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Les Chevaliers de l’Ordre de la Terre Plate, Part II: Courtillot’s Geomagnetic Excursion

Filed under: — raypierre @ 18 December 2007 - (Français)

This article continues the critique of writings on climate change by Allègre and Courtillot, started in Part I . If you would like to read either post in French, please click on the flag icon beside the post title above.

Prelude: It’s the physics, stupid

…which of course is a paraphrase of Bill Clinton’s famous quote regarding the economy. We put the last word in small letters since we’ve learned that it is not a good debating technique to imply (even inadvertently) that those who are having trouble seeing the force of our arguments might be stupid. What we wish to emphasize by this paraphrase is the simple fact that the expectation of a causal link between increasing long-lived greenhouse gases (like CO2) and increasing temperature does not rest on some vague, unexplained correlation between 20th century temperature and 20th century greenhouse gas concentration.

The anticipated increase in temperature was predicted long before it was detectable in the atmosphere, indeed long before it was known that atmospheric CO2 really was increasing; it was first predicted by Arrhenius in 1896 using extremely simple radiation balance ideas, and was reproduced using modern radiation physics by Manabe and co-workers in the 1960′s. Neither of these predictions rests on general circulation models, which came in during subsequent decades and made more detailed forecasts possible.

Still, the basic prediction of warming is founded on very fundamental physical principles relating to infrared absorption by greenhouse gases, theory of blackbody radiation, and atmospheric moist thermodynamics. All these individual elements have been verified to high accuracy in laboratory experiments and field observations. For a time, there was some remaining uncertainty about whether water vapor feedback would amplify warming in the way hypothesized in the early energy balance models, but a decade or two of additional observational and theoretical work has shown that there is no real reason to doubt the way in which general circulation models calculate the feedback. When modified by inclusion of the cooling effect of anthropogenic aerosols, the theory gives a satisfactory account of the pattern of 20th and 21st century temperature change.

No other theory based on quantified physical principles has been able to do the same. If somebody comes along and has the bright idea that, say, global warming is caused by phlogiston raining down from the Moon, that does not make everything we know about thermodynamics, infrared absorption, energy balance, and temperature suddenly go away. Rather, it is the job of the phlogiston advocate to quantify the effects of phlogiston on energy balance, and incorporate them in a consistent way beside the existing climate forcings. Virtually all of the attempts to poke holes in the anthropogenic greenhouse theory lose sight of this simple and unassailable principle.

In a paper entitled "Are there connections between the Earth’s magnetic field and climate?" published recently in Earth and Planetary Science Letters, Courtillot and co-authors attempt to cast doubt on carbon dioxide as a primary driver of recent (and presumably future) climate change; he argues instead that fluctuations in the Earth’s magnetic field (partly driven by solar variability) have an important and neglected role. Like most work of this genre, it is carried out in an intellectual void — as if everything we know currently about physics of climate had to be set aside in order to make way for one new (or in fact not-so-new) idea. But the problems don’t end there. With the help of a Comment published by Bard and Delaygue (available here at EPSL or here as pdf) , we’ll expose a pattern of suspicious errors and omissions that pervades Courtillot’s paper. Sloppiness and ignorance is by far the most charitable interpretation that can be placed on this pattern.

Let’s set the stage by noting that, as a significant competitor to anthropogenic greenhouse forcing of recent climate change, the direct radiative forcing by solar irradiance variations is dead on arrival. The solar output has been monitored by accurate satellite instruments since 1978. Measured peak to trough over the 11 year solar cycle, averaging over the Earth’s surface and allowing for albedo, the radiative forcing amplitude is under 0.2 W/m2. The trend left after averaging over the solar cycle is even smaller. This pales by comparison with over 2 W/m2 of radiative forcing arising from long-lived greenhouse gases that have accumulated in the atmosphere since 1750; it pales yet more by comparison with the forcing to come in the future if action is not taken to control emissions. There is nothing in climate physics to suggest that the sensitivity of climate to solar irradiance variation differs substantially from the sensitivity to infrared radiative forcing arising from greenhouse gas changes. As far as the climate cares, a Watt is (for the most part) a Watt, regardless of whether it comes from changes in the incoming solar energy or greenhouse-induced changes in the infrared radiation loss.

To get a bigger bang out of solar variability, one needs to invoke something else about the way the Sun affects climate. Something exotic, like magnetic field variations. Since there is no quantified physical mechanism linking field variations to climate, Courtillot must fall back on showing us a few supposed correlations between temperature variations and magnetic field variations. To make matters worse, Courtillot can’t always make up his mind even about whether an increasing field index should warm the climate or cool it, making it unclear just what correlations one is looking for. The lack of a physical model makes it impossible to treat the various forcings on an equal footing and make a reliable attribution of causes. This is particularly fatal when the various forcings are strongly correlated with each other. For example, on time scales of years to centuries, the magnetic field variability, cosmic rays and solar irradiance vary nearly in lock-step, so if there is a correlation with temperature (or cloud cover) one cannot tell whether it means that climate is responding with high sensitivity directly to luminosity changes, or whether something more exotic is going on. Over a period when temperature, greenhouse gas forcing, and some magnetic field index are all going up, a statistical attribution technique which ignores greenhouse gases and considers only the magnetic field index will of course find that the magnetic field "explains." the signal. If we knew nothing about how CO2 affects climate, this would put the magnetic field on an equal footing with CO2 as a candidate explanation but this is not the case. We know a great deal about how CO2 affects climate and no amount of additional fiddling with cosmic rays or magnetic fields can make this physics go away. One can get even more confused by forgetting about the important role of anthropogenic aerosols in the past century, as Courtillot all too often does.

The confidence with which Courtillot casts doubt on the generally accepted role of anthropogenic forcing in climate change of the past century is surprising, in view of the essential limitations of any argument from correlation alone. But it’s worse than just that: as Bard and Delaygue show, most of the correlations upon which Courtillot et al. rest their flimsy case are in fact bogus.

Solar variability and climate: The Good, the Bad, and the Ugly

Work on the influence of solar variability (and on its close cousin, the influence of the Earth’s magnetic field) tends to fall into one of three categories. There is the Good, in which careful scientists do their objective best to unravel a complex and probably small (but nonetheless important) signal. As examples of work in this category, I would mention Judith Lean’s tireless efforts on relating luminosity to sunspot number, the work of Bard and colleagues on developing isotopic solar proxies like 10Be, Shindell’s work on response to solar ultraviolet variability, and the work of Foukal et al on factors governing solar irradiance variations. I would also include the recent work by Camp and Tung diagnosing the amplitude of the solar cycle in temperature in the "Good" category; that it is an easy paper for greenhouse skeptics to misquote takes away nothing from the quality of the science. In fact, I’d say most work on climate and solar variability falls into the Good category. That’s rather nice. In fact, scientists have long recognized the importance of solar variability as one of the factors governing climate (see the very scholarly review of the subject by Bard and Frank, available here at EPSL or here as pdf) An understanding of solar variability needs to be (and is) taken into account in attribution of climate change of the past century, and in attempts to estimate climate sensitivity from recent climate variations. Further, the Little Ice Age demands an explanation, and solar variability at present provides the only viable possibility. (It’s less clear that the Medieval Warm period is a sufficiently coherent phenomenon to require an explanation).

Then, there is the Bad, exemplified by two papers by Scafetta and West that have been discussed on RealClimate here and here. This is just normally bad science, in the sense that there is something wrong in the approach taken by the authors which leads to erroneous conclusions. Perhaps some of this work should never have made it through peer review, but as long as the methods are well documented and honestly described, subsequent investigators will be able to identify the errors and either salvage or discard the results.

And then … there is the Ugly. These papers cross the line from the merely erroneous into the actively deceptive. Papers in this category commit what Damon and Laut judiciously call a "Pattern of strange errors.". Papers in this category often use questionable (and often hidden and undocumented) data manipulations to manufacture correlations where none exist. The work by the Danish solar boosters, discussed extensively by Damon and Laut, typifies the Ugly category. We’ll leave it to the reader to decide, after the discussion to follow, whether Courtillot’s paper is merely Bad, or has crossed over into the Ugly.

Spin vs. Scholarship

The general style of discourse in Courtillot et al. has more in common with the kind of one-sided polemic one finds in Lomborg or the Robinson et al. fake PNAS article distributed with the original Global Warming Petition Project than it does with scholarship whose intent is to get at the truth. It quotes papers uncritically and selectively if they can be made to appear to support the authors’ thesis (e.g. the uncritical use of the aforementioned single-factor Scafetta and West paper to support a large attribution of twentieth century climate change to solar variability). There is also a lot of general spin here; for example, greenhouse gases are listed last in a laundry-list of things that can affect climate, without any indication as to the relative magnitudes of the various forcings. Other problems include the following:

  • Courtillot exaggerates the cloud radiative forcing by a factor of four, because he attributes virtually all the Earth’s albedo to clouds and fails to take into account the cloud greenhouse effect.
  • He says that "Cooling from 1940 to 1970 is often disregarded as being part of the noise" whereas in fact it was intensive study of this period that lead scientists to appreciate the importance of the anthropogenic aerosol effect, at the time of the IPCC Second Assessment Report. Again ignoring the well-documented importance of anthropogenic aerosols, he says later: "Note that the leveling or drop in temperature from 1940 to 1970 matches solar and magnetic series, and not the monotonous accelerated rise in CO2" Not only is this a Crichton-esque obfuscation of a well-understood phenomenon, but as we’ll see later the supposed "match" is an artifact of questionable data manipulations.
  • Courtillot points to an energy-balance model study by Crowley as support for his thesis that there is some missing physics left out of models, which affects response to solar forcing. Specifically, Courtillot points to a model/data mismatch in the early 20th century. However, Crowley did not include the indirect aerosol effect, and the energy balance model has no geography and therefore can’t be expected to model things like continental vs. ocean seasonal cycles or ice and snow cover with complete fidelity. General circulation models forced with a combination of natural (including solar) and anthropogenic (aerosol and greenhouse gas) forcing have no problem reproducing early 20th century climate. Further, Crowley’s model accurately matches the observed response to solar forcing earlier in the millennium, so it is hard to see why the "missing physics" should suddenly kick in at 1850. It is always suspicious when selective quotes are used to draw a conclusion exactly opposite to what the paper’s own author concludes. For the record, here is what Crowley himself says in the paper about his own results:
    • There are therefore two independent lines of evidence pointing to the unusual nature of late-20th-century temperatures. First, the warming over the past century is unprecedented in the past 1000 years. Second, the same climate model that can successfully explain much of the variability in Northern Hemisphere temperature over the interval 1000–1850 indicates that only about 25% of the 20th-century temperature increase can be attributed to natural variability. The bulk of the 20th-century warming is consistent with that predicted from GHG increases. These twin lines of evidence provide further support for the idea that the greenhouse effect is already here.
  • Courtillot also cites an atmosphere-ocean model simulation by Zorita et al. (2004) as support for his claim that models fail to represent the 20th century response to solar or magnetic variability. However, as discussed here and in the peer-reviewed references cited therein, this simulation suffers from an inappropriate initialization which leads to a spurious cooling in parts of the run, and a large climate drift requiring detrending of the output before analysis. Besides that, the model explicitly neglects anthropogenic aerosol forcing, so how could one expect it to get 20th century climate right?
  • Courtillot claims that the correlation between geomagnetic "jerks" and Alpine glacier advances supports a solar-magnetic influence on climate. As Bard and Delaygue emphasize, this requires an exactly opposite sign of response to magnetic field variations as claimed by Marsh and Svensmark (2000), and as assumed elsewhere in Courtillot’s paper. Courtillot cooks up an ad hoc explanation for why this might be the case, but this leads him even farther afield from anything that can be justified by known, quantified physics. One can find all sorts of correlations if one allows oneself the liberty to change the sign of the sought-for relation whenever convenient, and without any constraint by physics.
  • There is hardly anything more embarrassing to a theory than success in explaining a phenomenon that turns out not to exist. Courtillot makes much of the fact that the millennial cycle of hematite-stained ice rafted debris in Gerard Bond’s data set — taken at the time to be a proxy for North Atlantic temperature — lines up nicely with geomagnetic variations. However, as Bard and Delaygue note, later work with better chronology, more cores and better time resolution show that Bond’s record does not represent a temperature index for the entire northern Atlantic region. The more complete record exhibits little or no relation to geomagnetic variations.

…and now for the really ugly part

Bard and Delaygue uncovered a number of errors of a more troubling nature. Courtillot et al. commit the "flat Earth" error from which our article draws its name: they give a misleading impression of the comparison of forcing by solar variability relative to greenhouse gas forcing by failing to take into account the Earth’s spherical geometry and albedo. After the very public humiliation suffered by Le Mouel on this point at the Academie debates (see Part I), in his article in La Lettre Courtillot took pains to show that he indeed understood the consequences of the Earth being round. However, this new understanding did not result in any sign of a corrigendum being sent to EPSL, so one can only conclude that the deception is deliberate. Further in their Fig. 1 Courtillot et al. show geochemical data from a Central Alpine stalagmite which purports to establish a highly tight correlation between climate variations and a solar activity proxy; as Bard and Delaygue note, Courtillot and co-workers have concealed the fact that the correlation is so good precisely because the chronology of the two series being compared has been finely tuned to expressly maximize the correlation. The original untuned data does not show nearly so tight a correlation.

The piece de resistance of Courtillot et al., is the following graph, which purports to show that for almost all of the past century, temperature correlates tightly with solar activity and magnetic field variability. The three curves on the graph are, according to the paper, Phil Jones’ global mean temperature record (Tglobe, in red circles) , a total solar irradiance reconstruction (S(t), in pink triangle; Courtillot cites Solanki’s reconstruction in the text), the magnetic field variability index at a site in Scotland (ESK, blue) and at Sitka Alaska (SIT, green). All the curves have been centered to have the same mean and standard deviation over the length of record, so as to make them more comparable. Note that the S(t) curve spans a shorter time than the others; this turns out to be important.

Looks pretty good, eh? Well it would, except for the minor details that "S(t)" is not actually the solar output, "Tglobe" is not actually the Jones global mean temperature it is claimed to be and neither "ESK" nor "SIT" look much like broader-based magnetic variability indices that provide more reliable indicators of solar activity. Bard and Delaygue thought it curious that Courtillot would use just the final snippet of the Solanki record when the full century was available. They checked what the curve would look like if it were normalized using the full length of the record. That’s the thick grey curve in Bard and Delaygue corrected version of the figure below; for comparison, the purple curve with triangles shows the results of using Solanki’s reconstruction truncated to the period Courtillot chose.

Get the picture? By snipping out just the last bit of the curve and normalizing to unit standard deviation, Courtillot inflates the variability and makes the fit look better than it would be if the full data set were used. As a bit of deceptive data manipulation, this has to go down in history with the selective smoothing used on some of the solar records that Damon and Laut discuss in their critique of the Danish solar work. Now, in his response to Bard and Delaygue (there’s always a response to Comments) Courtillot digs himself even deeper into a hole. He states that the reason he used a truncated solar series is that the data came not from Solanki (as implied in the paper), but rather from Tobiska’s SOLAR2000 model product. Tobiska’s paper is not even cited by Courtillot et al. (2007), whereas Solanki (2002) is cited there as well as in the authors’ earlier papers on related subjects. There is no legitimate reason for using SOLAR2000 in a study of the sort Courtillot et al. are attempting since, as noted by Bard and Delaygue, the SOLAR2000 model is restricted to the ultraviolet portion of the solar spectrum, making it the wrong choice unless one is explicitly investigating phenomena linked to ultraviolet forcing (see Lean (2002) ). One could guess that Courtillot et al.pulled this convenient rabbit out of the nearest available hat, because it was the first curve they found that gave them some excuse to truncate the record in a way that gave the desired result.

Bard and Delaygue noticed another strange thing. Courtillot’s "Tglobe" curve did not look much like the curve published by Jones. Jones’ curve, plotted from his actual data files, is shown in Bard and Delaygue’s corrected version of the figure; they also show the NASA reconstruction for comparison. These two curves are in agreement, but neither shows the sharp rise/dip pattern between 1940 and 1970 which is seen in Courtillot’s figure. So if Courtillot’s data is not Jones’ global mean temperature, what is it that Courtillot plotted? We may never know. In his response to Bard and Delaygue, Courtillot claims the data came from a file called: monthly_land_and_ocean_90S_90N_df_1901-2001mean_dat.txt. Bard and Delaygue point out, however, that Jones has no record of any such file in his dataset, and does not recognize the purported "Tglobe" curve as any version of a global mean temperature curve his own group has ever produced.

Whatever the source of the purported "Tglobe" data given in Courtillot et al., there is no legitimate reason — in a paper published in 2007 — for truncating the temperature record at 1992 as they did. There is, however, a very good illegitimate reason, in that truncating the curve in this way helps to conceal the strength of the trend from the reader, and shortens the period in which the most glaring mismatch between solar activity and temperature occurs.

In the corrected graph, Bard and Delaygue also plot the "aa" geomagnetic index. This is an index based on two stations at antipodal points, which has been found to correlate well with the overall geomagnetic variability based on a larger network of stations. One could argue that if one is looking at global mean temperature data, the aa index provides a more appropriate basis for comparison than the single-station high Northern latitude records that Courtillot uses. Note that the aa index tracks Solanki’s solar irradiance well, whereas the single-station measurements do not.

In the corrected graph, Tglobe, aa and S(t) track each other upward from 1900 to 1940, but note that greenhouse gases also go up monotonically in this period, as they do later. A purely statistical attribution could ascribe nearly all the changes from 1900-1940 to solar or magnetic variability, but a similar statistical attribution could do the same for greenhouse gases. Only physics can divvy up the blame. Since 1940, however, there is not even the appearance of correlation between Tglobe and either S(t) or any of the geomagnetic indices. There is a hump in both the solar and aa index around 1950, during which time the temperature is flat or decreasing. Courtillot’s erroneous analysis defers the decorrelation until 1985.

Between the embarrassing showing at the Academie debates and the travesty of science exposed by Bard and Delaygue in the case of the EPSL paper, You’d think that Courtillot would want to fine the nearest hole and go hide in it. Far from it, he was recently spotted giving a talk called "What global warming?" at this prestigious event gathering several famous physicists and chemists. Some people have no shame.

Postlude: Of silk purses and sow’s ears

Bard and Delaygue conclude with a figure, reproduced below, which nicely illustrates something we’ve been saying for years at RealClimate. On this figure they plot the Jones global mean temperature together with a global magnetic index (the aa index), a cosmic ray flux index (Climax) and the PMOD composite satellite record of solar irradiance. These curves are less smoothed than those shown in the preceding graph. The inter-annual temperature variability is linked to natural effects such as major volcanic eruptions, ENSO events and solar variability. However, only the Tglobe curve is characterized by a very significant upward trend — a trend which cannot be explained by these natural causes.

Say it three times every night before going to sleep: Temperature goes up. Solar stuff goes up and down and up and down and up and down. You can no more make a trend out of that than you can make a silk purse out of a sow’s ear.

A note added in proof, concerning the "Note Added in Proof"

The above discussion was based on the version of Bard and Delaygue’s comment and Courtillot’s response which was available on the Elsevier web site through December 15. Since the time of writing, some strange changes have occurred under the direction of the responsible editor, Robert van der Hilst of MIT. He deleted the "Note added in Proof" from the final version of Bard and Delaygue’s comment. Bard and Delaygue only found out about this when they received the proofs of their Comment. What is even more disturbing is that van der Hilst allowed Courtillot to change the text of his Response based on what Bard and Delaygue wrote in the now-deleted "Note added in Proof." Bard and Delaygue were given no opportunity to see or comment on these changes. I have left the above discussion as it is, in order that the reader will have a better appreciation of the strange history of this comment/response cycle.

In the revised "Response" Courtillot now admits that the temperature record called "Tglobe" is not from any of Phil Jones’ datasets at all. Courtillot now claims that the data came from a study by Briffa et al. (2001), giving the address of a file stored at NCDC. As specified in this study and in the head of this file, these data have been "recalibrated to obtain estimates of April-September mean temperatures from all land regions north of 20N". Thus, the temperature dataset used by Courtillot is definitely not Tglobe, does not represent the full hemisphere, and moreover is not even an annual mean.

Rob van der Hilst — recently a Visiting Professor at IPGP (Courtillot’s institution) — claims that these changes were made in the interests of scientific communication. I leave it to the reader to judge whether these actions were appropriate, or whether they were just an attempt to protect Courtillot from embarrassment.. In the interests of scientific communication, I append below the full text of the "Note added in Proof" which was stripped from Bard and Delaygue’s Comment:


Note added in proof:

In their Response to our Comment, Courtillot et al. state that for the total irradiance curve S(t) they had used the SOLAR2000 model product by Tobiska (2001) instead of the century-long record by Solanki (2002) cited in their original paper (Courtillot et al. 2007). However, the SOLAR2000 model is restricted to the UV component and their total solar irradiance is severely flawed as pointed out by Lean (2002).

For the global temperature Tglobe curve cited from Jones et al. (1999) in Courtillot et al. (2007), these authors now state in their response that they had used the following data file: monthly_land_and_ocean_90S_90N_df_1901-2001mean_dat.txt We were unable to find this file even by contacting its putative author who specifically stated to us that it is not one of his files (Dr. Philip D. Jones, written communication dated Oct. 23, 2007).

Tobiska, W. K. 2001, Validating the solar EUV proxy, E10.7, J. Geophys. Res. 106, 29,969- 29,978.

Lean, J.L., 2002. Comment on ”Validating the solar EUV proxy, E10.7” by W. K. Tobiska. J. Geophys. Res. 107, (A2), 1027, 10.1029/2001JA000137.


148 Responses to “Les Chevaliers de l’Ordre de la Terre Plate, Part II: Courtillot’s Geomagnetic Excursion”

  1. 51
    Hank Roberts says:

    Is there any similarity here?
    http://www.sgr.org.uk/climate/StormyTimes_NL28.htm

  2. 52
    Hank Roberts says:

    Parallels:
    http://www.csicop.org/doubtandabout/deja-vu/

    [Response: Some parallels are apt; in this case, it wasn't that the article was sent to an obscure journal; EPSL has a fairly high profile in the areas in which it is strong. EPSL isn't generally obscure, but it is fair to say that work in climate and atmospheric science is not its most familiar territory, and this was compounded by the paper having been sent to an Editor whose own field was completely orthogonal to climate science. That limits both the ability to judge the paper, and more importantly the pool of reviewers that are likely to respond to review requests. What isn't apt is the analogy between de Freitas and van der Hilst. While de Freitas is described as a known CO2 skeptic in Mooney's article, I have no reason to believe that van der Hilst is any kind of a CO2 skeptic, and much reason to believe the contrary. If there is any question regarding the editorial process, it stems from the following considerations: (1) It might have been better to hand the paper off to an Editor with more experience in climate, and (2) It might have been better to hand the paper off to an Editor who had less strong professional ties to IPGP. I am not saying that I have any evidence that the latter consideration compromised the editorial process, but I think it is unavoidable that the awkwardness of passing a strong judgement on an author who is both a colleague and a director of an institution at which one might want to spend more sabbatical and summer visits, could make it hard to be as fully objective and as forceful as might be warranted. It is a case where avoiding even the appearance of a conflict of interest could have avoided a lot of possibly misdirected suspicion and misunderstanding (some of it perhaps even on my part). --raypierre]

  3. 53
    Jaycee says:

    This controversy is ridiculous and it is getting worst. Some reporting in this post is worthy of the worst tabloids. Courtillot’s paper maybe garbage, it is sloppy, it may be completely wrong, but it is certainly not worth such turmoil. And had Edouard Bard done his job and reviewed the paper when he was asked, Courtillot’s paper would not have been published in the first place. What is clear from the reporting in the French press is that this post is being used for some kind of power struggle within the French scientific community. I hope Raypierre is not a willing party in this campaign of slander. I personally find that there is no excuse for using innuendos to try and tarnish the reputation of someone like Rob van der Hilst who did his job. “misdirected suspicion and misunderstanding (some of it perhaps even on my part)” You are not very subtle, Raypierre.

    [Response: I never claimed to be subtle. May I ask what is your source regarding the people asked to review Courtillot's paper? It was my understanding that such information is usually considered confidential. One can only speculate on what would have happened with a different set of reviewers; I myself, when acting as a reviewer, have seen many papers published over what I considered to be quite well-reasoned objections. Regarding the "academic power struggle," the only struggle I see is the struggle to expunge the stain of Courtillot and Allegre's junk science from climate policy debate in France in particular, and on the world stage in general.

    If this were a routine sloppy paper by some unknown, the errors would have received little attention, even if there is a pattern that appears to systematically overstate the authors' thesis. By becoming the public face of French climate skepticism, however, Courtillot has made himself a public figure, so how can it be surprising that this paper becomes news? As the responsible editor, van der Hilst has just been caught in the crossfire, but it's hard to see how a journalist could avoid mentioning whose watch this all occurred on, and what the full history was. --raypierre]

  4. 54
    William Astley says:

    In reply to Peter Wilson #13

    “It would be nice to have an explanation of the physical mechanism that Courtillot supposes, and a back-of-the-envelope calculation giving the order of magnitude of the effect he would expect based on theory, independently of the empirical results. That’s the sort of thing I’d expect as a referee, anyway.”

    I would be interested in others thoughts on this subject. Has anyone else looked at geomagnetic field intensity variance with time? Does the geomagnetic field vary over time? Is there any evidence of a cyclic change in the geomagnetic field?

    “Time variations in geomagnetic intensity”, by J.P. Valet

    http://ssn.dgf.uchile.cl/home/informe/2001RG000104b.pdf

    Last 75 kyrs.
    Look at figure 9, in this paper.

    Geomagnetic field intensity during the interglacial period is 2 to 3 times the intensity, of the field strength during the glacial period, over the last 75,000 years.

    Comments:
    1)Note figure 9, shows a determination of geomagnetic field intensity over the last 75,000 years using two different methods. A)The analysis of volcanic data which is not temperature sensitive and B)The analysis of ocean floor sediment which is temperature sensitive.

    2)The controversy in determining the geomagnetic field intensity, beyond 75,000 years is to appropriately correct the ocean floor sediment data for temperature affects. Valet believes that the geomagnetic field intensity cannot track planetary temperature and hence has “corrected” the ocean floor proxy data for temperature, beyond 75,000 years. (i.e. The geomagnetic field intensity correlates closely to planetary temperature before correction.)

    3)There are claims that the geomagnetic field intensity has a 100 kyr cycle.

  5. 55
    Jaycee says:

    You are not subtle, but you pretend to be naive. “the only struggle I see is the struggle to expunge the stain of Courtillot and Allegre’s junk science from climate policy debate in France in particular, and on the world stage in general”. Come on! They have all the influence they deserve, i.e. zero, in France or on the world stage.

    [Response: I hope that at least the latter part of what you say is true; others don't see it that way. As for the first part, I'm not pretending, I really am naive :) Seriously, a problem with blogging is that sitting in my pajamas late at night in front of the fire with my laptop open, it does sometimes become difficult to remember that there are thousands of people out there listening. --raypierre]

  6. 56
    Michael Smith says:

    May I submit what might be a hopelessly oversimplified question? In paragraph three of the article above, you say:

    “(T)he basic prediction of warming is founded on very fundamental physical principles relating to infrared absorption by greenhouse gases, theory of blackbody radiation, and atmospheric moist thermodynamics. All these individual elements have been verified to high accuracy in laboratory experiments and field observations. For a time, there was some remaining uncertainty about whether water vapor feedback would amplify warming in the way hypothesized in the early energy balance models, but a decade or two of additional observational and theoretical work has shown that there is no real reason to doubt the way in which general circulation models calculate the feedback. When modified by inclusion of the cooling effect of anthropogenic aerosols, the theory gives a satisfactory account of the pattern of 20th and 21st century temperature change.”

    Now as a layman, when I read something like that from someone of your obvious expertise, I’m inclined to believe that AGW hypothesis is firmly rooted in fundamental physics and that its hypothesis has been properly tested.

    Then, however, I read this article: http://www.realclimate.org/index.php/archives/2007/12/tropical-troposphere-trends/#more-509

    I see in that article that the range of outputs from the GCM models is, to this laymen, quite large. How — if the physics are so certain and so thoroughly tested and properly understood — can the range of model outputs be so large?

    [Response: First, notice that they all show warming. Second, while the basic physics behind the CO2 effect on warming is very secure, there is uncertainty in the physics behind some of the amplifying feedback factors -- principally clouds. That uncertainty leaves much more room for bad things to happen on the high side than it does for the warming to be much more moderate than the mid-range. Third, if we are looking at the warming so far, the signal is still relatively small because of ocean delays and because we've only gone a modest way toward doubling CO2. That means that offsetting factors with some uncertainty, like aerosols, have a lot of potential to make large relative swings in the amount or pattern of the warming. As time goes on and CO2 increases, the greenhouse gas radiative forcing will increasingly dominate such things. However, the uncertainty regarding how much clouds amplify the warming will remain, though there will be more data to use to test cloud behavior. --raypierre]

  7. 57
    Steven mosher says:

    Ray, thank god.

    I’m looking for some help on data posted by GISS. This is what they wrote:

    “GISS-ER
    Data issues:

    All rlus/rlds files were initially incorrectly saved. Values over the ocean have however been retrieved and are available by ftp for all experiments.
    rsdscs fields were calculated by sampling only clear sky boxes and cannot be compared to other models that calculated clear sky values for all boxes.
    As described in Hansen et al (2005; 2007a (in press); 2007b (in press)), stratospheric ozone depletion over the period 1979 to 1997 was originally underestimated by a factor of 5/9. Simulations with the corrected ozone changes are available: 20C3M and AMIP experiments. ”

    what does the 5/9 factor have to do with? it seems vaguely familiar…Struugling with physics here perhaps you can help me.

    [Response: I appreciate your confidence in the comprehensiveness of my knowledge, but the factor of 5/9 doesn't immediately ring a bell with me. 2/7, yes, 1/4 definitely, but not 5/9. I am not familiar with everything in all three of the Hansen et al papers you mention; I'd take a look but I'm about to shut down for Christmas and there are a few other critical things I need to clear off the desk first. Try me again in the New Year if you haven't gotten an answer from Gavin or one of the others by then. --raypierre]

    [Response: The 5/9 came from applying an 18 year ozone trend as if it were the decadal trend. It was just a simple mistake and was fixed in the online data. - gavin]

  8. 58
    raypierre says:

    I guess it’s time for me to begin winding down, and to commence the preparations for Christmas. My thanks to all who have commented here, and to all who have shown an interest in this article. My apologies to any I may have inadvertently offended, and may they find it in their hearts to forgive me if my passion for this subject (and my frustration with efforts to obscure the truth) may sometimes lead me to rhetorical excess. I will leave this thread open, and look forward to catching up with you all in the New Year. Meanwhile, to all a jolly Waes Hael!

  9. 59
    Richard Sycamore says:

    raypierre, anything else to add on the topic of “ocean delays” (#56) and “rhetorical excess” (#58)? Hank Roberts is patiently trying to help me out on another thread, but it isn’t really working out. (I enjoyed your book, BTW. Good luck with that in the New Year.)

  10. 60
    William Astley says:

    Is there a scientific interest in discussing geomagnetic field intensity variance or in research concerning solar modulation of clouds?

    1) In terms of modulation of GCR, the geomagnetic field variance (full variance from Laschamp minimum to interglacial maximum, according to Svensmark) only results in a 10% affect on GCR over the geomagnetic field intensity range. Therefore, according to Svensmark, geomagnetic field variance is not a first order climatic forcing factor, which I believe is supported by most in this forum.

    2) Solar modulation of clouds is, however, according to Svensmark, a first order climate forcing function which is in disagreement with what has been stated in this forum.

    3)There must a physical reason/cause for the apparent cyclic geomagnetic field variance and its apparent correlation with temperature. As an aside, if you are interested in the geomagnetic field and reversals (which is a separate subject from climate change if Svensmark is correct), I thought Ryskin’s hypothesis is interesting. I have reviewed all papers Ryskin’s referenced in this link and have found that they do support his hypothesis.

    Origin of the Geomagnetic Field by Ryskin.

    http://arxiv.org/abs/astro-ph/0312617

    Comment:
    There are a number of researchers that have presented interesting data and analysis to support the solar modulation of cloud hypothesis (such as Palle, Svensmark, Shaviv, etc.) I do not understand why we are discussing Courtillot’s weak paper.

  11. 61
    Hank Roberts says:

    Mr. Astley, put the other names into the Search box; they’re all discussed extensively at RC in earlier threads.

  12. 62
    Armagh Geddon says:

    Could 5/9 be about the conversion of Deg F to Deg C?

    [Response: Not in this case - gavin]

  13. 63
    Francis Albarede says:

    EPSL has currently 8 editors and the tradition is that authors “shop” for whichever editor they see as the most suitable for their paper. The upside is that they can pick up an editor for being more competent or less biased (I used either virtue as an author). The downside is that the editor will have to edit papers outside of his field of competence. One of the most seminal and most cited papers of my long term with this journal was one I accepted in spite of three unfavorable reviews. Ray Ladbury’s concept of “tunneling” tells it all. We have to live with the fact that such a system has pros and cons.

    Another aspect that does not show in the discussion is that solid earth geophysics is a damn small community. It is not because van der Hilst would not spend July in Paris that he would not closely relate to Courtillot or Allegre! Van der Hilst is Chair of the Seismology Section of the American Geophysical Union and as such voted last week the AGU motion calling for a reduction of greenhouse gas emissions. Do not make him one of the CO2 sceptics.

    Do not expect this incident to remain isolated, whether Bush and its likes will use it or not. Talk to biologists and geneticists: they are under the barrage of the creationists. Ask Pinker how much garbage he got for claiming that much of the human behavior is in the genes and not imprinted by the capitalistic society. We have to learn how to live and work amidst permanent hostile reactions to even the strongest concepts that we all struggled to establish. And, in the interest of science, I see some advantage in such a situation.

    Edouard Bard and Gilles Delaygue did their job, an expert job, and they must be commended for it. Let now the French scientific community and IPGP heal their wounds.

    Ray Ladbury: thanks you, your message will mean a lot to all the editors.

  14. 64
    Ray Ladbury says:

    Francis Albarede, I think that it is useful to remember that while science is a noble endeavor, it is a human endeavor. This is why science advances by no single research result or scientific paper, but rather by the collective efforts of the scientific community. Any of us can be wrong. All of us have our biases. It is our colleagues (and reviewers and editors) that keep us honest.
    The current story is actually a success story for science. A really bad article found its way into print, but was discovered for what it was, vivisected and can now sink into the obscurity it so richly deserves. That’s science. It is one of the few human endeavors that works consistently. Anti-science types can rail against it. They can attempt to subvert it. They can even try to imitate it (as with ID, climate denial,…). However science is predicated on the premise that the evidence will support the truth, so if you reject the evidence, you can’t arrive at the truth. As long as we cleave to the high ground, we cannot lose.

  15. 65
    Pierre Allemand says:

    The “cannot be found” file “monthly.land_and_ocean.90S.90N.df_1901-2000mean.dat.txt” can be easily downloaded on the following NOAA site : http://www.ncdc.noaa.gov/oa/climate/research/anomalies/anomalies.html.
    It is a little surprising to see that Bard and Delaygue were not able to find this kind of file.
    For people familiar with temperatures series, this format is the signature of a NOAA ascii files.
    Concerning their fig. 1, I agree that there are discrepancies between the original set of figures and the Courtillot’s one. But :

    - the sharp rise/dip pattern between 1940 and 1970 which is seen in Courtillot’s figure come simply from the number of plots taken for the running average. The rise/dip are strongly pronounced with a small number, and become almost invisible with a big one.

    - it seems that there is a 5 – 10 years offset for the temperature values.

    - a last important remark : when one plot a running average curve for time series, it is obviously stupid to put the calculated point in the middle of the averaged values : temperature for a given time does not depend at all on future values. For instance, if you plot the temperature of a bullet between it leaves the gun and the moment it reach the target (where temperature grows suddenly), according to this way of plotting, you will see a sudden increase in temperature before the bullet reaches the target…

  16. 66
    Rob van der Hilst says:

    Dear Ray,

    As I explained to you privately, I will not engage in this electronic debate. Anything that I have to say about the Editorial process concerning this ‘comment’ and ‘reply’ will be done in EPSL (in print and on-line).

    I offer this entry (motivated by one sentence in #53) only to state unequivocally that Edouard Bard did not review and was not asked to review the paper by Courtillot et al. that is now at the center of the dispute. If in the heat of the moment I have suggested otherwise, I was wrong and I apologize. I will submit, however, that the editorial process of this and related papers would have benefitted from a better response from the climate community to my (many) requests to help evaluate them.

    Best wishes,

    Rob van der Hilst
    Editor for EPSL

  17. 67
    Geoff Wexler says:

    As Raypierre argues the essence of contrarian arguments at many levels is to play down the physics. This is particularly true of contrarian propaganda in the media. This tends to work because many people are not that knowledgeable about physics. The difference between the Clinton/Carville slogan and that of Raypierre is that many people will be more directly interested in the economy than in physics. In addition people who get all their information from the media rather than from scientific papers have been starved of scientific explanations. In the UK the BBC is now rather sympathetic to climatology but they still tend to rely on the authority of the expert witness or the authority of numbers. This approach tends to disenfranchise people who are by nature anti-authoritarian and skeptical and hostile to the BBC. In my opinion such people have often been poorly served. When UK’s Channel 4 came along with the Great Global Warming Swindle (GGWS) they were watching an attack on a theory which had never been described. They were told that the consensus was based on an ASSUMPTION that man made global warming was entirely caused by CO2. It is not surprising that the programme has influenced people over here. Channel 4′s defence has been that the media had been biased in favour of people who believe in global warming theory and that this was an opinion piece providing balance. The policy of deleting the physics has continued. As far as I know there has never been a programme on UK’s TV to set the record straight in this respect. There is a more comprehensive coverage on the BBC’s web site but many people will never go there.

    Every now and then another major piece of misinformation is launched at the media. It is like a volcano. I believe that these eruptions do have some success in influencing public opinion as intended. In the UK we have had the House of Lords report organised by Nigel Lawson, followed by the several pages in the Sunday Telegraph devoted to Christopher Monckton’s unpublished ‘paper’ and ‘review’, and then the Great Global Warming Swindle on Channel 4. As far as the media was concerned Monckton’s paper was almost the first devoted to climate sensitivity (the issue was touched upon in a muddled way in BBC2′s Global Dimming programme) and the GGWS was the first devoted to the detection and attribution problems. The only place where I encountered the hockey stick was in Radio 4′s “Moral Maize” (highly biased against) and the House of Lords report. I hope the experts will try do something to remedy this deficit.
    ——————————————————————————–
    (Incidentally I prepared a line by line critique of the transcript of the ggws with my own opinions and those taken from everyone else: It is at http://tinyurl.com/2pxmnu or http://zcarb.net/wordpress//uploads/ggws.html)

  18. 68
    Pierre Allemand says:

    I just see that the link I’ve given does not work, due to the final dot…
    here is the correct site link:
    http://www.ncdc.noaa.gov/oa/climate/research/anomalies/anomalies.html
    And the file link to download:
    ftp://ftp.ncdc.noaa.gov/pub/data/anomalies/monthly.land.90S.90N.df_1901-2000mean.dat thank to moderation to correct my first text.

  19. 69
    Phil. Felton says:

    Re #65

    “The “cannot be found” file “monthly.land_and_ocean.90S.90N.df_1901-2000mean.dat.txt” can be easily downloaded on the following NOAA site : http://www.ncdc.noaa.gov/oa/climate/research/anomalies/anomalies.html.
    It is a little surprising to see that Bard and Delaygue were not able to find this kind of file.
    For people familiar with temperatures series, this format is the signature of a NOAA ascii files.”

    One of the problems in tracking it down of course was that that file wasn’t the data that was actually used in the paper!

  20. 70

    #67, Geoff, I was pleasantly surprised about the French press actually picking up on Raypierre’s corrections, they even added substance and are investigating further. Lets hope that this starts a media habit of redressing rampant disinformation about AGW, I believe there would be a feeding frenzy if only they paid a little closer attention, as there are plenty of modern myths out there. There are so many unchecked propaganda pieces, like a recent letter of 400 contrarian scientists including Allegre, Courtillot et al :

    http://www.huffingtonpost.com/joseph-romm/inhofe-recycles-unscienti_b_77945.html

    none of them, I am sure, predicted this recent significant warming period, having based their science on incorrect reasoning or even worse, not recognizing that there was any recent significant warming at all. I’ll know when there would be a societal about face when the famous contrarian logic drought is further exposed, like no one has picked up on another large contrarian fantasy: carbon taxes are bad for the economy, all while the price of petroleum nears $100 a barrel (without any carbon tax). I suppose contrarian claims are based on some discerning philosophy, if the price of petrol goes up (without a valid explanation) 4 times more , its not bad for the economy, but lo and behold a carbon tax, and its the end of the free market. The main distinction between contrarians and AGW proper science is pollution, seen as a necessary evil for the benefit of society, vs achieving the same thing without pollution, the moral high ground leads to a cleaner, healthier and happier planet.

  21. 71
    Jaycee says:

    Re: post #53. The suggestion that Bard might have been asked to review was a wild guess from my part. It did not come from Rob vdH. I was wrong: I apologize.

  22. 72
    Jaycee says:

    Re: 66. (53). I am very sorry to have contributed more confusion to the confusion. I never heard anything from Rob vdH about reviews of the paper, or about the paper. My statement was an uneducated guess. It was silly, and doubly wrong. I do apologize. I hope the rest of my comment can still be heard: there is no need or reason for such turmoil.

  23. 73
    henning says:

    #65
    I don’t think it matters whether you label a – say – 10year running average covering 1980-1989 1980, 1985, 1989 or whatever as long as you explain that you did so. An average is just a way to reduce some noise and make it easier for our imperfect human minds to see the forest despite of the trees. You always loose much of the data when doing so and no matter what you “call” the average (1980, 1985, 1989) it will never be anything else but the average for 1980-1989 and any other label will be there just for convenience. Despite all that – I thought it has become kind of a standard to label running averages using the middle label.

  24. 74
    Marion Delgado says:

    I don’t know where Pierre Allemand got “cannot be found” to put it in quotes – raypierre does not seem to have said it. Nor does it matter; it is a red herring. We are talking about Tglobe, and Tglobe was both misattributed and misrepresented, and moreover, when it’s correctly represented, it discredits the conclusions of the paper.

    It’s an interesting bit of info, the actual URL where they yanked their data from, just not germane here.

    ============

    1-Representation and Meaning.

    The three curves on the graph are, according to the paper, Phil Jones’ global mean temperature record (Tglobe, in red circles) , a total solar irradiance reconstruction (S(t), in pink triangle; Courtillot cites Solanki’s reconstruction in the text), the magnetic field variability index at a site in Scotland (ESK, blue) and at Sitka Alaska (SIT, green).

    (raypierre)

    2-Questioned.

    Courtillot’s “Tglobe” curve did not look much like the curve published by Jones. Jones’ curve, plotted from his actual data files, is shown in Bard and Delaygue’s corrected version of the figure; they also show the NASA reconstruction for comparison. These two curves are in agreement, but neither shows the sharp rise/dip pattern between 1940 and 1970 which is seen in Courtillot’s figure. So if Courtillot’s data is not Jones’ global mean temperature, what is it that Courtillot plotted? We may never know. In his response to Bard and Delaygue, Courtillot claims the data came from a file called: monthly_land_and_ocean_90S_90N_df_1901-2001mean_dat.txt. Bard and Delaygue point out, however, that Jones has no record of any such file in his dataset, and does not recognize the purported “Tglobe” curve as any version of a global mean temperature curve his own group has ever produced.

    (raypierre)

    3-Misrepresentation and Misattribution Acknowledged.

    In the revised “Response” Courtillot now admits that the temperature record called “Tglobe” is not from any of Phil Jones’ datasets at all. Courtillot now claims that the data came from a study by Briffa et al. (2001), giving the address of a file stored at NCDC. As specified in this study and in the head of this file, these data have been “recalibrated to obtain estimates of April-September mean temperatures from all land regions north of 20N”. Thus, the temperature dataset used by Courtillot is definitely not Tglobe, does not represent the full hemisphere, and moreover is not even an annual mean.

    (raypierre)

  25. 75
    geciktirici says:

    We can also joke about either old farts resisting change (fair enough) or that younger ones see themselselves as creative because they never read anything more than 5 years old (equally true). Junior and senior scientits having a different perception of science is a good thing after all: energy arises from differences in potential. The science you inherit today was left to you by this less than perfect system. We all fell victim to abusive or incompetent reviewers

  26. 76

    #74, Charles, corrections should be made whenever exaggerations are created. I read the french press as well, I find it in most times just as good or bad as anywhere else. The twist is actual media following up on a lead given by a scientist such as Raypierre. If a lot of that continues contrarians or bad science would have themselves as their audience. It comes down to accepting the point of view of a minority of scientists incapable of predicting future temperature trends, the same scientists who contend that those who have predicted this warming correctly; Hansen, the IPCC group etc, are wrong about the future. This same gang have also claimed that a carbon tax (for renewable energy production and GHG reductions) would wreck the economy. Wrong again they are, close to $100 a barrel without a carbon tax and still the economy survives. The key point is communicating when bad science is propagated, tag the contrarian chaps for their stance or lack of success in climate projections as a prerequisite, a media passing mark, especially in commenting about the future.

  27. 77
    Charles Muller says:

    #76 Euh… which comment ? The #74 you’re answering is not mine. And my recent comment concerning Pierre #65, Raypierre #16 and yours #70 is not published yet. Or maybe it was #74, I don’t know.

  28. 78

    #77 Charles, Curious, I did read something . thought it was by you… It is not there anymore..

  29. 79
    FLAGEOLLET says:

    [Response: Yes, indeed. That is the best-supported explanation for the interruption in global warming in the 50’s, and indeed in some regions this even shows up as an actual decline in temperatures. There is more uncertainty in aerosol forcing than in GHG radiative forcing, but what I said about “it’s the physics” applies to cooling influences like aerosols as well as warming influences like GHG — if somebody wants to say phlogiston (or magnetic fields) explain mid-century cooling, they can’t just ignore the known influences of aerosols when trying to do an attribution. –raypierre]

    Could you, please, given to me some other references about the role of aerosols in the temperature decreasing from 1950 to 1970 ?

    Thank you very much

  30. 80
    Hank Roberts says:

    Flageolet, have you looked for that with Google Scholar?
    http://scholar.google.com/scholar?q=aerosols++temperature+decreasing++1950++1970&num=100&lr=&newwindow=1&safe=off&scoring=r&as_ylo=2002
    Just one example:

    http://www.copernicus.org/EGU/acp/acpd/6/4897/acpd-6-4897.pdf
    [PDF] A global emission inventory of carbonaceous aerosol from historic records of fossil fuel and biofuel … –
    C Junker, C Liousse – Atmos. Chem. Phys. Discuss, 2006 – copernicus.org
    … France show a levelling off or a decrease of BC … A global emission inventory of carbon aerosol for 1860–1997 … a steep increase between the years 1950 and 1970.

    On RC, using the Search box (top of page) for “aerosol” will also find several discussions.

  31. 81
    Steve McIntyre says:

    You say:

    So if Courtillot’s data is not Jones’ global mean temperature, what is it that Courtillot plotted? We may never know.

    It is actually very easy to determine what Courtillot plotted. The Courtillot Tglobe plot can be replicated by using the column entitled “Observed temperatures from Jones et al. (1999) Rev Geophys” from the data archive for Briffa, Jones et al 2001 located at NCDC at ftp://ftp.ncdc.noaa.gov/pub/data/paleo/contributions_by_author/briffa1998/briffa2001jgr3.txt,
    and by carrying out the following operations: filter using a an 11-year running mean without end-period paddding, then normalizing on 1900-1990. [edit]

    [Response: I suggest you read the post in it's entirety. It will therefore be clear that the 'We may never know' comment was written before the location of the real data used was revealed in the update to the Courtillot response (now available at http://dx.doi.org/10.1016/j.epsl.2007.09.031). Well done for reading it though. -gavin]

    Even though Briffa, Jones et al 2001 was published in 2001, it only contained temperature data to 1997 – something that should have been picked up by reviewers at the time. Authors in 2007 should obviously not be using this sort of vintage data version, as modern versions are readily available, as others have observed. [edit]

    As others have observed, it appears that the data is a 20-90N composite. The description in the Briffa, Jones et al 2001 archive is not as precise as one might like, as it only says that the series is “Observed temperatures from Jones et al. (1999) Rev Geophys”. Jones et al 1999 only illustrated GLB, NH and SH indexes. The archived version for Briffa, Jones et al 2001 differs from vintage versions of these three series, being most similar to the NH version. The most plausible interpretation of the archive is that it is a 20-90N composite calculated in the course of Briffa, Jones et al 2001 (rather than one of the series from Jones et al 1999 itself.)

    Given that Jones is a coauthor of Briffa, Jones et al 2001 and the data in Briffa, Jones et al 2001 used data from Jones et al 1999, it is incorrect for Dr Pierrehumbert to say that the Courtillot temperature record is not “from any of Phil Jones’ datasets” regardless of [ad hominem comments and baseless allegations removed]. In my opinion, these allegations in Dr Pierrehumbert’s post should be withdrawn.

    [Response: Jones was asked what he knew about the file monthly_land_and_ocean_90S_90N_df_1901-2001mean_dat.txt (which was named as the source in the original response by Courtillot). He very helpfully and accurately stated it was not one of his (a file of that name is available from the NOAA/NCDC analysis but this is not what was plotted in any case). It only subsequently emerged that the data was from Briffa et al 2001. So it ends up that the data were derived from Jones' data, but how anyone was supposed to know this without being told is a mystery. (PS. posting comments at 5pm on Christmas eve is not conducive to a rapid response). - gavin]

  32. 82
    jean Ségalen says:

    je crois que vous êtes français , c’est pourquoi je vous ecris dans cette langue.Je vous ai envoyé 2 commentaires ces derniers jours mais ils n’ont pas eu l’heur de vous plaire et en moins d’une heure ils ont disparu. Censurés. Il est vrai qu’ils allaient à l’encontre de l’opinion établie et qu’ils étaient politiquement incorrects.Je trouve que Mrs Allègre et Courtillot que vous massacrez joyeusement ont des théories différentes des vôtres mais elles sont neammoins estimables. Vos querelles me font penser au concile de Nicée en 425 au cours duquel les plus hautes sommités savantes de l’époque s’étaient penchées sur le sexe des anges.Des arguments de grande technicité s’étaient alors échangés.
    Vous êtes certainement un chercheur prestigieux mais moi je vous assimile plutôt au savant Cosinus._regardez où vous mettez les pieds.
    Vous estimez que 90°/° de la production de co2 est provoquée par les activités humaines mais moi je soutiens que c’est faux.
    1) elle est provoquée à 80°/° par le volcanisme terrestre. Des milliers de volcans sur terre et sous les mers emettent des gaz 24h/24.
    2)La respiration des ^etres vivants-6 milliards d’êtres humains-beaucoup plus d’animaux-des myriades d’oiseaux,de poissons,d’insectes et même de bactéries qui respirent 24h/24 emettent 15°/° du co2
    Certes il y a beaucoup d’automobiles mais 50°/° d’entre elles ne roulent pas tous les jours, et 50°/° roulent moins d’une heure par jour. En tout cas pas une seule ne roule 24h/24.
    Un chercheur français-dont je tairai le nom car je ne veux pas vous le voir flingué par vous lui aussi a calculé que si par un coup de baguette magique on stoppait à 100°/° la production de co2 en France la température sur la planète diminuerait de 1 à 2 millionnièmes de degré. Est-il raisonnable de nous casser les pieds pour si peu? et de nous pénaliser si lourdement au point de vue financier?
    Moi j’affirme(j’ai peut-être tort mais ça me paraît tout à fait rationnel)que le global warming est dû à l’activité solaire. Comme sur la terre les calottes polaires martiennes son en régression permanente. Qu’ont en commun ces deux planètes? Elles ont le même soleil.
    Je suis pour le globalwarming. Il faudrait encore un effort. Il y a certes des inconvénients mais beaucoup moins que si la température baissait ce qui ne manquera pas de se produire et peut-être plus tôt que vous ne le pensez. Et c’est là qu’on ira à la catastrophe.
    [edit]

  33. 83
    Ray Ladbury says:

    Jean Segalen, Vraiment, je pense peut etre vous avez mal compris. Les activete’s humaine sont responsible pour presque tout de la augmentation de CO2. Les volcanes ne sont pas un contribuant tres grande, et nous connaissons que au cause de le rapport isotopique que le source de la plupart de CO2 et une source fossil.
    Les changement solaire ne peut pas explique le chaufement de la terre–meme les regiones palaires martiennes. Le climate martienne et domine’ par le tempete de la poussiere.
    Il faut apprendre un peu de la science.

  34. 84

    Monsieur Segalen, Ray a re-explique cette fois ci, en francais, ce qui est chose certaine, vos conclusions sont bases sur des references scientifiques? Priere les decrires. Le conceil de Nice n’est pas la meme chose que le IPCC, tu as la liberte de t’exprime, mais faut tout de meme s’appuye
    sur des fondations scientifiques solides, et non pas seulement a une croyance basee sur des idees simplistes.

  35. 85
    Philippe Chantreau says:

    Monsieur Segalen, vos commentaires revelent un ignorance assez grave de l’etat actuel de la science du climat. Il n’y a pas penurie de references serieuses pour mettre vos convictions a l’epreuve. La masse de dioxide de carbone provenant des activites humaines est a peu pres 150 fois celle de l’activite volcanique. De nombreuses etudes sur l’activite solaire et les reconstructions de l’activite solaire passee demontrent sans l’ombre d’un doute que les variations recentes ne peuvent expliquer le rechauffement observe depuis 1975. Les lois physiques qui gouvernent le comportement thermodynamique du dioxide de carbone constituent une realite incontournable. Si vous voulez vraiment comprendre ce qui se passe, je vous recommende les sources vraiment serieuses.

    Par ailleurs, il est tout a fait abusif de traiter Mr. Ladbury de “savant cosinus,” alors qu’il a derriere lui une carriere tres productive au sein d’institutions prestigieuses et bon nombre de publications traitant de sujets qui, a l’evidence, vous echappent.

    Pour l’attribution du dioxide de carbone:
    http://cdiac.ornl.gov/trends/co2/contents.htm
    Pour l’activite solaire:
    http://www.astro.phys.ethz.ch/papers/fligge/GL264W01.pdf
    Ces deux liens sont des exemples. La recherche qui supporte l’hypothese du dioxide de carbone est plus que considerable et il n’existe, a ce jour, pas d’alternative satisfaisante.

  36. 86
    Chuck Booth says:

    Re # 81 For the benefit of non-French speaking (or reading) visitors, I offer here a translation of jean Ségalen’s post (courtesy of Babel Fish Translation, http://babelfish.altavista.com/tr):

    I believe that you are French, this is why I you ecris in this langue.Je sent 2 comments to you these last days but did not have the hor you to like them and in less than one hour they disappeared. Censured. It is true that they went against the established opinion and that they were politically incorrects.Je finds that Mrs Allègre and Courtillot that you massacre joyeusement have theories different from yours but they are neammoins estimable. Your quarrels make me think of the council of Nicée into 425 during which the highest erudite celebrities of the time were leaning on the sex of the anges.Des arguments of great technicality had then been exchanged. You are certainly a prestigious researcher but me I rather assimilate you to the Cosinus._regardez scientist where you put the feet. You estimate that 90°/° production of CO2 is caused by the human activities but me I support that they is false. 1) it is caused with 80°/° by terrestrial volcanicity. Thousands of volcanos on ground and under the seas emettent gases 24h/24. 2)La breathing of the ^etres alive-6 billion human-much beings more animal-of the myriads of birds, fish, insects and even of bacteria which breathe 24h/24 emettent 15°/° CO2 Certes there are many cars but 50°/° of them does not roll tous.les.jours, and 50°/° roll less than one hour per day. In any case not only one does not roll 24h/24. A researcher French-to which I will conceal the name because I do not want to as see it to you flingué by you calculated to him as if by the waving of a magic wand one stopped with 100°/° the production of CO2 in France the temperature on planet would decrease by 1 to 2 millionnièmes by degree. Is it reasonable to break us the feet for if little? and to so heavily penalize us from the financial point of view? Me I affirme(j’ am perhaps wrong but that appears completely rationnel)que total the warming to me is due to the solar activity. As on the ground Martian polar caps sound in permanent regression. What has these two planets in common? They have the same sun. I am for the globalwarming. An effort would be still needed. There are certainly disadvantages but much less than if the temperature dropped what will not fail to occur and perhaps earlier than you think it. And it is there that one will go to the catastrophe.

  37. 87
    Philippe Chantreau says:

    Chuck, that is truly funny!!!!

  38. 88
    Chuck Booth says:

    Re # 86 Philippe Chantreau

    Funny, but I think it was easier to understand in the original French, and I don’t read or speak French.

  39. 89
    Ray Ladbury says:

    Chuck, Babelfish did a reasonable job of translation–though it seems to have trouble with pronouns, interestingly enough. It is reassuring to know that other countries have their loons, too.

  40. 90
    Nick Gotts says:

    Re #81 I notice that Jean Ségalen even managed to get the date of the (first) Council of Nicaea wrong: it was 325. Among its decisions on dogma was that angels are non-physical beings, hence unsexed. Sneers at what appear, taken out of their cultural context, to be absurd beliefs or disputes, are tokens of ignorance rather than sophistication.

  41. 91
    Hank Roberts says:

    Google Translator
    http://www.google.com/translate_t
    does a rather better job of rendering.

  42. 92
    richard schumacher says:

    #19: Conservation will be an important part of the answer for the United States but it does very little for the under-developed and developing world. At the end of this Century there will be nine billion people. Supporting them with a Western-style standard of living, even assuming a European level of energy efficiency, will require roughly 4x the current energy supply. Economic democracy and environmental responsibility together require both conservation and every non-fossil energy source we can bring to bear: Solar (ultimately space-based), nuclear (first uranium-fuelled breeders and later thorium), wind, geothermal, et cetera.

    #85: Yes, Mars and Earth share the same Sun, but they do not share the same orbital dynamics. Milankovic forcing would be about to send Earth into another ice age, but this is being overwhelmed by CO2 forcing. Mars’ Milankovic cycle in contrast is now warming Mars unopposed by any artificial forcings.

  43. 93
    Max says:

    “Wrong again they are, close to $100 a barrel without a carbon tax and still the economy survives.”

    Its not the price of oil that would really ever harm the economy, its the addition of more fingers in the pie that does, especially if they fail to put back into the economy in timely and distributed manner

  44. 94
    Steven mosher says:

    Ray P wrote:

    “In the revised “Response” Courtillot now admits that the temperature record called “Tglobe” is not from any of Phil Jones’ datasets at all. Courtillot now claims that the data came from a study by Briffa et al. (2001), giving the address of a file stored at NCDC”

    And HERE is the header to that file:

    Data file to accompany Plate 3 of Briffa et al. (2001)

    The following reconstructions have been taken from the source
    “references listed below, and then RECALIBRATED to obtain estimates”
    of April-September mean temperatures from all land regions north
    of 20N. All series are temperature anomalies in degrees C with
    respect to the 1961-1990 mean. Note that in Plate 3 of Briffa
    “et al. (2001) all the series had been smoothed, while the data”
    listed below are unsmoothed (though column 5 never had any
    sub-5-year variability even when unsmoothed).

    Full references and details of the recalibration are given in
    “Briffa et al. (2001) J Geophys Res 106, 2929-2941.”

    Columns are:
    1: Jones et al. (1998) Holocene
    2: Mann et al. (1999) Geophys Res Lett
    3: Briffa et al. (2001) J Geophys Res
    4: Briffa (2000) Quat Sci Rev
    5: Overpeck et al. (1997) Science
    6: Crowley & Lowery (2000) Ambio
    7: Observed temperatures from Jones et al. (1999) Rev Geophys

    And Phil Jones is a co-author on this Briffa paper, correct gavin?

    Low-frequency Temperature Variations from a Northern Tree Ring Density Network
    Journal of Geophysical Research,
    106 D3 (16-Feb-2001) pp. 2929-2941
    K. R. Briffa*, T. J. Osborn, F.H. Schweingruber, I.C. Harris, P. D. Jones, S.G. Shiyatov, and E.A. Vaganov.

  45. 95
    Eric says:

    Une bonne compréhension des justifications du réchauffement climatique nécessite des compétences dont je ne dispose pas.

    Je remarque néanmoins que le démontage des idées des uns et des autres passe souvent par la critique des modalités de fabrication des courbes. Oskar Morgenstern expliquait déjà cela trés bien dans les années 30. Il est vrai qu’il s’agissait d’économie, mais peut être assiste-t-on à une convergence des techniques d’argumentation des sciences molles et des sciences dures.

    J’aurai à ce sujet une question qui porte sur un argument souvent employé par les opposants à l’idée du rôle majeur du CO2 dans le réchauffement climatique.

    Il s’agit de l’écart inverse qui existerait entre la hausse du CO2 et l’élévation des températures.

    Certains critiques radicaux de la présentation d’ Al Gore expliquent en effet que la lecture fine des courbes présentées montre que le réchauffement précède l’augmentation du CO2 et non l’inverse.

    Je suppose que cette question a été tranchée. Merci de me donner les éléments de compréhension en votre possession.

    [Response: La correlation entre CO2 et température n'est pas 'inverse' du tout. Par apport la précédence d'un ou l'autre, il faut penser qu'il y a deux effets qui sont couplé - l'effet de climat sur la cycle carbonique et l'effet de serre. Si le climat change a cause d'un autre processus, le CO2 va suivre et ajouter (comme on trouve dans les cycles glacial/inter-glacial), et aussi, si le CO2 change a cause d'un autre chose (les activités humaines), la climat va suivre aussi. Voir ici pour un peu plus d'information. - gavin]

  46. 96

    Max # 93, “If they fail to put back into the economy in timely and distributed manner” , Re-investing in green energy technology has its own feedback process, which would ultimately require less oil,
    such as the “normal” market goes, a lesser demand would decrease the price of this commodity. With price of oil so high, without purpose all while not having economists frantically panicking about its damaging effects, leads me to conclude that the idea of a carbon tax dedicated for green energy investment is more than doable, even good for a “normal” economy, with a little more concern about the price of energy.

  47. 97
    Max says:

    Drifting of topic but when is the last time a government actually spent tax dollars on the purpose it was collected for. That is a pipedream to think there is a hardline dedication to causes in which money is collected for. For an example have a look at the tax which the Canadian Government collects for national road infrastructure, and how much it actually spends. The problem with governments is that they will collect the money for a cause and spend it on something else.

  48. 98
    Steve McIntyre says:

    #81. Gavin, you said:

    It will therefore be clear that the ‘We may never know’ comment was written before the location of the real data used was revealed in the update to the Courtillot response

    Well, after the updated response was available, Dr Pierrehumbert stated:

    In the revised “Response” Courtillot now admits that the temperature record called “Tglobe” is not from any of Phil Jones’ datasets at all. Courtillot now claims that the data came from a study by Briffa et al. (2001), giving the address of a file stored at NCDC.

    Given that Jones was a coauthor of Briffa et al 2001 and that study cited Jones et al 1999, Dr Pierrehumbert is incorrect to assert that Courtillot “admits” that the temperature record in question is “not from any of Phil Jones’ datasets at all”. It obviously is from one of Phil Jones’ datasets. Why not simply acknowledge this and move on?

    You also say

    So it ends up that the data were derived from Jones’ data, but how anyone was supposed to know this without being told is a mystery.

    In this case, Courtillot did cite Jones et al 1999 in their original article and that was one way that a reader might have known that Jones’ data was used. I agree that the absence of an accurate URL made it pointlessly difficult to decode precisely what Jones version was used, especially given the use of an obsolete version. I strongly endorse the principle of authors providing detailed data citations (with URLs) although Courtillot et al are hardly unique offenders in this respect.

    [Response: Is this the sound of a dead horse being beaten? It's clear that the data was derived from Jones' dataset. Yet you accuse me of not acknowledging that, one line prior to quoting my acknowledgment. Huh? There is a distinction between "derived from" and "one of" but frankly, I'm not interested in this kind of semantic micro-parsing. The issue is not the lack of URL but the mis-statement of what the record was (twice!). Let's "move on" shall we? (PS. If RayP has anything to add it will come after the New Year). - gavin]

  49. 99
    David B. Benson says:

    richard schumacher (92) states Milankovic forcing would be about to send Earth into another ice age, but this is being overwhelmed by CO2 forcing.

    Well, it turns out that the Holocene is one of the long interglacials. The soonest another stade (massive ice sheets) could arise, baring AGW, is in 20,000 years. But that forcing is so weak that it is the next chance, 50,000 years from now, that the next stade will certainly arise (baring massive AGW).

  50. 100
    henry says:

    I’m sorry, I guess I should have pressed the “1″ to get the replies in English…


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