Christopher Monckton Challenges Scott Denning Posting

A well-known British climate skeptic writes an extensive essay laying out his disagreements with climatologist Scott Denning’s recent Yale Forum posting.

British climate skeptic Christopher Monckton is having none of Colorado State University climate scientist Scott Denning’s recent posting calling for a change in the culture of climate change dialogues.

Denning in that piece singled-out Monckton and two other climate science skeptics as unlikely to have been swayed by Denning’s 2010 and 2011 presentations before skeptical Heartland Institute annual meeting audiences. He was right on that point, Monckton confirmed in a 10-page 4,547-word essay he submitted for posting.

Given the length of that response, The Yale Forum has decided not to post it as either a feature or as a comment, as it vastly exceeds the length of all but a few previous postings. The full Monckton commentary is available here.

Among points Monckton makes in his response to Denning:

  • He argues that “consensus will not do as the basis for policy-making” and rejects Denning’s citations to work pointing to widespread agreement among climate scientists.
  • He claims there is “much heat, little literature, and no consensus” on the question of how much global warming actually will occur, and argues that numerical methods based on “big computer models” about the climate’s long-term evolution amount to no more than “expensive guesswork.”
  • He argues that climate sensitivity analysis “openly questions whether we shall see more than about 1 Celsius degree of global warming this century” and says much of that warming “would be beneficial, not harmful.”
  • He says “the true difference between [what he calls] the true-believers and the skeptics” is found in temperature feedbacks, which he concludes will be “somewhat net-negative, attenuating rather than amplifying the direct warming and removing the climate problem altogether.” This leads him to conclude that “this century’s CO2–driven warming will be just 0.5 Celsius,” about .8 F.
  • “CO2 mitigation measures inexpensive enough to be affordable will be ineffective,” Monckton argues, and “measures expensive enough to be effective will be unaffordable. Since the premium exceeds the cost of the risk, don’t insure.”
  • He accuses Denning of setting up “a number of straw men” and maintains that the actual consensus is that “a degree or two [Celsius] of warming would indeed be good for us.”
  • He criticizes Denning for providing “not a single quantitative argument,” but rather for providing a commentary “full of politics and polemics and emotion and a startling number of fallacies.” “This does not impress,” he writes.
  • “Skeptics use reason. True-believers don’t,” Monckton concludes. “The general public — not half as dim as academe imagines — can tell the difference.”

Monckton’s views are unlikely to come as news either to those who accept or those who reject them and who have followed his frequent public presentations over the past few years in the U.S. and overseas. They are views that the scientific establishment by and large has repeatedly evaluated and found unconvincing based on the broad understanding of relevant scientific evidence.

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52 Responses to Christopher Monckton Challenges Scott Denning Posting

  1. Brian G Valentine says:

    ” … and found unconvincing based on the broad understanding of relevant scientific evidence.”

    If this “evidence” refers to “global warming,” there regrettably is none, other than the phenomenon of conviction of an external reality located nowhere other than the mind of the beholder of the conviction

    • jude says:

      Almost wrote: “LMAO,” but decided on sharing that your reply reflects the ridiculum (yeah, I just made that word up) of the entire man-made global warming hoaxers gang.
      I am planning on memorizing your statement & sharing it with my students.

  2. Brian G Valentine says:

    Comments are “moderated” herein and I am certain mine will displayed prominently for all readers to reflect on a self-evident truth

  3. Monckton is a babbling sideshow barker, a dilettante debater who jumps from print to video to live presentations. He prefers to follow through with print – since the a 4000 word screed can mask a careful evaluation of the issue.

    I await his response to the YouTube journalist Potholer54, who has made superb debate challenges to Monckton – so far unanswered.

    • Brian G Valentine says:

      I think it is quite fair to ignore “challenges” issued from apparently quite anonymous “you tube bloggers,” Mr Pauli, and I should hope you would do the same

      Brian G Valentine

      • Interesting that you insist on background on Potholer54

        He started writing for the British press in 1980 – wrote for Britain’s Sunday Times, and New Scientist magazine for 16 years. Lately to the London Daily Mail, the Observer and View magazine. He has been a Far East correspondent for many publications.

        Lately renowned for his “Golden Quack a Duck” awards, where he does line by line analysis to mistaken reportage.

        You may want to check for yourself. Or maybe not.

        • Brian G Valentine says:

          Thank you, Mr Hatfield is vaguely familiar to me, I don’t know why he elects to maintain a blog life in his moniker.

          Anyway I have no idea why Monckton ignores his overtures, Monckton has nothing to lose by responding.

          In the USA belief in “man-made global warming” by many “science” reporters is absolute, although their knowledge shaky; a situation few of them find disconcerting in the least.

          Confidence, or at least the appearance of it, and the ability to project and maintain that appearance, is everything

          • Mike says:

            Some more background for you.
            Monckton did engage Peter Hadfield in a debate on Wattsupwiththat. He stoppedresponding when Peter exposed every single misrepresentation in every single one of his arguments. He demonstrated inconsisitencies and direct self-contradictions by Monckton. I fully recommend checking out the exchange. It was at that point that Monckton refused to answer any of the criticisms levelled at him by Peter Hadfield. He was shown up to be a charlatan.

      • JC Smith says:


        What anonymity? Peter Hadfield (Potholer54) has a website that welcomes “all comers”. He is about as anonymous as Kobi Bryant.

        Hadfield SHREDDED Monckton and made Monckton look like a buffoon. And not only did Monckton look foolish, but now Anthony Watts has been exposes as a fraud, by cutting off the debate after Monckton was made a fool of.

        Monckton got caught lying….and now there is no way out. Here is but one of the videos done by Peter Hadfield that exposes Monckton:

  4. Barry Woods says:

    He does go on a bit (Monckton that is) oddly, he is probably far more well known in Australia and the USA than he is in the UK..

    I prefer Bishop Hill:

  5. gail Zawacki says:

    Surely this is all that is necessary to indicate how utterly vacuous are the qualifications of this climate change “challenger”?

    • Bruce says:

      Instead of directing people to youtube videos why not try reading Monckton’s lengthy essay and then attempt to rebut it – or is that too much bother for you? You’re like those premature cli-maxers who respond to sceptics by telling them to read the discredited “counter arguments” at the SS (Sceptical Science) website. Here’s a little exercise for you: pretend that Monckton’s essay was written by Michael Mann during a particularly lucid phase. Now go and tell Mann where he’s gone wrong.

      • gail Zawacki says:

        Yes. That is waaaaaay too much bother for me. I waste no time rebutting creationists or alchemists, either. Monkton’s blather is garbage, not science, and not worthy of my comment – and no more worthy of space than witchcraft or voodoo on this site either.

        • Randall says:

          You waste no time in rebutting other points of view. In other words…you hold to your religion?

    • Brian G Valentine says:

      If by “vacuous” you are referring to this Komedy Skit I would have to agree;

      I think it was Newton Minow who referred to Tele Vision as the “vast wasteland.”

      As Hubble’s observations expanded the known universe by about a hundred orders of magnitude, so the Internet expanded the void of meaninglessness that Television’s airwaves could never reach

  6. Why is Monckton’s nonsense to be found here? What on earth is going on?

    • Brian G Valentine says:

      Well, then, put him on your blog, for a change of pace from the hysteria that must be getting old for your audience

    • Bud Ward says:

      Tenney: Thanks for your question. You’re not the only one to ask it. My response is that I saw/see it as my journalistic responsibility, as I understand it having practiced journalism for more than three decades, to give our audience an exposure to a response written specifically to something we have posted. My paragraph at the end of the news item linking to Monckton’s response is also part of that responsibility as I understand it. To have not shared that response with our audience (and in the fashion we did) would have been to shirk our responsibility…again as I understand it.

      • Bud, I agree with Tenney. Monckton has many vehicles to post his nonsense. You legitimize his standing in the anti-AGW community by posting his ramblings here.

        Why do you suppose Heartland wants real climate scientists to come to their conference? Why do so few ever go?

        You have just opened the door to a possible flood of “essays” from Watts, Morano, Bastardi, D’Aleo, Singer, Coleman, etc.

        • Bud Ward says:

          Thanks, Scott. We get lots of unsolicited materials submitted, and we’re perfectly comfortable making decisions on case-by-case basis in the future. I don’t believe we’ve opened any such doors.

          • Dear Mr. Ward,

            Thirty years ago, there was a different type of journalistic conversation, where often the parties spoke in good faith.

            That is not what we have going on here, now.

            Monckton has been shown repeatedly to be anything but a real scientist. He has glibly spread his non-science across the globe at the behest of fossil-fuel companies, confusing audiences who have no good grounding in science. He has repeatedly attempted to smear the reputations of honest scientists. He has no standing in the scientific community.

            Thirty years ago, he would have been considered a member of the extreme fringe and given space only in the National Enquirer.

            He still belongs there.

            The conversation we so desperately need now is how we can move forward in solving the immense problems that climate change is bringing us.

            The fossil-fuel companies are laughing up their sleeves while we remain distracted by conversations we’ve already had, over and over again for the past several years — needless and regressive conversations.

            Mr. Ward, I would have to say that we live in a time when the gentlemanly rules of journalism are being used against us to our peril.

          • David L. Hagen says:

            Tenney Naumer
            Your comments appear to be as logically invalid ad hominem rhetoric as Denning’s claims to “consensus” that Monckton exposed. You might be credible were you to quantitatively and logically respond to the issues Monckton raises.

            For a glimpse into the uncertainties involved, see Nigel Fox of UK’s National Physical Lab on the TRUTHS project

            Fox observes that a 0.3% change on total solar irradiance (TSI) was the difference between the Little Ice Age with “Frost Fairs” on the Thames, and 20th century “global warming”.


            However the current uncertainty in TSI is ~0.7%. Fox notes that we have no observational basis to distinguish between models predicting 2C warming vs 10 C warming by 2100.

            Until we restore “climate science” to rigorous observational validation, alarmist visions of anthropogenic catastrophic global warming Denning etc. have as little validity or effect as King Canute commanding the tide.

      • JC Smith says:

        Perhaps as par of your “responsibility”, you could offer Peter Hadfield and Christopher Monckton a place to continue the debate they started at Wattsupwiththat.

        Yes….I think THAT, would provide a great service to your readers. A place to continue an important debate….one point at a time.

        Christopher Monckton has run away from Peter Hadfield before, and let’s see if he now wants to re-enter that debate with Hadfield.

        I sincerely doubt that Monckton would do so. Hadfield is working from a position of strength: Hadfield has facts and truth on his side. After being exposed, Monckton has no real choice but to avoid him.

  7. Jack says:

    Brian G. Valentine,

    Thank you so much for all the efforts you put forth to tell the real truth about the CAGW.

    Please don’t stop spreading the truth. Soon with you and the rest of the smart ones will put this CAGW to bed.

    Again, thank you, thank you, thank you so much.

    May God bless you and yours.

  8. Martin Lack says:

    Climate change deniers will always invoke the marketplace of ideas fallacy because, apart from little more than a handful of genuine climate scientists like Richard Lindzen, Patrick Michaels, Roy Spencer and Judith Curry, the vast majority of them have no qualifications that would validate their opinions. Whereas Lindzen, Michaels, Spencer and Curry are the modern-day equivalent of the Cold War Physicists of the 1980s (Bill Nierenberg, Robert Jastrow, Frederick Seitz and S Fred Singer) – who chose environmentalism as their new enemy when Communism fell apart.

    I say all this because Viscount Monckton has no qualifications to validate his opinions and he is very clearly ideologically prejudiced against accepting the reality of any environmental problem (if the solution will require significant deviation from the status quo).

    There is now a very long list of professional scientific bodies – such as the National Academy of Sciences and its equivalent in many other countries – that have affirmed the reality, nature and scale of the climate change problem we face. Therefore, to say there is no consensus necessitates belief in what must surely be the greatest conspiracy theory of all time. Viscount Monckton will not like this either but it is a fact: He is a conspiracy theorist and, as David Aaronovitch has pointed out, conspiracy theories are history for losers.

    Much of what Viscount Monckton says is reminiscent of the very misleading presentation Richard Lindzen gave to a packed Committee Room in the Palace of Westminster in February this year (which also invoked conspiracy theory on a grand scale). As did Lindzen, so Monckton relies heavily on climate sensitivity being low (i.e. 1 C rise for a doubling of CO2). However, given that we have already had a 0.8 C rise for a 40% increase in CO2, it does not make any sense to argue that climate sensitivity is lower than 2.5 C – and positive feedback mechanisms and non-linearity mean that it could ultimately be between 4 and 6 C.

    Furthermore, if positive feedback mechanisms do not exist, it is very hard to explain accelerating rates of terrestrial and sea ice melting in the Arctic (where change is happening even faster than the models predicted). However, before anyone protests, the hole in the ozone layer (slowly being repaired thanks to sensible human collaboration on a global scale to ban CFCs) has so far prevented warming taking hold in the Antarctic.

    Whatever minimal credibility Viscount Monckton had should surely be lost as a consequence of the audacity shown in his repetition of the “warming will be beneficial” meme? Not only does this ignore the fact that the 12,000 years of relative climate and sea level stability – which facilitated settled agriculture, urbanisation, and modernity – has now been brought to an abrupt end by the burning of fossil fuels; it appears to suggest that we need do nothing to change our behaviour. Whatever happened to “when in a hole, stop digging”?

    Finally, Monckton cites another of Lindzen’s arguments – that the public are not as stupid as scientists seem to think they are. Sadly, the problem is the public are not scientists and they generally listen to other non-scientists who are not as clever as they think they are.

    In the final analysis, the reason genuine climate scientists are having such a hard time getting their message across is the same reason so few people vote in elections – a post-modern rejection of all authority figures based on widespread cynicism. Again, as Aaronovitch says, this is why so many people prefer conspiracy theories – it absolves them of responsibility and makes the world seem fairer than it really is.

    As we have seen with Monckton v Abraham and Monckton v Hatfield – and as I have discovered myself – when he realises he cannot win an argument (this happens frequently), Viscount Monckton resorts to ridicule and/or intimidation and, if that does not work, he just gives people the silent treatment. Which, I wonder, will I now get?

    • Dave says:

      When will we get past the fallacy that Arctic sea ice is acting in some unnatural way? If the Arctic is the canary in the coal mine. The canary is fine.

    • I am appalled by the lack of understanding of the basic math and physics involved displayed by the entire “climate science” gaggle . The vast majority don’t show evidence that they know how to calculate the temperature of a radiantly heated colored ball but think you can design one whose interior will get hotter than its surface .

      The 0.3% warming we have seen since before the industrial revolution is near noise level and nothing unprecedented .

  9. Jack says:


    Thank you for approving my comment because I along with 65% of us who aren’t concerned about global warming/climate change want to let Mr. Valentine and the rest like him who saw the truth and dare speak the truth on this topic that their efforts are truly appreciated.

    Doesn’t matter how long one screams, the truth will come out in the end — I’m so certain about that.

    God bless all of you, especially Mr. Valentine.

  10. Brian G Valentine says:

    ” … such as the National Academy of Sciences and its equivalent in many other countries – that have affirmed the reality, nature and scale of the climate change problem we face.”

    “Climate change” has been a different animal, hasn’t it.

    The development of quantum mechanics, relativity, and a host of others, evolved from the considered criticism of others – people who were encouraged to find the logical gaps and shoot right through them. From these, the foundations were built.

    Climate science has evolved in exactly the opposite manner – a few people cooked up the subject matter and proceeded to take aim at anybody who criticized it, then invented names for them like deniers, then encouraged others to behave likewise, and when all else failed, ridiculed criticism and the people who delivered it.

    This is partly the fault of the Government, that did not pay for research to disprove assumptions (or “hypotheses”) people made while cooking this all up, or essentially, prove it false. It should have and I hope the situation changes.

    So we wind up with a collection of individuals who will be told, they are incompetent if they don’t go along with the demands of the few who by their own fiat have Divine authority to designate themselves, “the experts.”

    The foundations of this climate stuff are highly questionable, the results of it spurious, the predictions of it apparently meaningless, and it is unfortunately difficult to publish against it.

    I know this first hand, and the whole thing is a shame for all science. No wonder public confidence in Government and “science” is so low

      • Brian G Valentine says:

        “You are not like Galileo.”

        Ha ha ha you stole that line from Eli Rabbit, who said exactly the same thing to me

        • Martin Lack says:

          Brian – I think you need to watch the video (especially from 28 mins onward). It is ultra-conservative geoscience professor Barry Bickmore who both Eli and I are quoting…

    • Peter Sinclair’s latest video puts paid to this sort of nonsense. Margaret Thatcher knew well the science and warned the world in a speech at the United Nations:

      • Brian G Valentine says:

        “In a word-association game, it’s unlikely that many would bring up the names of Margaret Thatcher, or of Columbia University’s Wallace Broecker. Nor, for that matter, those of NASA scientist James Hansen; of the late biochemist and novelist Isaac Asimov; of theoretical physicist, author and cosmologist Stephen Hawking; of the late Cornell University astrophysicist and author Carl Sagan; of Microsoft’s Bill Gates; of Navy Admiral David Titley; or of Nobel Laureate, and now Secretary of Energy, Steven Chu.”

        Well put.

        In turn, Thatcher was doing anything she could to break the backs of coal miners, including resorting to junk science to eliminate them; Broeker nor anyone else explained why sulphate aerosol does not provide a discrepancy to be corrected between satellite and ground based temperature measurements of the Earth; Hansen projected an influence of CO2 extrapolated from erroneous calculations of influence on the Venusian atmosphere; Asimov did not consider authentic science sufficiently entertaining without fictional embellishment; Sagan might as well have postulated that CO2 was put on Earth by aliens from outer space to eradicate humans over a time span that is microscopic compared with cosmological time (Let’s see you prove that wrong!)

        Steve Chu, as a matter of fact, is my fourth level supervisor. He’s a good man, I have never had a discussion with him, I would like to.

        Somehow, I feel that I could convince him, if I had but forty five minutes of discussion with him, face to face.

        That is probably not going to happen.

  11. Christopher Monckton has submitted an extremely long and rambling piece that is somehow supposed to be considered a “response” to my post this week ahead of the Heartland Conference. Unfortunately, the piece has almost nothing to do with my post, and strangely seems almost entirely to present the writer’s views on the science of climate change.

    Of course the whole point of my piece was that the scientific debate is irrelevant to the much larger debate about what to do about climate which is taking place in the larger culture.

    [Perhaps this is not surprising given that there now seems to be some question as to <a href = "; title="whether there even is such a person as Viscount Christopher Monckton!" The writer may in fact be the latest character invented by a well-known comedian.] If the Monckton character wishes to argue about science, he should go back to his laboratory, or his computer, or whatever his method requires, and then submit his results to scientific journals. This is a communications forum, not a peer-reviewed journal, and is not the place to present science findings.

    Others might simply go back and read my post, in which I did not present a scientific argument at all. Rather, I argue that it is simply appalling that the political right has been absolutely silent on climate and energy policy or solutions. It is amazing to me that a once-proud tradition of ideology that values free markets and liberty has nothing whatsoever to offer on this important issue other than the sort of verbose pseudo-scientific poppycock that the Monckton character wrote here.

    Look: our ancestors forged a lasting bond between producers of goods and services and the consumers who pay for them. The free market thus created allowed the western world to grow a completely new system for energy and a global economy that lifted a billion people out of poverty. The cost of the system we enjoy today was far greater than the total wealth of the world in 1800, yet was paid by consumers who also earned salaries for producing the new goods and services. This kind of “bootstrap” economics is absolutely central to capitalism.

    Yet Heartland and the Monckton character pretend that the task of lifting billions more in the developing world out of poverty in the 21st Century will bankrupt our descendants! They whine about costs of 1% or 2% of global GDP, when of course such costs are in fact precisely the way our ancestors enriched our global society.

    Heartland and the other “gloom and doom” voices have abandoned their ideology and their proud intellectual roots. By clinging pathetically to the past, they fail to embrace the opportunity of the future. Human society has proven incredibly resilient in the face of plagues, wars, depressions, and natural catastrophes. I am optimistic that long before they run out of coal and oil, our descendants will invent a future in which billions of people can partake of an energy-rich world that emits no CO2 into the atmosphere.

    In the meantime, we can all enjoy watching for the next comedic hoax perpetrated by the fellow currently going by the name of Viscount Lord Monckton.

    Scott Denning

    • David L. Hagen says:

      Tad Patzek shows US oil consumption grew 9%/year compounded for 60 years from 1860 to 1940 and 3%/year from 1945-2005.
      China and India are now on that growth path. China is installing 1 GW coal fired power plant per week. Do not they also have the right to develop their economies?

      Global crude oil production plateaued in about 2005 at about 75 million bbl/day. The International Energy Agency projects no growth in crude oil. Jeffrey Brown shows Available Net (Oil) Exports have already declined 13% since 2005.
      Providing 1%/year growth while replacing current 6-7% depletion will require ~63 million bbl/day new supply by 2030 – about 6-7 new Saudi Arabia’s. Where will that come from?

      The Copenhagen Consensus shows global warming mitigation to be dead last on the top 30 global humanitarian projects for cost effectiveness.

      For 3 billion people living on less than $2.5/day to rise out of poverty, they will need rapidly increasing use of inexpensive fuel.

      Providing abundant inexpensive liquid fuel sufficient to grow developing economies is our greatest challenge, not the projected 5 cm rise in sea level. Lets seriously address the most important humanitarian issues facing our world, not unvalidated alarmist nightmares.

    • Martin Lack says:

      It was highly amusing to think that Monckton was just another creation of Sacha Baren Cohen. Unfortunately, the truth is that Viscount Monckton of Brenchley is a Classics graduate from Cambridge, and a former journalist and non-scientific advisor to Margaret Thatcher. As such, he was clearly not involved in drafting her speech to the UN…

  12. For those who have not yet had the pleasure of being entertained by the “Lord Monckton” character, I assure you he is brilliant! I sat at the head table at Heartland and watched the performance from perhaps 20 feet away: the makeup is incredible!

    A quick google search reveals that The British House of Lords has confirmed in writing that there is in fact no such person as Lord Christopher Monckton, and in their peevish Old World way have asked the actor to “cease and desist” from using the name.

    I suspect from the laughter during the Monckton performance last year that the Heartland folks are fully aware of the hoax. It is a bit surprising that they continue to book his act though, considering the way the character transparently lampoons the entire field of climate change denialism. At some point I suspect the act will become stale, even for Heartland.

    • David L. Hagen says:

      Scott Denning
      Rather than stooping to denigrate your opponent, you may wish to educate youself regarding Monckton’s peerage:

      Therefore, Lord Monckton remains a Member not only of the Peerage but also of the House of Lords, save only that he cannot for now sit or vote there, and he was and is fully entitled to say so.”

  13. Individuals who keep wanting the world to throw away its prosperity by denying the right to use fossil fuels, keep using the melting of Arctic sea ice as the proof increasing carbon dioxide is causing global warming. Past data keeps showing the surges and falls in Arctic sea ice has been happening for centuries when carbon dioxide changes were small. Some new information about sea ice has recently been published.

    This source is a recent discovery of Arctic Sea Ice Maps from 1893-1961 with gaps for WWII.

    It shows Northwest Passage open in the early 1900s in August. It shows sea ice receding in summer from 1910-1923 and comparable to 1979- 1990. This is a period of warming from 1910-1940.

    This is a great find that shows current reductions in Arctic sea ice took place about 70 years earlier when we had global warming with no change in carbon dioxide.

    James H. Rust, Professor of nuclear engineering

  14. I forgot to mention the commander of the first nuclear submarine Nautilus surfaced at the North Pole in 1958. I was a graduate student during his 1958 seminar at M.I.T. describing the event.

    In addition, for those who want to study sea ice in the Arctic and Antarctic can go to the website of the University of Illinois, cryosphere, and see satellite measurements of sea ice in both regions from 1979 to a few days ago. For the 33-year period, the sum of sea ice in both regions has essentially remained constant. When the North loses ice, the South gains ice.

    Both sea ice and ocean sea level rising have been of no significant difference for the periods of measurements. This indicates atmospheric carbon dioxide increases have no bearing on these two “fingerprints” the advocates of global warming maintain as justification for abandoning use of fossil fuels. This would impoverish the developed nations and doom undeveloped nations to perpetual misery.

    James H. Rust, Professor

  15. I am most grateful to Mr. Ward for having had the fair-mindedness and courage to provide a first-class summary of my essay of response to Dr. Denning’s posting, and to provide a link to the text itself. Those commenters here who have expressed displeasure at Mr. Ward’s even-handedness appear less than content with the amendment to the US Constitution that prohibits curtailment of free speech.

    Dr. Denning does himself no favors by responding to my essay not with reasoned argument but with an interminably tedious and not a little childish series of vituperative personal attacks. Some other commenters here have done the same. To attack the man and not his argument is yet another of the fundamental logical fallacies to which Dr. Denning and true-believers generally seem particularly prone. The argumentum ad hominem has no place in scientific discourse: and, more to the point, the general public – who are watching this debate with more alertness than the true-believers give them credit for – are able to spot this particular logical fallacy more rapidly and surely than any of the others. The true-believers really need to raise their game and talk about the science and economics of climate, not about whether in their inexpert opinion I am a Lord or not (I am, as my passport makes quite explicit: get over it).

    Though Mr. Lack, another commenter here, also lacks the courtesy to avoid large quantities of disfiguring ad-hom invective, he is the only true-believer among the commenters who also advances a scientific response to the scientific points that I had made. He says: “Given that we have already had a 0.8 C rise for a 40% increase in CO2, it does not make any sense to argue that climate sensitivity is lower than 2.5 C – and positive feedback mechanisms and non-linearity mean that it could ultimately be between 4 and 6 C.”

    Yes, temperature has perhaps increased by 0.8 K since 1750, and CO2 concentration may have increased by 40% since then. However, it is not logically legitimate to infer that the change in CO2 concentration was the sole cause of the change in temperature. The recovery of solar activity after the Little Ice Age is a natural cause that should not be overlooked; and, if the IPCC’s figures are to be believed (and I accept that it is a most unreliable, prejudiced, vested-interest source), there has also been a not insignificant contribution from greenhouse gases other than CO2.

    If all of the 0.8 K warming since 1750 were anthropogenic, as Mr. Lack implicitly assumes (consistent with the high-end IPCC estimate), and if 70% of the anthropogenic contribution were attributable to CO2 alone (that is the fraction that the IPCC assumes), then a 40% increase in CO2 concentration will have generated a 0.6 K increase in temperature. Double this to 1.2 K to allow for the difference between the transient warming that has occurred to date and the eventual equilibrium warming.

    From these considerations, we are able to determine the high-end overall feedback gain factor implicit in Mr. Lack’s example, thus: 1.2 / [0.3125(5.35 ln 1.4)] = 2. In that event, climate sensitivity to a doubling of CO2 concentration would be 2[0.3125(5.35 ln 2)] = 2.3 K per CO2 doubling. That is the worst we can expect.

    As a checksum before proceeding, we assume ad verificationem that a doubling of CO2 concentration will cause an equilibrium warming not of 2.3 but of 3.3 K, the multi-model mean central estimate given by the IPCC at Box 10.2 on page 798 of its latest Assessment Report. Then the same method shows an overall feedback gain factor not of 2 (the high-end value we have just determined by observation, but of 3.3 / [0.3125(5.35 ln 2)] = 3. In other words, the IPCC assumes that strongly net-positive feedbacks approximately triple the direct warming from a forcing: and this is the value that is often cited.

    But what if only half of the warming since 1750 were anthropogenic? This assumption is the IPCC’s low-end estimate. In that event, just 0.3 K is attributable to CO2. Double this as before to allow for eventual equilibrium warming. In that event, the implicit feedback multiplier is 0.6/[0.3125(5.35 ln 1.4)] = 1, implying net-zero temperature feedbacks.

    Net-zero or net-negative feedbacks are a feature of a temperature-stable climate. The question arises whether the climate of the past 64 million years has been temperature-stable. According to the literature, the temperature (as best it can be reconstructed, and admittedly subject to many uncertainties) has fluctuated by little more than 3% in absolute terms either side of the long-run mean. Given the very considerable shocks and forcings to which the climate has been subjected over that period, such formidable temperature stability would indeed imply net-zero or net-negative feedbacks.

    In these admittedly rather simple (but not simpliste) calculations, I have not taken account of the fact that the IPCC’s value of 0.3125 Kelvin per Watt per square meter (the reciprocal of 3.2: see AR4, p. 631 fn.) for the Planck zero-feedback sensitivity parameter may be appreciably exaggerated, and that the value of 5.35 ln(C/C0) for the CO2 radiative forcing, where C0 is the unperturbed concentration, may also be exaggerated (the IPCC has already been compelled to reduce the coefficient and hence the forcing by 15%, for the “consensus” was wrong about that too, and may well still be wrong now).

    The bottom line is that the warming we have seen over the past 260 years or so is inconsistent with the high climate sensitivity imagined by the IPCC but consistent with the appreciably lower and probably harmless sensitivity that my calculations suggest. All attempts to determine climate sensitivity other than by observation for a sufficiently long period are doomed to failure because the values of the CO2 radiative forcing, of the Planck parameter, and of the half-dozen most climate-relevant feedbacks are unknown and unknowable, and cannot be either measured directly or inferred by any theoretical method.

    I note the demands by some commenters that I ought to publish my results in the reviewed literature: but they are already there in numerous papers, demonstrated by a variety of methods. Dr. Denning, in his original posting, was accordingly factually incorrect to state that no climate scientist has published a peer-reviewed paper challenging the “consensus”. There is a growing body of such papers: and, as I pointed out in my essay, events have already demonstrated that the early projections of the “consensus” were exaggerated and, accordingly, wrong.

    Those commenters who insist upon pleading “consensus” as their chief or even their sole argument, long after events have thoroughly disproved the key predictions made by the “consensus”, may care to remember the words of John Maynard Keynes: “If the facts change, I change my opinions. What do you do, sir?”

    I note the total silence of the commenters on my economic conclusion, which is that even if the “consensus” about climate sensitivity were right it would be one or two orders of magnitude more cost-effective to spend not a single red cent on trying to make global warming go away today than to follow the vain spend-spend-spend policies of the global classe politique. Remember Canute.

    Since the premium exceeds the cost of the risk, don’t insure. That is a precautionary principle worthy of the name.

  16. There is old Chinese saying. ‘ When mouth open ; ears cannot hear ‘.
    I have never heard such rubbish as written above . Very obvious, most have not researched, and have just been sucked in by the past windbags , About time , many of you grew up and opened your minds ! Research past history.

  17. Bud Ward says:

    As Editor, I’m calling a time-out (perhaps a permanent one) on comments on this thread. Increasingly severe and indefensible comments are being submitted, unworthy of your (or our) time and attention. THE COMMENTS PERIOD ON THE DENNING/MONCKTON SUBJECT IS CLOSED.