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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. 251
    CM says:

    Tom Lehrer,who gave us “The Elements” and “New Math” in popular song, turned 82 yesterday. As a small tribute, I have plagiarized done research on one of his lesser-known songs, “Sociology” (for the tune, see the original at Regular readers here will recognize the references and (sad anoracks that we are) perhaps even get a laugh out of it.

    Deranged / is the change / they are trying to arrange / today in Climatology
    Fanatics / in their attics / don’t need fancy mathematics / to do Climatology
    Persuasion / by defamation / they all feel is much more satisfactory
    In congressional hearings / you don’t need to know your tree rings / to testify on Climatology.

    PR flacks / write attacks / based on hacks / into institutes of Climatology
    They’ll / steal your mail / and then rail / about a moral lapse in Climatology
    Stock consultants / grow exultant / at the peer review they get in E&E
    Trashing the science / can profit their clients / so now they’re into Climatology.

    Viscounts / double count / their discounts / of the estimates of Climatology
    Excel / lets them tell / even Hell* / is freezing, to hell with Climatology
    Six-year trends / with cherry picked ends / using monthly data points to minimize p
    They don’t need no schooling / to say that it’s cooling / and pretend it’s Climatology.

    *) I have verified this with blog science tools. I’ve found a highly significant cooling trend for Hell over the very arbitrarily sampled 200-day period August 8, 2009 – February 23, 2010. You can replicate my work from data at Weather
    statistics for Hell

  2. 252
    Rod B says:

    caerbannog (233), Your question re NH vs SH heating and cooling is quite interesting (I think I can answer it), but its connection with the CO2 lead/lag question is totally obscure (to me, anyway — which means maybe I can’t answer it…) Can you shed some light on this?

  3. 253
    Jim Steele says:

    Dhoagza “223 “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?”

    I appreciate your attempts to discredit me vs discussing the points, but please at least accuse accurately. You take the quotes out of context. The 2nd quote “How can the same CO2 concentrations and the same temperature lead to both rising and falling temperatures?” is still me consistently arguing against CO2 as the only driver. That quote was calling into question RC’s explanation of the interglacials as “From model estimates, CO2 (along with other greenhouse gases CH4 and N2O) causes about half of the full glacial-to-interglacial warming.”

    Is this attack due to your grudge regards my “just so “ comment? Well, I look forward to the time we discuss the science and put aside the personal attacks.

  4. 254
    Theo Hopkins says:

    With all such articles, I do think that Real Climate would do better – be more constructive – if you were to say what is correct as well as what is wrong.

    Thus I could say to someone…”Yes, DER SPIEGEL, is right on point A but is talking cr@p on B and C”.

    This would make for a better argument from me if I was talking to someone not versed in climate stuff.

  5. 255
    Jim Steele says:

    BPL said “: 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.”

    BPL: Too simple. Let me try to explain my concern a little differently. Lets start at a glacial minimum temp and call it 0 degrees. On the upstroke of the cycle after 800 years orbital forcing global temps to rise to 1 degree(I am keeping the numbers simple for illustrative purposes).Then the lagging CO2 starts contributing, and according to RC’s logic and the degree of sensitivity assigned to CO2 (50% of the temperature rise), the increasing amounts of CO2 raise temperatures to 2 degrees. Starting with a peak of 2 degrees, what starts the cooling. I am assuming it is mostly changes in orbital forcing that cools the oceans allowing CO2 to be taken out of the air. So the change in orbital forcing reduces the temp back to 1 degree. So if RC’s logic is that at 1 degree temperature on the upstroke, CO2 was released raising temps another degree, to be consistent we should not expect CO2 to be significantly pulled out of the atmosphere just because we are on a down stroke. It is still 1 degree. The difference here is that we lost the 1 degree due to orbital forcing so I would not expect the temperature to rise as it did on the upstroke, but hover at 1 degree.
    My question is “how then did temperatures go back to “0”. Some posters have listed several things that could absorb CO2. But that stills begs the questions, if global temps are at 1 degree, the net balance of CO2 release and absorption and radiative forcing is approximately the same at 1 degree. Most biological activity is driven by enzymatic rates that are controlled by temperature.

    BPL you say I assume CO2 stays fixed by temperature. I don’t but its release and uptake from the ocean varies directly with temperature. The confusion may lie in separating what I assume, vs what is assumed in RC’s explanation of CO2’s role in the glacial interglacials.

    If the CO2 is both lagging the decreasing temperature and also had the ability to increase temperatures to the degree RC suggested, then the lagging CO2 on the down stroke will inhibit further decrease in temperature. But because the temperature records show temps do continue to fall I am left with a few possible explanations. 1) The negative orbital forcing on the downstroke is greater than the positive orbital forcing on the upstroke. But that defies our knowledge of orbital cycles 2) New or stronger processes happen at 1 degree to absorb more CO2 only on the down stroke. That seems much too arbitrary. For example albedo? At 1 degree on the upstroke why wouldn’t I expect greater ice coverage remaining from the glacial peak and thus greater albedo, than on the down stroke when glaciers have all retreated and are just starting to grow. 3) The climate is not so sensitive to CO2, its ability to amplify and raise temperatures in the upstroke is overstated. 4) #3 implies then that we have not yet accounted for all climate variables.

    Now you could argue that my time interval is misleading as I just make one big step . But if you do the calculus, and the time intervals approach zero you would still have lagging CO2 resisting further decreases in temps. if it has the power RC attributed to it. I find scenarios 3 and 4 most likely.

    I saw one poster ask how dare I ask for better accounting. You might as well ask “how dare I think for myself?” And Spencer Weart really doesn’t address this concern, so that suggestion is not helpful.

  6. 256
    Publicola says:

    @ Walter Manny:

    You still haven’t answered question I asked you, Walter – here it is again:

    How, in your mind, can statements in the Landsea-coauthored study including the following:

    “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.”

    in any HONEST way be translated, as the Der Spiegel article did, into meaning that the link between global warming and hurricanes has been “finally disproven”?

    Please answer the question, and while doing so please spare us the circumlocution – which again may be fun but not particularly illuminating.

  7. 257
    David B. Benson says:

    Jim Steele — Humans have added about 500 GtC to the active carbon cycle. All that carbon dioxide has to go somewhere so its certainly not coming out of the oceans but rather going in. I previously suggested you study
    and now even more strongly urge you to do so. You’ll find that the last 13 decades are fairly easy to explain.

  8. 258
    MapleLeaf says:

    I have not figured out yet if Jim Steele is a ‘concern troll’ or a ‘tone troll’, or a bit of both. Anyhow, it is fascinating to observe.

    Sadly, he does seem to be being quite successful at detracting/distracting from the DS fiasco though.

    Theo @254, I agree with your sentiments. Can you provide some examples of what they unequivocally got right, to get us started? And I am being sincere when I ask that.

    PS: Stefan did preface his post saying that he was busy and did not have much time to spend on the DS article.

  9. 259
    dhogaza says:

    Well, I look forward to the time we discuss the science and put aside the personal attacks.

    Before you can discuss the science, Mr. Steele, you must first understand the science. An even stronger statement may be made that before you can claim to be *refuting* the science, you must first understand what you claim to be refuting.

  10. 260
    MapleLeaf says:

    Jim Steele, did you not see the post (#154) where Hank Roberts outed you?

  11. 261
    David Miller says:

    Jim Steele says in #248:

    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.

    Jim, I’m not sure you realize just what you said here. For one thing, you answered quite clearly the question Gilles posed about why there was a serious danger posed to civilization by AGW.

    But the other is that you’re completely ignoring known, proven, observable physics when you suggest something like that.

    You propose the question of whether rising temperatures could have been causing the rise in CO2 levels. On the face of it this is absurd. To say that rising temperatures is responsible for rising CO2 ignores all the CO2 that we’ve added through fossil fuels. It’s been proven that this additional CO2 in the atmosphere is of fossil origins by isotopic signature.

    It also ignores the radiative physics of CO2 and other greenhouse gases that was demonstrated more than a century ago.

    If, Jim, you really want to say that increased CO2 is a result of increased temperatures rather than the other way around you need to demonstrate how modern radiative physics, isotopic analysis, and historic fossil fuel consumption estimates are all wrong. Then you need to prove what WAS responsible for the increasing temperature – where’d all that energy come from? Lastly you’ll have to demonstrate where the carbon came from.

    Increased CO2 IS a result of increased temperatures. There was a thread on that right here on RC recently. That’s a real problem. Increased CO2 means more warming; more warming means more CO2. If you think BPL has cause and effect backwards you have a lot of explaining to do.

  12. 262
    Green Marauder says:

    It might not seem like much consolation now, but there’s only 2 more years of climate science bashing to endure with luck

    “Supporters of a new ecocide law also believe it could be used to prosecute “climate deniers” who distort science and facts to discourage voters and politicians from taking action to tackle global warming and climate change.”

  13. 263
    Ron Broberg says:

    Steele: but it almost sounds like you are saying more warming, more snow then more glaciers

    Is that difficult for you to conceptualize?

    change in glacier mass = snow additions – melting

    If a warmer, moisture atmosphere drops snow at an annual rate greater than the increased melting due to rising temps, glacier mass (and presumably glacier length) increases. Four scenarios: hot & dry, hot & wet, cool & dry, cool & wet.

    And that’s only looking at what are probably dependent variables of temp and moisture. In many regions, melting due to aerosol pollution (black soot, dust from drought) exceeds temperature dependent melting.

    Steele: Something seems to be missing but I am just a ignorant biologist

    The problem with playing the fool is knowing when to stop.

    So, Jim, do you still believe that you have demonstrated an inconsistency in AGW? If so, what would that be, since you have never stated it? Or are you having more fun raising charges of being ‘attacked.’ What is your inconsistency? How have you demonstrated it? Don’t be shy. I would really like you to stick to the point you have alluded to and defend it.

  14. 264

    #184, Wilt, #166 was meant “tongue-in-cheek.” I’m not going to give up on the social & behavioral sciences so easily.

    However, as a person who has been trying to tell people about AGW for 20 years, and about the great economic savings they can realize by reducing the GHGs, without lowering living standards, I am totally exasperated with this ever increasing brick wall I’m running into.

    And a most exasperating point is that while the Catholic popes and bishops have written eloquently about how prudence requires us to mitigate climate change, even if we don’t quite understand or accept the science, this doesn’t get down to the parish level. And the Catholic denialists (some like the Acton Institute, funded by Exxon — see ) keep harping on what they see as the main problem…that environmentalism leads to neopaganism & Gaia-worship. Now I’ve known a few neopagans and one pagan in my life, and I wouldn’t call them environmentalists necessarily. Furthermore the fora in which these Catholic denialists air their fears of neopaganism are composed of very conservative Catholic audiences, and frankly I really don’t know of a single conservative Catholic who is a neopagan, but I do know plenty who are anti-environmentalists.

    I’m not too aware of the trials and tribulations of climate skeptics — sorry for whatever you and others have suffered. I would hope such skeptics don’t receive death threats and harassments. I’m sure no one would wish the level of harassment, bashing, job-threats, job losses (I’m thinking of Pat Newman), and death threats climate scientists have received on even their worse enemy.

    So, let’s just say I use humor to get through my exasperation.

  15. 265
    Hank Roberts says:

    > Jim Steele says: 10 April 2010 at 3:03 PM
    > … You say I created a straw man by saying CO2 is the “only driver”.
    > Never have I argued that… The 2nd quote … is still me consistently
    > arguing against CO2 as the only driver.”

    Jim, no climate scientist seriously claims CO2 is the only driver.

    Some people set up that claim as a strawman — a fake opponent that’s easy to knock down.

    When you argue against CO2 as the only driver, you’re attacking a strawman.
    You found it somewhere — someone set it up.

    Check for bunk. Here’s a good example:“co2+is+the+only+driver”

  16. 266
    Hank Roberts says:

    Argh, those should be ordinary double quotes, not curly quotes.
    Jim, put the string in double quotes in the Google search box.

    Somehow your doublequotes work and mine don’t.
    Let’s see if I can copypaste them. Weird, even copying the curly quotes out of my earlier response and pasting them back seems to fix them. I dunnnnnooo.“CO2 is the only driver”“co2+is+the+only+driver”

  17. 267
    Hank Roberts says:

    ermgh. Apparently it’s the plus sign that breaks the link now?

  18. 268
    Geoff Wexler says:

    “How can the same CO2 concentrations and the same temperature lead to both rising and falling temperatures?” is still me consistently arguing against CO2 as the only driver.

    But your conclusion does not follow from your starting point anyway. I went to some trouble to explain the mechanism in my previous comment.

  19. 269

    Walter, #235, you claim that I show “an obvious bias.”

    Tell me, what differentiates a justly-reached conclusion from bias?

    My experience was as I described it. When one side–call it “contrarian” if you wish–is predominantly characterized by a lack of self-consistency, a lack of attention to detail, a tendency to revert to conspiracy theory, etc., etc., how long must I forbear what appears to me to be a merited judgement, if I wish not to be accused of “bias?”

  20. 270
    Petro says:

    Jim “Steele”:
    The physics of global warming is simple;
    1) CO2 is a greenhouse gas
    2) Greenhouse gases make the atmosphere warmer
    3) Mankind consumes fossil carbon creating CO2
    4) CO2 levels have raises
    5) Global temperatures raises

    What step above you do not comprehend?

  21. 271
    David B. Benson says:

    Jim Steele (255) — I take your question about the role of CO2 during a transition from interglacial to glacial is quite a reasonble one. Lets start with a simpler example.

    Consider the variation in global temperature over the average solar sunspot cycle. Starting from the minimum, increased insollation begins to heat the globe, but as winds thoroughly mix the top few meters of the ocean this upper portion and the atmosphere warm together. We only measure the temperature of the surficial air over land and SSTs in the ocean. As those few meters take awhile to warm up, there is a delay in the response to the increasse of about one year. That is called a phase lag in linear system theory and there is a full development for this example in the appendix to Tung & Camp (2008?).

    Similarly, but more complexly, there is a phase lag between the orbital forcing and the climate response. So at the maximum recorded temperature of an interglacial the orbital forcing has already begun to decline. This phase lag could well be on a millennial scale (I don’t know) which resolves your difficulty. Of course, there is the same phase lag at the minimum during the stade.

    [Response: Any future postings which do not follow David’s example here of sticking strictly to scientific explication–sans put-downs, name calling and various direct and indirect innuendo–will be summarily deleted , regardless of authorship. I’m completely sick of it–Jim]

  22. 272
    Walter Manny says:

    240. (Bob)

    “Simply being able to say ‘I’m right’ doesn’t make it so.” We are in perfect agreement there. As to your feedback doubts (hardly a footnote in my opinion) isn’t that ultimately THE crux of debate?

    I offered the inverted paragraph as an example of an easily refuted statement, one that does not appeal to me in the least, just as the original does not. As to your attempts to read my mind, I think you need better proxy data.

  23. 273
    Walter Manny says:

    Kevin (270)

    “Tell me, what differentiates a justly-reached conclusion from bias?”

    Perhaps when the justly-reached conclusion is freed from disrespectful characterizations of one’s opponents, especially in a post simultaneously purporting to promote civility, it would be less likely to appear as bias. That bias is not necessarily unmerited, of course, but I did find the post ironic. Not a big deal, though, and I understand what you are trying to get at, elusive as it may be.

  24. 274
    Andrew Hobbs says:

    Jim Steele – Where to begin? Just a few major points.

    #202 Jim Steele says

    “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.”

    What on Earth are you talking about. Your ‘model’ you talk about is nonsense. Additive effects such as you describe are nonsense. The negative effects you seem to want are nonsense.

    Your apparent misunderstanding of the basic atmospheric physics is pretty profound. There isn’t a default temperature of the Earth to which solar or CO2 effects add (increased) or subtract (decreased).

    The default temperature is 0 K, ie absolute zero. On a world without a greenhouse effect, solar input would raise average global temperature to about 255 K. On Earth, H2O, CO2 and other minor atmostpheric constituents provide a greenhouse effect which raises this value to about 287 K. The orbital ‘changes’ (cycles) affect the solar power input raising the basic no-greenhouse temperature above absolute zero to a greater or lessor amount than 255 K. Variations in H2O, CO2 etc cause a greater or lesser greenhouse effect raising the temperature to a greater or lesser amount above the basic temperature. So there is no need for some sort of negative repression.

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

    No you don’t. All you need is for the solar imput to start being reduced due to orbital changes so that the feedbacks start to cause a reduction of CO2 and a reduction in CO2 forcing. Over the longer term one may also get CO2 removal due to geological processes such as the formation of carbonate minerals (rocks).

    This is all really basic physics which is available to anyone who wishes to learn it from one of numerous textbooks on climate, or from internet sites such as this one.

    #248 Jim Steele says

    “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”

    1. You are making a major prejudgement when you say ‘due to this direct correlation of temperature induced CO2’ when you don’t actually know that to be true in this case.
    2. As a scientist I would have expected you to know that you can never make use of correlation to ascertain causality. So to say that this correlation may be hiding other factors is nonsense. Causality requires suitable hypotheses or models, followed by specific testing of those hypotheses or models. Correlation doesn’t come into it.

    First you say

    “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.”

    So you are saying regional temperature changes due to mankinds land use causes the major part of the increase in global temperature.
    Then you say

    “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.”

    So now you say that the effects of even strong regional changes such as the PDO can be diluted and lost when averaged into the global temperature. So which is it. You can’t have it both ways.

    “But you must then always justify the correlation with well understood processes.”

    I think the best justification would be the extremely well understood physical principles that have been used to understand the basic processes in Earth’s atmosphere and were used to predict global warming due to increased CO2 more than a century ago.

    “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?”

    It is called weather, affected by large scale atmospheric circulation, which is potentially affected by global temperatures, which is controlled to some extent by increases in CO2.

  25. 275
    Daniel J. Andrews says:

    Jim Steele said

    And Spencer Weart really doesn’t address this concern, so that suggestion is not helpful.

    I am a biologist too, and have published on small mammal cycles in the Arctic, and also do work on boreal forest songbirds (population fluctuations). Our educational backgrounds and decades of accumulated experience are probably more similar than different.

    So I strongly recommend you read Weart’s book. It was extremely helpful for me. And please listen when numerous posters tell you that you misunderstand the science because they are absolutely right. You are missing some very essential basics, and without those basics, you are going to draw the wrong conclusions when dealing with more advanced material.

    As someone pointed out, think of creationists trying to discuss evolution. E.g. They try to discuss things like ERVs, but don’t know how DNA replicates and therefore think that just because the same ERV bit isn’t found in every tested individual of a particular species tested, then this missing sequence is proof that ERVs disprove evolution.

    [Response: Edit–I meant what I said. Scientific discussion ONLY.–Jim]


  26. 276
    Edward Greisch says:

    234 Gordon Cutler: So you are saying the article is not an April fool’s day joke because it is too ironic and sarcastic? It is just vicious, not joking, and I could tell that if I could read German. Then it is very bad indeed. Thank you.

  27. 277
    Jim Galasyn says:

    Echoing Jim’s fatigue with our discussion with Jim Steele, let me suggest that we all let Mr. Steele brush up on climate science with the Start Here and Weart links, and call it a day.

  28. 278
    Gordon Cutler says:

    276 Edward Greisch: So you are saying the article is not an April fool’s day joke because it is too ironic and sarcastic?

    Jawohl! [Yes, indeed] In my letter of complaint, which routes to the three ‘journalists’ and their editors, I asked if they also believed the earth was less than 10,000 years old. Haven’t had a reply to that…

  29. 279
    RaymondT says:

    @216 Barton Paul Levenson,

    In your attachment entitled “Are the Models Untestable” you gave a list of qualitative predictions that the models can perform while also giving a list of on-going research areas. While TRENDS in temperature global temperature, TRENDS in the poleward movement of storm tracks and TRENDS in the expanded range of the hurricanes and cyclones, are useful, policy makers require more (i.e. regional quantitative predictions of peak temperatures, precipitation, wind speed, ENSO variability for example) which climate models cannot provide at the moment. I am skeptical also of the temperature and precipitation projections which are shown in the IPCC report on the century scale which are then used to estimate the impacts of global warming. The climate models are not able AT THE MOMENT of predicting QUANTITATIVELY the global temperatures and much less precipitation. The impact estimates are used to alarm the public into action. The XXXgate errors were found in the second IPCC report which deals with the impacts. I think the skeptical backlash of the international press is a reaction to the constant alarmism we have heard from environmental groups and some climate scientists such as Stephen Schneider.

  30. 280
    MapleLeaf says:

    I found it telling that DS chose to speak to and quote Landsea in the section about tropical cyclones rather than speak to and quote the lead author Knutson.

  31. 281
    Bob says:

    272 (Walter),

    I think most educated people agree that the only real debate is in the actual value for climate sensitivity, low or high. All of the other arguments about a supposed MWP being warmer than the current, or our understanding of GHG physics being wrong, or the surface temperature record having been purposely adjusted, and a million other arguments, are all dead and buried. I won’t even visit them, unless the perpetrator seems open to being corrected.

    On the question of climate sensitivity, I’ll restate my position and leave it to you to refute. There is an accumulating body of evidence from the paleoclimate record, simulation ensembles, our understanding of the physics involved, and other approaches which all point to a sensitivity of approximately 3˚C per doubling of CO2.

    Some people have put forth the idea that climate sensitivity is much lower, but without proving their case to any reasonable degree. They have suggested that a negative feedback from an increased albedo from increased cloud formation will offset other positive feedbacks, but without providing a specific mechanism, evidence in past climate events, or evidence that it is currently happening.

    I do also remember one argument that implied that the water vapor feedback which would lead to 3˚C per doubling depends on relative humidity holding constant, and arguing that this would not necessarily be the case, that relative humidity could drop enough to hold specific humidity down if not constant, thus limiting overall climate sensitivity. I thought that particular argument had some hint of merit, but I have yet to find a serious scientific paper (i.e. something other than any old random soul posting his thoughts on a web page) which logically qualifies, quantitatively defines or quantitatively measures that factor.

    Can you point me to any paper which makes a serious, strong, arguable case for a lower sensitivity than 3˚C per doubling? Until someone (a skeptic? a climate scientist? a skeptical climate scientist?) does serious work in that area, I’m afraid it is just a footnote. It needs depth and substance to elevate from being a footnote to a serious argument.

  32. 282
    Septic Matthew says:

    166, Lynn Vincentathan: Ergo, it seems to me more and more like it’s the work of the devil. For those familiar with the Twilight Zone, there is an episode “The Howling Man” (see ). In ordinary times the devil is locked up, and the wickedness in the world can easily be explained by human nature or our fallen nature, but there are times when things are just so evil, that ordinary reasons aren’t enough to explain it. So, it looks like someone has been deceived into thinking the devil is an unjustly locked up person, and has removed the “STAFF OF TRUTH” (don’t you love it) holding him locked in, and the devil has now escaped and is running rampage, corrupting humanity into very evil deeds.

    Didn’t the moderator insist that we focus on the science?

    [Response: Not soon enough apparently.–Jim]

  33. 283
    Jim Steele says:

    dhogaza 259, “Your claim that professional scientists are publishing peer-reviewed papers that amount to “just so” arguments is the vilest, most dishonest, and lowest form of anti-science.”

    Gee, looks like a few of you all went to to the same school for slanderous baseless ad hominem attack. I would suggest such attacks are the real anti-science. So you really need to heed your own words.

    Look at the article which prompted my comment, claiming that global warming was the selective force causing birds with shorter wings and less weight. I offered several arguments based on 25 years of experience and knowledge in that specific field. I have banded over 30,000 birds myself. (I would even wager that I have done more to improve the environment and people’s understanding the you ever have. One of your moderators has met me so you start there.)

    Now if you can show me how any of my objections were unwarranted, or distorted or without scientific merit and indeed those authors controlled for even half of the confounding variables I mentioned, then I will gladly apologize and accept the scorn you so venomously and ignorantly administer. I would also admit I was I was unworthy and never post here again.

    But I know that field very well. I know the variables how difficult they are to account for. In return, if you can not show me show me my objections were without merit, then all I ask from you in return is more respectful dialogue.

    [Response: I have removed the offending post and commented that all posts from this point forward must address the science questions/topics only, without personal attack of any kind. ]

    [Response: Everyone needs to make a sincere effort to ask specific, substantive questions and to respond with similar answers, without the insinuation of nefarious intent, slander, questioning of backgrounds, etc., which never result in anything other than in fact making the situation continually worse.–Jim]

  34. 284
    Rod B says:

    Green Marauder (262), I’m curious: would spouting utter nonsense be considered polluting the atmosphere?

  35. 285

    Walter (#273), if “denialist” seems disrespectful to you, then so be it; it is quite accurate, for those whom I was discussing–those who deny facts, logic, and reason on the topic of AGW.

    Moreover–and FWIW–my post wasn’t intended to “promote civility.” (Though that wouldn’t be a bad thing.) If you look back, you’ll find it was a comment about my perception of life on the dark side, AKA WUWT. (And before you jump on me about the adjective “dark,” let me assure you that it’s just a stock metaphor for ignorance–again, objectively merited when considering the class as a whole. Not every individual.)

    An extreme example of that ignorance would be one Mr. Wilde, who apparently recently penned–in a WUWT guest post, no less!–the immortal phrase “density per unit volume.” Think about that one for a second!

    I respect Mr Wilde as a living, feeling human being whose “inherent worth and dignity”–his human rights–are fully equal to mine, yours, or Dr. James Hansen’s. Does this mean I owe “respect” to ideas–and I use that term loosely–so wrong as to be overtly laughable? I think not.

  36. 286
    Jim Steele says:

    David 261 and similar replies “But the other is that you’re completely ignoring known, proven, observable physics when you suggest something like that.”

    Let me show you why I was not ignoring any physics. First I did not claim all things you suggest. I simply advised caution in BPL’s regression interpretation. I did not ever even suggest that the amount of CO2 now present is due to only to warming. I have not ever denied that humans have added more CO2.

    Exactly in keeping with all accept physics, because changing temperatures change CO2 solubility, then we would expect and observe a correlation with rising temperatures and CO2 leaving a liquid. It is precisely for this reason the RC’s interglacial explanation states that rising temperatures due to orbital forcing will release more CO2. That is something I agree with.

    I also was not suggesting BPL reversed cause and effect.

    I was most definitely suggesting that BPL’s claim of attributing 74% of the temperature change to CO2, needed to be treated with caution, because to make that claim he would need to partition out the natural correlation of CO2 concentrations and global temperatures that are caused by other forcings such as orbital forcing. Everything else people here may attribute to my comment was due to misunderstanding, perhaps in part due to my lack of clarity, and for some due to a rush to demonize what I said.

    This issue however does speak to a major skeptic point. The sensitivity of climate due to CO2 by itself vs other feedbacks.

    Let me quote Dr. Spencer “It is well known that most of that warming is NOT due to the direct warming effect of the CO2 by itself, which is relatively weak. It is instead due to indirect effects (positive feedbacks) that amplify the small amount of direct warming from the CO2. The most important warmth-amplifying feedbacks in climate models are clouds and water vapor.”

    So if there are changes in the PDO, ENSO, etc and they cause changes in water vapor and clouds that cause a positive increase in temperature, how is do you separate the positive feedback effects of CO2 from the effects of the PDO and other processes, and thus how do you determine attribution. I think once we go through another PDO cycle, and with new satellite observations of clouds, and soil moisture that in 30 years we will be able to more definitively assess the power of CO2.

    I know some feel they can’t wait that long and went to jump to conclusions, and move to quickly to save the environment. I however will most likely remain skeptical regards CO2 until that time , or earlier if the evidence gets stronger. I believe we should actively work and advocate to restoring wetlands and streams and that would be a more valuable way to spend our efforts.

  37. 287
    Jim Steele says:

    Jim, Thank you. And I want to applaud the more open nature here at RC that allows skeptical discussion.

  38. 288
    Ron Broberg says:

    Jim, this will be my last attempt to engage you on this question.

    In #180 you stated: And the pattern if advancing and retreating glaciers was another inconsistency with the AGW theory.

    You have indicated that several of the commentators, including myself, have misread what you intended to say in this statement. I have asked for clarification. I ask again.

    In what way is the pattern of advancing and retreating glaciers in the Swiss Alps inconsistent with the AGW theory?

  39. 289
    CM says:

    Lest Green Marauder’s (#262) Guardian quote on a private proposal for an international crime of ecocide derail us into another free-speech debate, it should be noted that: 1. Ms Higgins’s proposals do not appear to be on any UN agenda as suggested in the article, so the whole thing is probably moot. 2. Both moderators and many regular visitors on this site have on several occasions come out strongly for free speech and against suggestions that climate denial be criminalized.

  40. 290
    David Klar says:

    Jim Steele(255)”If the CO2 is both lagging the decreasing temperature and also had the ability to increase temperatures to the degree RC suggested, then the lagging CO2 on the down stroke will inhibit further decrease in temperature. But because the temperature records show temps do continue to fall I am left with a few possible explanations. 1) The negative orbital forcing on the downstroke is greater than the positive orbital forcing on the upstroke. But that defies our knowledge of orbital cycles 2) New or stronger processes happen at 1 degree to absorb more CO2 only on the down stroke. That seems much too arbitrary. For example albedo? At 1 degree on the upstroke why wouldn’t I expect greater ice coverage remaining from the glacial peak and thus greater albedo, than on the down stroke when glaciers have all retreated and are just starting to grow. 3) The climate is not so sensitive to CO2, its ability to amplify and raise temperatures in the upstroke is overstated. 4) #3 implies then that we have not yet accounted for all climate variables.”

    Other climate forcings such as reduced solar radiation or geologic forces such as increased vulcanism or orbital changes must also be considered for explaining this apparent paradox. The CO2 forcing has been well known as one of several forcings.

  41. 291
    James Allison says:

    Go Jim Steele. If you want non adhom attack debate and disussion visit WUWT. I’m sure some of the hundreds of thousands of regular viewers there would be happy to engage you with stimulating debate.

  42. 292
    Geoff Wexler says:


    Correction to my earlier comment. The time scales were geological. So it would have been more realistic to start from energy balance at any temperature. On the way up you consider the effect of adding a bit more power by means of an external driver (non-CO2). This causes warming , more CO2 and more warming. If you reverse the sign of the external driver the rest of the argument is also reversed and the reduced CO2 produces more cooling.

  43. 293
    Gilles says:

    David : “Similarly, but more complexly, there is a phase lag between the orbital forcing and the climate response. So at the maximum recorded temperature of an interglacial the orbital forcing has already begun to decline. This phase lag could well be on a millennial scale (I don’t know) which resolves your difficulty. Of course, there is the same phase lag at the minimum during the stade.”

    Is there any reason why the phase lag should depend on the nature of the forcing, and why wouldn’t it be also around 1000 years for anthropic forcing ? i anticipated that you could distinguish between PHASE lag and TIME lag, but I think that the most relevant physical quantity would indeed be a TIME lag, which would convert as a phase lag following the characteristic timescale. But actually a long time lag To would smooth any high frequency variation , so the instantaneous sensitivity to a 30 years variation of forcing for instance would only be 30/To times the asymptotic sensitivity – if To is of the order of 1000 yrs, it means that the effect of anthropogenic forcings should be essentially non measurable.

    [Response: The simplest possible climate model (energy balance model) provides some insight here. Imagine we had the simple balance CP dT/dt = S(t) where T is global mean temperature anomaly of a pure mixed layer ocean, CP is its effective heat capacity, and S(t) is some cyclical forcing S(t)=S0cos(wt) with period tau=2pi/w. It is easy to show that the temperature response to the forcing will be 90 degrees out of phase with the forcing, i.e. the phase lag will be 90 degrees. So If the forcing timescale is 8 years, the lag will be 2 years, if the forcing timescale is 100 years, the lag will be 25 years, etc. The real world is of course more complex, and you can find some further discussion in this paper, and references therein. However, the point is that we start out from even the simplest model with the expectation the lags in response to a simple radiative forcing are directly proportional to the periodicity of the forcing. As it happens, that basic property survives in more realistic climate models. -mike]

  44. 294
    wilt says:

    Bob (#281), I am grateful that you finally bring us all back to a focus on the science, and on one of the most relevant questions of them all: climate sensitivity and feedback. With respect to water feedback you wondered whether there were serious articles that suggest that humidity may not be constant.
    I suppose that you are familiar with the recent Solomon’s paper in Science, about changing water vapor in the stratosphere. Here is the (complete) abstract: ‘Stratospheric water vapor concentrations decreased by about 10% after the year 2000. Here, we show that this acted to slow the rate of increase in global surface temperature over 2000 to 2009 by about 25% compared to that which would have occurred due only to carbon dioxide and other greenhouse gases. More limited data suggest that stratospheric water vapor probably increased between 1980 and 2000, which would have enhanced the decadal rate of surface warming during the 1990s by about 30% compared to estimates neglecting this change. These findings show that stratospheric water vapor represents an important driver of decadal global surface climate change.’

    As for the troposphere: Paltridge has published an article suggesting that in the upper troposphere humidity is not constant and that both relative and specific humidity have decreased in the last decades, especially above the tropics. Considering that his article is about trends I think it is difficult to ignore it, even when there would be doubt about precision of some of the data in an absolute sense. Paltridge illustrates that both relative and specific humidity have decreased, especially above the tropics.

    There is a site where you can do your own analysis regarding time series of humidity data from NOAA:

  45. 295

    Re Walter Manny (235),

    I have to agree. “Denialist” or “Denier” isn’t a good term.

    How about “tinfoil-hat, pseudoscience crazies helping to destroy human civilization?” That would be more accurate, wouldn’t it?

  46. 296

    Adrian O (237),

    Try calculating the percentage increase in each case. dT is proportionate to ln CO2.

  47. 297

    SM (238),

    Houghton’s book is probably the best general overview. But you have to work the problems!

  48. 298

    Gilles (245),

    You said specifically that the climate models had never passed a crucial predictive test. I gave you 17 counterexamples. Case closed.

  49. 299

    Jim Steele (248),

    The causality runs from CO2 to temperature, not the other way around. I know this for two reasons:

    1. When it runs from temperature to (ln) CO2, there is an average lag time of 800 years. The r = 0.87 correlation I found between the two from 1880 to 2008 is for the same year.

    2. Granger causality tests show the influence running unequivocally from ln CO2 to dT, not the other way around.

  50. 300

    Rod B (250),

    To make it more accurate, you need to use emissivities other than 0 and 1. Older GCMs used to use εvis = 0.95 for the ground, but recent research indicates the figure should be much higher, and ECHAM5 now uses 0.996. In addition, you need to break the atmosphere up into levels to simulate the fact that it is not really a uniform temperature at all levels (i.e., you need to “discretize” the actual continuum). And a better model would include clouds, break up radiation into 20-200 bands rather than just visual and IR, calculate layer levels of O3 and water vapor, etc., etc. My RCMs, which are nowhere near as sophisticated as a GCM, currently use 20 levels, ten gases, and 54 bands, and usually wind up around 1,400 lines of Fortran code.