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Climate scientist bashing

Filed under: — stefan @ 7 April 2010

A new popular sport in some media these days is “climate scientist bashing”. Instead of dealing soberly with the climate problem they prefer to attack climate scientists, i.e. the bearers of bad news. The German magazine DER SPIEGEL has played this game last week under the suggestive heading “Die Wolkenschieber” – which literally translated can mean both “the cloud movers” and “the cloud traffickers” (available in English here ). The article continues on this level, alleging “sloppy work, falsifications and exaggerations”. By doing so DER SPIEGEL digs deeply into the old relic box of “climate skeptics” and freely helps itself on their websites instead of critically researching the issues at hand.

As a scientist I do not have the time to dedicate a whole day to one article and to do much research on it, which is why I here discuss only a few of the most obvious flaws and distortions of facts in this story.

Temperature data

Cynically and inhumanely the article sets off with remarks on our British colleague Phil Jones. The authors extensively revel in sentences like this:

He feels a constant tightness in his chest. He takes beta-blockers to help him get through the day. He is gaunt and his skin is pallid.
Jones is finished: emotionally, physically and professionally. He has contemplated suicide several times recently.

And this is the result of a media campaign consisting of precisely such poorly researched and fact-twisting articles as this one, for which Marco Evers, Olaf Stampf and Gerald Traufetter are responsible.

What is first greatly hyped is then gleefully destroyed. According to DER SPIEGEL “the entire profession” of climate science “based much of its work on his [Jones’] research” and “almost every internal debate among the climate popes passed through his computer”. Now it happens that I, most likely not an untypical example, have never worked with Jones’ data and have only exchanged a handful of emails (out of tens of thousands every year) with him, although I do probably count as part of the “profession”. There is a whole set of other data of global temperature, e.g. the data from NASA which is based on weather stations (and which I prefer for various reasons) or data from NOAA or the satellite data from RSS or the UAH. As is always scientifically useful, important conclusions are based not on one single set of data but on the fact that a whole range of competing scientific groups find consistent results, using different methods (see Figure).

Global mean temperature (annual means) according to the 5 most often used data sets. The graph shows the deviation from the mean of the last 30 years, as well as the linear trend over the last 30 years. The data from the Hadley Center, NASA and NOAA use measurements from surface weather stations, each with its specific method of quality control (e.g. correction for heat island effects) and interpolation and spatial integration. Independently, the satellite data from RSS and UAH (available from 1979 onwards) provide two different analyses based on the same microwave raw data. These measure the temperature of the middle troposphere, the variations of which can differ from those of the surface temperatures on short time scales. The record El Niño year of 1998 is an example. It has caused a greater temperature anomaly in the troposphere, presumably as warm air rising in the tropics spread in middle altitudes. The climatic trends, however, do not differ significantly since on longer time scales the surface and tropospheric temperatures are closely coupled due to turbulent mixing processes.

The quality of raw data from worldwide weather stations and vessels is indeed often unsatisfactory, especially if one goes further back in time – after all they were gathered to help forecast the weather and not to determine long-term climate trends. However, the error margin has been carefully analyzed – as is standard in science – and is shown in the temperature graphs on the Hadley Center´s website as well as in the IPCC report, and to date there is no reason to assume that the actual temperature evolution lies outside these error margins – the more so as the satellite data correspond well with the ground data. Whether the global warming trend was 0,15 or 0,17°C per decade in the past decades is of no relevance to any practical concerns.

IPCC-Figure of global mean temperature 1850-2005 (Fig. TS6).

According to DER SPIEGEL Jones has erased raw data and is “an activist or missionary who views ‘his’ data as his personal shrine” who “is intent on protecting it from the critical eyes of his detractors”. However, Jones is neither the producer and owner nor the archivist of these data – it is simply data from the national weather agencies, who also are responsible for its archiving or for the question to whom and under what circumstances they may be passed on. The majority of these data is freely accessible online. However, some weather services do not allow their data to be passed on because they sell such data. Other scientists have compared the CRU-data with freely available raw data from weather stations. And at NASA one can find the computer algorithms which are used to calculate the global mean temperature, publicly available for everybody. There is hardly any other scientific field in which more data and computer codes are freely accessible than in climate science (e.g. also codes and data of my current papers on sea level rise in Science 2007 and PNAS 2009). Do for example economists, on whose advice many political decisions depend, disclose their raw data and the computer codes of their models?

The British House of Commons has just published the report by the committee which has been appointed to examine the accusations made against Phil Jones. The report concludes:

The focus on Professor Jones and CRU has been largely misplaced. […] The scientific reputation of Professor Jones and CRU remains intact.

The fact that Jones has been rehabilitated will be welcomed by all those who know this decent, always helpful and universally well-liked scientist. For the general public the conclusions on his scientific findings will be even more important:

Even if the data that CRU used were not publicly available-which they mostly are-or the methods not published-which they have been-its published results would still be credible: the results from CRU agree with those drawn from other international data sets; in other words, the analyses have been repeated and the conclusions have been verified.

The ever-popular “hockey stick” discussion

DER SPIEGEL resurrects one of the oldest shelf-warmers of the “climate skeptics”: the hockey stick debate and a series of flawed accusations with it. The so-called “hockey stick” is a temperature construction for the Northern Hemisphere for the last millennium published by Michael Mann, Ray Bradley and Malcolm Hughes in 1999, of which DER SPIEGEL writes that the Canadian Steve McIntyre unmasked it as “a sham”. (And this is the only clue within the whole article pointing to the alleged “falsifications”). This is not true. Even a committee of the National Academy of Sciences looked in 2006 at the accusations made by McIntyre and has cleared the authors of all suspicions.

Raw data and computer codes of the “hockey stick” are online and publicly available, and independent scientists have recalculated everything years ago using their own codes (also available). The current IPCC report from 2007 shows in Fig. 6.10 these reconstructions together with a dozen more which have meanwhile been added; the Copenhagen Diagnosis published in 2009 shows some even more recent ones in Fig. 19 (page 43). All show consistent results, not in detail but in their fundamental aspects. This is why the conclusions drawn in the IPCC report of 2007 were stronger than back in 2001, when the “hockey stick” had been shown for the first time. The IPCC report 2007 concludes:

Palaeoclimatic information supports the interpretation that the warmth of the last half century is unusual in at least the previous 1,300 years. [Summary for Policy Makers, S. 9]

In the third report from 2001 such a statement had been made only for he last 1000 years.

All reconstructions – with or without using tree-ring data – agree that the temperature in the Northern Hemisphere (for the Southern Hemisphere insufficient data existed until recently) is higher today than in medieval times. DER SPIEGEL simply claims the opposite:

There are many indications that in medieval times, between 900 and 1,300 A.D., when the Vikings raised livestock in Greenland and grape vines were cultivated in Scotland, it was in fact warmer than it is today.

No scientific evidence in support of this claim is mentioned. Locally – in the North Atlantic region – climate reconstructions do indeed show higher temperatures than today (see Fig.); hence there is no contradiction to the anecdotal evidence about Greenland and Scotland.

Temperature difference between the middle ages (years 950 to 1250) and the modern period (years 1961 to 1990) according to a reconstruction by Mann et al. 2009. The grey shadinghatching shows regions with statistically significant results.

Incidentally, looking at the forcings, it would be surprising if it had been warmer in medieval times than now. Forcings are the factors which affect the global radiation budget of the Earth, such as variation of solar activity, volcanic eruptions or changes of the amount of greenhouse gases in the atmosphere. If we compute the temperature evolution from the known forcings over the last thousand years, the result is consistent with the temperature reconstructions mentioned above. Merely one (in the meantime corrected) model simulation by Zorita and von Storch is an exception. These model calculations (18 in total) are compiled and compared with data in the IPCC report in figures 6.13 and 6.14 .

Only by looking at the forcings can one draw conclusions about the causes of global warming – the fact that currently it is unusually warm does not by itself tell us anything about the causes. If only natural and no anthropogenic forcing existed it would be much colder now than in medieval times.

The hockey stick debate exemplifies how the „climate skeptics“-lobby has tried to discredit an inconvenient scientific finding over the course of many years, without success. The scientific conclusions have proven to be robust.

Tropical storms

Under the subheading “The Myth of the Monster Storm” the SPIEGEL article reports on a “hurricane war” amongst US climate scientists:

The alarmists, using the rhetoric of fiery sermons, warned that Katrina was only the beginning, and that we would soon see the advent of superstorms of unprecedented fury. Members of the more levelheaded camp were vehemently opposed to such predictions and insisted that there was no justification for such fears.

Sadly, no example for the “rhetoric of fiery sermons” is quoted. “Levelheaded” is the well-worn SPIEGEL-parlance for describing anyone who downplays climate change, regardless of whether their claims are scientifically well-founded.

Then a recent study from Nature Geoscience is cited which allegedly announces “the all-clear signal on the hurricane front” and which signifies “another setback for the IPCC”. This is because “the IPCC report warned that there would be more hurricanes in a greenhouse climate”. Let us simply quote from the abstract of the new study:

Future projections based on theory and high-resolution dynamical models consistently indicate that greenhouse warming will cause the globally averaged intensity of tropical cyclones to shift towards stronger storms, with intensity increases of 2-11% by 2100. Existing modelling studies also consistently project decreases in the globally averaged frequency of tropical cyclones, by 6-34%. Balanced against this, higher resolution modelling studies typically project substantial increases in the frequency of the most intense cyclones, and increases of the order of 20% in the precipitation rate within 100 km of the storm centre.

Long story short, fewer but heavier tropical storms can be expected. By the way, the potential destructiveness of storms increases more steeply than the wind velocities; a 2-11% higher speed means a 6-37% higher destructiveness. (Emanuel 2005).

And what did the IPCC report have to say on this topic?

Based on a range of models, it is likely that future tropical cyclones (typhoons and hurricanes) will become more intense, with larger peak wind speeds and more heavy precipitation associated with ongoing increases of tropical sea surface temperatures. There is less confidence in projections of a global decrease in numbers of tropical cyclones. [Summary for Policy Makers, page 15.]

Long story short, fewer but heavier tropical storms can be expected, even if there was still less confidence about the first aspect at the time. The WMO, whose expert group has published this study, consequently describes the result as follows:

Substantial scientific progress has led the Expert Team to raise their confidence levels on several aspects of how tropical cyclone activity may change under projected climate scenarios.

This means: there is no reason for speaking of a “setback” in a “war”; rather the early findings of the IPCC report have been given a higher confidence level. The SPIEGEL story on this issue falls into a category of false allegations against IPCC mentioned by us already in February, namely those which can be falsified by simply reading the report (in this case even a quick look at the Summary for Policy Makers would have sufficed).

IPCC mistakes

According to DER SPIEGEL “more and more mistakes, evidence of sloppy work and exaggerations in the current IPCC report are appearing”. We already investigated this and came to the conclusion that of the mistakes discussed excitedly in the media, nothing much remains except for the Himalaya mistake. The SPIEGEL does not have anything else to offer either – it counts “Jones’ disputed temperature curve” as one of them; apart from that “the supposed increase in natural disasters” – wrongly so as we have already showed (in German) reacting to an article published in Die Welt which claimed the same.

DER SPIEGEL elaborates on the story of the alleged “phantom graph” by Robert Muir-Wood which we have explained there as well. According to DER SPIEGEL, Roger Pielke “tried to find out where the graph had come from” and “traced it” to Robert Muir-Wood. This must have been hard indeed, given that Muir-Wood, who provided the graph, is named by the IPCC in the figure caption. The only difficult thing is to find this graph (which incidentally is correct but not very informative) at all: other than DER SPIEGEL claims, it is not in the IPCC report itself but only provided as “supplementary material” on its website, where the IPCC publishes such background material. Although on the 3,000 pages of the report there was no space for it, the graph now seems to be important to SPIEGEL readers for reasons unknown.

What is it all about?

SPIEGEL defames some of the best scientists worldwide, who not least for this reason have become prime targets for the “climate skeptics”. If you look at publications in the three scientific top journals (Nature, Science, PNAS), the just 44-year-old Mike Mann has already published 9 studies there, Phil Jones 24 (comments, letters and book reviews not included). In contrast, DER SPIEGEL always calls upon the same witness, the mathematician Hans von Storch, who has published only a single article in the prime journals mentioned (and that was faulty). But he says the politically wanted thing, even if without any supporting evidence from the scientific literature: in his view we can easily adapt to climate change. He also publicly accuses the vast majority of his colleagues who disagree with him of alarmism, calls them “prophets of doom” or “eco-activists” who indoctrinate the public. He also insinuates political or financial motives for disseminating horror scenarios. In this article he says things like “unfortunately, some of my colleagues behave like pastors, who present their results in precisely such a way that they’ll fit to their sermons”. This quote matches the article´s inflationary usage of the words “guru” “popes” “fiery sermons” “missionaries” and so forth. And he goes on: “It’s certainly no coincidence that all the mistakes that became public always tended in the direction of exaggeration and alarmism.” The following statement would have probably been more correct: it is certainly no coincidence that all the alleged errors scandalized in the media always tended in the direction of exaggeration and alarmism.

It is obvious that DER SPIEGEL does not care about science. This really is about politics. This year will decide about the future of the German climate policy: in the fall the government will announce its new energy strategy. This will decide whether the energy transformation towards a sustainable electricity supply, increasingly based on renewables, will be pushed forward or thwarted. In a global context the issue is whether global warming can be limited to a maximum of 2 ºC, as the Copenhagen Accord calls for, or whether this opportunity will be lost. The power struggle on this issue is in full gear. The energy transformation can best be prevented by creating doubts about its urgency. The fact that scandal stories about climate science have to be invented to this end just proves one thing: good, honest arguments against a forceful climate policy apparently do not exist.

p.s. (26 April): It’s just a curiosity, but telling: DER SPIEGEL calls Pachauri’s novel “Return to Almora” an “erotic novel”. The novel follows the life story of Sanjay Nath, from a childhood in the 1950s in the Himalayas through decades spent in the US building up a chain of meditation centers, until his final return to the Himalayas at age 60. The 400-page book contains a handful of love scenes, only gently hinted at in a few sentences. Calling this an “erotic novel” is devious; it can only serve the purpose of letting Pachauri appear in a dubious light.

Correction: As Roger Pielke has pointed out to us, the Supplementary Material to the IPCC reports is not only available on the IPCC website, but also on a CD-ROM distributed with the printed books.

[This piece is a translation of an article that originally appeared in German on the KlimaLounge weblog.]


Emanuel, K., 2005: Increasing destructiveness of tropical cyclones over the past 30 years. Nature, 436, 686-688.

Knutson, T. R., J. L. McBride, J. Chan, K. Emanuel, G. Holland, C. Landsea, I. Held, J. P. Kossin, A. K. Srivastava, and M. Sugi, 2010: Tropical cyclones and climate change. Nature Geoscience, 3, 157-163.

Mann, M. E., R. S. Bradley, and M. K. Hughes, 1999: Northern hemisphere temperatures during the past millennium: inferences, uncertainties and limitations. Geophysical Research Letters, 26, 759-762.

Mann, M. E., Z. Zhang, S. Rutherford, R. S. Bradley, M. Hughes, D. Shindell, C. Ammann, G. Faluvegi, and F. Ni, 2009: Global Signatures and Dynamical Origins of the Little Ice Age and Medieval Climate Anomaly. Science, 326, 1256-1260.

517 Responses to “Climate scientist bashing”

  1. 451
    Jim Eager says:

    “So let’s stop with the “flat” moniker, hmm?”

    Fine by me, I didn’t and don’t use it.

  2. 452
    Brian Dodge says:

    “but then in the summer the ice melts instead of radiating heat” Septic Matthew — 13 April 2010 @ 6:56 PM
    Nope. If it’s melting, it’s warmer, and radiates more – Stefan Boltzmann law, grey body generalization – see
    “Water, ice, and snow generally have a high emissivity, 0.94 to 0.99, across the thermal infrared region. Snow is unusual in that it has a high reflectance in the solar (visible) region where most of the downwelling energy is during the day, and a very high emissivity in the thermal region.” Wet snow is less reflective, so when the temperature reaches this threshold, more visible wavelength energy gets absorbed, accelerating the melting -“Soot absorption causes the melt season on glaciers to begin earlier and last longer. This has a large impact, because wet snow is much darker than dry snow.” Also, since the energy(mostly) goes into melting instead of raising the temperature, the emitted energy doesn’t change – all the additional absorbed energy goes into melting ice as long as it’s available.

  3. 453
    Andreas Bjurström says:

    “Instead of dealing soberly with the climate problem they prefer to attack climate scientists, i.e. the bearers of bad news. ”

    Climate scientists are bearers of many things, including news and personal opinions. Why don´t YOU want to deal soberly with this? Why reduce the climate problem to only its physical basis? You don´t find the badness there, badness is a value, and you are the bearer of that value …

  4. 454
    Geoff Wexler says:


    in the summer the ice melts instead of radiating heat
    The law was derived (IIRC) for radiation from a cavity of a black body.

    You are right about the derivation of the law which refers to the radiation inside the cavity at equilibrium. Rippling of the walls is irrelevant. Next step is to use it to deduce radiation from the walls required to balance radiation striking the walls. Now break open the cavity and place its walls on the ground. This has no effect on the radiation from the walls , (at a given temperature) even though the system is no longer at equilibrium; and this includes the possibility of evaporation and melting. Its the emissivity which counts and this tends to be nearly 1 (I think) in nearly all cases for infra-red (but not for gases).
    Report from Royal Society’s Inquiry out to-day.

  5. 455
    Geoff Wexler says:

    My Previous comment.

    The blockquote should have been restricted to the first five lines (including the….).

  6. 456

    wilt (410): I know of no method of attributing warming to various individual factors and feedbacks, either positive or negative.

    BPL: It’s called “analysis of variance.”

  7. 457
    Bob says:

    436 (wilt),

    It’s only an impression, but I get the feeling that you are putting far more weight into the Solomon paper than it deserves. You seem to interpret a “most” statement by the IPCC as if “most” means 99%, yet you also seem to latch onto the 30% figure as if it so greatly minimizes the effects of GHG as to think that you don’t need to worry about it. All of this, to me, demonstrates a strong tendency to see what you want to see all from one single paper that discusses one unexpected observation in the stratosphere.

    Your statement that stratospheric warming “must probably be looked upon as an independent effect (at least independent from CO2)” again appears to demonstrate a personal bias and wishful thinking, rather than any foundation in fact. Why “must probably?” What logic leads to that conclusion? See the quote below taken from another commentary on the paper.

    Water vapor is formed through evaporation from the Earth’s bodies of water. A key factor that affects how much water vapor enters the stratosphere is the coldest temperature that air encounters as it rises from the Earth.

    Most of this upward movement occurs in the tropics—a region where “cold point” temperatures have dropped in the past decade.

    As a result of these lower temperatures, less water vapor ended up in the stratosphere. That, in turn, helped lower the warming rate, the study concludes.

    What might have caused the “cold point” temperature changes? Any chance it could have been climate change induced by CO2? Yes. It definitely warrants further study.

    I do think that you should also recognize that the amount of warming seen from 1980-1996 was only a small fraction of the warming that is resulting from CO2 (the planet doesn’t heat instantly), so the 30% estimate does not cut the total impact of warming we are going to see by 1/3, or in any way suggest a reduction in climate sensitivity. It just added to the warming seen for 16 years, then subtracted from it for 10 years, introducing some variability, but not affecting the total, final amount.

    It’s more like a person with a $50K a year salary and a gambling problem. Their salary will stay at $50K, but their monthly income will vary with their winnings and losings.

    At a minimum you should look at the skeptical science take on it.

  8. 458
    Geoff Wexler says:

    More on melting ice , evaporating water and Stefan- Boltzmann (SB).

    I should expect that the infra-red (IR) photons would emerge from a thin surface region in which they were in equilibrium with the phonons (vibrations) in the ice or water. The phonons have the temperature of the melt , say 0 degs.C and share it with the photons which would emerge as a normal Planck distribution at 0 degs.C.

    Since the water and ice are nearly black for IR , the SB result would still be valid. I have been a bit speculative and know nothing else about it, in particular whether anyone has thought it worth while to check experimentally.

  9. 459
    t_p_hamilton says:

    Andreas said:”Climate scientists are bearers of many things, including news and personal opinions. Why don´t YOU want to deal soberly with this? Why reduce the climate problem to only its physical basis? You don´t find the badness there, badness is a value, and you are the bearer of that value …”

    Coroner reports of a determination of murder do not include the value judgement that murder is bad.

  10. 460
    Rod B says:

    PS to my 449: To clarify, as Brian Dodge points out, whether something reflects and does not absorb/radiate much, or vice versa, depends on the wavelength. Ice is a bad emitter/absorber in the visual, pretty good in the infrared.

  11. 461
    wilt says:

    Double correction:
    Barton Paul Levenson wrote (#457):”
    “ wilt (410): I know of no method of attributing warming to various individual factors and feedbacks, either positive or negative.”

    I have never written the words that BPL puts in my mouth here. They come from a comment by Bob (#389).

    2. Then Completely Fed Up (#461) found it necessary to repeat this (wrong) citation. He added some words of his own, apparently in an effort to discredit me. Needless to say that there is no basis for what Completely Fed Up wrote.

    Concluding remark: we could gain so much time if people just would carefully read first before they start to formulate a comment.

  12. 462
    wilt says:

    In order to prevent further confusion about what I wrote 14 April 12:13 PM: Barton Paul Levenson made his comment 14 April 5:08, the present number is #456. The comment of Completely Fed Up mentioned in my remarks apparently has been removed in the meantime by the moderators (for which I express my gratitude).

  13. 463
    CM says:

    > Coroner reports of a determination of murder do not include the
    > value judgement that murder is bad.

    Corollary: … but most coroners would in fact say that murder is bad, the more so because they see its grisly effects every day, and yet for some reason, there is no campaign of “murder skeptics” attacking coroners for their lifeist bias.

  14. 464
    Doug Bostrom says:

    wilt says: 14 April 2010 at 12:30 PM

    Got a flow chart on that?

  15. 465
    wilt says:

    Bob (#457), you asked me to explain my statement that stratospheric warming must probably be looked upon as an independent effect (at least independent from CO2). This statement is not based on wishful thinking as you suggest, but rests on the observations in Solomon’s article. The water vapor in the stratosphere increased during 1980-2000 but then decreased during 2000-2009. As we both know, CO2 was increasing during all those years, at approximately the same rate per year. So even if you would be right that the increasing CO2 caused the “cold point” temperature changes you refer to, why would this reverse all of a sudden in 2000 whereas CO2 kept on increasing?
    “The planet doesn’t heat instantly”, you wrote. But you seem to be familiar with the important facts, so you know that most of the temperature rise in recent decades was not between 1950 and 1975, or between 1995 and 2010, but in the years 1975-1995. If the water vapor changes added about 30% during 1980-2000 and caused a decrease of 25% in 2000-2009 then overall it has definitely affected the total, final outcome. To me, that strongly suggests that the attribution to CO2 may be lower than previously thought.
    Finally, I would like to respond to your remark “You seem to interpret a “most” statement by the IPCC as if “most” means 99%, yet you also seem to latch onto the 30% figure as if it so greatly minimizes the effects of GHG as to think that you don’t need to worry about it.” Of course I realise that ‘most’ was never meant as 99%, there are several other important drivers of temperature increase (for instance black carbon). For that reason, I would not claim that the CO2 effect was one-third lower. But I remain convinced that the water vapor changes had a significant effect, making it in my view even less likely that 3 degrees is the correct value for climate sensitivity. That does not mean there is nothing to worry about. I have not suggested here or elsewhere that there is no effect of CO2. I am just trying to find out how large the effect is, with respect to temperature and with respect to temperature related effects like sea level rise. And somehow I have the idea that you are trying to do exactly the same thing.

  16. 466
    Completely Fed Up says:

    “This statement is not based on wishful thinking as you suggest, but rests on the observations in Solomon’s article.”

    Which is rather wishful thinking that Solomon’s article is right and 99.99% of the other papers wrong.

    Since trapping heat in the troposphere reduces flux to the stratosphere on it’s way to the exosphere, why do you consider it to be independent of CO2?

    And YOU answer it, wilt. Don’t pass it on to Solomon, he’s quite capable of writing here himself. YOU’RE pushing it as a reason why you made your statements and have asserted it’s from real consideration rather than wishful thinking.

    Therefore you MUST have understood.

    ‘else it’s just wishful thinking that one paper is right.

  17. 467
    wilt says:

    Final correction with respect to: “Completely Fed Up says:14 April 2010 at 1:13 PM”
    The links you are providing here now were not part of your previous comment that has briefly been displayed before it was removed. You know this, I know this, the moderators know this, and those people who happened to read that previous comment before it was removed know this. ‘Keep it classy’, you wrote. I will do just that, and waste no more words on this.

    [Response: And on that note, all other non-substantive wastes of time will be deleted.–Jim]

  18. 468
    Brian Dodge says:

    The nail in the coffin of “the MWP was a natural global phenomenon where temperatures were as high or higher than today” is provided by Dr. Roy Spencer on his blog. He makes the argument that rising temperatures driving exsolvation of CO2 from the oceans account for about 80 PPM of the CO2 rise we have seen (posts at and
    If one accepts this (and I do, I do; honest I do &;>) then the lack of CO2 increase during the alleged MWP ( is not just a nail in the coffin but a stake through the heart of claims that the MWP was global, They may have been farming in Greenland, or growing grapes in Gloucestershire, but the seas weren’t warming and wafting CO2 into the air.

  19. 469
    David B. Benson says:

    Assume my previous model of ocean CO2 resevoir with maximum amplifying feedback and a forcing of I9t) = cos(at). The response is

    O(t) = cos(at) + (1/a)sin(at)

    so the lower the frequency a = 2.pi.f the larger the amplification (and the longer the phase lag). So while eccentricity is a quite small orbital forcing, the period is so long that the amplification is about 16. So maybe eccentricity helps explain the long cycle glacials of the last 1.1 million years.

  20. 470
    Bob says:

    I don’t know if anyone is still following this thread. In looking at the Solomon and the Paltridge papers at the same time, and then studying some theories on how the water vapor changed in the stratosphere, atmospheric physics, etc…

    Has anyone considered that the observations in the Solomon paper go hand in hand with the Paltridge paper? That is, if we expected water vapor to increase in the mid to upper troposphere, and it didn’t, it dropped… but water vapor also increased in the stratosphere… doesn’t it make sense that the planet warmed, and the extra evaporation happened, but the water vapor didn’t wind up where it was expected? Changes in atmospheric patterns lead to more mixing than expected, with the end result that the mid to upper troposphere became mildly drier, while the stratosphere became much wetter.

    Following this line of reasoning, is it possible that cause and effect for the behavior seen since 2000 is reversed? That is, instead of the drop in water vapor in the stratosphere contributing to the lack of warming, the water vapor in the stratosphere dropped (at least partly) because of the lack of warming. [Of course both could be true to varying degrees, but is the basic idea sound?]

    In the end, this would mean that the “total” water vapor feedback in the system is roughly as expected, but may take place in the stratosphere rather than the mid to upper troposphere. Worse than that, depending on how the system ultimately “fills out,” if the stratosphere gives the water vapor “some place else to go,” it may ultimately take more evaporation to fill the pot, so to speak. That is, the final water vapor in the atmosphere may increase in both the troposphere and the stratosphere, once the system reaches some sort of equilibrium, so that final climate sensitivity is dangerously in excess of 3˚C due to even more water vapor heating than currently expected.

    It would be interesting to work up a “water vapor” budget, based on expected evaporation (using temperature over water covered grid cells), measured or modeled precipitation, and measurements of humidity throughout the atmosphere, to see if it balances. Or is such a thing really beyond our current capabilities?

    Is anyone who knows of what they speak able to comment on any of this?

  21. 471
    Rod B says:

    Brian Dodge (468), you raise an interesting parameter. But I’m a bit confused. Are you saying the lack of CO2 increase shows the MWP was not global? Or that it shows the MWP did not exist anywhere – despite the temp readings…?

  22. 472

    “. . . don’t pass it on to Solomon, he’s quite capable. . .” (@466)

    I believe you have the wrong pronoun, sir. Susan Solomon, isn’t it?

  23. 473
    Marco says:

    @Brian Dodge:

    Amazing model Spencer makes. But he completely fails to explain how the atmospheric CO2 is increasing at a *slower* rate than the amount we’re putting in. He mentions this little inconvenient factoid in the start, and then completely ignores it in the end.

  24. 474

    wilt at 461,

    I apologize for misattributing the quote.

  25. 475
    Brian Dodge says:

    “Are you saying the lack of CO2 increase shows the MWP was not global?” Rod B — 14 April 2010 @ 2:06 PM
    Yes, since the SST was not warm enough over large enough area(s) to increase CO2, and the sea covers ~2/3 of the globe. As Eric said, it “…is shown to be largely a regional phenomenon”, and Bob said “The periods labeled as the MWP can vary by as much as a half a millennium from one study to the next”: I would add that many papers show cold periods at the same time as others show warming
    “The high-elevation site chronologies were characterized by common long-term variability, with high values centered around the 11th and 12th centuries and low values during the beginning of the longer records (8th–9th centuries).”
    “a warmer period prevailed in the NE Caribbean from AD ~700-950.” Nyberg et al 2002 “A centennial-scale variability of tropical North Atlantic surface hydrography during the late Holocene”
    If you download the data from, and plot the delta 18O for the last 2000 years, maybe ~850-950 shows a consistent warm bump, but mostly the data are up and down.

  26. 476
    wilt says:

    BPL (#474): apology accepted, no problem.

  27. 477

    Rod (445): NO ONE has EVER measured (or even observed) the global temp increase caused by CO2 going from 400 to 800ppmv.

    BPL: Unless you think that transition is governed by different physical laws than the one governing other such transitions which we HAVE measured, your observation is pointless cherry-picking.

  28. 478

    Rod (449),

    Ice is reflective in visual wavelengths, not IR.

  29. 479
    Completely Fed Up says:

    “Or that it shows the MWP did not exist anywhere – despite the temp readings…?”

    Uh, the temp readings do not show MWP was global and tend to show that that it was NOT global.

    The global CO2 measure also shows that the MWP was not global.

    You seem to be trying to create an internal inconsistency in Brian’s message that doesn’t exist.

    And adding in “anywhere” is a strawman you’ve made up, by the way.

  30. 480
    Septic Matthew says:

    Rod B. and David B. Benson, thanks for the comments. I expect that we’ll meet again on other threads.


  31. 481
    Bob says:

    465 (wilt),

    I think my problem with your approach is that just because CO2 increase is linear, that does not mean that changes in temperature, water vapor, or any other aspect of the earth system must also be linear to have been caused by CO2. There is obviously a complex interplay of factors, so counter-intuitive or at least less than obvious events can occur.

    I also disagree with your statement that most of the warming has been from 1975-1995. On the contrary, when looking at the satellite record (see a great amount of the warming (all, if you let yourself be fooled by Dr. Spencer’s graphing tricks) is from 1995 to the present.

    Given this… that changes are non-linear, and warming has been fairly evenly if very erratically distributed over the last 30 years, I see no reason at all why changing events, primarily instigated if not directly caused by CO2, could not result in an increase in stratospheric moisture for 15 years, then a surprising drop for another 10.

    See changes in Hadley cells for one example.

    Stratospheric Humidity and Climate Sensitivity for another.

    Look here for the paragraph on “Why did stratospheric water vapor drop in 2000?” to see one possible connection.

    As always, Eli has a pretty educational write up here, and Eli talks about himself in the third person, which is always unsettlingly cool.

    I’m not saying that it’s likely, or unlikely. I’m saying that the Solomon paper pointed to something unexpected, and it’s overreaching, to me, to use that observation to draw any conclusions whatsoever about climate sensitivity (which is where this whole line of conversation began).

  32. 482
    Rod B says:

    CFU (479), how exactly would you expect temperature readings that barely exist to show temperatures did not increase???

    My “anywhere” was not an assertion but part of a clarification question, which Brian D. answered.

  33. 483
    Completely Fed Up says:

    “CFU (479), how exactly would you expect temperature readings that barely exist to show temperatures did not increase???”


    You making this shit up, again?

    Let me ask you, since you say temperature readings hardly existed for the MWP, how do you know it was warmer or as warm then?

    NOTE: I never said the temp readings hardly existed. You said that.

    “My “anywhere” was not an assertion but part of a clarification question, which Brian D. answered.”

    Nope, you asked if Brian figured that the CO2 measures showed that the MWP didn’t exist anywhere.

    That Brian said it wasn’t global, doesn’t mean it didn’t exist.

  34. 484
    Rod B says:

    CFU (), One of the main factors trying to show that the MWP was regional was the scarcity of temp measurements in the SH compared to the measurements in and around Europe. And no it’s not the only factor…

    Going too fast for you again?

    You got my “anywhere” clarification so convoluted there is no saving it.

  35. 485
    Completely Fed Up says:

    “CFU (), One of the main factors trying to show that the MWP was regional was the scarcity of temp measurements in the SH compared to the measurements in and around Europe”

    See, this is why a little knowledge is a dangerous thing.

    Mostly because the owner doesn’t realise how little it is and over states it.

    This is the root of the Dunning-Kruger.

    No, the factor trying to show the MWP was regional is NOT the paucity of measurements.


    Temperature measures and their location in the SH was MERELY ONE.

    With the temperature record, there’s the opportunity that because the selection was sparse and therefore clumped that more proxies filling in those gaps could show a different picture, ***IF*** those unrepresented places *happened* to be indicative of something very different to the places with data.

    That is not that there’s insufficient data to show MWP in the SH, just that there’s still a chance that, if we were unlucky in our selection for reconstruction, it *could* show something global.

    Two “Ifs” required and no evidence to show this would or could be assumed.

  36. 486
    Completely Fed Up says:

    PS the temperature record has nothing, I repeat NOTHING to do with the CO2 record.

    So why did you conflate?

    Were you going too fast for yourself?

  37. 487
    Rod B says:

    CFU (486), MWP is referring to temperature, and not CO2??? Glad you pointed that out. And nice and slowly, too!

  38. 488
    Completely Fed Up says:

    “CFU (486), MWP is referring to temperature, and not CO2???”

    Yup, so why do you keep going on about how the lack of a global MWP has something to do with CO2 as you did in post #471:

    “Are you saying the lack of CO2 increase shows the MWP was not global? Or that it shows the MWP did not exist anywhere – despite the temp readings…?”

    That you sneer is merely because you’ve been caught with your pants down and want to divert attention by going “look! flying monkies!”.

    Now, given that you already thought that the case against a global MWP was because there wasn’t data enough in the SH, is the assumption that you would think that the MWP was to do with CO2 is actually a fairly plausible error.

    You’ve made so many, it’s no stretch AT ALL to figure you made another one.

  39. 489
    John Dodds says:

    Re 291 by Anaonymous Coward
    OK for a summary BUT just how can a +1K change in the incoming (solar) energy) result in a +2K increase in temperature? Whatever happened to conservation of energy?
    I claim that positive feedbacks are impossible.
    You can’t get energy & temperature increases unless you increase the energy in.- pureconservation of energy.
    IF the sun rises and the incoming energy increases, then the temp goes up partly (about 11% or 32 of 289) due to the GHE. Because there is EXCESS water vapor already in the air then any increase will use this water vapor or GHG to increase the GHE, WHEN the solar energy increases. It will NOT wait until more CO2 is added to raise the temperature to increase the amount of WV in the air to provide a positive feedback.
    The better question is what limits the GHE to 11% or about 32C on a yearly average basis? Since there is much more excess water vapor in the air, then WHY doesn’t the GHE use it up to create a runaway GHE?
    My answer is that the amount of incoming energy is limited and the IPCC/Climate scientists do not model this since they insist that More GHG means more warming, when Arrhenius clearly said that you must add a photon of energy to a GHG to get more warming.

  40. 490
    Hank Roberts says:

    > John Dodds
    I think your confusion about feedback was answered here in 2005:

    Perhaps an analogy would help?

    Take a bucket. Poke a small hole in the bottom.
    Start trickling water into the bucket, so the water level rises up partway and stays there.

    Water in balances water out.

    Now, halfway block the hole in the bottom of the bucket.

    Let the water trickling in continue at the same rate, no change in incoming water.

    Lo, the water level rises, although you are not adding water any faster than before.

  41. 491
    Anonymous Coward says:

    John Dodds,

    I encourage you to experiment with the conservation of energy by laying on a bed for one hour before putting a blanket on your body and waiting another hour. You should feel some warming. Conservation of energy is not being violated: the blanket is simply slowing the dissipation of your body heat.

    In my thought experiment there is no water vapor (I’m a god so, for simplicity’s sake, I made it so).
    But your question about a runaway GHE is a fair question. I see you are interested in gravity. Well, gravity is what is believed to prevent such a runaway on Earth. If Earth had less gravity, it might well have turned into a Venus-like planet. Please look up the Kombayashi-Ingersoll limit. I’m sure you’ll find this stuff very interesting. Perhaps it will encourage you to learn more about the physics of the GHE.

  42. 492
    Robert Murphy says:

    Hank, you’re arguing with someone who claims that gravity is the biggest source of heat on Earth:

    “…gravity which is the largest cause of 99.99% of the Earth’s temperature. You can’t geoengineer gravity.
    The IPCC global warming models ignore gravity and only analyse the impacts of solar insolation which is less than 1/100,000th of the total energy.”

    Might as well spend time arguing with a flat-earther.

  43. 493
    Rod B says:

    CFU (488), It’s very confusing and incomprehensible why you turn my questions into my “keep going on about.”

  44. 494
    John Mayer says:

    I’m not sure if this is the most appropriate place for this question, but I’ve done a search on RealClimate and a number of other climate sites and found a surprising dirth of information. One of the most common slurs aimed at climate scientists is that they’re only in it for all that beg grant money. Since the debate about AGW really “heated up” during the Bush administration, wherein a scientist could lose his job for mentioning the subject, to say nothing of the fact that grant money is hard to win and seldom lavish, this seems a preposterous claim. Yet it is one of the more frequent one of the deniers, and I’m not finding anything that refutes it in any detail (what sort of AGW grant money IS available, and from whom, and how that compares with what a sell-out scientist (those Paul Watson likes to call biostitutes) could make by working as a contrarian for the fossil fuels industry or CCF.

    Since I’ll probably never find my way back to this comment page I’d appreciate an email at

  45. 495
    Completely Fed Up says:

    Rod B it’s because you keep going on about how Brian *must* be wrong because the MWP existed somewhere at some time.

    As if it “proves” that the IPCC is wrong.

    Since neither Brian nor the climate science says what you’ve been saying, you repeat it until someone forgets that you made it up and starts believing the lie.

  46. 496
    Completely Fed Up says:

    “OK for a summary BUT just how can a +1K change in the incoming (solar) energy) result in a +2K increase in temperature? Whatever happened to conservation of energy?
    I claim that positive feedbacks are impossible.”

    So clothes are pointless?

    Wearing a shirt in the snowstorm is as sensible as a thick jumper?

    That covers on the bed don’t keep you warm while asleep?

  47. 497

    John Dodds (489),

    So now you’re admitting Arrhenius is right? Because if so, it undermines your whole argument.

    “Positive feedback” is not the same as “runaway feedback.” The water vapor feedback is a converging series, not a diverging series. Do you understand what that means?

  48. 498
    M Roberts says:

    There have been several quotes by deniers in Britain re some one called Webster in Der Spiegle with issues about the Jones temperature measurement.
    Anyone like to put the record straight? I don’t want to read through the rubbish .

  49. 499
    Rod B says:

    CFU, well, it might make things easier and clearer if you commented on stuff that I actually wrote.

  50. 500
    Alan of Oz says:

    I don’t understand why the targets of this abuse are so reluctant to bring charges of slander and libel against these kind of trolls, particularly in the UK where such laws are very strong. If nobody is willing to drag them into court it will only get worse.