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Skepticism About Lower Atmosphere Temperature Data

Posted on 8 January 2012 by dana1981

Note: This article was submitted to Forbes as a correction to the op-ed by James Taylor in question, but Forbes declined to publish it, so instead we're posting it here.

Forbes recently published an op-ed written by James Taylor of the Heartland Institute on the subject of the University of Alabama at Huntsville (UAH) atmospheric temperature measurements on the record's 33rd anniversary.  Unfortunately, the article contained a litany of errors which completely undermine its conclusions, and exhibited a distinct lack of true skepticism.

The main subject of the article was the fact that according to climate models, the Earth's lower atmosphere should warm approximately 20% faster than the surface, whereas UAH estimates place the lower atmosphere warming at about 20% less than surface temperature measurements.  A true skeptic would acknowledge that there are three possible explanations for this discrepancy:

  1. The models are incorrect and the lower atmosphere should not warm faster than the surface.

  2. The surface temperature estimates are biased high, showing more warming than is actually occurring.

  3. The UAH lower atmosphere temperature estimates are biased low, showing less warming than is actually occurring.

Because the climate model expectation of greater lower atmosphere warming is based on solid fundamental atmospheric physics, and the accuracy of the surface temperature record was recently independently confirmed by Richard Muller and the Berkeley Earth Surface Temperature (BEST) project, the third possible explanation appears to be the most likely.  This possibility is further supported by the fact that other groups have estimated greater atmospheric warming than UAH, and measurements by radiosondes (instruments on weather balloons) also show greater atmospheric warming than UAH.

It is certainly a possiblity that is worth considering, and yet it was notably absent from the three possible explanations for the model-data discrepancy provided by James Taylor in his article.  In fact, every one of the three possible explanations offered by Taylor involved the man-made global warming theory being either exaggerated or incorrect.  Refusing to consider a possibility which is inconvenient for one's pre-conceived notions and/or biases reveals a distinct lack of true skepticism.

Taylor's article contained a litany of additional errors.  For example, he reported that the UAH temperature data "seem to show warming closer to 0.3 degrees over the 33 year period, or 0.09 degrees Celsius per decade," as opposed to the UAH-reported 0.14°C per decade warming.  This is false.  John Christy reported that if the influences of volcanic eruptions (which have a temporary cooling effect by releasing particulates into the atmosphere which block sunlight) are filtered out of the UAH record, the warming trend is reduced to 0.09°C per decade.  However, in order to make an apples-to-apples comparison, the volcanic influence must also be removed from the climate models, which neither Christy nor Taylor did.

Additionally, a recent study by Foster and Rahmstorf filtered out the effects of not just volcanic eruptions, but also the El Niño Southern Oscillation (ENSO) and solar activity, which can also have significant short-term impacts on global temperatures.  They confirmed Christy's finding that removing volcanic effects decreases the warming trend over the past three decades, but additionally removing ENSO and solar influences increases the trend over that same period.  In other words, by only removing the influence of volcanoes, Christy and Taylor cherrypicked the effect which would minimize the observed warming trend.  This again exhibits a distinct lack of true skepticism.

Taylor also implied that unlike surface temperature measurements, the UAH satellite data do not "require guesswork corrections."  In reality, the UAH record requires a great number of corrections, because the satellite instruments do not even directly measure atmospheric temperatures.  Rather, they measure the intensity of microwave radiation given off by oxygen molecules in the atmosphere, from which the scientists estimate the temperature.  The satellites sensors face down toward the Earth and radiation therefore reaches the satellites having travelled upwards through a warming lower atmosphere and cooling upper atmosphere. This influences any warming signal received by the satellites, and because the lower atmosphere is what is being measured. creates a cooling bias that has to be accounted for. But it doesn't end there; bias also exists between the various instrument sensors on each satellite, and the satellite orbits decay over time. These and a number of other obstacles mean a lot of careful and painstaking analysis is required. As a result of all this complexity and data correction, there's much that can go wrong.

Considering these challenges, it's not a surprise that there have been a number of major corrections to the satellite temperature data over the years.  Groups outside of UAH identified two major errors in the UAH analysis, both of which had caused Spencer and Christy to significantly underestimate the atmospheric warming.  Despite the difficulties in the available data, and the numerous adjustments made to their analysis, Spencer and Christy have all along insisted that their data set is correct, and they (and James Taylor) continue with this overconfidence today.  However, the most likely explanation for UAH showing less warming than models and atmospheric physics predict is that UAH is biased low.

Taylor's error-riddled article demonstrates that when it comes to climate science, we should listen to climate scientists, who are true skeptics, rather than a law and policy expert from a fossil fuel-funded think tank.

Rather than correct the errors by publishing this article, Forbes compounded the problem by publishing a very similarly erroneous post from serial misinformer Patrick Michaels (who admits that like Taylor, he is also heavily fossil fuel-funded).  Ironically, Forbes recently published Peter Gleick's 2011 Climate B.S.* of the Year Awards.  If Forbes continue with this trend of publishing and compounding misinformation while ignoring corrections, perhaps they will make a run for the 2012 award!

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Comments

Comments 1 to 39:

  1. They are rather strong contenders!
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  2. A new acronym is emerging: fossil fuel-funded think tank = ffftt. It is pure coincidence that ffftt is the sound of methane or CO2 escaping from confinement ...
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  3. Modeled is upper left.
    RATPAC (raobs) is lower left.
    UAH MSU is upper right.
    RSS MSU is lower right:



    General warming trend in the troposphere and cooling trend in the stratosphere do appear to be corroborated by the observations.

    The tropical upper tropospheric hot spot and a general maxima of warming aloft appear to be contradicted by the observations.
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    Response:

    [DB] It is considered good form to also publish the paternity of graphics used in one's comments.  For example, the URL of your graphic is:

    http://photos1.blogger.com/x/blogger2/.../gse_multipart51047.png

    Which unfortunately tells us nothing of the sources used for the images.

  4. Very good rebuttal, but "Unfortunately, the article contained a litany of errors...", a litany is not a list, it is a series of supplications to God.
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    Response:

    [DB] I believe definition #2 is in play:

    lit·a·ny/?litn-?/

    Noun:
    1. A series of petitions for use in church services, usually recited by the clergy and responded to in a recurring formula by the people.
    2. A tedious recital or repetitive series.
  5. CW @3, please learn the difference between 'pattern' and 'trend'. Also see our 'hot spot' rebuttals.
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  6. climatewatcher @3, the upper tropospheric hotspot is not an predicted consequence of greenhouse warming per se, but of any warming, whether due to changes in solar forcing, green house forcing, albedo or internal variability, and is a consequence of increased absolute humidity reducing the lapse rate. The one certain consequence of those predictions being wrong is that the lapse rate feedback, an important negative feedback will not be as strong as expected. The lack of the hotspot certainly does not call into question the fact that the Earth is warming, as can be seen in the surface measurements in all your illustrations. Therefore, as it is a predicted consequence of all forms of warming, it cannot call into question warming by greenhouse gases.

    Further, there is good reason to question the accuracy of all the measurements used by you. In particular, the satellite measurements use a channel that detects a signal from both the troposphere and the stratosphere, which is cooling. There is good reason to think that neither RSS and (particularly) UAH have completely removed the stratospheric signal, a fact that would obscure the existence of the hotspot. Other evidence suggests the hotspot in fact exists, although the science continues to remain very ambiguous on this point.

    Further discussion on this point is best conducted on the tropospheric hotspot thread where much of the relevant evidence is already presented in the main article.
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  7. climatewatcher.@3. Since you haven't given the source for your graphics it is very hard to make a judgement about them. If they are radiosonde based, you need to be very careful which series you are using since a great deal of work has gone into correcting problems with them, particularly issues related to instrumentation changes and problems with temperature measurements at higher altitude.

    If it is the satellite data you are referencing, you need to be aware that of the 4 temperature series produced by UAH & RSS, only their lower Troposphere and Lower Stratosphere series are relatively uncontaminated by mixing Trop & Strat temps together although the lower Troposphere series still has issues with larger error margins due to the processing methods needed and more contamination from ground sourced signals.

    The Mid Troposphere series is biased low because around 20% of its signal actually originates from the Stratosphere. Even more so the Upper Troposphere series is sourced nearly 50/50 from the actual Upper Troposphere and the Lower Stratosphere. As such it is actually worthless as a true measure of Upper Tropospheric warming.

    I comment on some of these issues here http://www.skepticalscience.com/Eschenbach_satellite_part.html and here http://www.skepticalscience.com/Primer-Tropospheric-temperature-measurement-Satellite.html
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  8. "The Mid Troposphere series is biased low because around 20% of its signal actually originates from the Stratosphere."

    That would be true if just the raw signal were used to compute the temperature. That isn't the case though. Both RSS and UAH attempt to remove the influence of the signal from the stratosphere by different algorithms. Unfortunately, until both share their code, we don't have any independent confirmation of how successful they are. RSS was running about 0.1 C higher than UAH for global middle troposphere temperature anomaly until the demise of the Aqua satellite sensor. Now UAH is ~0.1 C higher than RSS. It will be interesting to see how Version 6 of the UAH code changes things.

    The other thing is that the surface temperature is just that and is inside the surface boundary layer. As I remember, the GCM's do not model the actual surface boundary layer so comparing satellite temperatures to models to GISS or HADCRUT is something of an apples to oranges to bananas comparison.
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  9. This diatribe is almost as bad as Taylor’s abysmal effort titled “New NASA Data Blow Gaping Hole In Global Warming Alarmism”. This is the second misleading press release that Spencer and Christy and University Alabama in Huntsville have been implicated in in recent months.

    Mr. Taylor should really stick to being a lawyer.

    It is clear that Spencer and Christy have a close partnership with the Heartland Institute and Cato Institute. Together they make quite a misinformation/propaganda machine.

    Spencer and Christy release a misleading press release, them paid misinformers from Heartland/Cato propagate that and add further distortions and misleading information in the mass media.

    Spencer and Christy stand by silently and let the errors and distortions made by their friends at Heartland go uncorrected.

    The spate of appalling misinformation articles by "skeptics" and deniers of AGW that Forbes has allowed to be published in recent months underscores the very serious issue that the media have with false balance, and shows how the media are intimately involved in propagating myths and misinformation and even falsehoods about AGW. To say the media have largely let the people down is a gross understatement.

    As someone noted in the thread following the Michaels misinformation piece:
    "You devalue your publication by publishing easily debunked climate myths written by a oil industry shill."

    Exactly.
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  10. DeWitt Payne @8,

    Good points, but I do not agree with this "the GCM's do not model the actual surface boundary layer".

    The models do simulate temperatures in the low levels of the atmosphere, including in the boundary layer. The number of data levels in the vertical and their spacing are much coarser than in numerical prediction models though. The highest density of layers is in the low levels with the spacing between data levels increasing with height.

    With that said, and as you correctly note, it is incorrect to compare near surface temperatures (screen level near 1.2 m above ground level) with the temperatures in a deep layer in the lower troposphere.
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  11. Pat Michaels engages in some very disingenuous cherry picking and lying by omission in his Forbes article. Sometimes I wonder if people like Taylor and Michaels have an honest bone in their bodies….

    One especially good example of this is his very confident claim that:
    "The average warming trend in the one-third century of satellite data is 0.14°C per decade, but the warming rate in the UN’s midrange climate models is 0.25°."

    Ironically, the warming rate of 0.25 C/decade is from Santer et al. (2011), a paper that includes amongst it conclusions that:
    "There is no timescale on which observed trends are statistically unusual (at the 5% level or better) relative to the multi-model sampling distribution of forced TLT trends. We conclude from this result that there is no inconsistency between observed near-global TLT trends (in the 10- to 32-year range examined here) and model estimates of the response to anthropogenic forcing."

    So Pat is using data from a paper that finds no statistically unusual in the trends between the rate of warming predicted by the models and found satellite estimates to try and demonstrate that the models are wrong and that there is no concern for doubling or trebling CO2. Similarly to Santer et al. (2011), Thorne et al. (2010) find that:
    "It is concluded that there is no reasonable evidence of a fundamental disagreement between tropospheric temperature trends from models and observations when uncertainties in both are treated comprehensively."

    Now it is true that the models are running slightly too warm, at least when compared against the satellite estimates, but the satellite data are far from the gold standard and still have unresolved issues. Not for one minute does Michaels share with readers the possibility that the satellites have unresolved cool biases as noted by Mears et al. (2011):
    "This further confirms our finding for our data set that unambiguously resolving the diurnal drift effect correction and its impacts is likely to be a key determinant in reducing the uncertainty in long term tropospheric temperature changes from MSU/AMSU records."

    Michaels then goes on to make his uber confident statement of fact:
    "....the UN’s average forecast of 3.2°C of warming this century is off by about 40%, which should spell the victory of the lukewarmers and the death-knell of apocalyptic global warming."

    Note how definitive his language is, completely void of any qualifiers or mention of uncertainty. He says "is off by 40%" (not "perhaps", "could be", "may be"). This brazen overconfidence in "skeptics" assertions while calling into doubt the findings of real climate scientists is a consistent theme in this misinformation campaign being waged by people like Michaels and Taylor.

    Additionally, Michaels chooses not to share with readers that part of the outstanding discrepancy between the model estimates and satellite estimates could be attributable to the fact that the any of the model runs have not included some negative forcings (e.g., increased aerosol loading, the recent prolong solar minimum). Instead, Michaels is trying to have people believe that the sole reason for the discrepancies is attributable to "model response errors" and for that reasons there is no cause for concern should we double or treble CO2. Wrong, and I suspect deep down he knows it.
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  12. I love the strawman constructed by Pat Michaels in his Forbes article. Nowhere in the IPCC assessment reports do they speak of “apocalyptic global warming”– so his point is a complete strawman and red herring. He falsely claims:

    “In other words, the UN’s average forecast of 3.2°C of warming this century is off by about 40%, which should spell the victory of the lukewarmers and the death-knell of apocalyptic global warming. Indeed, it is not the heat, it’s the sensitivity, which looks to be quite a bit lower than what’s in those computer simulations.”

    I discussed the issue with this misleading statement in my previous post. But there is an equally important issue that Michaels would have readers of his article ignore. Like other “skeptics” Michaels likes to try and claim that models are the only way of estimating climate sensitivity. They are not, and he knows that. Matt Huber’s (Purdue University) excellent quote below calls BS on Pats’ above assertion. The sage words of the respected Dr. Matt Huber are well worth reading:

    “Climate scientists don’t often talk about such grim long-term forecasts, Huber says, in part because skeptics, exaggerating scientific uncertainties, are always accusing them of alarmism. “We've basically been trying to edit ourselves”, Huber says. “Whenever we we see something really bad, we tend to hold off. The middle ground is actually worse than people think.
    “If we continue down this road, there are really is no uncertainty. We’re headed for the Eocence. And we know what that’s like.”


    Dr. Matt Huber, October 2011.

    Also, like Mr. Taylor, Pat is happy to let readers remain blissfully unaware of the problems with the satellite record (especially the UAH product) and that other groups processing the satellite data arrive at higher rates of warming (close to 0.20 C per decade for the satellite era) in the lower troposphere. Pat also wants readers to remain ignorant of the fact that the weather balloon data also shows a rate of warming for the middle atmosphere (about 1.5 km to 10 km above sea level) satellite era of near of ~0.18-0.20 C per decade.
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    Moderator Response: [RH] Fixed close italics.
  13. Re: litany

    which dictionary? I haven't seen one where the wrong meaning has been adopted for this word. Does it also have the wrong meanings for: belabo(u)r, careen, disinterested, enormity &c?
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    Response:

    [dana1981] Any dictionary.  See definition #4 here or #2c here, for example.  It's very common usage to describe a long list of something as a litany.

  14. 13, calywhatever,

    Are you serious?

    Type "litany" into Google.

    Look at the definition that Google displays at the top of the page.

    Or click on the dictionary.reference.com link.

    Or click on the Merriam-Webster link.

    Or the thefreedictionary.com link.

    Or actually pick up a dictionary.

    You really have to be kidding me. You're in denial about what a fricking word means?
    0 0
    Response:

    [DB] And with that, let us close this chapter on the definition of words, lest we again question the definition of is...(unless it's an unknown scientific term, such discussion is now OT on this thread).

    My kingdom for a built-in dictionary gidget...

  15. Dan,

    What the heck is a "gidget"? Do you even know what "gidget" means?

    Gidget (character)
    Gidget (TV series)
    Gidget (Film)
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  16. Gidget is a conflation of gadget and widget...all in portent
    of what you are working on, 'cause 'tis 'portant...
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  17. DeWitt Payne @8

    Sort of true. The satellites have three sensors that read microwaves at slightly different frequencies. These each record for three nominal altitude bands - Mid Troposphere, Upper Troposphere and Lower Stratosphere. The first 2 have roughly 20 & 50% of their signals respectively originating from the lower stratosphere. Incontrasr the 3rd sensor only gets about 5% of its signal from the Upper Troposphere.

    What you are referring to is a 4th 'pseudo-sensor'. RSS & UAH take the data from the first, mid-tropspheric centred sensor and apply additional processing that removes much of the stratospheric bias (although not all) and also produces a result that is centred in the Lower Troposphere. This is the data series (referred to as TLT) that is usually shown as the headline 'Atmospheric Temperature'

    However the other series are taken from the 3 sensors without this additional processing so they show data that still contains the stratospheric bias.

    Also there is another group that is doing satellite temp series with some quite different processing methods and they are showing significantly higher readings for the mid-Troposphere sensor. As yet they haven't produced a TLT product although they apparently plan to.

    http://www.star.nesdis.noaa.gov/smcd/emb/mscat/mscatmain.htm
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    Response:

    [DB] Fixed link.

  18. “However, the most likely explanation for UAH showing less warming than models and atmospheric physics predict is that UAH is biased low? ”. Really?

    If we go to the Met Office HADAT site we will find a detailed comparison of MSU and HADAT data by RSS.
    Their figures are interesting because they compare mid-troposphere radio-sonde data with satellite data from 1978. The perturbation of the lapse rate on which AGW depends must start in the mid troposphere, where additional CO2 can make its presence felt.

    Satellite data is global, whereas the radio-sonde is not, and it is particularly sparse in the Southern hemisphere. To compensate, RSS sampled the satellite data to match the radio-sonde locations, and calculated matched data trends as follows:

    Mid-troposhere:
    HADAT 1.08 degrees per century
    RSS 1.35 degrees per century
    UAH 0.95 degrees per century

    But what about the lower troposphere?
    HADAT 1.95 degrees per century
    RSS 1.7 degrees per century
    UAH 1.76 degrees per century.

    So the satellites are not significantly lower than the radio-sondes, and their global figures should be respected as the best available.

    The crucial data is for the global mid-troposhere, where UAH quotes 0.5 degrees per century. For the lower troposphere the UAH trend is 1.4 degrees per century.

    These figures neatly reverse all the model data for mid versus lower troposphere trends
    Still, if the facts do not agree with the theories, so much the worse for the facts.
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    Response:

    [DB] "These figures neatly reverse all the model data for mid versus lower troposphere trends"

    Please provide a source citation for this assertion.

    Inflammatory/trolling struck out.

  19. "However, the most likely explanation for UAH showing less warming than models and atmospheric physics predict is that UAH is biased low"

    This is a legitimate possibility that is supported by the data. A 2006 report on which John Christy (developer of the UAH product) was a lead author concluded that:

    "These results could arise either because [1]“real world” amplification effects on short and long time scales are controlled by different physical mechanisms, and models fail to capture such behavior; or [2] because non-climatic influences remaining in some or all of the observed tropospheric data sets lead to biased long-term trends; or [3] a combination of these factors. The new evidence in this Report favors the second [2] explanation."
    [I added the numbering for clarity]

    This figure from the UK Met office shows UAH (blue square) to be biased low:


    Caption: HadAT2 radiosonde data (black) vs. UAH (blue) and RSS (red) lower troposphere temperatures, and HadCRUT3 surface temperatures (green) [Source]

    Note that the surface rates of warming compare well with RSS and HadAT and RATPAC.

    The point was that the satellite data, in particular the UAH data are biased low is a very real possibility that should not be ignored. Yet, Taylor did just that. Satellite data are not the gold standard that "skeptics' imagine them to be, corrections to the satellite data have been numerous and are ongoing. Mears et al. (2011) note that there are still outstanding issues:

    "This further confirms our finding for our data set that unambiguously resolving the diurnal drift effect correction and its impacts is likely to be a key determinant in reducing the uncertainty in long term tropospheric temperature changes from MSU/AMSU records."

    Also, something else Mr. Taylor and Dr. Michaels decided to not share with their readers is that other satellite products that use different techniques to correct for stratospheric contamination obtain much higher rates of warming in the mid troposphere than do UAH, see here.
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  20. Fred Staples @18:

    1) The satellite data only has near global coverage, being very restricted in its coverage of the poles. UAH does publish polar data, but RSS does not because the imprecision (error bars) of the data are too large relative to the rest of the globe.

    2) The Temperature Middle Troposphere (TMT) channel is poorly named as it includes significant data from the lower stratosphere and the surface (see figure below). As the lower stratosphere is cooling and the surface may not be warming as fast as the middle troposphere, that under reports middle to upper troposphere temperature trends and makes direct comparisons the model predictions of a tropospheric hotspot difficult. Such comparisons require construction of an explicitly weighted function of temperature to match the signal strengths in the TMT channel which you have neither done nor cited. Therefore absent such a weighted model prediction, the TMT comparison is irrelevant.



    3) For the Temperature Lower Troposphere (TLT) channel, UAH understates the HADAT radiosonde trend by 10%, the RAOBCORE radiosonde trends by 5%, the RICH radiosonde data by 8%, but overstates the IUK radiosonde trend by 6%. The IUK radiosonde trend is a clear outlier among the radiosonde data sets understating the average trend of the other three sets by 12%. The RSS trend is lower than the UAH trend when compared to the first three radiosonde data sets, but (illustrating the idiosyncracies that can arise with small data sets) overstates it compared the UAH in the IUK comparison.

    Based on this, satellite data understates the TLT trend by at least 4%, and probably closer to 10% when compared to radiosondes. Given that the TLT channel still includes surface data, biasing it low, that means the satellited data from RSS is entirely consistent with a tropospheric hotspot. Once adjusted for endogenous factors as per Foster and Rahmstorf 2011, that means the long term trend in tropospheric temperatures is at least equal to the surface trends, and probably greater. The same adjustment for endogenous factors clearly illustrates that UAH is a low outrider, with an adjusted trend of 0.14 C/decade compared to the RSS trend of 0.16 C/decade.
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  21. The BEST analysis does not prove the surface temperature record is perfect, and there hsa to be some error in this record. Whether it is 0.0001 or 0.01 I don't know. It seems that whatever the error may be it is not large enough to fundamentally change our view that the globe is warming significantly.

    But there still could be a large enough error in surface records to at least partly account for why the troposphere is not measusred as warming faster than the surface.

    A true skeptic would consider the possibility that more than one factor could be contributing to the discrepancy.

    And perhaps the models aren't 100% correct in their predictions of the atmosphere's vertical temperature profile. Of course if we start changing the vertical temperature profile of the atmopshere this could result in unexpected changes in convection, and therefore in rainfall and severe weather.
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  22. “ The same adjustment for endogenous factors clearly illustrates that UAH is a low outrider, with an adjusted trend of 0.14 C/decade compared to the RSS trend of 0.16 C/decade”.

    Presumably, Tom, you quote these trends to 2 decimal places per decade to show that you have a sense of irony. It would be difficult to measure the trend in a garden shed to this accuracy (I know because it was one of my responsibilities in a nuclear power plant). You would need well calibrated continuously recording equipment – systematic errors in trends imply the measurement of drift.

    It would be impossible to measure such a trend in your garden, and difficult even to define it – holes in the ground, water temperatures, air temperatures above ground?

    “The main subject of the article was the fact that according to climate models, the Earth's lower atmosphere should warm approximately 20% faster than the surface, whereas UAH estimates place the lower atmosphere warming at about 20% less than surface temperature measurements”

    The moderator asked for a citation for the above. RC wrote many articles on the subject (they are great proponents of the “higher is colder” lapse rate theory – Google RayPierre Humbert). When it became obvious that the lower troposphere was warming the faster they introduced the cooling stratosphere as a confounding factor, just as Tom does above.

    Go to the HADAT site, transfer to their “frequently used graphics” page, and look at the lower stratosphere temperatures. You will see that there has been no cooling for the last 18 years.

    And Tom, if you read the RSS paper you will find that they did exactly what you suggest to compare satellite with radio-sonde data.

    Finally, while you are on the Global Warming at a Glance site, have a look at the plot of all radio-sonde temperatures. The chart starts at 1958, when temperatures were below their previous peak in the forties. Look at the trend to 1977, and the rise of almost one full degree between 1972 and 1974, and the subsequent fall between 1974 and 1977.

    Even without the statistics, which I have posted elsewhere, you should not need to be convinced that there has been no significant tropospheric warming between 1945 and 1997. Now look at the Mauna Low CO2 data on the same chart.
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  23. 22, Fred,
    It would be difficult to measure the trend in a garden shed to this accuracy
    Do you mean accuracy or precision?

    Either way, this comment demonstrates a clear misunderstanding of averages and statistics. Measuring a single temperature at a single location to this accuracy (or precision) may be difficult. Measuring an average (the sum of many temperatures, regardless of precision, and dividing them by the number of measurements) at one location over an entire single year can be done and can yield a result of greater precision.

    When done over the entire globe, over many years, accuracy and precision can very easily be represented to two decimal places.

    Your (snide) complaint is unwarranted.
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    Moderator Response: Fred, look up the "law of large numbers."
  24. 22, Fred,

    I'd ask that instead of constantly referring people to data and citations using vague words, that you learn to embed links in your posts. Vague statements like "RC wrote many articles" and "Google RayPierre Humbert" and "on the Global Warming at a Glance site" (I get 39,000 hits on that... to exactly which one are you referring?) require too much effort on the part of the reader, and leave the reader to wonder if he has actually found what he was supposed to find.

    You said "Tom, if you read the RSS paper you will find that..." This is similarly vague and unenlightening. Provide a reference to the section that you reference, and if possible extract a quote. As worded, this is again a mere assertion, albeit one with the implication "I know something you don't, but if you knew what I knew you'd agree with me." It is of little value in convincing me that your points are valid.

    To put it another way, your vague references to references for your assertions are themselves assertions and not citations (say that ten times fast without frying your brain)... and they cause me to completely dismiss your statements. If your position were as strong as you imply, it wouldn't be difficult for you to properly support it.
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  25. Folks,

    We have a troll who is determined to try and derail this thread by making numerous off-topic, unsubstantiated, unreferenced remarks and being argumentative., while also ignoring the citations and facts presented to themAnything to distract from the disgraceful behaviour of Mr. Taylor and Dr. Pat Michaels. In fact, they do not seem to have read the OP in its entirety or followed the links provided. This is entirely consistent with people calling themselves "skeptics" when they are not true skeptics at all.

    I strongly encourage people to ignore such disingenuous behaviour and focus instead on the facts at hand. That is, as detailed in the main post, Mr. James Taylor, like Dr. Pat Michaels are wholly unskeptical when it comes to the UAH data. Worse yet,Taylor and Michaels continue to misrepresent, distort and use those data in their ongoing misinformation and PR campaign. While Fred may be OK with that (he has not said anything to the contrary) most of us with a conscience, ethical standards and a humble respect for science will not stand for it.

    Now there are other examples of "skeptics" being unskeptical of the satellite temperature estimates, in particular the UAH data, and i am more than happy to discuss those too.
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  26. Agreed with Albatross @25. The point of this post is not to say that UAH is wrong, the point is that the fake skeptics like Taylor and Michaels (and based on their comments, also Christy and Spencer) have refused to consider the possibility that UAH data could be the source of some of the discrepancy. The post shows that this is probably even the most likely explanation.

    As Michael Hauber noted @21, a true skeptic would consider the possibility that more than one factor could be contributing to the discrepancy, and would certainly not ignore the inconvenient possible explanations. The individuals in question have not behaved as true skeptics.
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  27. (-snipI sit in a London Flat overlooking the River Thames, with a patch of lawn, and the paved Thames Walk between my window and the river. The Thames here is tidal, rising some 40 feet twice a day, and halving its surface area. The flats are built on the site of an old wharf (dock) with its workings and its warehouses long gone.

    Let us go back to the beginning of the 20th century and attempt to measure its surface temperature trend from 1900 to 1997, almost 100 years. To define the temperature we could install a few max/min thermometers close to the foreshore, a few meters above the high water mark, and take the temperature of the water from Putney bridge with a bucket a few times a day (across the oceans they used buckets from ships).

    We would rapidly accumulate a large amount of time series data, moderator, which we could average daily, weekly, monthly, and annually..

    Over time we would have to move the thermometers, the wharf and all the surrounding area would be extensively developed (and re-developed), traffic, trains, and planes would be introduced, and the population would rise at least ten-fold.

    We might also be uncomfortably aware that we have not even attempted to measure the temperature at the actual surface; we are measuring atmospheric temperature with all its wind-based variability. But we can face all that squarely and pass on.

    Over the period, almost a century, we will be looking for the impact of a CO2 increase from about 290ppm to 360 ppm, or 24%.

    What would our results have looked like? How can we possibly tell? As a matter of fact we can get a good idea, because the Central England Temperature record is measured like this, averaged over three sites, without the complication of water.Their trend temperature over the period was 0.54 degrees C per century.

    Did the surface temperature, with all its systematic (not random, Tom) variations, really increase by half a degree? Who knows. It is, at best, suspect.

    We do know that we climbed out of a Little Ice Age over at least half of this period. In the nineteenth century the Thames here frequently froze in the Winter, as did the sea round our coasts.

    If the surface temperature really did increase, what caused it? Was it the CO2 increase (24%)? If we had known this result in 1900, would we have stopped all the development, left our coal in the ground and not looked for oil?
    Will China and India abandon their development today on this kind of evidence? Will the Americans give up their air conditioning?
    -)
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    Response:

    [DB] The subject of this thread is Skepticism About Lower Atmosphere Temperature Data, a discussion of satellite global temperature variations & the misrepresentation of the same by fake-skeptics.

    Off-topic musings on regional and local temperature variations & misc things snipped.

  28. Your comment, Tom, repeats the regular comment at RC that the mid-troposphere satellite record is distorted downwards by stratospheric cooling, and that this cooling is the principal AGW signature.

    If you look at the HADAT charts, you will see that this cooling stopped after the last major volcanic eruption in 1994.

    From your weighting chart (repeating Roy Spencer), the stratospheric temperatures between 10 and 15 kms will affect the satellite readings. From the HADAT data, the overall cooling trends at these altitudes from 1958 to 2010 are:
    9.13 Kms +1.27 degrees per century
    11.74 kms - 0.28 degrees per century
    13.5 Kms -1.02 degrees per century
    15.75 Kms -2.26 degrees per century

    However, the data shows an absence of cooling after the mid-nineties. We can ask, therefore, how far back we must go from the present at these altitudes to detect a significant cooling trend.

    These are the answers:
    9.14 Kms 19 years to significant warming
    11.74 Kms 53 years
    13.5 Kms 52 years
    15.75 Kms 22 years

    So, Tom, if the effect you, and RC, cite so regularly exists at all, it can only ever have been marginal, (at 15 kms) and it ceased about 20 years ago.
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  29. Fred Staples @28, below are the HADAT trends for 1958-2002 (black), 1958-1978 (light blue), and 1979 to 2002 (red) with the 95% confidence intervals marked. I have marked the altitude in Km (to the nearest half km)of the respective pressure gradients for convenience. I have also marked the range of altitudes that contribute information to the TLT channel (dark blue), and the TMT channels (light blue) for convenience. The (unmodified) is figure 10 upper of Thorne et al 2005.



    Several points are worth noting. First, the 5-95% confidence intervals are clearly marked, and show statistically significant cooling between 1978 and 2002 for all altitudes above 12 km, including a significant part of the TMT channel range, and a small part of the TLT channel range. Second, that means your calculated minimum period for statistically significant coolings for 11.74 Km and 13.5 Km are in error. Third, that clearly indicates that over the duration of observations, both the TLT and (particularly) the TMT channels have had tropospheric warming trends reduced or counteracted by including data from the stratosphere.

    The situation is complicated recently (post 2000) for the lower stratosphere as you indicate. During that period, the lowest reaches of the stratosphere have been warming. That may be due to a combination of factors, with stratospheric temperatures being effected not just by CO2 concentrations, but also by ozone concentrations and Aerosol Optical Depth, both of which have varied over that period. It also may be why UAH has been showing higher TLT trends of late. However, it has no overall implication on the 1979 to present trend which, as can be seen above, is still strongly negative over that period for the lower stratosphere including those levels of the stratosphere included in the TLT channel.
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  30. I use the data, Tom, not the charts, which stop at 2002. However, the charts are interesting. Consistently significant cooling at all altitudes between 1958 and 1978, before the satellite data.

    We are discussing the impact on the satellites’ field of vision of the stratospheric temperatures. The weights of the relevant altitudes are shown on Roy Spencer’s chart, at your post no. 20.

    So, what does the TMT blue line see of the stratosphere? We are looking for the altitude at which the relative area under the blue line ceases to be significant. Would you agree that there is nothing significant above 15 kms, and little above 10kms, the point where the stratosphere might be said to commence?

    If so, Tom, you can download the HADAT data and repeat my calculations with EXCEL. My results have surprised you, so you suggest that they are in error. You will find that you are wrong.

    There has been no significant cooling for more than 50 years at 11.74 kms, which is the most influential altitude. At 15.75 kms the cooling has been more pronounced, but you still have to go back 22 years to achieve significance.

    What can we conclude from these facts. At the higher level the effect on the TMT line is marginal, both as to the trend itself and its possible impact. At the higher impact level, 10kms, there is almost no cooling trend. In between, a cooling trend of 1.0 degrees per century, but nothing significant for 50 years.

    So Tom, if your second and third points (29) are wrong, why (on what grounds) do we reject the mid-troposphere satellite data?.
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  31. Fred Staples @30, are you suggesting that the Hadley Center did not use the data in constructing the graph?

    Regardless you are using a very simplistic analysis. By eye, the weighting function above 10 Km of the TMT channel represents approximately one quarter of the channel weight. I will use 0.2 to be conservative. From 1979-2002 the positive trend over the altitude range of 0-10 Km has been 0.1 C per decade according to HADAT. Over the same period, the average over the range 10-20 Km has been around -0.5 C per decade. The effect is then that over the whole channel the trend is (-0.5 x 0.2) + (0.1 x 0.8) = -0.1 + 0.08 = -0.02.

    These figures are of course very inexact. They merely serve to show that looking solely at the relative area of the weighting function to determine the effect on the trend is a gross distortion.

    It may require 22 years to find statistically significant cooling at 15.75 Kms, but it is still a cooling trend, and a larger cooling trend than the warming trend in the troposphere. Therefore it significantly distorts the TMT channel as a measure of tropospheric temperature trends. Pretending otherwise is nothing but wishful thinking.
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  32. Sorry, Tom, but you can’t make a trend significant by printing in bold. Over 18 years, the trend at 15.75 kms is warming, not cooling, but not significantly so.

    So, I ask again, on what grounds do we reject the mid-troposphere data.
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  33. This paper may shed some light on the uncerainty of lower Trop and Strat temperature trends:

    Strat Trop temp trends etc

    Another paper to go with the above. I think a person needs to read the above paper first to understand the conclusions of this paper:

    Trends not matching CCM's
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  34. Fred Staples @32, I notice that you:

    1) You are asserting that a microwave channel which measure microwaves over a 20km altitude band accurately measures the temperatures of just an 8 km altitude band, and that the effect of the other 12 km in no way effects the temperature measured by that channel. That is a startling claim, but you sole defense of that claim is to insist that your protagonists have the burden of proof to disprove your claim; and that if they do not disprove it, not just on balance of probabilities which I have done, but beyond reasonable doubt, then you purport that the failure to disprove the claim beyond reasonable doubt establishes your claim as true. That does not constitute scientific argument on your behalf, but a silly rhetorical game for which I have no more time nor patience.

    2) You are further asserting that temperature trends measured over 30 plus years using the TMT channel cannot be effected by stratospheric cooling because the stratospheric cooling is not statistically significant for periods less than 22 years. I note the obvious that 30 years is greater than 22 years, so that your point is in fact irrelevant. Indeed, it amounts to little more than a verbal shell game in which you raise any objection regardless of whether it establishes your case, or disproves your opponents argument. There is no point in discussing anything with a person who takes that approach.

    The relevant information has been sufficiently canvassed above. If anybody is uncertain as to whether the TMT channel gives an accurate measure of temperature changes solely over the middle troposphere (2-10 km altitude), they are welcome to reread it. But I am not going to endlessly reargue the case with you as you evidently have nothing intelligent to contribute to such a discussion.
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  35. Camburn @33, I notice that your "descriptions" of the content of your links is so uninformative it could have been written by a bot. As such I believe it to violate the comments policy, specifically the requirement that:

    "No link or pic only. Links to useful resources are welcome (see HTML tips below). However, comments containing only a link will be deleted. At least provide a short summary of the content of the webpage to facilitate discussion (and show you understand the page you're linking to). Similarly, images are very welcome as they can be very useful in explaining the science. But comments with pictures in isolation without explanation will be deleted."

    (My underlining.)

    I therefore request that you provide a summary of the content of the two papers to which you linked, and how the relate to the ongoing discussion.
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  36. Camburn#33: It is also helpful if you note the age of your cites. These papers are from 2009 and are therefore not news; they may not even be shedding any valid light on current trends.
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  37. Tom@35:
    Instead of discussing my posting skills, why not discuss the findings of the papers.

    nuoncounter@36: I will try to do so in the future. I have not noted any papers since the two that I posted that have changed the conclussions of the above papers.

    Do you know of any that disagree with the findings?
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    Moderator Response: [Dikran Marsupial] The comments policy does indeed forbid link only posts, and a substantive description of the content provided by the link is required. In future, please provide your interpretation of the evidence provided by the referenced material and explain how it is relevant to the discussion. This will encourage others to discuss the findings of the paper.
  38. Camburn @37, I have often noticed that you have a modus operandi of providing a small link or undefended disparaging comment on the topic of any given post, thereby imposing a significant argumentative burden on those who wish show that the evidence in your links is irrelevant/off topic/ or just plain wrong. I do not have time to waste on those games of yours. Consequently I will simply point out where those comments or links violate the comment policy.

    If you actually want to discuss the topic, do so in good faith and take up the burden of explaining your sources, and showing the relevance to the topic. If in your opinion the sources are not worth that effort, I will take you opinion of their worth at face value and treat them as irrelevant to the discussion.
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    Moderator Response: [Dikran Marsupial] The point has been made, please lets go back to the science. I am sure that Camburn is now aware of the comments policy on this issue and will conform to it in future. Any further contravention of the comments policy will result in posts being deleted.
  39. Dikran Marsupial:
    I shall do so in the future. I was pressed for time yesterday, and had reviewed the papers I posted not to long ago. They do add to the disucssion.

    Thank you for explaining the policy.
    0 0
    Moderator Response: [Dikran Marsupial] No problem. If in doubt, this format ought to be safe: (i) make an assertion, (ii) provide link, (iii) explain how the link supports assertion.

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