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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.]

References

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. 201
    JRC says:

    I go to WUWT from time to time. And not trying to be rude, because I believe there are some true skeptics that visit the site, but the lack of basic science by many of those commenting really is sad. I read and get a headache because just a basic knowledge of physics, chemistry, etc refutes their posts. I consider myself a true skeptic. When first visiting this site after the e-mail hack, I had quite a few questions. The most important I think was, exactly what variables are Climate Scientists looking at, having a sense that maybe they were being to simplistic. Wow was I wrong! After visiting RC and reading what actually makes up the science I was so quite astounded at bulk of the evidence. Not being a Climate Scientist, I really didn’t understand the history going back over 100 years. I will say that on this site there is debate between those that agree with the theory whereas with the WUWT site, I rarely see corrections from “skeptics” on easily recognizable incorrect statements on science or fact if it backs up the position that AGW is somehow incorrect or a hoax.

    Does WUWT have some interesting articles, of course. But could I honestly say that it’s a site based on science. No. I was being a skeptic when a friend told me about something he read on the site. So I read the article, and researched it. Isn’t that what real skeptics do? I don’t see that happening much on WUWT.

  2. 202
    Jim Steele says:

    Bryson #196. “any credible hypothesis requires some really careful thinking through to see whether it works or not.” And that is exactly what I am doing. And that is the value of all skeptics. I am not just sharing my thinking with a choir of skeptics, but I lay it bear to the most strident opponents, while willing to expose myself to all manner of insults to my intelligence and integrity by Ladbury et al. I would suggest it is the psycho babblers who have thrown in the towel on respectful dialogue and careful thinking.

    GAVIN,:[Response: Huh? The explanation is exactly the same. During the ice age *cycles*, CO2 acted as an amplifying feedback on the orbital *cycles*. For those not familiar with the jargon, *cycles* go up and down. Please get serious. - gavin]

    The explanations are definitely not the same. Simply stated, CO2 amplifies warming, but resists cooling. Although I really appreciate your in depth explanation of a cycle, I would hope we could dig a little deeper. Orbital cycles increase and decrease solar input due to well described cycles eccentricity, axial tilt, and precession. But I am unaware of a carbon cycle that is independent of temperature. Assuming the orbital cycles are (RC’S) “unknown process” that accounts for 50% of the warming and CO2 represents the other 50%, here is a simple mathematical model. Let’s assign solar increase due to orbital changes +1 and solar decrease as -1(I realize there are 3 components and this is oversimplified). Let’s also assign +1 to CO2’s warming. There is no “negative” value assigned to CO2 because it always amplifying warming. When the orbital cycles are warming then CO2 reinforces the warming +2. When orbital cycles are cooling they are antagonistic net change 0. Every small decrease in forcing from orbital changes would be resisted by the CO2’s warming effect.

    At the very least this suggest that we need to account for processes that increase cooling effects to offset the warming effects of CO2. This accounting is not needed when you described the warming inter-glacial. We perhaps can argue against this mathematical oversimplification by suggesting the CO2 responds immediately to changes in temperatures caused by orbital forcing. But that is not what is observed. CO2 lags temperature changes on average by 800 years.
    So I see a need for better accounting. Gavin, a more in depth explanation why you think the explanations are exactly the same would be greatly appreciated and make it a more fruitful discussion.

    Ray: I am always impressed. No matter what the evidence or the argument, you can always sweep away all disagreements by simply saying if we disagree with you, we don’t understand, or we are stupid, or one of your myriad of denigrating variations. Why bother with respectful dialogue to those of us who do not measure up to your certain superiority.

  3. 203
    Radge Havers says:

    Ray Ladbury @ 194

    “I do not understand why people are so resistant to learning the actual science!”

    Seriously? Don’t you listen to talk radio?

    Climate science was invented by a bunch of climate scientists, ergo why waste time learning something invented by people who are only fit for harassment by definition.

  4. 204
  5. 205
    Edward Greisch says:

    132 wilt: Agreed that we are not psychologists or psychiatrists. Disagreed that psychology and psychiatry are not needed. They certainly ARE needed. Purely doing physics isn’t gaining any or enough ground. We need to do something else. We need to deal with those psychological factors that are preventing people from taking a more scientific approach. What is the sticking point? Is it purely fossil fuel money or is there something else as well? Do we need to reassure the boss at Der Spiegel that he can keep his view? Is it purely a fear of change? Is it ignorance that can be corrected by better education? Maybe there are lots of sticking points. We need to apply psychological lubricant to enough sticking points to get our legislation passed.

    We need psychologists and psychiatrists to prescribe the psychological lubricants.

  6. 206
    Doug Bostrom says:

    Time for yet another reminder. As Lay Radbury suggests:

    The Discovery of Global Warming by Spencer Weart, a mandatory prerequisite for intelligent discussion of climate change whether by rejectionist, skeptic, logical positivist, whomever or whatever.

  7. 207
    Edward Greisch says:

    149 Fred Magyar is correct. It was published on 1 April. Where did the April Fool’s Day tradition begin? The Wikipedia article says it is widespread, but I see nothing about Germany in particular.
    It could be a well written prank, but it is too well written. There should be internal clues that it is a prank. Perhaps the translation is imperfect?

  8. 208
    flxible says:

    This Wisconsin article discusses some interesting developments in the US insurance industry, driven by the CERES “Investors Network on Climate Risk” via the National Association of Insurance Commissioners – might be stirring up some of the heat on climate scientists, maybe even on Junior? Seems to indicate that capitalists have a different risk assessment approach than politicians . . . . . can capitalism get it right?

  9. 209
    Edward Greisch says:

    166 Lynn Vincentnathan: Yes but NO but Aha! Perhaps creationists do see themselves as chimps [human is a race of chimpanzee] and it Scares them! They have to deny evolution to reassure themselves. So how does this apply to climate? The denialists are like clueless creatures in a runaway car that is about to go over a cliff. They are scared because they don’t know what to do AND they don’t trust us because they confuse what scientists and engineers do with what corporations do. Corporations sell them dangerous medicine and dangerous cars.

    So what we have to do is: Tell them the difference between what scientists and engineers do and what CEOs and management does. They think that scientists are running the place. We are not. The Stockholders are! Management blames the “market.” But the “market” is the general public that makes decisions based on “theories”/instincts that are EXACTLY wrong. To replace the instincts with correct theories, we have to give everybody a degree in engineering, and that requires math. They are afraid of math…….

  10. 210
    Edward Greisch says:

    179 Simon Tytherleigh: “We live in a new age of superstition”
    I can’t remember whether it was “The Long Summer” by Brian Fagan or “Collapse” by Jared Diamond that said something like: “As the starvation worsens, they get more and more religious until the very end. They have one last super ceremony, then they kill the priests and change religions. At that point, civilization has collapsed.” But they are still religious.
    A new age of superstition is an omen of impending collapse. The problem is, how to get them to change to our “religion” to avoid the collapse? Recognizing that science is not religion.

  11. 211
    Harmen says:

    Simon #179
    blockquote cite=”I am also wondering what is behind the viciousness and rabidly anti-science thinking of the denialists. Never mind the corporate sponsoring, there are a lot of ordinary people out there who are now suspicious of anything a scientist says, who believe that there is a big conspiracy to shut down their way of life, and who are buying the line that we are nowhere near the limits to growth.
    Surely this sort of denial is a defence-mechanism against something that they conceive of as being terrifying (this is amateur psychology, help me out someone…), and because it is so frightening anger is part of the response?”

    I do think we can learn something from psychology in this regard..

    For example..
    Can you recognize the six types of denial in the climate debate?
    http://en.wikipedia.org/wiki/Denial#Types_of_Denial
    http://en.wikipedia.org/wiki/Denial

  12. 212
    Ned says:

    The attac on climate sciense is so far based on the question regarding the rate of recent global warming, and its cause. Even sceptics (so called climate deniers) do not dispute that the reality of the greenhouse effect assuming implicitly that it’s due to trapping of infrared radiatiation by ‘greenhouse’ gases. However, here is a very interesting pece of empirical evidence: The global average downwelling infrared radiation from the atmosphere is about 343 W m-2. This energy flux is some 43% larger than the TOTAL absorbed solar radiation (239 W m-2) by the ENTIRE earth-atmosphere system. Question: if the greenhouse effect is due to atmospheric absorption of thermal radiation from the surface, which is essentially transformed shortwave sunlight, how is it possible that the atmosphere sends MUCH more energy towards earth than the sun? In the context of the current greenhouse theory, such evidence appears to violate the First law of thermodynamics regarding conservation of energy. Therefore, the current greenhouse theory is missing something big as a physical mechanism responsible for providing additional warmth to the surface…

  13. 213
    Gilles says:

    “In other words, CO2 does not initiate the warmings, but acts as an amplifier once they are underway. From model estimates, CO2 (along with other greenhouse gases CH4 and N2O) causes about half of the full glacial-to-interglacial warming.””

    This sentence is a little disingenuous, in my sense. I discussed that with a mathematician on a French forum. For a retroaction loop, there is a characteristic retroaction factor f increasing after “one loop” the increment of temperature. ∆T-> ∆T(1+f). Applying a recurrence relation, ,we end with ∆T(1+f+f^2+….) = ∆T/(1-f).

    Note that 1/(1-f) is very sensitive to f if it gets close to 1. for instance if f=0.8 1/(1-f) = 5 but if f= 0.9, 1/(1-f) =10 , so the final amplification factor doubles if f increases only by 12 % !! this occurs of course only close to the “catastrophic runaway” threshold f= 1.

    Now if you have SEVERAL independant retroaction factors f1, f2, … fn (which is the case on the Earth where you have to consider water vapor, CO2, ice coverage, vegetation, and so on… the calculation shows that the final amplification factor is
    1/(1-f1-f2..-fn) . This can NOT be expressed as a sum or a product of a function of f1, f2…. etc… Only the “one loop” factor f can be expressed as a sum f= f1+f2…

    Now what can mean that “the factor number i is responsible for Xi % of the warming?”. This is not an obvious statement. The only sensible thing that can be expressed as percentages is the contribution to f : fi/(f1+f2+…fn). But it doesnt mean that without i, the warming would have been Xi% less because of the non linearity of the global factor.

    Taking the same numerical example as above, assume that f1=0.8 so that “1″ produces an amplification 5. Adding a mere f2=0.1 (12% of the total) will double this value again. So in some sense we can say “2 explains 50 % of the retroaction”. But it is somewhat disingenuous as I said since it actually account only for 12% of the factor f.

    It is precisely the case of the GES retroaction where f1 is the main factor due to water vapor and f2 only a small contribution from CO2, which has a large impact only because f1 is already close to 1.

    Personally I feel uncomfortable with these estimates for two reasons :
    * the effect of f2 is very sensitive to errors made on f1. In the previous example, it is enough to have an uncertainty of 12% on f1 to explain the same result.
    * a global factor f close to 1 is necessary to get a large retroaction , and it is dangerously close to the catastrophic runaway threshold. If water vapor would enter in a runaway cycle, there would be no limit and the whole ocean could warm, boil, and evaporate until all the water would be in the atmosphere – a kind of H20 Venus. To my knowledge , this never happened. Although mathematically possible, I think that a “global f factor” close to 1 and dominated by water vapor is physically unlikely.

  14. 214
    Completely Fed Up says:

    Wilt, give it a rest, kid.

  15. 215

    TomS (116),

    For the Nth time, where N increases without limit,

    95% of the CRU data was already in the public domain.
    The other 5% was proprietary and CRU couldn’t legally release it.
    McIntyre organized a campaign to harass and disrupt CRU by flooding it with FOI requests.
    CRU consists of 3 people. Fully complying with a UK FOI request takes 18 hours.
    CRU got 40 FOI requests from McIntyre’s people in one weekend.

    Do you get it yet? Nobody is concealing data. Mcintyre’s harassment campaign plus the ClimateGate thefts were a concerted campaign to destroy Phil Jones and CRU. And they pretty much succeeded because dupes just like you uncritically bought everything you read in the deniosphere.

  16. 216

    I said I wouldn’t answer Gilles… but once again, the smell of the stupid is so intoxicating, I get drawn in like a moth to a flame.

    Gilles (126): there is no spectacular confirmation of their theories

    BPL:

    http://BartonPaulLevenson.com/ModelsReliable.html

    http://BartonPaulLevenson.com/Correlation.html

  17. 217
    Jean S says:

    Stefan:
    “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 .”

    All model simulations above seem to have a clear cooling trend in the period 1000-1900. If a temperature reconstruction does not exhibit this cooling trend, do you think it is plausible to say that the reconstruction is somehow flawed?

  18. 218

    Jose’ (137),

    Es verdad, tristamente.

  19. 219

    DavidC (162),

    And did you miss how Tamino and independent workers around the country took Watts’s data and utterly demolished the false claims Watts had made, and Watts responded by the classic legal technique of admitting nothing, denying everything, and making counter-accusations? Or that he banned people who tried to call him on it from WUWT? This is “courtesy?”

    “Tell it the marines, the old soldiers won’t believe you.”

  20. 220

    Jim Steele (180),

    I regressed NASA GISS temperature anomalies 1900-2008 on CO2, TSI, and PSO. CO2 accounted for 75% of the variance. The PDO was indeed significant–it accounted for about 4% of the variance. This is “a major driver of climate?” TSI, BTW, wasn’t significant, and nor was sunspot number.

  21. 221

    DavidC (181): Ray – since you’re so doctrinaire about these issues, may I respectfully ask what your own scientific credentials are?

    BPL: ROFLMAO!

    Ray Ladbury is a Ph.D. physicist who works with Earth satellites. He has a string of peer-reviewed publications as long as your arm.

  22. 222

    Randy (191),

    I agree, the deniers are going to win, and it may well already be too late. Nonetheless, we should go down fighting. “The ship may be sinking, but that is no reason to let it be a living hell while it still floats.” –C.S. Lewis.

  23. 223
    dhogaza says:

    Jim Steele first says …

    You say I created a straw man by saying CO2 is the “only driver”. Never have I argued that, so check your own straw men.

    And later, as other point out, implicitly assumes the very same strawman …

    How can the same CO2 concentrations and the same temperature lead to both rising and falling temperatures?

    See why we don’t take your objections to both the science and to your being labelled a denialist seriously, Steele?

    Ray sez:

    Jim Steele, the more you post, the clearer it becomes that your confusion is due to your lack of understanding of the science. I am serious. You need to first unlearn all the crap you think you understand and then go to the Start Here button and start learning. There is no shame in not knowing the details of the science–it isn’t your field. Start with Spencer Weart’s History. I do not understand why people are so resistant to learning the actual science!

    Oh, I think it’s obvious why.

  24. 224
    Sou says:

    I looked at Dr Meier’s post (which was really very good) and was also surprised at the relatively polite tone of many of the comments.
    The politeness was offset to some extent by all the allegations by commenters of scientific fraud and manipulation, with some people saying that Dr Meier was not a good scientist.

    The comments in the main boil down to the standard lines that are well rebutted on SkepticalScience.com. I looked over the comments and found the most common ‘rebuttals’ are:
    - AGW is a hoax, it’s not happening, there is no evidence.
    - CO2 is not a forcing, it does not cause warming.
    - Measurements of temperature are false, biased, sloppy, inaccurate.
    - What about water vapour?
    - CO2 lagged temperature in the past.
    - Phil Jones said there has been no significant warming for the last 15 years.
    - The scientists are dishonest and cannot be trusted and/or don’t know their subject and/or peer review is corrupt.
    - It will cost too much to reduce emissions.

    Plus a couple of comments like
    - There is no forcing that causes climate to vary. It is harmonic oscillation;
    - Water vapour is a negative feedback.
    - Atmospheric CO2 is not rising.
    - Greenhouse gases reflect heat they do not radiate heat.
    - It’s the oceans.
    - It’s the sun.

    Surprisingly, there weren’t many comments referring to medieval warming or urban heat islands. Maybe they’ve gone out of fashion :D

    (When I’ve made comments in the past I’ve received some very impolite responses. And it’s not just commenters who can be extremely rude over there, many of the posts are nasty, such as disparaging people who are trekking in the arctic. It’s not a site I’d visit to learn about climate science. A lot of posts are just plain wrong. As Anthony has demonstrated on more than one occasion he still doesn’t understand anomalies, yet he’s been posting about climate and weather for at least a couple of years. I believe he used to read out weather reports on television.)

  25. 225
    Richard C says:

    Jim
    You are mixing up rates, temperatures and equilibria.

  26. 226
    wilt says:

    “Agreed that we are not psychologists or psychiatrists. Disagreed that psychology and psychiatry are not needed. They certainly ARE needed. Purely doing physics isn’t gaining any or enough ground. We need to do something else.” “We need psychologists and psychiatrists to prescribe the psychological lubricants” (Edward Greisch #205).
    If you agree that you have no qualifications in psychology or psychiatry you should stay away from it (the word ‘you’ is not directed at you personally but at anyone in this forum that relies on some pseudo-psychological cliché’s).
    [edit - you are becoming tiresome and off-topic]

  27. 227
    chris says:

    re #202 Jim Steele

    That’s not right. Temperature-induced changes in atmospheric [CO2] amplify both Milankovitch-induced warming and cooling during ice age cycles. Obviously if the warming (glacial to interglacial) stages of Milankovitch cycling recruits [CO2] to give (ultimatly) a change from around 180 (glacial) to 280 ppm (interglacial) with the latter’s amplification of warming, so the cooling (interglacial to glacial) stages of Milankovitch cycling (which results ultimately in a reversible sequestering of CO2 into oceanic and terrestrial sinks) will be amplified by the reduction of [CO2] from the interglacial levels near 280, back to around 180 ppm.

    temperature-induced [CO2] feedback amplifications act in boyh the warming and cooling directions

  28. 228

    JS (202): Simply stated, CO2 amplifies warming, but resists cooling.

    BPL: The reason the effect of warming and cooling are both amplified by CO2 is that when it warms for other reasons, it puts more CO2 IN the air, and when it cools for other reasons, it takes more CO2 OUT OF the air.

    JS: Let’s assign solar increase due to orbital changes +1 and solar decrease as -1(I realize there are 3 components and this is oversimplified). Let’s also assign +1 to CO2’s warming. There is no “negative” value assigned to CO2 because it always amplifying warming. When the orbital cycles are warming then CO2 reinforces the warming +2. When orbital cycles are cooling they are antagonistic net change 0. Every small decrease in forcing from orbital changes would be resisted by the CO2’s warming effect.

    BPL: You’re assuming the amount of CO2 stays fixed with temperature. It doesn’t.

    JS: CO2 lags temperature changes on average by 800 years.

    BPL: See

    http://BartonPaulLevenson.com/Lag.html

    JS: Ray: I am always impressed. No matter what the evidence or the argument, you can always sweep away all disagreements by simply saying if we disagree with you, we don’t understand, or we are stupid, or one of your myriad of denigrating variations.

    BPL: Clearly, from the above discussion, you in fact DON’T understand–and apparently don’t want to learn. And out of your incomplete knowledge of the subject, you lecture climatologists that “more accounting is needed.” Your model is useless because you didn’t do very basic homework on the subject.

    Ignorance is not a moral failure. Militant ignorance, refusing to learn, is. But you don’t HAVE to remain ignorant. If you want to learn about this, I can direct you to sources. IF you want to learn, that is.

    General discussions with little or no math:

    Spencer Weart, “The Discovery of Global Warming” (2008).
    S. George Philander, “Is the Temperature Rising?” (1998).

    General climatology with a little math:

    Dennis Hartmann, “Global Physical Climatology” (1994).
    Ann Henderson-Sellers and Peter J. Robinson, “Contemporary Climatology” (1986).

    Radiative transfer in the atmosphere, with a good deal of math (in order from easiest to hardest):

    John T. Houghton, “The Physics of Atmospheres” (2002).
    Grant W. Petty, “A First Course in Atmospheric Radiation” (2006).
    R.M. Goody and Y.L. Yung, “Atmospheric Radiation” (1989).

  29. 229

    Ned (212): how is it possible that the atmosphere sends MUCH more energy towards earth than the sun?

    BPL: I’ll take it a bit at a time. First, let’s look at a physical law, the Stefan-Boltzmann law which relates photon radiation to temperature:

    F = ε σ T4 [1]

    Here

    F is the flux density given off–power per unit area, in Watts per square meter in the SI.
    ε is the emissivity, or efficiency of radiation, which is dimensionless and can range from 0 to 1.
    σ is the Stefan-Boltzmann constant, 5.6704 x 10-8 W m-2 K-4 in the SI.
    T is the temperature (Kelvin scale in the SI).

    Thus, assuming perfect or “blackbody” emissivity, ε = 1, the Sun at 5778 K gives off F = 63,200,000 W m-2, the Earth’s surface at 288.15 K gives off 391 W m-2, and a human body at 308 K surface temperature gives off 510 W m-2.

    With me so far?

    Now imagine a climate system with only three parts, stacked vertically–space, containing the sun. An atmosphere. The ground.

    Space gives off 237 W m-2 which gets absorbed by the climate system (the rest is reflected away).

    Let’s say the atmosphere
    absorbs NO visible light (sunlight, εvis = 0)
    but ALL infrared light (IR from the ground, εIR = 1).

    And let’s say the ground
    absorbs ALL visible light (sunlight, εvis = 1)
    and ALL infrared light (IR from the atmosphere, εIR = 1).

    If we give the atmosphere and ground temperatures as Ta and Tg, the energy outputs for each layer are:

    Space: F = 237 W m-2 [2]
    Air: Fa = σ Ta4 [3]
    Ground: Fg = σ Tg4 [4]

    The atmosphere gives off Fa both up and down, since it has a bottom and a top. But the ground gives off Fg only up, since land is opaque and ocean nearly so.

    So the energy input is:

    Space: Fa [5]
    Air: Fg [6]
    Ground: F + Fa [7]

    And that means, assuming conservation of energy applies at every level, that the energy balances may be written as:

    Space: F = Fa [8]
    Air: Fg = 2 Fa [9] (remember, it radiates up as well as down)
    Ground: Fg = F + Fa [10]

    Substituting in from the Stefan-Boltzmann law, and taking the emissivities as given (1 everywhere except 0 for atmospheric absorption of sunlight),

    F = σ Ta4 [11]
    σ Tg4 = 2 σ Ta4 [12]
    σ Tg4 = F + σ Ta4 [13]

    Let’s divide through by σ to simplify:

    F/σ = Ta4 [14]
    Tg4 = 2 Ta4 [15]
    Tg4 = F/σ + Ta4 [16]

    Now, given that the ground temperature, Tg4, appears on the left sides of both equation 15 and equation 16, we can eliminate it between them to find

    2 Ta4 = F/σ + Ta4 [17]

    From equation 14, we know Ta = 254 K. From equation 17, we know Tg = 302 K. That means we can also calculate Fa = 237 W m-2 and Fg = 472 W m-2.

    Plugging all this into equations 8-10, we have:

    237 = 237 [18]
    472 = 2 x 237 = 474 [19]
    472 = 237 + 237 = 474 [20]

    The discrepancy between 472 and 474 comes about from roundoff error; if you calculate everything with 8 decimal places you get Fg = 474.

    Everything balances. Energy is conserved. The sun gives us 237 W m-2, but the Earth gets twice that, because it’s getting it from both the sun and the air. Flux density is NOT conserved. Temperature is NOT conserved. Energy is.

  30. 230
    François Marchand says:

    Gilles #216.
    Sounds more and more like Gilles is actually a front for MM. Claude Allègre et al. of the dubious “Ordre des Chevaliers de la Terre Plate” fame.
    [edit] He is getting to be a bit of a bore

  31. 231

    My perception of the WUWT thread is close to that of Sou’s–perhaps Dr. Meier contributed to it by his calm & respectful tone. I have to say, though, that I don’t find accusations of fraud to be especially polite, and there were several, IIRC. And I don’t think this thread was typical, based on my past forays to WUWT–the nastiness I’ve found there in the past is one reason that I seldom venture back anymore.

    In general, I’ve been amazed by the willingness of many denialists to broadcast accusations of fraud, while pillorying what seemed to me valid criticisms of past work or credentials of some public figures as “ad homs.” I’ve argued in the past that it’s more productive to maintain an even tone, and I still think that’s true.

    But sometimes pointed humor serves a purpose, and the trolling and zombie arguments so often encountered are certainly frustrating to deal with.

    The bottom line is fidelity to fact coupled with integrity and consistency of argument. I’ve found the mainstream to score much, much higher in these areas than the denialists–one of whose characteristic hallmarks is arguing anything, as long as it could cut against the mainstream science (and self-consistency be damned.)

  32. 232
    Steve P says:

    Is there a down side to asking the skeptic cohort to put up or shut up? Are they incapable of developing their own models of climate dynamics? We have been stuck watching their death-by-a-thousand-cuts campaign, driven by persistent zealots spreading disinformation ginned up by the likes of Exxon Mobil, Fox, and Koch. And as we stand by, their efforts are achieving their intended goal of wasting valuable time. Is it too much to ask to see the models that the skeptics have developed? If their models have less skill than those models which predict significant warming from anthropogenic carbon dioxide, shouldn’t they be publically encouraged to stand down and shut up?
    There are, of course, risks in this strategy, perhaps the greatest among them being that the skeptics will do exactly what they have accused climatologists of doing, and make a clever but bogus model. Can peer review make such a scam unlikely?
    And what if a skeptic climate model does show more skill than any current climatology models? Well, bravo. Then those of us who are currently 95% certain that mankind is warming the planet will have to look at that model very closely, and if the model stands up to intense scrutiny, we will perhaps have to change our level of certainty accordingly.
    I think that such a challenge is a reasonable alternative to this continual bombardment of half baked, dim witted, time wasting arguments, anecdotes, and dirty tricks. Skeptics, where is your highest skill model? Why don’t you put it out there, or else shut up? Surely the giga-bucks of the oil giants and their cronies can create an honest computer model to prove their point… or maybe the honest application of the laws of physics won’t allow that, and they already know that, hence their current rope-a-dope strategies.

  33. 233
    caerbannog says:

    For those who argue that CO2 isn’t responsible for global-warming because CO2 lagged temperatures as the Earth cycled between glacial and interglacial periods over the past few hundred-thousand years, here’s something to consider.

    The Earth came out of glacial periods (i.e. warmed) when orbital changes caused the Northern Hemisphere summer to coincide with orbital perigee. And the Earth went into glacial periods (cooled) when the NH summer corresponded to orbital apogee (approx).

    So when the Earth was warming, the NH was receiving more solar energy and the SH less. Vice-versa for when the Earth was cooling (i.e. going into a glacial period). Note that when the SH was receiving *less* solar energy, it warmed along with the NH! And when the SH would cool along with the rest of the planet even as it was receiving *more* solar energy (when the Earth went into glacial periods).

    So skeptics, what kept the NH and SH “in sync” temperaturewise? Why didn’t the SH cool when the NH warmed (or vice versa)? Why would the SH warm up when it received less solar energy and cool down when it received more?

  34. 234
    Gordon Cutler says:

    207 Edward Greisch: “There should be internal clues that it is a prank. Perhaps the translation is imperfect?”

    Edward, I speak German, read the article on the 2nd and immediately sent a complaint. It’s even worse in the original.

    In my experience it’s next to impossible to convey in English translation the irony and sarcasm that its native speakers can bring to bear when they want to.

    Der Spiegel is known for a style, since its earliest days in the aftermath of WWII, of a flippant attitude to authority and the creation of similar neologisms. But until the last decade or so its work grew from a bedrock of some of the best journalism in the world. Their journalists used to have–I haven’t checked the masthead recently–an astonishing number of PhDs which used to be reflected, especially in the sciences, in work superior to anything one would find in the US or UK. According to an earlier poster to this thread from Germany it looks as though I have to mourn its passing.

  35. 235
    Walter Manny says:

    Kevin, you would do well to leave your obvious bias out of your arguments if you are trying to dispassionately analyze tone: you tip your hand when you define your terms, “the mainstream” and “the denialists”. Gosh, I wonder who’s going to come out on top now? It’s not really about politeness or nastiness, is it? You can find both of those qualities on either side of the debate, especially the latter. It’s about what you come to believe is true.

    Invert the name-calling in your last paragraph, and you get: “The bottom line is fidelity to fact coupled with integrity and consistency of argument. I’ve found the skeptics to score much, much higher in these areas than the alarmists – one of whose characteristic hallmarks is dismissing anything, as long as it could cut against the skeptic’s questions (and self-consistency be damned.)”

    Pretty easy for an RC regular to pick that one apart, just as a WUWTer would be able to do with your original. You “have argued in the past that it’s more productive to maintain an even tone”, and so have I, but I don’t think that’s likely to happen, especially if everyone continues to toss terms like “alarmist” and “denialist” around so carelessly! No wonder Mann’s attempt to define himself as a skeptic was met with giggles. It should’t have been, of course, but that is where incivility on both sides leads us, I believe.

  36. 236
    Geoff Wexler says:

    Simply stated, CO2 amplifies warming, but resists cooling.

    Whether a given concentration of CO2 warms or cools depends on the global temperature which determines the heat lost by radiation. If the temperature is too low for energy balance then there will be a positive energy imbalance and the globe will warm. This is what happens on the way up out of a glaciation. On the way down the effect is reversed.

    Imagine start with ‘cool-energy balance’ during glaciation. To initiate a thaw you have to reduce the outgoing energy somehow so that you get a positive energy imbalance which favours warming. As a result CO2 is liberated, illustrating feedback. Effect is to reduce outgoing energy even more. Amplification of initial energy imbalance leading to more warming.

    Eventually a new ‘warm-energy balance’ is created. This is upset by the same mechanism (initially orbital changes) but time has moved on and the orbital changes
    are now negative producing cooling. This removes CO2 from atmosphere (same cause as before) which causes even more energy to escape from atmosphere (same CO2 mechanism as before) and get even more cooling.

    A given level of CO2 is too much for cool-energy-balance on the way up thus producing warming and too little for warm-energy- balance on the way down producing more cooling.

    Conclusion: Gavin was right ; the two effects are basically the same. Also the quote at the top is wrong.

  37. 237
    Adrian O says:

    Did anyone notice on the IPCC graph of global mean temperature 1850-2005 shown that the slope, size, shape of the warming between 1910-1940 matches EXACTLY the slope, size, shape of the warming between 1970-2000?

    Since CO2 industrial emissions were extremely low between 1910-1940 compared to 1970-2000, how could the first ones be natural while the latter be caused by humans?

    If we could bring back the industrial levels of 1910 with the current population, which would basically be North Korean levels around the world (no cars or heating, starvation and foraging for roots and bark), wouldn’t we have EXACTLY the same global warming slope as in the last 30 years, as shown by nothing other than the IPCC graph?

    I am a mathematical physicist who likes to read and understand graphs.

  38. 238
    Septic Matthew says:

    228, Barton Paul Levenson: Spencer Weart, “The Discovery of Global Warming” (2008).
    S. George Philander, “Is the Temperature Rising?” (1998).

    General climatology with a little math:

    Dennis Hartmann, “Global Physical Climatology” (1994).
    Ann Henderson-Sellers and Peter J. Robinson, “Contemporary Climatology” (1986).

    Radiative transfer in the atmosphere, with a good deal of math (in order from easiest to hardest):

    John T. Houghton, “The Physics of Atmospheres” (2002).
    Grant W. Petty, “A First Course in Atmospheric Radiation” (2006).
    R.M. Goody and Y.L. Yung, “Atmospheric Radiation” (1989).

    I have ordered the book on thermodynamics by Prigogine and co-author, and I plan to buy Raymond Pierrehumbert’s book when it comes out (CUP predicts Dec 2010). Is there one of the books on that list that you would recommend as the best complement?

  39. 239
    JiminMpls says:

    #224 Sou – Thank you for mentioning Dr Meier’s post on WUWT. He has a real knack for articulating the uncertainties while at the same time underscoring what is fairly certain – all in language that anyone with a sixth grade education should be able to understand.

  40. 240
    Bob says:

    Walter, #235:

    The problem with your “reversal” is that it includes untrue statements. It may appeal to you, but that doesn’t make it accurate. You may argue that my own “belief” is a result of the original statement’s appeal to me, but that still doesn’t make your statement accurate.

    That’s the core problem. Simply being able to say “I’m right” doesn’t make it so. And every effort to actually discuss facts with someone who is not truly skeptical and intent on learning inevitably wanders off into insanity.

    As an aside, I was raised Catholic, so to get married, I had to go to “pre-cana”. One invaluable lesson I learned there is to recognize when an argument resorts to tactics in an effort to “win” rather than to arrive at the truth. Such a situation is damaging to a marriage, and needs to be nipped in the bud.

    I started several years ago as a “skeptic” in the true sense of the word, not the warped usage we see in the current debate. I believed no one and nothing on any particular aspect of climate until I felt I thoroughly understood it myself. Even now, when I see what looks like a good argument against GHG, I investigate it thoroughly until I feel I understand perfectly. I don’t stop as soon as any argument agrees with any preset belief, and I usually don’t stop even when I feel satisfied, because I’ve found that often there is still more understanding and truth to be gleaned beyond that point.

    But what I’ve found, over time, is that not once, not in any single area or facet, can a denial argument hold water*. I have always, always found the flaws. Very, very often those flaws are so obvious and indisputable that it makes the skeptics look silly. It demonstrates a lack of fidelity, a lack of integrity, a lack of consistency, or all three. I have never, ever found the same to be true in arguments for GHG — period.

    [* footnote: one exception I will grant the "denial camp". The Lindzen/Spencer argument that cloud feedbacks will ultimately constrain climate sensitivity is a possibility, although only that. To date no one, despite all of their efforts, has been able to present any convincing mechanism or evidence to show that this will in fact be the case, so I put "clouds will save us" into the "hope and faith" department, not the "scientific fact" department. But I do honestly hope that some day a true skeptic will prove that theory and so let us all breathe a sigh of relief.]

    If you honestly believe what you are saying, then I can unequivocally tell you two things. First, you don’t understand any of the facts nearly as well as you believe, and second, you are not a skeptic, because you stopped investigating and understanding too soon, before you worked your way even close to the truth. When you arrived at a position with which you were comfortable, you stopped there, and have stayed there ever since.

    Now, some advice. The way I worked my way to where I am now was by using Google, spending a lot of time, reading in detail from both sides of the argument about a zillion different subjects, and always, always, always taking a seriously skeptical approach. Every single time I read something for either side, I went to Google and tried to find a good, solid argument against it. Once I’d found one or several, I then took the opposite approach, and tried to find good, solid arguments against those.

    Over time I learned to recognize hyperbole, selective logic, misrepresentation, obfuscation and any number of other common debate techniques. I learned to tell the difference between someone who is trying to sell me something, and someone who is trying to teach me something. And that, by the way, is the difference between WUWT and RC.

    Along the way I also learned (or in some cases, re-learned) a whole lot about physics, chemistry, tree rings, ice cores, glaciers, ocean currents, wind patterns, geometry, and a whole lot more. No matter where you wind up, or expect to wind up, it’s worth it, just for the knowledge gained.

    But to get there, first you have to be a skeptic.

  41. 241
    Ron Broberg says:

    Steele: At the very least this suggest that we need to account for processes that increase cooling effects to offset the warming effects of CO2

    You mean like albedo effects: a warming atmosphere holds more moisture, which falls as more snow, which could take longer to melt, leading to increased cooling through albedo.

    Steele, if you really are interested in this, might I suggest studying some of the mathematical models from the 50-70s? If nothing else, it will make you a better skeptic.

    Manabe and Möller, 1961, On the radiative equilibrium and heat balance of the atmosphere, Mon. Weather Rev. 89 (1961), pp. 503–532

    Manabe, S., and R.F. Strickler, 1964, Thermal Equilibrium of the Atmosphere with a Convective Adjustment, Journal of the Atmospheric Sciences, 21(4):361-385, 1964.

    Manabe, S., J. Smagorinsky, and R.F. Strickler, 1965, Simulated Climatology of a General Circulation Model with a Hydrologic Cycle, Monthly Weather Review, 93(12):769-798, 1965.

    Manabe, Syukuro and Richard T. Wetherald, 1967. Thermal Equilibrium of the Atmosphere with a Given Distribution of Relative Humidity, Journal of Atmospheric Science 24, 241-259.

    Budyko, Mikhail I., 1969, The effect of solar radiation variations on the climate of the Earth, Tellus 21, 611–619

    Sellers, W. D., 1969, A global climatic model based on the energy balance of the Earth-atmosphere system, Journal of Applied Meteorology 8, 392-400.

    Hasselman, 1976 Stochastic Climate Models

    North, 1981, Energy Balance Climate Models

    how could the first ones be natural while the latter be caused by humans?

    Monkeys eat bananas.
    A banana was eaten.
    Therefore a monkey must have eaten the banana.

    Really? This is an argument being presented by a mathematical physicist?
    http://en.wikipedia.org/wiki/Affirming_the_consequent

  42. 242
    Doug Bostrom says:

    A nice summary of CEI’s recent deep dive into moldering email at DeSmogBlog:

    http://www.desmogblog.com/cei-fails-manufacture-its-own-stolen-emails-controversy

    Proper credit is awarded to CEI’s “Senior Chewing Gum Scraper” Chris Horner.

  43. 243
  44. 244
  45. 245
    Gilles says:

    BPL#216 : again there must be some misunderstanding between us. I never said climate models are totally wrong – and I never said either that CO2 wasn’t producing GH effect contributing to a global warming. So listing a number of correct results of the models isn’t at all at odds with what I’m saying. It would be actually very surprising that models relying on known physics should fail on all their predictions when tested against reality. So what you’re trying to prove is a relatively expectable thing : that the models aren’t wrong on anything ! but none on the items you’re listing is the definite proof of the quantitative effect of CO2 (else they would have been presented as such a proof by IPCC for sure !!), nor their combination. They may be described as “a good support to the idea that CO2 absorption contributes to the warming” – at best. Well I have nothing against this idea. This doesn’t imply at all that the whole Earth in distress, nor that this is the most important issue in the world. You have to prove a lot of other things before reaching this conclusion.

    F. Marchand #230 : please avoid this kind of useless statements. I don’t know Pr. Allegre, I never interacted with him in any way except a handshake 10 years ago when he was a minister, I don’t draw false graphics , and he doesn’t believe in a near PO. We have very little in common actually.

  46. 246
    dhogaza says:

    Adrian O

    I am a mathematical physicist who likes to read and understand graphs.

    April Fool’s Day was over a week ago …

  47. 247
    David B. Benson says:

    Adrian O (237) — The climate has internal variability and the AMO is an index for it. In addition, the forcing due to excess CO2 only approximately doubled in the past 40 years or so. For details, study
    http://www.realclimate.org/index.php/archives/2010/03/unforced-variations-3/comment-page-12/#comment-168530

  48. 248
    Jim Steele says:

    PBL 220 “I regressed NASA GISS temperature anomalies 1900-2008 on CO2, TSI, and PSO. CO2 accounted for 75% of the variance. The PDO was indeed significant–it accounted for about 4% of the variance. This is “a major driver of climate?” TSI, BTW, wasn’t significant, and nor was sunspot number.”

    PBL it is good to see, that like me, you are also doing your own critical thinking and questioning authority to check their validity. I however see one major statistical problem with regressing CO2 vs temperature. It is well known that not only can increasing CO2 raise temperatures, but equally so rising temperature increases CO2. This makes the transition from correlation to causality difficult to ascertain for this correlation. It also means that due to this direct correlation of temperature induced CO2 that any change in temperature due to forcings and processes other than CO2, could be mistakenly attributed to CO2, and perhaps “hiding” other factors. For that reason, I suggest caution and more analysis for any positive CO2 correlations.

    My experience is mankind’s disruption of the environment/climate is due more to land use issues like altered hydrology that cause regional temperature changes that then get averaged into a global mean. There are numerous peer reviewed paper’s supporting this, many of which can be found on Pielke’s website. Likewise the PDO may have a strong correlation on a more regional scale as demonstrated by the Alps example. However the importance of the PDO can then be lost when you average temperatures on the global scale. (BTW the PDO was discovered by salmon fisheries biologist, and serves as an example of biologist contributing to climate science)

    Another problem with your regression is that the oceans can absorb and release heat creating lag effects. El Nino’s release heat stored for how long? How does the synchronicity or lack thereof between the PDO and ENSO affect variance in your correlation.

    And third, assuming CO2 is this global blanket that increases global temperatures, uneven heating points to the roles of natural variations that may or may not be well understood. A good example of this problem of regional vs global interpretations was illustrated recently on Pielke’s blog where despite wide spread cooling (about 25%), February the average temperature for February was the warmest in 32 years as reported by Spencer and Christy, due to a much more confined Arctic hot spot. http://pielkeclimatesci.wordpress.com/2010/03/19/an-example-of-why-a-global-average-temperature-anomaly-is-not-an-effective-metric-of-climate/ . Could the PDO have been the driving factor, >4%, causing cold anomalies throughout North America, Europe and Asia, but due to the weight given to the Arctic warm anomaly, its significance as a climate driver would be hidden by your regression.

    Your regression may show a good correlation with record CO2 and the record February warm anomaly. But you must then always justify the correlation with well understood processes. So I am sure you have examined this in your investigations of these driving factors, so looking at the February anomaly map how would you attribute 75% of February’s Arctic warm anomaly and the rest of the NH’s cold anomaly to CO2?

  49. 249
    Jim Steele says:

    Ron #241, “You mean like albedo effects: a warming atmosphere holds more moisture, which falls as more snow, which could take longer to melt, leading to increased cooling through albedo.”

    I’m having a problem getting by your first remark. The warmth of the interglacial leads to “atmosphere holds more moisture” (no problem there), which falls as more snow,(quantum leap in assumptions here. Why snow? Why not more rain?. I really don’t understand the mechanism where warming creates more snow? I don’t mean to misinterpret you, but it almost sounds like you are saying more warming, more snow then more glaciers? Something seems to be missing but I am just a ignorant biologist. Ray you got a PhD in Climate science, help us out here.

  50. 250
    Rod B says:

    BPL (229), these calculations don’t match the reality all our energy budget, I assume, because of the helpful simplifying assumptions you make. If those possible assumptions were realistic then I would assume your numbers would also be realistic. It tells me two things: the temperature of a planet’s atmosphere and ground is a function only of the distance from the sun and its surface temperature, which determines insolation — again given the assumptions on emissivities. At the base level the composition of the atmosphere has no effect, which I assume is why you get a Ta that is about the same as the no GHGs case (254K). It also says that the atmosphere radiates as a blackbody according to the Stefan-Boltzmann law regardless of it material composition. If so it might (I still have to think about it) answer a long standing question of mine, similar to Ned’s: where does the 333 watts/m2 downwelling come from? Am I getting this correctly?


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