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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. 301

    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: BPL: Too simple.

    BPL: No, it really isn’t. Your labored following paragraphs to the contrary are just wrong. Until you read up on how this actually works, you won’t get it. And you seem to think CO2 exerts additional warming on any change, up or down. No. A fixed amount of warming per molecule, but when the Earth is cooling, there are fewer molecules, and the CO2 warming DECREASES, because THERE’S LESS OF IT. Thus amplifying the cooling.

    This is a well understood process and they have modeled it mathematically and matched empirical data many, many times. Again, please study the science. If you don’t like Weart, try Houghton and Petty.

  2. 302
    C. Streif says:

    I just read the whole, very long Spiegel article and after the sickening human-interest stuff in the first paragraphs it isn’t quite as bad as Stefan makes out.
    The only serious mistakes I found were two also mentioned by Stefan: citing McKitrick as a bona fide paper when it isn’t, and overdoing things a bit on the medieval warming period side(they’re right that it’s statistically possible that it was warmer, only of course the best estimates say it wasn’t, and that’s what they conveniently forget to mention). However, the rest of the long article is largely factually okay on the climate science side of things. As regards two things Stefan criticizes, but slightly misrepresents in my view: They do come to the conclusion that the CRU temperature record will in the end be shown to have been perfectly correct, and they do say that tropical storms are projected to become more severe (if rarer). Accusing Der Spiegel’s basically correct account of hurricane research of distortion seems a bit overdone on a website that touts Al Gore’s movie (where if I remember rightly Katrina is presented as a consequence of global warming when current evidence says it wasn’t, apart from the fact that the main culprit were the levees in this case).
    To be honest, what I as a green veteran found most shocking was the quote by Prof. Schellnhuber who tells us that he personally sees absolutely no reason to curb his carbon emissions (or how should I interpret his glib statement that he drives a BMW of all things, eats meat and isn’t “green” at all — even though he believes climate change will spell disaster). This felt like a slap in the face to someone who owns no car, has refrained from flying for years and does or rather doesn’t do lots of other things to keep his carbon footprint down. So is it okay to guzzle carbon? Maybe Stefan could explain that to us, seeing Prof. Schellnhuber is at the same institute and probably a close friend of his. (Or maybe he isn’t?)

  3. 303
    The Ville says:

    Back to the subject of Der Spiegel and the media…

    Surely the media will literally follow the money as the skeptics like to say.
    We shouldn’t be surprised to see allegedly friends of climate science in the media to change, when their budgets and salaries are at stake.

    Ironically if the ‘follow the money’ skeptics are correct, we will see scientists swapping ‘sides’ to denounce the research they had conducted to prove AGW, all in order to keep their research budgets when party politics demands change based on political ideology.

    Of course the fact that no scientist is going to change ‘sides’ just proves what a load of junk the statement ‘follow the money’ is.

  4. 304

    One more for Jim Steele #255: you say “the lagging CO2 on the down stroke will inhibit further decrease in temperature”.

    Think it through.

    The decrease is caused by a change in the forcing (orbital change, usually, in the paleo climate). Only once that change starts to take effect can feedbacks amplify that change. These feedbacks include less water vapour, more ice and less CO_2 as the oceans’ capacity to absorb CO_2 increases. The timescales of these feedbacks differ considerably: water vapour is near instantaneous in geological time; complete mixing of the oceans 800-1000 years.

  5. 305
    Walter Manny says:

    [Not intended to be posted, but it's your site.]

    Dear Jim:

    I can’t begin to tell you how grateful I was to see:

    [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]

    I have tried for years now, here and elsewhere (Friedman, Revkin…) and with some success, to propose getting rid of the term “denier” for self-evident reasons I won’t get into here.

    [edit -- we see nothing wrong with that term here. Those who deny the existence of something that the scientific community has provided overwhelming evidence for being true, such as AGW, are 'deniers', plain and simple. Those who complain about the label, in general, are just objecting to being called out for exactly what they are. Sorry Walter, if the shoe fits!]



  6. 306
    dhogaza says:

    Jim Steele:

    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

    Only if the atmospheric concentration of CO2 and the given liquid (the oceans, mostly, in this case) are in equilibrium. Since we’re pouring massive amounts of CO2 into the atmosphere, this precondition doesn’t hold.

    Let me show you why I was not ignoring any physics

    You are ignoring physics, observations, or both.

  7. 307
    dhogaza says:

    I can’t begin to tell you how grateful I was to see:

    [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--JimL]

    I do hope that JimL will moderate with an even hand and will delete comments that accuse the peer-reviewed literature of consisting of “just so” stories.

    If that’s not a put-down, a form of name-calling, and indeed bordering on an accusation of scientific fraud, I don’t know what is. It is certainly an anti-science claim.

    [Response: I think you are completely over-reacting on that. If something like that sets you off, how can you maintain any sense of equilibrium in this debate?--Jim]

  8. 308
    dhogaza says:

    Jim Steele:

    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.

    False dichotomy.

    BTW, I’m extremely curious as to why you think the fact that you’ve banded 30,000 birds is relevant to anything regarding ecology or climate science? I’ve banded thousand of raptors, and have taught a hundred or more people from many walks of life how to trap and process rapters, how to run a migration count site, worked with satellite telemetry, etc and know from personal experience that the mechanical and observational skills associated with doing so are to population ecology as changing a tire is to the chemistry of rubber.

    Perhaps some here think such claims lend you some sort of authority when you speak of science. I don’t.

    Nor does the fact that you’ve learned enough about the ecology of the Sierras to teach the subject at some level give you any particular authority to talk about ecological research and most certainly not climate science (I’ve taught classes in the ecology of the Great Basin, big whoop).

    You really need to follow the advice given here by several posters: learn about the science before you make public claims that you’ve managed to refute the science.

    [Response: You know, that statement typifies a big part of this whole problem. Jim Steele did not in fact argue that he'd refuted the science. He stated that he saw what appeared to him to be inconsistencies in the science, and then made some statements and asked some questions about them. It then went downhill from there as people started in with the name calling and put downs. Mis-characterizations of other peoples' stances is what leads to 95% of the problems here, as it does in life in general. Nobody likes it, and for good reason.--Jim]

    Errors such as your claim that warming a liquid will necessarily lead to a (net) outgassing of CO2 regardeless of atomospheric concentrations make clear that your understanding is tenuous, at best.

  9. 309
    Rich Creager says:

    Let’s just remember that “The Just So Stories” are creative, beautifully written and entertaining, so maybe we could cease smearing them by association. Can all agree to leave kipling out of discussions of climate change please?

  10. 310
    David Miller says:

    JS says in 286:

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

    For the life of me I can’t figure why “skeptics” think this is a point for “their side”. Every bit of science I’ve read points to the direct sensitivity due to a doubling of CO2 to the 1 to 1.5 degree range. The rest is known to be the result of side-effects of that increased temperature, such as relative humidity remaining nearly consistent. That’s all built into the “consensus” model, and why deniers like to pretend climate scientists are somehow ignorant of this is beyond me.

    The relevant question is “how much warming do these side-effects cause”. At the 95% confidence level the combined CO2+side-effects number is between 2 and 4.5 degrees, with 3 degrees having the greatest probability based on multiple lines of evidence.

    Jim continues:
    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.”

    OK, good. Dr Spencer gets it.


    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.

    Is this really a serious question from a (non climate) scientist? Are you really asking about a basic methodology?

    [EDIT: Science only--Jim] I’ll answer the question for any reading this who are new to the subject and may think what you’re saying makes sense….

    How we know the difference between the two is basic science. The PDO doesn’t change the energy balance of the earth. The PDO – and other natural variables – redistribute heat, they don’t create it.

    Water vapor is a feedback, Jim, not a forcing. If it were not so the Earth would long ago have burned up during a previous warm phase. Think about it: if water vapor provided a forcing it would warm the planet more, water vapor would increase, forcing temperatures higher still. It doesn’t work that way because the water condenses and falls out.

    It takes a warmer atmosphere – caused by the radiative properties of CO2 and other GHG’s (given stable orbital geometry) – to keep the higher level of water vapor in the air. Please try to internalize that, it’s important.

    On the other hand, CO2 has known radiative properties that does warm the surface. We know how much more CO2 is in the air and what effect that has on temperature. The only quibbling is over how much additional warming occurs as a result of the direct forcing.

    We have a historic record reaching back more than a million years, and while the PDO has been in effect most of that time it has yet to cause either continued warming, or a temporary warming of the speed and amplitude we’re currently experiencing.

    In other words, we have no historical record of current variations happening as a result of natural variability, and we have known radiative physics of GHGs.

    Jim adds:

    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.

    Finally, something we can agree upon. There’s no doubt we’ll know far more about all Earth systems in three decades.

    So here’s a question for Jim. [Edit-OT. Jim]

  11. 311
    wilt says:

    Is the comment that I sent at 4.09 AM still under consideration, or has it been overlooked somehow? As far as I can judge it is on topic (it is a direct response to a request from Bob #281 regarding publications on changing relative humidity), and it is formulated in a factual way (no name calling, or addition of any degrading qualifications). Can you have a look at it, and publish it if acceptable? For your convenience I am enclosing the comment again here in its original form:

    [Response: It was just waiting in the queue there--Jim]

  12. 312
    Walter Manny says:

    I don’t know which moderator I am responding to, but that you can request that posts be,

    “sans put-downs, name-calling and various direct and indirect innuendo.”

    and in the next breath state that the shoe fits a term that is all about innuendo is confusing at best. Still, any attempt at civility is better than no attempt at all, so thanks again.

  13. 313

    Perhaps the bashing is because you hear climate-this, green-that, eco-thus all the time….

    [Response: Even if I were to accept that premise, which I don't, that's not the fault of scientists--Jim]

    I do beleive we should treat our environment with respect though.

  14. 314
    Walter Manny says:

    ~281 (Bob) You leave it to me 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.”

    Sorry to disappoint, but no refuting that here. I could be fussy about your dismissal of paleo. considerations re. a MWP, and your immediate reliance upon paleo. in your next paragraph, but I agree that 3 is the consensus number of choice, plus or minus some other number. “Accumulating body of evidence” is a good way to put it as well, but that takes me neither to “we understand this well enough to act now and act big,” nor “there is a global warming hoax.” I appreciate the argument that there will always be uncertainty, nevertheless we must act, but I am fully open [others would say stubbornly adhering] to the idea that the uncertainty, most especially in the models, modelling, and retrofitting of models, might cut the other way.

    Further, when such skepticism is almost invariably met with refutations such as, “you are just trotting out the same old evil-oil-funded denialist talking points that have been debunked by all right-thinking scientists,” up go the antennae. When such refutations are then backed up by a chorus of “Troll! Cherry-picker! Straw Horse! D-Word!” the antennae positively resonate, fairly or otherwise, and that takes me back to pleas for civility, always and every time, so that readers can have a chance to weigh evidence rather than supposed character.

  15. 315
    Septic Matthew says:

    296 Barton Paul Levenson: Houghton’s book is probably the best general overview. But you have to work the problems!

    OH NO! Not more homework!

    To correct my previous imprecision, the thermo book that I got is “Modern Thermodynamics” by Dilip Kondepudi and Ilya Prigogine. It has problems, too.

    302, The Ville: Of course the fact that no scientist is going to change ’sides’ just proves what a load of junk the statement ‘follow the money’ is.

    Yet, people think that Exxon-Mobil money is corrupting. Perhaps you think that statement is junk as well?

    282, Jim: [Response: Not soon enough apparently.--Jim]

    My belief is that you’d be more effective if you never strayed from science: all science, all the time. RC has been “suckered” (or has “taken the bait”, or whatever your favorite expression) into defamations, financial and psychoanalytic tangents, dismay over the decline of formerly high journalistic standards, and every other way of diluting your expertise. It isn’t too late to remember the adage about wrestling the pig: you get filthy dirty, and the pig enjoys it. I don’t really mean that the denialists are always pigs; I enjoy Marc Morano’s web page sort of the way I enjoy the headlines on the rags at the supermarket checkout counter. But they lose credit with some of their off-target expressions, and so do the AGW promoters.

    It’s going to be a long, long, long (really long, etc) debate. A boring scientific repetitious, repeating, repetitive, etc. re-iteration of all the main facts is what will win the debate by 2020. At least that’s my opinion, though I can’t claim to be very humble about it.

  16. 316
    Septic Matthew says:

    Back to the analogy of wrestling with the pig: it weighs 600 lbs, is extremely strong and vicious, and has tusks.

    If you are going to argue in the public arena with Der Spiegel, The Guardian, and Marc Morano, your only superiority is your knowledge of science. On everything else, you are just ordinary folks.

  17. 317
    Jim Steele says:

    Several posters state that I don’t understand that CO2 amplifies on both the upstroke and down stroke.

    First I do understand that when the CO2 is sequestered from the atmosphere, that then, the resulting loss of radiative forcing by CO2 will cause a further drop in temperatures thus adding to the initial temperature drop initiated by the change in the other primary forcing caused by solar/orbital. If this is what you mean by amplifying the cooling then we are in agreement. If not, a specific example and concept would help. To tell me I am ignorant on some level is not helpful. Obviously we disagree. To list a few a links and say “be off with you” does not induce me to want to learn more.

    Second, the outgassing and sequestering of CO2 in the oceans is a function CO2′s partial pressure. In the context of the interglacials discussion, I have just looked at changes in temperature as the primary driver. To those who assume I do not understand that increased concentrations of human derived CO2 can also increase the partial pressure resulting in some of that CO2 entering the ocean’s today, I say you are taking my comments out of context and mis-applyng them to a different scenario than what I am focused on.

    My sticking point remains, and I refer to a simple model I described, If on the upstroke when the initial forcing raised temperatures to 1 degrees, my interpretation of the RC explanation of CO2′s role was that after the lag time CO2 will increase and incrementally (not saying linearly) thus increasing radiative forcing and further amplify the temperature rise.

    I am assuming that at the 1 degree in my simple model that lag due to heat capacity reaches a point where the physics of the ocean changes the solubility and outgassing of CO2 increases. I also assume that those conditions are the same on the upstroke or down stroke. The one minor difference being that there is a lower concentration of CO2 on the upstroke than downstroke when arriving at that temperature.

    So the simplest question I am asking is “Without any additional loss of solar forcing on the down stroke, what causes CO2 to be sequestered any further, if according to RC’s explanation that at the same temperature on the upstroke CO2 was being released.

    I have read sincere answers that said it is because a new cooling radiative balance occurs. It is not clear to me, obviously, how that differs from what I outlined. So I will state how I understand the change in energy balance. Loss of orbital forcing results in less input, temperatures fall in response, the new balance is a lower temperature and less outgoing radiation to balance the lower incoming. I am assuming that the radiative forcing due to CO2 does not change unless the concentration of CO2 changes. I assume the concentrations of CO2 will not change unless the temperature changes.(Again in the context of glacial interglacial, before humans confounded the situation)

    Mike said “The simplest possible climate model (energy 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 later 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]”

    I find responses like this very helpful as foundations for discussion. It is much more educational than a brush off and a link.
    I understand and accept the dynamics of that lag. Can you expand upon that simple model in terms of what I ask above?

  18. 318
    Jim Eager says:

    Jim Steel’s suggestion that some portion of the current observed increase in atmospheric CO2 could be caused by warming of the ocean, as during the termination of a glacial stade, demonstrates a shortcoming in his understanding of the physical science involved and a basic error of logic.

    The fact that humans emit more than twice the annual increase in atmospheric CO2 each year means that the combined biosphere and ocean sinks are net absorbers of CO2. For these sinks to make a net positive contribution to any increase in atmospheric CO2 the portion of human emissions that they do not absorb, the so-called “airborne fraction,” would first have to decrease to zero.

    Much ado was made late last year of the absence of exactly such a drop demonstrated by the much misunderstood and misrepresented Wolfgang Knorr paper Is the airborne fraction of anthropogenic CO2 emissions increasing? (GRL 2009).

    Apparently someone has not been keeping up with the literature. Possibly because it is outside his field of science, perhaps?
    A lot of that going around lately.

    Moreover, in view of Mr. Steel’s citing of CO2′s nominal 800 year lag of temperature increase, what would be the source of his proposed 800-year-old warming supposedly driving the current observed increase in atmospheric CO2? The Medieval Warm period, perhaps? The problem with that is that the MWP was not sustained as it was terminated by a period of lower temperatures. You know, the Little Ice Age.

  19. 319
    Jim Steele says:

    dhogaza, I feel like you are my new best friend, hanging on my every word,but that I have terribly upset. Can you explain why comments like “Creationists such as Roy Spencer who do science are, of necessity, capable of highly compartmentalizing their lives.” is respectful of a scientist but my comment about a study was really a “just so” story is anti-science. I based my conclusion on several lines of evidence and stated such. You attack his personal life. If you disagree with peered review papers by Spencer, Christy, Lindzen, Pielke, Scarfette, etc I would suspect you would categorize their work as something akin to a “just so” story. So I think you are hung up on the semantics. But when in Rome.. so if I think a paper like the bird evolution paper lacks scientific merit to make the conclusions it did, what would be acceptable to turn of phrase?

  20. 320

    JS (317): To list a few a links and say “be off with you” does not induce me to want to learn more.

    BPL: What WOULD induce you to want to learn more?

  21. 321

    UN climate chief Yvo de Boer at end of 3-day Bonn climate meeting: pledges to cut emissions far short of avoiding catastrophic global warming:

  22. 322
    Rod B says:

    Bob (281), you say, “…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…….. are all dead and buried.”

    Just a pro forma rebuttal: the hockey stick debate was about the MWP being warmer or not, not about the value of climate sensitivity per se.

    2, I have no proof of what the actual climate sensitivity is, but then again, despite your assertions, neither do you. You have some pretty good stats over the last 100 years or so that provides insight into sensitivity under (only) the conditions of the last 100 years or so. Also some physics theory replete with numerous convenient assumptions. Then some very loosey-goosey indications in paleoclimatic history, most of which are looking at CO2 lag. Admittedly, these don’t make your assertion wrong, but IMHO, it is miles from unassailable evidence as you contend. My “proof” to justify my assertion need not be better than yours just to get a seat at the table.

    BTW, these comments in no way support the DS article.

  23. 323
    MapleLeaf says:

    Moderators, Jim Steele and Walter Manny,

    Jim you stated earlier that “And I want to applaud the more open nature here at RC that allows skeptical discussion.”

    So Jim, do you still stand by this statement?

    “I would try to have discussions with the scientists at RealClimate but they would selectively delete any posts that they couldn’t dismiss. … these scientists would manipulate a public website … what would they do behind closed doors.”

    In light of those comments and your behaviour here, I do not believe this to be a genuine discussion on your part about the science. Many posters have politely directed you to resources and even explained the basic science to you. Yet, you stubbornly insist on ignoring the information and explanations, and I doubt very much if you have even consulted the information/links provided.

    [Response: Not a fair characterization. It's been a mixed bag of substantive answers mixed with personal attacks, with some cop-outs about going to the "Start here" section thrown in.--Jim]

    I think that you are very much taking advantage of the good nature of the moderators here. There is no way that CA or WUWT would also someone to go on off topic for so long. And your posts have largely been off topic. This thread is about Der Spiegel.

    [Response: Is there an RC post that doesn't go off topic?--Jim]

    Yes, some have been harsh, but you should having published papers know that science is not always polite.

    [Response: So that's a justification to be rude here???--Jim]

    Now, IMHO, if you have anything which pertains directly to what Stefan had to say about the Der Spiegel article, then I’m sure people would be happy to engage you and discuss the science about those points.

    Moderators, I sense that you are moderating people engaging Jim and other contrarians here (and that is OK, I expect that you will moderate portions or all of this post, and I am OK with that), but I do not sense you editing Jim’s OT comments. What gives?

    [Response: What gives is that we find ourselves playing 3rd grade teacher because certain adults cannot find it within themselves to simply discuss science instead of attacking and slighting others. Then some of us have to try to slow down a run away freight train with a lasso, while catching flak from those who started it rolling in the first place.--Jim]

    Anyhow, thanks to all at RC, you have a thankless and trying job, and have infinitely more patience than I do.

  24. 324
    Rod B says:

    Barton (300), thanks for the help. In addition to just insolation, I can see how emissivities can affect the end results — though this will not be significant. I also see how making the system more granular will improve the accuracy. None-the-less, the physics of your simple model are correct (given the assumptions) if maybe not exact, which still tells me that the composition of the atmosphere is not an independent factor — at least not a material one. If earth was devoid of GHGs it still would have a Ta of near 254K and a surface temperature of around 300K. Correct?

  25. 325
    Petro says:

    Jim Steele 317:

    Can you tell what you mean with this sentence:
    “To those who assume I do not understand that increased concentrations of human derived CO2 can also increase the partial pressure resulting in some of that CO2 entering the ocean’s today, I say you are taking my comments out of context and mis-applyng them to a different scenario than what I am focused on.”

    How come “humand derived CO2 can also increase partial pressure”. Why not “humand derived CO2 increases partial pressure”, because that is what happens. Do you accept that burning of fossil fuels by humans increases CO2 levels in the atmosphere or not?

  26. 326
    Petro says:

    Also Jim Steele:

    It is very hard to follow, what is your problem. The many-worded sentences you produce are really hard to understand. That is main reason you get attacked: Nobody really undestand, what is your point, especially when some of your clearest sentences includes:

    89 “If you look at the Swiss Alps, the percentage of advancing glaciers have 2 peaks in 1920’s and 1980’s each followed by an increase in retreating glaciers like we see now. Those changes correlate very well with the PDO and no correlation with rising CO2.” which is a classic cherry picking omitting major part of data.

    “But your collection of “climate driven” changes are nothing more than a lot of “just so “ stories.” where you dismiss hundreds and thousand of ecological studies being trivial

    “Jim Steele| 11.26.09 @ 11:48AM
    Is this Godfather III: “The higher I go, the crookeder it becomes.” ?
    … I would try to have discussions with the scientists at RealClimate but they would selectively delete any posts that they couldn’t dismiss. … these scientists would manipulate a public website … what would they do behind closed doors.
    … I wonder how high this whole climate gate will go. There is a strong effort to play this down as if nothing has happened but clearly there have been attempts by the major players in climate science to exert tyrannical control over the scientific process….”

    Would you mind pick one topic at time, you want to have clarity and stick to that one topic until it has been managed here? That way you would avoid being misunderstood, and maybe get less attacks towards you.

  27. 327
    dhogaza says:

    Jim Steele:

    Can you explain why comments like “Creationists such as Roy Spencer who do science are, of necessity, capable of highly compartmentalizing their lives.” is respectful of a scientist

    What in the world leads you to believe I meant to be respectful to Roy Spencer???

    To those who assume I do not understand that increased concentrations of human derived CO2 can also increase the partial pressure resulting in some of that CO2 entering the ocean’s today, I say you are taking my comments out of context and mis-applyng them to a different scenario than what I am focused on.

    Baloney. Since CO2 is always outgassing from and being dissolved into the ocean, clearly the only thing that matters is the net exchange.
    [Edit--is there something about my requests for no personal attacks that you don't understand? Jim]

  28. 328
    dhogaza says:

    Jim Steele did not in fact argue that he’d refuted the science. He stated that he saw what appeared to him to be inconsistencies in the science.

    And the consequences of such inconsistencies? A refutation of mainstream conclusions that don’t recognize those supposed inconsistencies.

    You’re letting him off the hook far too easily. As MapleLeaf points out above (and as others have pointed out earlier), there’s really no reason to supposed that Jim Steele is genuinely interested in learning.

    [Response:If you spent 1/10 the time and energy you spend trying to crucify others based on your assumptions of what their motives are, on addressing the science instead, everyone would be far better off. In fact, unlike numerous others, I've not seen you give a single on-topic answer to any of the points he raised. I could pick apart numerous statements you've made here if I wanted to. And unlike you, I know Jim Steele, and know more about his likely intentions than you do.--Jim]

  29. 329
    David B. Benson says:

    Jim Steele (317) — All macrophysical responses have some form of lag. For example, the foxes and rabbits example found in beginning population biology texts. With simplified equations for population growth and decay for each of rabbits and foxes seperately leads to a solution with both populations changing sinusoidally, with the foxes lagging the rabbits both in growth pahase and in decline phase. Think of foxes as a (negative) feedback on rabbits.

    Now lets do some linear system theory. Of course on the scale of orbital forcing responses, the actual climate does not have linear responses, but the general ideas are still applicable. I’m going to do the calculations with Laplace transforms, in the s plane as it is called. This makes the calculations very easy and then we look in a table of function-transform pairs to see the time domain response. The first rule is

    O(s) = T(s)I(s)

    where O is the output, T is the system transfer function and I is the input. In this example, O is the global temperature, I is orbital forcing and T is the Terrean climate.

    The second rule is for feedback. I’ll use the simplified form

    O(s) = I(s)/(1-H(s))

    where H(s) is the feedback transfer function. In effect I am treating the climate temperature response as having a direct feedforworrd of 1. This is quite reasonable on a millennial scale; temperature O(s) directly depends upon orbital forcing I(s). So Terra’s climate transfer function is T(s) = 1/(1-H(s)) with H(s) the feedback due to CO2 and the minus sign because it is a positive feedback. [Sorry about that, but that's how it works out.]

    Now we need an approximate feedback system function H(s) which resembles the cycling of CO2 in and out of the deep ocean. Since I’ve learned that the characteristic time for the deep ocean is about a ky, a good choice is

    H(s) = 1/(s+1)

    which in the time domain is H(t) = exp(-t). Remember time is on a millennial scale.

    The orbital forcing is approxximately the sum of several sinusoids:
    Being a linear system, we can just add up the responses to the different sinusoids but (for reasons unknown to me) obliquity is the most important for glacial cycling and just consider that. The Laplace transform for a cosine is

    I(s) = s/(s^2+a^2)

    with the value of a being around 2pi*0.023 = 0.145 from Tamino’s graph.

    Now we just need to do the arithmetic. T(s) = (s+1)/s so

    O(s) = (s+1)/(s^2+a^2)

    and looking in a table of function-transform pairs

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

    which can be written as a cosine with a phase lag as

    O(t) = sqrt((1/a)^2+1)cos(at+p-pi/2)

    where p = arctan(a)

    Now arctan(0.145) = 0.144 so the lag is about 1.427 ky which is ok, however the amplified response is 6.9, instead of around 2–3. But the principle is at least illustrated that the temperture O(t) lags the sinusoidal orbital forcing posited.

    [Response: Thanks once again David.--Jim]

  30. 330
    Bob says:

    294 (Wilt),

    Forgive me, I’ve been out most of the day, and will be out again in a moment. I will re-read your info (I’ve read them before) before I comment, although off the top of my head, the stratospheric study says absolutely nothing about the mechanism or likelihood of water vapor remaining in the stratosphere. My recollection is that it was an anomaly that was noted and of interest, but in no way implies a future, permanent negative feedback.

    I do have to look into the other more closely before commenting.

  31. 331
    Bob says:

    314 (Walter),

    So I bring the conversation to science, and your response is that you agree with me, but then launch into a series of diatribes about trolls and evil-oil-empires that had nothing whatsoever to do with anything I said.

    Do you want to discuss the science, or not? Anything else is a waste of time.

  32. 332
    Bob says:

    322 (Rod B),


    I have no proof of what the actual climate sensitivity is, but then again, despite your assertions, neither do you

    Would anyone here like to direct Rod to the myriad studies that justify a 3˚C per CO2 doubling climate sensitivity?

  33. 333
    Jim Eager says:

    Mea culpa: @318 I wrote “For these [natural CO2] sinks to make a net positive contribution to any increase in atmospheric CO2 the portion of human emissions that they do not absorb, the so-called “airborne fraction,” would first have to decrease to zero,” which is exactly backwards.

    It is the fraction of human emissions that are absorbed by those sinks that would first have to go to zero.

  34. 334
    Jim Steele says:

    Maple leaf et al , “So Jim, do you still stand by this statement?
    “I would try to have discussions with the scientists at RealClimate but they would selectively delete any posts that they couldn’t dismiss. … these scientists would manipulate a public website … what would they do behind closed doors.”

    I did indeed make that comment because that was exactly my experience. I offer this example because if it is possible to prove what I am saying, RC may be able to find the deleted post and verify the following. When the Steig paper was published I checked in here just as discussion of it was first posted. My comment was that I felt that portraying Antarctica as warming did not eliminate the inconsistent behavior because it was really dependent upon the start date. I cited Chapman, an IPCC author on polar climates,who said “Trends computed using these analyses show considerable sensitivity to start and end dates, with trends calculated using start dates prior to 1965 showing overall warming, while those using start dates from 1966 to 1982 show net cooling over the region.”

    I asked if the more pressing question isn’t to ask why,that when the recent warming since the 60′s was elsewhere being attributed to global CO2, why was Antarctica cooling. And that a more valuable scientific discussion is to clarify when and why start points are chosen when demonstrating trends. My post first appeared as the 3rd post but was soon deleted. I looked later to see and still did not see it. I had several similar experiences, sometimes where my first post gets attacked with the same ad hominem witnessed here , but denying me any posts to rebut.

    My experience in this thread has been different, at least regards the moderators. They have allowed respectful skeptical comments if it adheres to the science.And they are trying to keep it respectful by eliminating ad hominem attacks, but allowing pointed and sharp criticism. I think that is correct arena for debate. So I do indeed applaud that change, because despite what you may think of me, I visit here to get balance to my input on climate issues, whether or not I agree with the final interpretation. So I stand firmly behind both statements.

    Now I thought this thread was not just about DS, but how DS addressed the perceived inconsistencies. I thought some were fair and some not. I also found the title interesting because both sides are guilty of bashing. Most of my subsequent posts were in response to others, not some nefarious design to lead the post astray. please.

    I realize it might be frustrating to restate something you believe is clear to you. But as an educator you realize that just because you explained something well to the last class, the next class will need to start over. I suggest that is the fate of an educational blog.

    Then to prove that I am what? a troll? a climate science hit person” or whatever, you say “This is also evidenced by the fact that after two days, we are not further ahead in this ‘debate’ than when you arrived here. ” Part of the reason there has not been a meeting of the minds is that some of the things I asked get mis-applied, or jumped on in such a way that I interpret it to mean you did not understand my point. Sometimes I felt comments were not intended for educationa purposes but solely to discredit me. So I will be slow to follow any proposed links when I feel talked down or attacked. And perhaps it wasn’t me who was cleear enough. So I have painstakingly tried to make my point clearer, and be more careful to say in the correct jargon. Hi hope my last point, clarified my sticking point, and that it may lead us closer to better communication and perhaps a better mutual understanding.

  35. 335
    David Miller says:

    Jim says in #317:

    ….. It is not clear to me, obviously, how that differs from what I outlined. So I will state how I understand the change in energy balance. Loss of orbital forcing results in less input, temperatures fall in response, the new balance is a lower temperature and less outgoing radiation to balance the lower incoming.

    Yes, this is right… However this next bit misses the point:

    I am assuming that the radiative forcing due to CO2 does not change unless the concentration of CO2 changes. I assume the concentrations of CO2 will not change unless the temperature changes.(Again in the context of glacial interglacial, before humans confounded the situation)

    The “insulating” effect of the CO2 doesn’t change – the GHG’s will reflect about the same percentage of outbound IR. But you answered your own question. Orbital and albedo changes change the temperature. Over a sufficient length of time this cools the oceans. Cooler oceans absorb more CO2 from the air. This is exactly the same mechanism as the positive feed back when coming out of the glacial, just running backwards.

    So the simplest question I am asking is “Without any additional loss of solar forcing on the down stroke, what causes CO2 to be sequestered any further, if according to RC’s explanation that at the same temperature on the upstroke CO2 was being released.

    I’m not sure which part of the down stroke you’re referring to. The only time you hit stable insolation in this context is at the top or bottom of the cycle. On the up stroke warming leads CO2 increases for a while until the change in forcing of the CO2 exceeds the change in insolation, after which CO2 will have more effect on increasing temperatures than changing insolation. On the down stroke it just works in reverse. The simplest general answer to your question, however, is “because the CO2 concentration is much higher coming out of glacials and much lower upon entering them”.

    There is a huge wealth of information available on this site, and a nice search engine with which to find it. On the topic of CO2 changes leading/lagging temperature there have been two articles here at RC that discuss it at some length here and here

    [OT, sorry] It’s interesting to note how things have changed. The 2004 article had 4 responses and the 2007 post – defending the science in AIT – had 87. Now relatively quite posts sport 200-300 comments, and the CRU kerfuffle had several threads in excess of 1000. How things have changed!

  36. 336

    Climatology and IPCC bashing is on the rise, and even if one may deplore unfair personal attacks, it would be too easy to reject all recent critics as being too far away from the real thing (i.e. having allegedly not much published, as Hans von Storch is given as an example). Claude Allègre, a geochemist, former French minister of Education and holder of the 1986 Craaford Price in geochemistry (<a href=""<here) has just published a very caustic book in France “L’imposture climatique” (approximate translation: climate swindle). This book is so successful, that more than French 600 “climatologists” are asking their minister for help and censuring. If this non-scientific, very outspoken book makes such a splash, is it that all buyers are imbeciles or uniformed? Or could there well be some truth in both Allègre’s book and in the Der Spiegel article?

    [Response: Allègre's book is garbage - full of basic errors, misrepresentations, and simply made up 'factoids'. And I doubt that you are really wanting to make and argument that book sales numbers trump scientific truth? I recall that Velikovsky and Erich von Daniken were both very successful.... - gavin]

  37. 337
    John Peter says:

    There are approaches that could be much more effective than complaining about climate scientist bashing. Recently Jim Hansen, a respected climate scientist, has become more active against some of the contributors to AGW. As far as I can tell, the MSM has been supportive, or at least non-critical of his activity.

    “…In the face of recent Obama administration actions to regulate and not abolish mountaintop removal, which has wiped out 500 mountains and destroyed historic communities, the action launched a yearlong national campaign to bring mountaintop removal to an end.

    “I am not a politician; I am a scientist and a citizen,” said Dr. James Hansen. “Politicians may have to advocate for halfway measures if they choose. But it is our responsibility to make sure our representatives feel the full force of citizens who speak for what is right, not what is politically expedient. Mountaintop removal, providing only a small fraction of our energy, should be abolished…”

    Less worrying about combating “public opinion”, climate-gate and such, and more attention to the details of destructive climate change might, IMO, be better use of our energy.

  38. 338
    Jim Steele says:

    David B. Benson, Thanks for the lengthy reply. I will need to spend this evening digesting it, so the lack of a quick reply should not be interpreted as if I am not appreciative.

    Petro: 2 things. You say “my Alps vs PDO was cherry picking”. Please explain. I am not sure what you refer to. If you conclude this because I did not also compare aerosols, again, that was due to not knowing how to quantify and graph it. I would be glad to know how to do that and will follow a link to that data, as I said earlier.

    2nd when you say I have too many topics and quote 3 things. One quote was something I made months ago on a different site that has been brought her by others to prove I am a nefarious person or some how my questions are not sincere. Other than that It has been a bit scattered because I have tried to reply to the many other posts. Would you suggest I ignore them?

  39. 339
    Geoff Wexler says:

    Re: #322

    the hockey stick debate was about the MWP being warmer or not, not about the value of climate sensitivity per se.

    I beg to differ. The debate could have been about the science. It could have been a genuine polite,discussion about confidence, statistical significance etc. As it turned out, most (not all) people who promote (promoted) the idea of the hotter MWP do (did) so as part of a propaganda campaign against the whole of climate science. Melanie Phillips and Nigel Lawson are just two examples from the UK.

    The argument about the hockey stick, has been so remarkably unpleasant that it appears that the real agenda has not been about the warmth of the MWP but about an attempt to discredit individuals. Although the attempt failed, there is ample evidence that it has never really stopped, for example according to Stefan’s article, the temperature reconstructions are being described as a “sham”.

    If on the other hand it was the conclusion which mattered most, we should have heard much more about the implications, if any,of the speculated hot MWP on the climate sensitivity. After all, that is what matters most for our future. But unless you suppose that an enhanced and global MWP was unforced (a highly speculative conjecture ) you would have to find some extra forcing from somewhere or end up with a higher climate sensitivity.

    Please see Raypierre’s article

    and Stefan’s earlier one

    Given arguments like these, it is not surprising that the propagandists have emphasised opportunities they see for sewing distrust.

  40. 340
    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 is not particularly illuminating.

    And please quit pretending that you somehow keep not seeing my question too – thanks.

  41. 341
    David B. Benson says:

    Fixing my comment #329: its been decades since I have wielded linear system theory in anger, as the Briticism goes, and I made a mistake regarding the phase lag. The lag of 1.427 radians (not ky) is nearly, but not quite 90 degrees of arc. If we want to write the cosine as


    for a time lang of l, divide by a;

    l = 9.84 ky

    For a nonlinear model of climate following orbital forcing, I recommend E. Tziperman, M. E. Raymo, P. Huybers, C. Wunsch, 2006.
    Consequences of pacing the Pleistocene 100 kyr ice ages by non linear phase locking to Milankovitch forcing
    available as a pdf from Carl Wunsch’s homepage.

  42. 342
    John Peter says:

    A more recent example:

    “…* Outside the courthouse, there will be a mock trial, with experts like NASA’s Jim Hansen providing the facts that should be heard inside the chambers. We don’t want Tim on trial—we want global warming on the stand…”

    In political debate the one who “frames” the question is likely to be much more successful than an opponent who accepts that framing. By continuing to discuss the emails, etc. in your opponents terms, you gain little more than keeping attention focused in the wrong place.

    There are plenty of examples, every day, of local actions that contribute to AGW. If the objective of your activity is to use your science to improve the continuation of civilization as we know it, examine Jim’s example and his advice. (BTW – Ram too)

  43. 343
    Septic Matthew says:

    329, David B. Benson: Can you estimate the lag of temperature change behind CO2 change that way?


  44. 344
    ghost says:

    RE: Bob # 240:

    This isn’t a comment on the science, but I find Bob’s story of his search for truth (and all of the similar stories before his here on RC) to be truly inspiring. One wonders how far along that path the Der Spiegel writers have traveled. It fits right in with the 12 March “Why we Bother” post’s theme, and is a good reminder to me that people who are not in-field special_ists can access AGW’s complexity. I admire a convergence of industry with applied intelligence, and Bob’s story and the entire RC experience very much exemplify that convergence for me. A thankful nod to Bob, to the RC moderators, and to all of the serious contributors here. If there are any antidotes for the ‘new age of superstition’ (nos. 179 and 210), Bob’s path and the work of RC surely must be two of them.

  45. 345
    David B. Benson says:

    Septic Matthew (343) — Not from millennial scale effects. I chose a decade for the lag of global temperature behind CO2 in
    based on the fast effects obtained in actual climate models; those led to Tamino’s two box model (linked in the above link) and using that and some knowledge of big climate models simplified the physics down to simply stating “about a decade”. Simplifiedd, but not overly so.

  46. 346
    Ray Ladbury says:

    Francis Massen@336,
    I am afraid that the problem is less one of intelligence and more one of human psychology. Humans generally do a very poor job of of-the-cuff risk analysis. We exaggerate the risk posed by immediate threats, e.g. terrorism, vaccination, etc., and underestimate risk posed by more remote threats–e.g. cell phones and driving, smoking, etc. Climate change is more likely to affect our progeny than ourselves, so we tend to 1)underestimate the risks and 2)think we will be able to deal with them later. Another aspect of human psychology that works against us is that the more horrible the consequences of a threat, the more likely humans are to simply shut down cognitively. This is one of the aspects of anti-smoking advertising that was slowest to sink in: the more harsh the warning or horrifying the picture of the diseased lung, the less likely was the smoker to notice it.
    The appeal of the denialists is that they are telling people what they want to hear. Climate change is bad news for everyone. There are even some scientists–from cynical opportunists like Allegre who see it as a way of advancing their agenda to starry-eyed utopians like Dyson who just don’t want to think about a threat to their Tecnopia–who fall victim to wishful thinking.

    Still, science is the only tool we have to make us turn away from comforting lies to confront reality. When the truth is unpleasant, though, the messengers of truth are bound to pay a price.

  47. 347
    Ray Ladbury says:

    Rod B.@322
    Rod, that has to be one of the most ignorant statements I’ve heard you make. CO2 sensitivity is constrained by about a dozen different studies, all of which aggree on the range of possible values and the overwhelming majority of which favor a value around 3 degrees per doubling. So, in fact, Bob DOES have evidence. Here’s some of it. Now, as to your words, as Julia Childs would say, “Bon Apetit!”

  48. 348
    MapleLeaf says:

    Just to expand on Ray’s comment @347. For those looking for a less technical discussion on climate sensitivity:

    And yes, independent lines of evidence point to +3C. Also see Dr. James Annan’s work.

  49. 349
    Bob says:

    347 (Ray),

    I think you intended to provide links supporting CO2 sensitivity…

  50. 350
    RaymondT says:

    @ David Miller (310),
    In response to the following statement by Jime Steele (286)
    “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 do you separate the positive feedbacks of CO2 from the effects of the PDO and other processes, and thus how do you determine attribution”

    you wrote:

    “1) The PDO does’t change the energy balance of the earth. The PDO-and other natural variables-redistribute heat they don’t create it. 2) It takes a warmer atmosphere – caused by the radiative properties of CO2 and other GHG’s (given stable orbital geometry) -to keep the higher level of water vapour in the air”.

    I agree with your statement on a time scale beyond that of the PDO (30 years or more). The question raised by Jim Steele is still valid in the history matching (hind casting) of the temperature history and therefore in determining quantitatively the forcings. According to Mojib Latif 10% to 50% of the warming in 1990′s could be attributed to internal decadal oscillations.

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