the way to 2000, or did they splice the SAT?

  33. welikerocks
    Posted Jun 27, 2006 at 9:25 AM | Permalink

    June 26,2006
    Boston University

    New model shows
    Antartic More Dynamic
    than previously believed.

    “”The reason the frequency is not observable in records is because ice volume change occurred at both poles, but out of phase with each other. When ice was growing in the Northern Hemisphere, it was melting in the Southern,” said Raymo.

    The team believes scientists have been operating under the assumption that Antarctica has been exceptionally stable for 3 million years and very difficult to change climatically. “We don’t tend to think of ice volume in that region as varying significantly, even on geologic time scales,” said Raymo. “However, only a modest change in Antarctic ice mass is required to “cancel” a much larger Northern ice volume signal.”

    http://www.sciencedaily.com/releases/2006/06/060625123103

  34. welikerocks
    Posted Jun 27, 2006 at 9:28 AM | Permalink

    whoops, apologies.
    there should be “.htm” at the end of link in #33

  35. Paul
    Posted Jun 28, 2006 at 5:41 AM | Permalink

    re: 14, 15, 16, 17, 18 and 19!

    I think there is some confusion here over the use of oxygen isotopes in plaeoclimate reconstruction (palaeotemperatures) and ice volume estimates. To unravel this we need to consider the two main palaeo-archives: 1) The deep sea foraminefera record, and 2) The precipitation record (ice record at high latitudes).

    The foraminefera record largely records changes in the isotopic composition of the global ocean. This is dominated by the ice volume record. During ice ages isotopically light water (depleted in oxygen 18) is locked up in the ice sheets. Hence the oceans become enriched in oxygen 18 and so do the foraminifera. The ice age to intergalcial shift is on the order of 2 to 3 per mille. Any temperature signal resulting from changes in ocean temperature is much smaller than this shift and depends on location.

    The precipitation record, on the other hand, is much more strongly modulated by temperature. We can think of the water cycle in the atmosphere as a distillation process with Rayleigh type fractionation. Basically water evaporating of the ocean is depleted in oxygen 18. The first water to condense and precipitate from an air mass is enriched in oxygen 18 with respect to the vapour and close to the original ocean composition (by definition 0 per mille). This has the effect of depleting the residual water vapour in oxygen 18 and thus making subsequent precipitation isotopically lighter. Moreover for precipitation to continue out of this air mass it is necessary to reduce temperature. In very broad terms this is the origin of the correlation between precipitation isotope composition and mean air temperatures.

  36. Steve McIntyre
    Posted Jun 28, 2006 at 6:57 AM | Permalink

    #36. Paul (or Tas or anyone), can you explain to me the basis for the NAS panel statements on Antarctica excerpted above?

  37. welikerocks
    Posted Jun 28, 2006 at 7:51 AM | Permalink

    Hi Paul,
    I don’t think I am confused, but I am a “civllian” so who knows?
    The article I posted above says: “If our theory holds true, it is a cause for concern with regard to climate changes not associated with orbital patterns as well,” said Raymo”

    This next webpage I’ll post below pretty much reflects my understanding ; exact oxygen ratios can show how much ice covered the Earth, and they use a universal standard to work out the formula. I think “in very broad terms” however exact “temperatures” are not possible at this point in time. Guesses? Sure. And other chemicals are looked at along with the oxygen isotopes in ocean critters/plants/ shells, etc. to guesstimate the temperature as well.

    I (and my husband the environmental geologist) have a problem with broad terms that pronounce exactness about the globe, since we are looking at very small temp ranges on these GW graphs, and the uncertainty and chance for errors are huge over time, space, and “thermometers”.
    Here’s the link from NASA:

    http://tinyurl.com/krc24

    Cheers!

  38. Paul
    Posted Jun 28, 2006 at 8:55 AM | Permalink

    #37 Steve, I’ve yet to look at the NAS panel statements in any detail. However, I will do so over the next few days and also pull out some data for other Antarctic sites to look at. Climatologists and palaeoclimatologists often take either the delta 2-H or delta 18-O signal as recorded in the ice as a measure of local temperature during precipitation. In the sense that both altitude changes of the ice surface, and the seasonal pattern of precipitation will result in associated changes of the ‘average’ precipitation temperature, then these will be recorded as a change in the isotope composition.

    The magnitude of the gradient of the correlation between isotope composition and local temperature is not easy to define. It is often assumed to be the same as the local regional, or indeed global gradient. i.e. Plotting rain and snow isotope compositions against local temperature for the earth as a whole produces a remarkably correlation with temperature. This is strongest when annual mean compositions and temperatures are used. Over the past few decades evidence has come to light that shows this ‘geographic’ gradient isn’t the same as the ‘temporal’ gradient. i.e. take precipitation at just one site and plot it as a function of temperature going back in time. The gradient tends to be somewhat lower. i.e. a smaller change in the isotope composition with a degree change in temperature than the present day regional patterns suggest. Remarkably we can not only do this trick for ice core material where the precipitation can be dated by counting layers and past temperatures can be estimated from borehole data. We can also do it for some groundwaters where we can date the water using radiocarbon methods on dissolved inorganic carbon, measure the oxygen and hydrogen istopes and also independently estimate temperatures using dissolved noble gas concentrations!

    Whilst we don’t fully understand the temperature – isotope relationship in rain and snowfall it is remarkably robust, and strongest at high latitudes. Increasing 18-O is the result of higher temperatures, decreasing 18-O the result of lower temperatures.

    There are other more subtle effects on isotope composition such as the source region for the water vapour etc., humidity in the source region etc. These are seen in parameters such as the deuterium excess. My hunch is they are secondary to the temperature signal. Unlike tree rings the link between temperature and isotope composition of precipitation is much clearer and more robust.

    #38 Hi welikerocks,

    The NASA link is a pretty good summary and has a nice plot of precipitation isotope composition versus annual average temperature as per my note to Steve above. My point is the ocean water isotope composition responds to changes in the global glacial ice (not sea ice) volume. Precipitation composition responds to local temperature. More specifically it responds to the temperature difference between the source region and the site of precipitation. It is not inconceivable to see large shifts in the isotope composition of precipitation with no change in the mean isotope composition of the ocean.

    The raymo paper looks interesting. I’ll try and find time to take it in. Thanks for pointing it out.

    Paul

  39. welikerocks
    Posted Jun 28, 2006 at 11:04 AM | Permalink

    Hi Paul,

    Yep I think we agree.

    I think this is where I am coming from:  the method was developed to map sea level high stands in geologic history. So then oxygen ratios found how much ice covered the Earth at given points in time. That all matters to the “global”; Warmer/Colder earth. It doesn’t matter what made these molecules respond, the ratio is the ratio, and this answers a “global” question.

    So another question is: is one study or five, from different places around the globe: a reflection for determining past temps everywhere on the planet? Temperatures and weather can differ widely over small distances. I am sitting on a beach here and the desert is not very far away.

    What do we know about reconstructing past or present global temperature so exactly is the question I have. The use of the isotopes in this way is a new idea in terms of their development and scientific certainty.

    That’s why maybe Steve has questions about the NAS ice cores. :)

  40. jae
    Posted Jun 28, 2006 at 11:19 AM | Permalink

    Steve M: Have you tried to contact Cuffey and ask him to back the statements up?

  41. beng
    Posted Jul 23, 2006 at 9:20 AM | Permalink

    The Cook et al treerings, which are at a high altitude in Tasmania, show a 20th century spike. Could be another possible case of CO2-starved trees responding to CO2 increases.

  42. eric
    Posted Sep 8, 2006 at 9:19 AM | Permalink

    Steve,

    A colleague pointed out this post of yours from back in June, and I wanted to make a couple of comments.
    Like you, I’m a bit miffed by the NAS panel statements about ice core results from Antarctica.

    As a regular contributor and founding member of RealClimate, I suspect some of your readers will take everything I say with a grain of salt. However, I am actually interested in contributing to clarity, not obfuscation, whatever one may choose to believe about my colleagues.

    First, it is worth pointing out that your various commenters made a remarkable mess of discussing delta 18O. There is an amazing amount of confusion out there on what is actually a very simple concept. It would help your discussions if your commenters refrained from talking about thing that they have evidently not taken more than 15 seconds to think about, let alone read about. It is such a mess that I feel compelled to explain it on a RealClimate post at some point, so there is no excuse for this sort of confusion in the future.

    Regarding the NAS panel statements: I don’t think any of the statements you quote about Antarctica are valid. In fairness the panel was not charged with rigorously evaluating the Antarctic data, and much of what they said may well be from talking with colleagues (including me) more knowledgeable on the subject. Still …..

    Here is my take on what the Antartic records do and don’t show:

    I spent some time a while back trying to determine whether there was any discernable spatial pattern to the so called “LIA” and “MWP” in Antarctica. The results suggest that during the “classic” LIA time (say, 1400 – 1900 A.D.), it was colder (by which I mean that isotope concentrations were lower) in much of East Antarctica but warmer in much of West Antarctica. This is tantalizingly similar to the pattern on sees in El Nino vs. La Nina years. However, the data — in particular the dating — of the cores is simply not good enough to do this rigourously, so I never published it. Ellen Moseley-Thompson suggested this sort of pattern back in 1992 or so, but, like me didn’t make a big deal about it because she knew the data were not good enough to make any kind of definitive statement. I hope to revisit this when we have more very-well-dated long ice cores available (we are getting close). The bottom line is that there is no clear signal of the classically defined LIA/MWP in Antarctica, which supports but by no means proves (by itself) that these were regionally restricted phenomena (i.e. especially strong in the North Atlantic; I think the evidence for that is quite strong but that’s another matter; I’m just talking here about Antarctica).

    As to “some coastal sites show 20th century warming” I have no idea what they are talking about. The only paper I’m aware of on this is the one that just came out by my grad student Dave Schneider and me, which is a very-first-cut at carefully analyzing the last 200 years of data for those few cores we have so far that are precisely dated enough to do this carefully. Tas is a co-author. We DID find that the Antarctica has warmed up on average in the last century. But the average trend for the last 200 years is indistinguishable from zero. And these cores we use are not “coastal.”

    The link to the paper in GRL is here: http://www.agu.org/journals/scripts/highlight.php?pid=2006GL027057. Note this is actually the link to the Editor’s Choice article about it, which gives a reasonable summary (though the “prediction” of the future he cites is a bit strong: what we said is that our results “suggest” Antarctica will warm with the rest of the globe in the future).

    I hope this clarifies things a bit.

    Oh, one last point.. you wondered why “deltaD” rather than “del18O” was used in the plot of Taylor Dome data. The answer is simple: I produced the deltaD data and made it available quickly, 10 years ago or so. So these are the data most folks had their hands on. The del18O data wasn’t “mine” and didn’t get out there as fast (though all these data are easily accessible now). ***Important point: it makes no difference whatsoever. del18O and delD are correlated at something like 0.95 (probably better!), as one would expect from the physics.

    Eric

  43. Barney Frank
    Posted Sep 8, 2006 at 10:08 AM | Permalink

    #42

    The results suggest that during the “classic” LIA time (say, 1400 – 1900 A.D.), it was colder (by which I mean that isotope concentrations were lower) in much of East Antarctica but warmer in much of West Antarctica. This is tantalizingly similar to the pattern on sees in El Nino vs. La Nina years. However, the data “¢’‚¬? in particular the dating “¢’‚¬? of the cores is simply not good enough to do this rigourously, so I never published it.

    This statement is unclear to me. Are you saying there may have been a five hundred year long stasis of either El Nino or La Nina or that the data indicate El Ninos and La Ninas fluctuated much as today. If the latter then what exactly is tantalizing about it since the fluctuation between El Ninos and La Ninas seem to be a regular feature of the Pacific.
    I’m sure you are sincere in trying to clarify, but can’t actually say that you have for this admitted amateur.

  44. Steve McIntyre
    Posted Sep 8, 2006 at 10:10 AM | Permalink

    Eric, thanks for thoughtful comments.

    I don’t think any of the statements you quote about Antarctica are valid. In fairness the panel was not charged with rigorously evaluating the Antarctic data, and much of what they said may well be from talking with colleagues (including me) more knowledgeable on the subject.

    I think that it’s fair to criticize the panel on this point as it was something that they emphasized at the press conference as showing that medieval proxies were supposedly a dog’s breakfast. The point was one that I noticed quite quickly and I have minimal experience with Antarctic data. Perhaps you might post something up at RC on it. Anyway thanks for commenting and clarifying about the NAS panel.

  45. bender
    Posted Sep 8, 2006 at 10:14 AM | Permalink

    Re #43
    I think he means the LIA was much colder than now, but that the degree of difference was regionally variable, and that the spatial pattern of regional variability is reminiscent of ENSO spatial modes of variability exhibited today. (I thought he was pretty clear.)

  46. bender
    Posted Sep 8, 2006 at 10:26 AM | Permalink

    Re #43:
    I also presume the long time-frame in reference to LIA was not meant to imply stasis, but instead was a way of covering off against data resolution limitations.

    The only thing not clear to me was whether “warmer” western Antarctic was intended as a purely a spatial contrast (vs. eastern Antarctic), or a temporal contrast (vs. today) as well. I assume the former.

  47. John Hekman
    Posted Sep 8, 2006 at 10:31 AM | Permalink

    Eric
    Thank you for the clarifying information. Several things are still unclear for me:

    –is the warming trend that you see in the Antarctic over the last 100 years more consistent with a recovery from the previous cold period (LIA) or with sharp warming in the last 30 years as has occurred in the NH?

    –I believe that there has been little or no warming in the last 30 years in the SH; so “global warming” is a net warming due to the NH. If this is accurate, then to evaluate whether the MWP was “global” we would judge it to be just as global as the current warming if the net of the NH and SH was positive. Do you agree?

    –I am trying to sort out all of these judgements about regional versus global and how they relate to the attribution question. The NAS panel seemed to say that if MWP was regional and today’s warming is global, then that points to a human cause. Do you think that there is solid evidence for this conclusion?

    thank you. Interesting subject.

  48. Eric
    Posted Sep 8, 2006 at 10:33 AM | Permalink

    Heaven forbid I should get too embroiled in discussions at ClimateAudit (because I disagree quite strongly with the tone of a lot of it, most notably accussations of dishonesty on the part of my friend and colleague Gavin Schmidt). [NB please don't bother arguing with me on this point; I haven't time!].

    BUT to try to clarify the ENSO point a bit:
    The point is simply that if (for example) there if the MEAN climate were a little more “El Nino like” (which does not require “static” El Ninos, but simply more-El-Ninos-than-usual), this would be reflected in a mean pattern of temperature in Antarctica that was more like the pattern that exists during El Nino years. There is some theoretical and modeling basis for thinking this kind of thing can happen; this is really just saying that there is likely a significant low frequency component to El Nino. It would be interesting if this were the case. Note that this would be very hard to demonstrate because Antarctic climate may “care” about El Nino but cannot be said to be dominated by it. We’d only see it if it were a very big signal. Hence the word “tantalizing” because the results do *look* like that. But it is not defensible at any sort of rigorous level; hence no publication on this.
    I’m not saying the Antarctic climate during the LIA (as defined by the timing of changes in the North Atlantic, which is the only sensible definition of it) was much colder than now. It may well have been warmer as Wally Broecker has strongly (though not convincingly) argued. Most likely it was warmer some places, colder in others.

  49. Eric
    Posted Sep 8, 2006 at 10:42 AM | Permalink

    John#47.
    Quick answers to your questions, but NB I am signing off and am unlikely to be a regular visitor here!

    “–is the warming trend that you see in the Antarctic over the last 100 years more consistent with a recovery from the previous cold period (LIA) or with sharp warming in the last 30 years as has occurred in the NH?”

    What does “recovery from the previous cold period” mean? This is a commonly used phrase but it doesn’t mean anything unless there is very long term persitence driving the mean climate. There might be (Wally B thinks there is), but the evidence is sketchy at best. Are our results “consistent” with the NH records. Yes. But so would a lot of other results. Climate is messy. The important point is that our results are (as far as we can tell) consistent with models, which show warming in Antarctica over the last century but at a far slower rate than the average for the globe. That’s exactly what we find.

    “–I believe that there has been little or no warming in the last 30 years in the SH; so “global warming” is a net warming due to the NH. If this is accurate, then to evaluate whether the MWP was “global” we would judge it to be just as global as the current warming if the net of the NH and SH was positive. Do you agree?”

    Yes. 30 years is a short time to examine trends — that’s a major point in our paper! Over the last century, both hemispheres have warmed. Hence the entirely appropriate term “global warming”. I am pretty sure that is also true of the last 30 years taken alone but it wouldn’t bother me if it weren’t. Antarctica (surface temperatures at least) HAS been cooling over much of that time. See my varoius posts on this over at RealClimate.

    “–I am trying to sort out all of these judgements about regional versus global and how they relate to the attribution question. The NAS panel seemed to say that if MWP was regional and today’s warming is global, then that points to a human cause. Do you think that there is solid evidence for this conclusion?”

    YES, I do, but then that is the fundamental “battle” going on on which ClimateAudit is based. I don’t actually want to get into it here!

  50. bender
    Posted Sep 8, 2006 at 10:44 AM | Permalink

    Thanks for the clarification, Eric.

  51. TCO
    Posted Sep 8, 2006 at 10:51 AM | Permalink

    I think it is the totality that matters. It is acknowledged by warmers that AGW may vary in extent regionally, that some areas may even cool based on changed weather patterns. Similarly previous warm periods (if they existed) may not have been completely global. The important thing is the totality. The average.

  52. Barney Frank
    Posted Sep 8, 2006 at 11:04 AM | Permalink

    Re #48,

    Thanks eric. That clarifies it quite nicely.

  53. bender
    Posted Sep 8, 2006 at 11:09 AM | Permalink

    “–I am trying to sort out all of these judgements about regional versus global and how they relate to the attribution question. The NAS panel seemed to say that if MWP was regional and today’s warming is global, then that points to a human cause. Do you think that there is solid evidence for this conclusion?”

    YES, I do

    Wait a second, here. On the surface this seems to make sense. But if the temporal and spatial resolution of proxy data for the MWP is sparse compared to the present, I’m not sure how you make that comparison fairly. [All problems with proxy interpretation aside.]

    Also, there seems to be a logical error here: if the current warming is unprecedented, but due, say, to some solar effect we don’t understand yet, then it is possible you could have a regional-scale effect (weak forcing) during the MWP, but a global-scale effect today (stronger forcing). The spatial extent of the trend doesn’t allow you to infer anything about the cause, does it? Why couldn’t you have a single forcing process that varies by degree, thus producing different spatial patterns and extents of impact?

    Thinking aloud … willing to listen to reason …

  54. TCO
    Posted Sep 8, 2006 at 11:14 AM | Permalink

    (Piling on.) If there is something which caused the regional MWP a while ago (even if not global), what was it? Do we understand it? Do the models show it.

  55. Ken Fritsch
    Posted Sep 8, 2006 at 11:40 AM | Permalink

    re: #53

    Wait a second, here. On the surface this seems to make sense. But if the temporal and spatial resolution of proxy data for the MWP is sparse compared to the present, I’m not sure how you make that comparison fairly. [All problems with proxy interpretation aside.]

    I have been thinking about the global “coverage” of proxy and even modern day instrument measures of temperature and whether that has been handled in some formal and/or statistical manner so that when global mean temperature is used we know how confidently it should be used. From my knowledge (which may be the problem) of the literature it seems it is almost a hockey stick like leap of faith to accept accounts of global mean temperatures today versus the era of proxies.

    If “localized” differences like the MWP and LIA, with their respective good and bad climate influences can be realized with little changes in the global mean (that evidently is so important for the AGW theorists to maintain) than maybe we should be doing more work with local effects ala Peilke’s Sr. and Jr. What are the explanations for these “local” and evidently persistent variations in the times of MWP, LIA and potential AGW?

  56. TCO
    Posted Sep 8, 2006 at 11:52 AM | Permalink

    I guess you could do some mathematical method that looks at regional variability (from instrument) and then looks at what coverage one gets proxy-wise over different time periods. Then one can impute some uncertainty based on the lower coverage. I wonder if sampling statistic methods from polling or market research would be helpful to think about this.

  57. Dave Dardinger
    Posted Sep 8, 2006 at 11:57 AM | Permalink

    Couple of passing thoughts. I enjoyed having Eric here, but wonder why he’s so skitish? I don’t think anyone was impolite to him, or likely to become so. The regular skeptics here have been uniformly polite to warmers who come here until and and unless they become impolite themselves. I suppose he’s worried about becoming embroiled in time-wasting discussions with people who might not be able to keep up. Still, why shouldn’t the team have an “embassador to the skeptics” with the portfolio of working through disagreements in a polite and leasurely way? I’m sure Steve M would be more than happy to set up one or more threads which could start with a warmer statement and then Steve or others could add directly to the actual post and then add the replies sent directly to him, etc. Meanwhile us regulars could do our potshots from the peanut gallery and the “embassador” wouldn’t even have to read them unless and as they chose to, or when Steve quoted one as being worthy of moving to the top.

  58. Steve McIntyre
    Posted Sep 8, 2006 at 12:11 PM | Permalink

    but then that is the fundamental “battle” going on on which ClimateAudit is based. I don’t actually want to get into it here!

    I’m trying to determine what statements are solidly based and what aren’t. It seems that my comments about Antarctic proxies were accurate.

    Eric, my beef with Gavin was that realclimate posted up a webpage trashing me and then censored my reply, which raised questions for me about his commitment to professed objectives of fostering scientific exchanges. I posed it as as a question and made no categorical statements. You don’t need to respond or explain.

  59. welikerocks
    Posted Sep 8, 2006 at 12:54 PM | Permalink

    re: #58
    Alot of us have had experiences like that with Gavin.

    FYI these are sort of on topic with #53 here:

    “constructed by combining measurements from 57 globally distributed deep sea sediment cores. The measured quantity is oxygen isotope fractionation in benthic foraminifera, which serves as a proxy for the total global mass of glacial ice sheets. Lisiecki and Raymo constructed this record by first applying a computer aided process of adjusting individual “wiggles” in each sediment core to have the same alignment (i.e. wiggle matching). Then the resulting stacked record is orbitally tuned by adjusting the positions of peaks and valleys to fall at times consistent with an orbitally driven ice model (see: Milankovitch cycles)”

    This article talks about the two hemispheres and is authored by the same people as the graph and I linked when this topic was new :
    “Antartica more dynamic than previously believed”

    http://www.sciencedaily.com/releases/2006/06/060625123103.htm

  60. Eric
    Posted Sep 8, 2006 at 1:05 PM | Permalink

    re57

    “Still, why shouldn’t the team have an “embassador to the skeptics” with the portfolio of working through disagreements in a polite and leasurely way?”

    I agree. That would be great. I don’t want to play the role though because I always play that role (at my University, in city politics, etc.).
    If I’m not careful I’ll wind up playing that role between Senators Bill Frist and Patty Murray. No thanks! Got a life to live, kids to raise, not to mention skiing to do, before all the snow melts …;)

  61. Eric
    Posted Sep 8, 2006 at 1:10 PM | Permalink

    P.S. I’m not on “The Team”

  62. TCO
    Posted Sep 8, 2006 at 1:20 PM | Permalink

    Eric: stick around, man. You might teach us something. Might learn something yourself. There is joy in life from such things.

  63. Steve McIntyre
    Posted Sep 8, 2006 at 1:40 PM | Permalink

    Eric, you should be aware that I had lunch with Ammann in San Francisco last December, pointed out to him that our codes reconciled and that we should be able to produce a clear statement of agreed results, clear statement of what we disagreed on and how these disagreements could be resolved, as an alternative to continuing controversy. I proposed a 2-month ceasefire to attempt to draft such paper and if no agreement could be reached, we would revert back to the present position. I sent reminders to him, but he did not even reply. Had he done so, much aggragavation would have been avoided.

    I thought that Wahl and Ammann were very irresponsible in their attitude and will ultimately regret their decision. Doesn’t matter to me; I’ll play the ball where it lies.

  64. welikerocks
    Posted Sep 8, 2006 at 1:52 PM | Permalink

    Yes, we all dream of skiing in September Eric! (?) :P

  65. Eric
    Posted Sep 8, 2006 at 1:58 PM | Permalink

    A basic climate fact: There is a lot of snow in the mountains near Seattle, even in Sept.

    I (try) to ski 10+ months/year.

  66. John Baltutis
    Posted Sep 8, 2006 at 5:12 PM | Permalink

    #49:

    Climate is messy. The important point is that our results are (as far as we can tell) consistent with models, which show warming in Antarctica over the last century but at a far slower rate than the average for the globe. That’s exactly what we find.”

    Which models might those be? The GCMs, which have never been validated? Using those model outputs to justify the results from data seems bassackwards to me. From my perspective, the correct order is that you collect data, generate results, run the models, and see if their results are consistent with your results. Are they?

    BTW, what do your results which (paraphrasing what you wrote) “show that the warming trend in Antarctica the past two centuries is indistinguishable from zero” tell you about the so-called “global” or regional temperature trends?

  67. Eric
    Posted Sep 8, 2006 at 6:31 PM | Permalink

    John Baltutis,

    Why don’t you read our paper and then you’ll know precisely what I mean? If after careful reading you still don’t get it (it ain’t that complicated), hopefully the RealClimate post I’ll put up on this at some point will clarify further. Your emphasis on “validated” belies a fundamental but common misunderstanding of the use of GCMs. The point of all field or experimental data is to examine our understanding of the important physics (as represented, for example, in GCMs). My point was that our results do not in any way cause us to “go back to the drawing board”. Is short, yes, the results are entirely consistent.

  68. ET SidViscous
    Posted Sep 8, 2006 at 7:20 PM | Permalink

    Eric

    If your going to clarify, might I suggest you copy your post over here. It’s a bit unfair to go “You can find your answer to your question by going to someone elses blog”

    If your going to discuss it here it is only fair to also post the answers here.

    Doing a copy {ctrl-c} and paste {ctrl-v} is not all that difficult, and I know Steve would appreciate the post here.

  69. Ken Fritsch
    Posted Sep 8, 2006 at 7:56 PM | Permalink

    Why don’t you read our paper and then you’ll know precisely what I mean? If after careful reading you still don’t get it (it ain’t that complicated), hopefully the RealClimate post I’ll put up on this at some point will clarify further.

    If it is not that complicated, why not give us a post here to summarize your paper’s results/conclusions and answer the JB question. We might “get it” sufficiently to engage you in a discussion and at least prepare you for the really hard hitters over at RealClimate.

    My point was that our results do not in any way cause us to “go back to the drawing board”. Is short, yes, the results are entirely consistent.

    That sounds like the results could be conveyed briefly and without any equivocation.

    The important point is that our results are (as far as we can tell) consistent with models..

    Should that “far as we can tell” cause us any unease or is that being used more as a polite figure of speech? I sometimes think that I am just not sufficiently nuanced to appreciate what is truly being stated in these cases.

  70. TCO
    Posted Sep 8, 2006 at 8:27 PM | Permalink

    What form of difference would cause a problem? Aren’t the models full of parameters to tweak so that any eventuality can be dealt with?

  71. maksimovich
    Posted Sep 8, 2006 at 8:42 PM | Permalink

    Your emphasis on “validated” belies a fundamental but common misunderstanding of the use of GCMs. The point of all field or experimental data is to examine our understanding of the important physics (as represented, for example, in GCMs). My point was that our results do not in any way cause us to “go back to the drawing board”.

    You suggest you can replicate in the models to replicate the physics of the parameters(variables).

    Are you doing this at present-NO
    Do the models replicate or assimilate the biochemistry as observed -NO
    Do the models replicate or assimilate the physics of solar free energy-NO
    Do the models replicate the physics of biochemistry in the biosphere,free atmosphere-oceans-Lithosphere-cryosphere NO
    Do the models replicate or incorporate the energy inputs of free energy NO

    The understanding of the “experiments” does not seem to meet the necessery parameters of the “PHYSICS”

    Incorporate these into the models and then you will have a reasonable experiment for GCM

  72. Steve Bloom
    Posted Sep 8, 2006 at 9:18 PM | Permalink

    Re #68: Life is unfair. As Eric has pointed out, he has limited time for this sort of thing and the focus of his blogging activity is RC. You can read and comment there.

    Re #69: Let me try to sum it up for you, Ken: There’s a consensus because the bulk of climate scientists have concluded that AGW is happening and that it has potential for being a major problem. The scientists are also aware that there are varying degrees of uncertainty associated with each and every one of the building blocks of the consensus, but that taken as a whole there is a strong case for it that tends to grow stronger as more evidence comes in. While the uncertainty is very much part of the science, when a scientist decides to spend time educating the public about climate science it makes limited sense to participate in a venue whose primary purpose is to undermine the consensus by placing too much emphasis on the uncertainty. (Note that this may not be Steve M.’s stated purpose, but is IMHO a fair conclusion to be drawn from observations of the general tenor of the discussion here.) Occasionally a scientist may decide otherwise, as apparently with Judy Curry (and we’ll see how long that lasts), but I suspect that any scientist who has been familiar with this site over an extended period of time will conclude that such an attempt will likely just end in frustration.

  73. bender
    Posted Sep 8, 2006 at 10:52 PM | Permalink

    On the one hand the frustration mentioned by Bloom in #72 does tire me. He’s got a point. Like Eric, I really don’t have time for it.

    On the other hand this blog is more democratic & organic than others. Bottom line is that CA regulars are all in favor of auditing tools and accessible data sets to be made available to all parties – warmers, deniers, fence-sitters, whatever. Those against the idea of open discussion and increased competition in the free marketplace of ideas, are, in my opinion, part of the problem.

    So how about it, Bloom, are you going to teach me something about Bayesian statistics this weekend?

  74. John Creighton
    Posted Sep 8, 2006 at 11:09 PM | Permalink

    #67 (Eric) in another post, Willis pointed out that the GCM models do not agree with the instrumental data in terms of higher order statistics. Also I believe there was disagreement with expected temperatures in terms of latitude, longitude, altitude and time of year.

  75. Ken Fritsch
    Posted Sep 8, 2006 at 11:15 PM | Permalink

    re: #72

    While the uncertainty is very much part of the science, when a scientist decides to spend time educating the public about climate science it makes limited sense to participate in a venue whose primary purpose is to undermine the consensus by placing too much emphasis on the uncertainty.

    Steve B thanks much for the long (and perhaps standard) answer to my questions that I asked of Eric. I can and will read Eric’s paper on the Antarctic and make my own judgments.

    I guess I have a little trouble understanding why a consensus of scientists and their supporters that was formed on circumstantial evidence would be concerned about or would even contemplate being undermined by a venue (and a minority one at that) that places too much emphasis on uncertainty. I think the larger frustration from scientists of the consensus will come when they realize that regardless of what the skeptics say or do they simply do not have practical answers for the politicians of the world to apply in order to mitigate global warming. We are seeing this with the tardy compliance to the Kyoto accords even in those nations that have at least committed to talking a good game. At some point I judge that the interest in climatology with regards to global warming will fade as the public recognizes the lack of practical political solutions. That is, however, not to say that market forces cannot lead us away from the use of fossil fuels with the resulting carbon dioxide emissions and making the point of AGW irrelevant. I am almost certain that we will be obtaining many more out-of-sample temperature data points before our GHG levels subside significantly.

    The only disclaimer I would make to this scenario would be in the event of some catastrophic weather over a period of a couple of years that could be associated with AGW (but not necessarily shown to be the result of AGW) and people panic. If people are in a panic mode for any length of time I think their reactions can be very unpredictable.

  76. fFreddy
    Posted Sep 9, 2006 at 3:02 AM | Permalink

    Re #72, Bloom

    the focus of his blogging activity is RC. You can read and comment there.

    … if the censors permit it …

  77. fFreddy
    Posted Sep 9, 2006 at 4:20 AM | Permalink

    Re #75, Ken Fritsch

    At some point I judge that the interest in climatology with regards to global warming will fade as the public recognizes the lack of practical political solutions.

    With respect, I think this is a trifle optimistic. There will always be a large segment of the public for whom the solution to all political problems is “the government should pay for it”, largely via taxing big companies/the rich/anyone else they hate. I don’t think issues of practicality come very high in their judgements – for example, see here.
    As long as this segment of voters exist, there will be a market for the sort of politician who will take advantage of them.

  78. Ken Fritsch
    Posted Sep 9, 2006 at 12:39 PM | Permalink

    re: #77

    As long as this segment of voters exist, there will be a market for the sort of politician who will take advantage of them.

    I think that we have a large number of voters who see an unending free lunch from government involvement in some of these issues or at least for themselves. Reality must at some point come into play even though the current strategy appears to be to put problems off unto future generations, e.g. the existence in most advanced nations of large unfunded liabilities for government health and pension programs and the voters seeming willingness to forego doing anything precipitously about it. The Peilkes have talked about the difficulty of motivating voters to approve of the necessarily painful current time effects of any potential climate policies (that will have any significant future climate effects per current climate modeling calculation/projections) where the benefits are delayed into the longer term future, and then only with a probability that is poorly defined and determined.

    I do not see the scientists that attempt to make the case for AGW really having much to say about what would actually be required in mitigating it. They talk about it in general terms, like Dr. North of NAS panel fame did recently, but specifics are seldom mentioned, or at least not in the material that I read. Western Europe has talked a really good game with policies to mitigate what they see as the negative effects of AGW but they have not resulted in any significant changes in GHG emissions or any pain for the citizens — so talk remains cheap.

    I think it is easier at the current time for the advocates of AGW and more immediate mitigation to blame skeptics and their backing by “special interest”, but at some time soon I think they will be diverting their attention to a bulky public unwilling to make current sacrifices for long term benefits that cannot be readily guaranteed with any good probability. I think the tipping point arguments for catastrophic climate effects in the near future are aimed at “softening up” that public hesitancy. If the predicted events do not occur, that approach could backfire by the lose of credibility of those willing to make predictions that can be quickly tested out-of-sample or just by the public’s feeling that someone was crying wolf.

    I think a voting constituency in full panic would give politicians a window in which to enact some rather draconian measures in what would be heralded as the only way to mitigate AGW. I doubt that the scientific community at that point would have much input into policy as it would be a very emotionally and politically charged environment. I even wonder how many scientists have actually thought through the possible political scenarios.

  79. Eric
    Posted Sep 9, 2006 at 1:16 PM | Permalink

    Let me just note that Steve Bloom’s intelligent and insightful comments are an example of a reason to bother engaging with those that contribute to this site.

    On the other hand the ignorance and outright hostility of maksimovich and fFreddy are illustrative of exactly the problem. (Not to say we don’t get such drivel from commentors (on both “sides”) over at RealClimate as well).

  80. fFreddy
    Posted Sep 9, 2006 at 1:29 PM | Permalink

    Re #79, Eric

    On the other hand the ignorance and outright hostility of maksimovich and fFreddy are illustrative of exactly the problem.

    Hmmm. I freely admit that there are many things I don’t know, but there is nothing I can’t know.
    Incidentally, where do you feel I have been hostile to you ?

  81. Barney Frank
    Posted Sep 9, 2006 at 1:59 PM | Permalink

    #79,
    eric,

    Steve B is intelligent and insightful, unfortunately much of his time is spent being inciteful.

    I also must confess to not seeing the outright hostility of either person you mentioned. In fact I have seen very little hostility to anyone here who has not earned it. Poor old TCO is a skeptic himself and he gets plenty of scorn so I don’t thinks its position driven but rather behaviorally driven.

    As to ignorance, guilty as charged. That’s one reason I would like to hear some reasonable discussion from both sides here.

  82. Ken Fritsch
    Posted Sep 9, 2006 at 3:01 PM | Permalink

    re: # 81

    As to ignorance, guilty as charged. That’s one reason I would like to hear some reasonable discussion from both sides here.

    Sometimes I think you have to make judgements on what you do not hear and particularly so when asking what one thinks is a reasonable question. Silence can be telling and one can learn from it.

  83. TCO
    Posted Sep 9, 2006 at 3:17 PM | Permalink

    fFred is cool. Eric, you got something twisted inside you…

  84. Barney Frank
    Posted Sep 9, 2006 at 3:21 PM | Permalink

    #82

    You are correct Ken. I am trying to resist the conclusion that comes from either silence or hostility to reasonable questions. Simply telling people several times that they are ignorant and hostile hardly engenders confidence does it?

  85. Eric
    Posted Sep 9, 2006 at 3:52 PM | Permalink

    My apologies guys for evidently giving offense. Let me try to explain a little better.

    First, I thought an accusation of my involvement in censorship was a pretty good example of hostility, but I’ll let it slide.

    Second, my reference to ignorance wasn’t meant to imply that “not knowing” is somehow a crime. It’s the combination of ignorance and hostility I have trouble with. I read maksimovich’s comment on GCMs as hostile because it implied I didn’t know what I was doing, and ignorant because it is full of bizarre terms like “solar free energy” and appeals to worry about “biogeochemistry” when addressing recent Antarctic climate change. This is so far off the mark of what is relevant that I’m actually, honestly, not sure where I’d begin in trying to respond! This all comes back to Steve Bloom’s point that most scientists trying to engage on this site, no matter how open minded they are, will quickly become very frustrated. I certainly have. Accusations that my “silence” are somehow speaking to some ulterior motive or fear of engaging on my part are similarly not very encouraging. It’s particularly bizarre to be accused of this given that I wrote inthe first place (me, a RealClimate guy!) to AGREE with Steve McIntyre on something).

  86. TCO
    Posted Sep 9, 2006 at 4:16 PM | Permalink

    Eric:

    1. fFred is one of the nicer guys on the site. I know. I’m one of the less nice. You show lack of discrimination or insight by talking about him as the bad guy.

    2. I don’t know if you participate in the censoring. I do know that I have been very routinely censored there. You can’t ask a very simple yes/no question, like “was the off-centering in MBH PCA intentional” or “why was it not disclosed in the methods”. You CAN’T even ASK it. They preview the comments and if you push them too much on a vulnerability, then they stop your posts.

    3. Hang around here. No one will censor you.

  87. maksimovich
    Posted Sep 9, 2006 at 6:25 PM | Permalink

    I read maksimovich’s comment on GCMs as hostile because it implied I didn’t know what I was doing, and ignorant because it is full of bizarre terms like “solar free energy” and appeals to worry about “biogeochemistry”

    It is not a hostile attack it is a statement of fact,your comments suggest a lack of knowledge of the additional parameters(variables)Do not take it personal it is business(science).If you do not understand the coeffcients of nuclear (solar and galactic)radiation as an energy inputand its qualitative energy budget or the biochemistry of say refrigerant bacteria such as phylum Pseudomonas the activators and inhibitors of chemical thermodynamics and thermodiffusion state it in your discourse,ie provide a risk matrix of the levels of understanding of unquantified variables and the correlation of accuracy (proof) of the gcm.It does not disprove the experiment.

    As Swift wrote on the scientists of the grand academy of Lapunda who became so diversed in their specialist subjects they failed to relate reality to virtuality ie they lost objectivity.

    It is now the post industrial information age. Each day we experience data transformed in both electronic visual and print mediums to our senses and perceptions. The data transcends both virtuality and reality. The convergence of reality and virtuality in News and entertainment, with science and controversy, with chaos and catastrophe, and the transformation of the delivery of data along the various modes of information have resulted in uncertainty and confusion.

    Indeed how can it be expected to identify reality, when there are difficulties of distinction between reality and the unreal when the unreal is being realized, and the real being shown as unreal. Each day we experience a growing crisis of unrealized proportions .As Umberto Eco observed “crisis sells well” The question such crisis pose is whether attitudes have been undermined by the experience of modernity, or whether reality itself, something objective and firm, is an illusion .Is the paradigm now one of “there is no reality?” When the media, governments, and advertisers tell us that dreams are becoming realities, does this mean conversely, reality is becoming a dream?

    The philosophical ideology of what is, or not real are continuing debates.The primary questions being ontological and epistemological. The former is about being: what is real? Is there reality and form behind appearance? The epistemological question is about knowing: what is truth?. Is knowledge by reason or experience? Or do our everyday systems distinguish between reality and appearance, and truth from falsity. We expect the system of road rules to regulate the traffic, and do not question if the other drivers are rationalists, or empiricists .Although the parentage and marital status of the regulators is often questioned .Previously the normality of the result of an experiment, performed by a scientist, did not rest on whether the scientist performing the experiment is an idealist or materialist, or the source of funding, but the outcome and replicability of the experiment that showed reality.

    The transformation of the interpretation of science and the contemporary views on the ways science operates in both form and validation, and the variances of the determinants of science have caused obfuscication of the basic tenets and norms of the characteristics of the scientific model. This has formed an ideological involvement in scientific validation that has created uncertainty and confusion. and. a convergence between reality and virtuality that have obscured the outcomes and development. The loss has been one of order and objectivity, and its replacement by chaos and controversy. The underlying philosophical conditioning, the interpretation of the results, rather then the scientific model and reality. The Divergence from Realism and its objective reality and existence to one of the Feyerabend model of anything goes and his promotion of anarchy as an antidote against epistemology and the scientific method.

    The social component of science also is an important determinant in the truth of the outcome. This is not only within the scientific community, but in the areas of funding and oversight. This form can see the suppression of some theory and the enhancement of others. The theories suppressed are not always incorrect, but in some instances far ahead of their time and interpretation. The example of the Austrian Ludwig Boltzmann and the connections he discovered with heat and thermodynamics and the notion of entropy that went against the social climate rather then logic whilst questioning Newtonian mechanics. Another is the Russian Boris Belousov whose work showed entropy could move both forward and backwards along the arrow of time. His experiments proved the mathematical theories of Turing were possible.Belousov theories and publications were dismissed as against the laws of thermodynamics ,but obstinacy and the persistence of one of his post graduate students and the publication of the BZ reaction saw it enter the real world of science and that a theory is changeable.

    The philosophical intents of Feyerabend and also the misrepresentations of the ideals of Thomas Kuhn and his structure of scientific changes by Paradigms by the alternative and anti science movements meant the order or formalization of the scientific method has undertaken structural change that blurs the line between reality and virtuality,of possibility and probability.

    The constraints of the formal method has seen pseudo science take equality with recognized science theory ,and often the merging of the real and virtual worlds.

    We have seen the transformation from the Merton norms of Originality, detachment, universality, Skepticism.and public accessibility, and its cognitive structure, to theories that have the form and reason of Pseudoscience. These rely on a casual approach to evidence, spurious similarities, explanation by scenario, research by literary interpretation and a refusal to revise.

  88. Barney Frank
    Posted Sep 9, 2006 at 6:49 PM | Permalink

    Eric,

    I should have made a distinction in my post.
    I was not referring to you when I responded to Ken’s point about silence or hostility in response to a reasonable question. That was a general point that had nothing to do with you.

    The other point about accusations of ignorance and hostility were directed to you. My only point was that they were kind of disappointing. Certainly there are people quite ignorant of the issues involved; I’m living proof of that, but that is an opportunity to enlighten not dismiss isn’t it?
    And I never saw an insinuation that you had engaged in censorship. If someone did, that was certainly uncalled for without some evidence to back it up.
    In any event some of the scientists here have made eerily similar remarks regarding the frustrations involved in interacting at RC. I’m not sure what that says other than some people and issues are contentious in just about every walk of life and discipline. Perhaps ignoring the ones you find contentious and engaging the ones you don’t would lessen your frustration. There seem to be quite a few scientists here who engage in productive discussions. I hope you’re not confusing disagreement with hostility.

  89. TCO
    Posted Sep 10, 2006 at 6:08 PM | Permalink

    I’m going to stop commenting here. Since this was supposed to be an ice core thread. Let’s move the blog discussion to the Europe thread or the Road Map thread.

  90. Steve McIntyre
    Posted Sep 14, 2006 at 12:25 AM | Permalink

    I’ve moved some wrangling to Road Map in the hopes that a thread for Antarctic ice cores can be one.

  91. Hank Roberts
    Posted Sep 14, 2006 at 12:33 PM | Permalink

    Eric, I’ve appreciated what you’ve posted here and at RC. A question I haven’t seen you answer:

    What are some unanswered questions you hope to find answers toward — either by further study of the cores already obtained, or by further drilling in the Antarctic?

    (Or, post a pointer, not asking you to retype anything already written elsewhere.)

    I’m curious not just about the ‘big climate’ issues but whatever comes to mind, given the position you are and able to look and wonder.

    I’d imagine things like — do you ever find insects or insect fragments in the ice?
    What sorts of colors do you notice? How does it taste from different levels (grin).

  92. Andrew Francis
    Posted Dec 3, 2009 at 6:52 AM | Permalink

    Came across an interesting CRU email on this topic:

    http://www.di2.nu/foia/1153233036.txt

    From: Jonathan Overpeck
    To: Tim Osborn
    Subject: Re: Law Dome figure
    Date: Tue, 18 Jul 2006 10:30:36 -0600
    Cc: Ricardo Villalba , Keith Briffa , Valerie Masson-Delmotte , Eystein Jansen

    Hi Tim, Ricardo and friends – your suggestion to
    leave the figure unchanged makes sense to me. Of
    course, we need to discuss the Law Dome ambiguity
    clearly and BRIEFLY in the text, and also in the
    response to “expert” review comments (sometimes,
    it is hard to use that term “expert”…).

    Ricardo, Tim and Keith – can you take care of
    this please. Nice resolution, thanks.

    best, Peck

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