Climate Change Opinion

Climate Closure

In the battle of public opinion over climate change, we can play to science's strengths by shifting tactics: Instead of struggling to prove humans are to blame, let's prove denialist fantasies wrong.

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Global warming science has concentrated on proving the theory that the postindustrial warming is largely caused by human activities. Yet no scientific theory can be proved beyond all doubt, and our attempts to convince people of the science are entering a period of diminishing returns.

For example, the Fifth Assessment Report (AR5, 2013) of the International Panel on Climate Change (IPCC) reiterated its 2007 statement “that human influence has been the dominant cause of the observed warming since the mid-20th century,” only upgrading it from “likely” to “extremely likely.” Meanwhile, those who reject this anthropogenic hypothesis have continued to push their theory that the warming is a giant fluctuation of solar, nonlinear dynamics that are internal to the atmosphere or other natural origin. For brevity we will call this group the “denialists,” following the suggestion of Gillis [2015].

In order to end the scientific part of the debate—to reach “climate closure”—it is therefore necessary to demonstrate that the giant fluctuation theory has such a low probability that we can confidently dismiss it. To do this, we can use a fundamental asymmetry in scientific methodology: although no scientific theory can ever be proved in a mathematically rigorous sense, even elegant theories can be disproved by a single decisive experiment.

Below, we summarize a straightforward disproof that achieves this closure so that the only viable explanation of the warming is anthropogenic [Lovejoy, 2014a, 2014b, 2015; hereinafter L1, L2, L3]. The same methodology also shows how the anthropogenic theory is compatible with the “pause” in the warming since 1998 and, indeed, in a statistical sense, that such a pause is extremely likely. As a bonus, denialist arguments based on the uncertainties of complex numerical models are rendered irrelevant because this demonstration does not require these models [Lemos and Rood, 2010; Norton and Suppe, 2001]. Finally, the basic argument can be understood by the lay public.

A Simple Approach to Determine Human Effects

The effects of climate forcings are difficult to quantify and contribute to the large model uncertainties. However, since 1880, the forcings have been linked to economics. To a good approximation, if you double the world economy, double the carbon dioxide (CO2), double the methane and aerosol outputs, and double the land use changes, you get double the warming. This justifies using the global CO2 forcing since 1880 as a linear surrogate for all the anthropogenic forcings (L1; using CO2 equivalent yields nearly identical results).

Fig. 1. (a) Global temperature anomalies (NASA, 1880–2013) as functions of radiative forcing using the carbon dioxide (CO2) forcing as a linear surrogate. The line has a slope of 2.33°C per CO2 doubling. Some dates and corresponding annually, globally averaged CO2 concentrations are indicated for reference. GISS, Goddard Institute for Space Studies; ppm, parts per million. Adapted from Lovejoy [2014b, Figure 1a]. (b) The residuals from the straight line in Figure 1a; these are the estimates of the natural variability. The vertical dashed lines are the same as in Figure 1a. The arrows indicate notable events. Adapted from Lovejoy [2014b, Figure 1c].
Fig. 1. (a) Global temperature anomalies (NASA, 1880–2013) as functions of radiative forcing using the carbon dioxide (CO2) forcing as a linear surrogate. The line has a slope of 2.33°C per CO2 doubling. Some dates and corresponding annually, globally averaged CO2 concentrations are indicated for reference. GISS, Goddard Institute for Space Studies; ppm, parts per million. Adapted from Lovejoy [2014b, Figure 1a]. (b) The residuals from the straight line in Figure 1a; these are the estimates of the natural variability. The vertical dashed lines are the same as in Figure 1a. The arrows indicate notable events. Adapted from Lovejoy [2014b, Figure 1c].
Figure 1a shows the global annual temperature plotted not as a function of the date, but rather as a function of the CO2 forcing. Even without fancy statistics or special knowledge, it is easy to see that the temperature (plotted in green) increases very nearly linearly with some additional fluctuations; these represent the natural variability. The slope (black), 2.33°C per CO2 doubling, is the actual historical increase in temperature due to the observed increase in CO2: the “effective climate sensitivity.” As a check on our assumptions, this figure sits comfortably in the IPCC range of 1.5°C–4.5°C per CO2 doubling for the (slightly different) “equilibrium climate sensitivity.”

The difference (residues) between the actual temperature and the anthropogenic part is the natural variability, which is plotted in Figure 1b. We can confirm that this is reasonable since the average amplitude of the residues (±0.109°C) winds up being virtually the same as the errors in 1-year global climate model hindcasts (±0.105°C and ±0.106°C from Smith et al. [2007] and Laepple et al. [2008], respectively). So knowing only the slope of Figure 1a and the global annual CO2, we could predict the global temperature for the next year to this accuracy (L3). Clearly, this residue must be close to the true natural variability.

Disproving Natural Causes

The range of the straight line in Figure 1a is an estimate of the total anthropogenic warming since 1880—about 1°C. What is the probability that the denialists are right and that this is simply a giant natural fluctuation? This would be a rare event but how rare?

To check that comparisons of the current period against the historical record are valid, L1 reconstructed records of volcanic and solar activity. That study concluded that the statistics of the industrial epoch variations are no different from the preindustrial ones. Volcanic activity was highly intermittent but no more so than usual; solar activity, which denialists often blame for the observed warming, has, if anything, diminished over the last 50 years [Foukal et al., 2006].

Then, L1 used preindustrial temperature series drawing on several sources to estimate the likelihood of a given amount of natural temperature change. Applying the usual statistical approach—the bell curve—to these data leads to the conclusion that the chance of a 1°C fluctuation over 125 years being natural is in the range of 1 in 100,000 to 1 in 3,000,000. This is a rough estimation: for long periods, the standard deviation of temperature differences is twice the 0.1°C value. Hence a 1°C fluctuation is about five standard deviations, or a 1 in 3,000,000 chance.

However, nonlinear geophysics tells us that the extremes should be far stronger than the usual bell curve allows. L1 shows that 1°C, century-long global-scale fluctuations are more than 100 times more likely than the bell curve would predict. This gives a probability of at most 1 in 1000, which is still small enough to confidently reject this possibility.

A Necessary “Pause”

One can apply the same type of analysis to the hiatus in the warming (the relatively flat part of the fluctuating line in Figure 1a after 1998), also referred to as the pause. Figure 1b shows that it is actually a natural cooling event sufficiently large (≈0.3°C) that it has masked the more or less equal anthropogenic warming over the period.

Although this cooling is somewhat unusual, it is not rare: statistical analysis shows that similar 15-year coolings have a natural return period of 20–50 years (L2). Additionally, in this case, the cooling immediately follows the even larger prepause warming event (1992–1998; Figure 1b). That is, the pause is no more than a return to the mean; it can be accurately hindcast (L3).

Alternatively, Karl et al. [2015] has recently produced a temperature series with new ocean and other bias corrections. In this warmer series, the amplitude of the corresponding natural cooling is 0.09°C less than that shown in Figure 1b. Since the return period for this smaller natural cooling is only about 10 years (L2, Figure 2), decadal trends cannot (and did not) detect any statistically significant pause at all.

In any case, far from supporting denialist claims that the warming is over, this return is a necessary consequence of the theory of anthropogenic warming that predicts that the natural variability will cause fluctuations to stay near the long-term anthropogenic trend in Figure 1: without it, the warming would have soon become unrealistically strong.

Quod Erat Demonstrandum

The scientific method is much more effective at rejecting false hypotheses than in proving true ones. By estimating the probabilities of centennial-scale preindustrial temperature changes, with 99.9% confidence we are able to reject the denialist hypothesis that the industrial age warming was from solar, volcanic, or other natural causes, leaving anthropogenic origin as the only alternative.

The scientific debate is now over; the moment of closure has arrived. Although climate scientists must move on to pressing scientific questions such as regional climate projections and the space–time variability, our species must tackle the urgent issue of reducing emissions and mitigating the consequences of the warming.

References

Foukal, P., C. Frohlich, H. Spruit, and T. Wigley (2006), Variations in solar luminosity and their effect on the Earth’s climate, Nature, 443, 161–166, doi: doi:10.1038/nature05072408.

Gillis, J. (2015), Verbal warming: Labels in the climate debate, New York Times, 12 Feb.

Karl, T. R., A. Arguez, B. Huang, J. H. Lawrimore, J. R. McMahon, M. J. Menne, T. C. Peterson, R. S. Vose, and H.-M. Zhang (2015), Possible artifacts of data biases in the recent global surface warming hiatus, Science, 348, 1469–1472, doi:10.1126/science.aaa5632.

Laepple, T., S. Jewson, and K. Coughlin (2008), Interannual temperature predictions using the CMIP3 multi-model ensemble mean, Geophys. Res. Lett., 35, L10701, doi:10.1029/2008GL033576.

Lemos, M. C., and R. B. Rood (2010), Climate projections and their impact on policy and practice, WIREs Clim Change, 1, 670–682.

Lovejoy, S. (2014a), Scaling fluctuation analysis and statistical hypothesis testing of anthropogenic warming, Clim. Dyn., 42, 2339–2351, doi:10.1007/s00382-014-2128-2.

Lovejoy, S. (2014b), Return periods of global climate fluctuations and the pause, Geophys. Res. Lett., 41, 4704–4710, doi:10.1002/2014GL060478.

Lovejoy, S. (2015), Using scaling for macroweather forecasting including the pause, Geophys. Res. Lett., doi:10.1002/2015GL065665, in press.

Norton, S. D., and F. Suppe (2001), Why atmospheric modelling is good science, in Changing the Atmosphere: Expert Knowledge and Environmental Governance, edited by P. N. Edwards and C. A. Miller, 385 pp., MIT Press, Cambridge, Mass.

Smith, D. M., S. Cusack, A. W. Colman, C. K. Folland, G. R. Harris, and J. M. Murphy (2007), Improved surface temperature prediction for the coming decade from a global climate model, Science, 317, 796–799.

—S. Lovejoy, Department of Physics, McGill University, Montreal, Quebec, Canada; email: [email protected]

Citation: Lovejoy, S. (2015), Climate closure, Eos, 96, doi:10.1029/2015EO037499. Published on 20 October 2015.

© 2015. The authors. CC BY-NC 3.0
  • bookspeople

    May I offer a suggestion regarding a standardized title for those objecting to climate change correlated to human-produced CO2?
    In 1800s London, John Snow claimed the cause of deadly cholera outbreaks could be traced to contaminated water. This was denied by traditionalists, who felt that poisonous vapors- “miasmas”- were the source of the epidemics. Scientific quibbling stalled any effective response to the crisis for years and the citizenry quietly died and the water supply company amassed regular profits as a result. Snow then carried out his dramatic “remove the pump-handle” experiment, and demonstrated that the contaminated water from a single well had doomed numerous local residents. The miasma concept, nonetheless, was supported until Pasteur and Koch nailed down the science years later.
    And so the term: “Miasmists”- as in “Climate change is not caused by the product supplied by a benevolent, profitable industry, a product which can be largely replaced by the determined substitution of alternative practical technologies, but some mysterious ‘miasma’.”

  • Arno_Arrak

    Climate Closure by S. Lovejoy in EOS

    The author purports to disprove the “denialist” hypothesis that warming is a giant
    fluctuation of solar, nonlinear dynamics that are internal to the atmosphere or
    other natural origin. The source of this is apparently Gillis of the New York
    Times which is not a scientific journal. For the record, I am one of those “denialists”
    but I have never heard of this so-called “theory” he chooses ti impute to us. If he wants to
    fight it let him fight it. I simply question his competence to do climate
    science. His figures 1A and 1B are an example of what we can expect from him –
    obfuscation of the issue to hide the actual science involved. ` Markovitz and Hancock of Stanford have a paper out in J. Language & Social Psych. called “Linguistic Obscuration in in Fraudulent Sience” in which they define an obfuscation index. Yours must be high because you seem to have trouble even looking at a simple global temperature curve. If you actually looked at it you would be amazed what it can tell you. First, people like you believe that that global warming is caused by the greenhouse effect of carbon dioxide. The more carbon dioxide in the air, the higher the warming rate. That of course is a belief because it has never been experimentally verified. James Hansen attempted to verify 1988 in front of the Senate when he brought out a 100 year warming curve as proof of the greenhouse effect. His claim was picked up immediately by the IPCC, established that same year. Fortunately he left a record of his presentation and when you look at his 100 year temperature curve you notice that it is not 100 years of warming at all. A good twenty percent of it is actually cooling. This is not proof of greenhouse warming but his talk is used as an excuse to tell us that global warming is greenhouse warming. The argument your pseudo-scientists most commonly use is to point to the fact that global temperature has been going up and parallel to it carbon dioxide has also been going up. What is more natural than to assume a cause and effect relationship between the two? Unfortunately this is not science: correlation is not causation. Greenhouse effect involves physics and the laws of physics must be satisfied before you can talk of any cause and effect relationship. And when you start comparing global temperature change with its putative cause as recorded for us in the Keeling curve it turns out that the laws of physics are not satisfied. Not only dissatisfied in general but in the very specific case of comparing corresponding time slices of global temperature and what the Keeling curve was doing then. It should not be hard to understand that if a cause and effect relationship exists and the global temperature suddenly begins to increase the corresponding section of the Keeling curve must show an increase of carbon dioxide which started this sudden warming. There are numerous parts of the global warming curve where temperature suddenly to warm. And likewise where it suddenly starts to cool. Or even. more interestingly, it simply stands still as during the current hiatus. There should be kinks in the Keeling curve whenever global temperature shows sudden warming, cooling or standstill if the greenhouse effect is responsible for these well-defined changes. And I hate to tell you that there are no such kinks in the Keeling curve (or its extensions) anywhere since the temperature record began. This is so simple a that a child could do it but your so-called “climate scientists” are so totally brainwashed that they missed the simple fact that their emperor has no clothes on.

  • The reason for the choice of the CO2 forcing was that it was a well measured forcing that could be used as a surrogate for all the anthropogenic forcings. I have also used the estimated CO2 equivalent forcing (from IPCC AR5) which gives almost identical results with an effective climate sensitivity 1.12 times smaller (but with nearly identical residual statistics, hence nearly identical results). The key problem with going beyond the CO2 itself (and this includes the CO2 equivalent that I just mentionned) is that the aerosol forcings are particularly uncertain.

    Using the CO2 directly as a proxy is thus one approximation. Estimating the full forcing (especially aerosols) is another. The former is more direct, simpler, the latter – if we could have confidence – is more scientifically satisfying. For the moment, take your pick: the results barely change.

  • Tyler Durden

    Thank you for replying Prof Lovejoy. From your SLIMM paper table 1 I found the reference “The average of the three multiproxies from Huang (2004), Moberg et al. (2005) and Ammann andWahl (2007). These analyses were discussed in Lovejoy (2014b)”. So your multiproxies are boreholes and tree rings. Would have been easier if you had just said so in your article. Of course, “preindustrial temperature series drawing on several sources” sounds more credible than “borehole and tree ring studies”. This is an example of why I have little trust in climate scientists.

    To paraphrase your argument in a single sentence: You claim that the standard deviation of preindustrial temperature variations over 125 year periods is only 0.1C, based on tree ring and bore hole studies, and therefore a 1.0C change over a 125 year period due to natural causes is virtually impossible.

    To this I say, estimates of preindustrial temperatures from tree rings, boreholes, pollen, or other proxies are HIGHLY UNCERTAIN, and could easily be VERY wrong. There is no “control” to compare against to test the accuracy of the estimates. I have no argument with the rest of your conclusions. If std dev really is 0.1C then I would agree with you. However, here is the fundamental difference in our beliefs. I believe that 125 year std dev of past temperatures could easily be 0.5C or even higher. We have NO WAY TO KNOW. You believe that you do know based on tree rings and boreholes. You are entitled to your own beliefs. But when you insist on unfavorably shaping government policy based on your warped beliefs, I will fight you to the ends of the earth. And when you refer to me as a denier, I take that very personally.

  • monckton

    Mr Lovejoy’s post unfortunately contains a number of errors that would not have passed peer review in a scientific journal. He has, in effect, assumed that correlation necessarily implies causation; he has failed to take due account of the absence of correlation between the strong anthropogenic forcings since the beginning of 1997 and the near-total absence of warming since then (for absence of correlation necessarily implies absence of causation; he has posited a linear correlation between CO2 concentration and warming, when mainstream science holds that the relationship is more closely modeled by a logarithmic than by a linear approximation; and he has resorted to the hate-speech word “denialist”, which any respectable journal should have realized is entirely unacceptable, in that in the past decade dozens of demands for the trial, imprisonment and even execution of “deniers” or “denialists” have been made, often with an explicit comparison with Holocaust denial.

    The climate debate needs to avoid this kind of hate-speech, which – in Scotland and Austria, at any rate – is a criminal offense. In Austria, exploiting the Holocaust in this artfully disingenuous way is an imprisonable offense. Better to stick to the science.

    • Sorry to hurt your feelings.
      I suppose your term “climate-Communist faction” is your attempt to be neutral in characterizing climate scientists?

      In any case, I do not assume causation. However, it turns out that since 1900, only knowledge of CO2 concentrations and the twenty years of temperatures prior to a given year is enough information to allow the annual global temperature to be predicted (hindcast) one year ahead with an accuracy of +-0.092 oC. This includes the postwar cooling, the prepause warming and the pause itself. Implicitly it includes the responses to any solar and volcanic forcings even though (contrary to the GCM’s) no information on these is used. This accuracy is enough to settle any relevant issues of natural variability, it is an average of over 100 hindcasts (every year since 1900).

      • monckton

        I am glad we are now agreed that the word “denialist” is not to be used. As for “climate Communist”, this term is used only of a team of anonymous, paid trolls of more than customary narrow-mindedness who infest threads like this and make personal attacks on those they disagree with. Most websites now ban anonymous contributors from making personal, ad-hom attacks on named individuals, which has greatly improved the quality of the discussion. Anonymous contributors can still post, but they must be polite. Of course, one can be as rude as one likes about the climate-Communist trolls because they are anonymous, so one is not making personal attacks at all.

        The problems with your curve-fitting are the same as with all curve-fitting. One can get far closer hindcasts than yours by using the time-integral of solar activity, for instance, and even assuming a zero influence from CO2, but retrospective curve-fitting of this sort by finding some sort of formula to fit the past data is at best a dodgy technique and most statisticians rightly eschew it. It leads its practitioners to think they are not assuming causation when in fact that is exactly what they are doing.

        I’d like to write a proper, statistical reply to your posting, but I’m quite certain that Eos is not open to any but a single, narrow viewpoint on the climate. So, if I find the time, I’ll write something elsewhere. I’d probably say something like the following:

        Dr Lovejoy says “… post-industrial warming is largely caused by human activities.”
        However, the mainstream climate-science journals do not support him. Only 0.3%
        of the abstracts of 11,944 climate-science papers published in the 21 years
        1991-2011 state that recent global warming was mostly manmade (Legates et al., 2013). The scientific as opposed to propagandist position on this actually quite complex question of attribution is that it may or may not be true that the warming that ended with the last
        millennium was chiefly manmade.

        Lovejoy cites the IPCC with approval when it upgrades from 90% to 95% confidence its
        assertion to the effect that recent warming is mostly manmade. However, the IPCC’s flagrant misuse of statistical confidence intervals as a purported gauge of what is no more than an unquantifiable opinion not at all strongly supported in the reviewed journals is unacceptable, as anyone familiar with statistical methods would have known.

        Lovejoy calls those who disagree with him on the supposed near-certainty that recent
        warming is mostly manmade “denialists”. This is not merely unscientific but anti-scientific.

        Next, he mischaracterizes the fundamental postulate of logic – that every proposition that is true is consistent with all other propositions that are true and inconsistent with each and all propositions that are false – as a “fundamental asymmetry in scientific methodology”, whatever that may mean. The context appears to suggest that all he means is that he will attempt a proof by contradiction.

        He proceeds to assert that various papers by him “disprove” the possibility that recent warming was mostly natural. Two central errors in his approach are his false assumption that, in the absence of any identified systematic natural forcing of sufficient magnitude, the only possible cause for the 20th century’s warming (there has been none to speak of in the 21st) is Man, and his equally false assumption that synoptic variability is incapable of
        causing warming at what he falsely considers to be the unprecedented rate observed in the second half of the 20th century.

        His analysis also fails to take any account of the fact that the warming rates in 1860-1880 and again in 1910-1940 were statistically indistinguishable from the warming rate of 1975-1998, and yet that the anthropogenic forcings in the earlier two periods were very considerably less than the anthropogenic forcings in the later period. Of course, the anthropogenic forcings in the period 1998-2015 were still greater, but no statistically significant warming (and, on the two satellite records, none at all) occurred in that later period.

        The essence of Lovejoy’s argument is that “If you double the world economy, double the carbon dioxide, double the methane and aerosol outputs and double the land-use changes, you get double the warming.”

        However, Lovejoy has insufficiently studied the warming rates of earlier periods. For instance, at the end of the last Ice Age 11,700 years ago temperatures in Antarctica rose by 5 degrees in 3 years (i.e, 2.5 degrees globally once polar amplification is allowed for). Man had nothing to do with it. And at the end of the Little Ice Age, in the 40 years 1694-1733, temperature in central England rose at a rate equivalent to 4.33 degrees per century (subject to error margins of 1.5 degrees either side of this value). Central England has proven a not unreliable proxy for global temperature. Again, Man had nothing to do with it. Lovejoy’s elementary error here is in failing to appreciate the extent to which
        natural variability, whether systematic or synoptic, is capable of altering global temperature.

        Lovejoy includes aerosols in his account of Man’s positive climate forcings, apparently
        failing to understand that an increase in the atmospheric burden of particulate aerosols causes cooling, not warming.

        He then makes the remarkable and statistically-untenable assertion that because, in his opinion, a doubling of economic activity equals a doubling of warming, “This justifies using the global CO2 forcing since 1880 as a linear surrogate for all the anthropogenic forcings”. Setting aside the monstrous and self-evident non-sequitur, the CO2 forcing is not linear but approximately logarithmic (Myhre et al., 1998; IPCC, 2001, ch. 6.1). Since not all other anthropogenic forcings are logarithmic, it is self-evident that CO2 cannot be naively taken as a linear surrogate for all forcings.

        Next, he provides a figure in which the x axis is explicitly denominated in tenths of the base-2 logarithm of the proportionate change in CO2 concentration since the pre-industrial era and is implicitly simultaneously denominated in years. His assumption – statistically untenable – is that, provided that one uses the much-altered GISS data that show a slower
        rate of early-20th-century warming and a more rapid rate of late-20th-century warming than earlier versions of the same data showed, the relationship between the logarithm of the proportionate change in CO2 concentration and the linear change in global temperature is linear.

        His assumptions, therefore, are that cherry-picking a single carefully-chosen and much-tampered-with dataset and demonstrating a linear fit necessarily entails a causative link between changes in CO2 concentration and changes in temperature. This is the central error in his papers: for it cannot be too often asserted that, in logic, correlation does not necessarily entail causation. There may or may not be a causative link.

        Indeed, quantifying the magnitude of CO2’s influence on temperature is no easy matter.
        If it were as naïve as Lovejoy suggests, it would scarcely have been necessary for the IPCC to devote five successive multi-thousand-page reports to that question, concluding in its latest report that it is no longer possible to provide a central estimate of climate sensitivity.

        Yet Lovejoy blithely tells us that, on the basis of his logical error in assuming that the correlation he identifies implies causation (bearing in mind that even the correlation itself is suspect given that the technique has been applied to a single and notorious outlier dataset), climate sensitivity is 2.4 Celsius degrees per CO2 doubling.

        For a start, he draws an insufficient distinction between transient sensitivity over a given period and equilibrium sensitivity after the climate has settled back to a presumed (but actually non-existent) pre-existing equilibrium after a perturbation. If his given value is intended to represent transient sensitivity, it is considerably higher than the mainstream value. If it is intended to represent equilibrium sensitivity, it is on the low side compared of the mainstream interval.

        Recall that in all of his analysis he makes no attempt to exclude by estimation the extent of systematic variability from various natural forcings (such as the considerable but not systematically or systemically measured variability in the activity of the world’s 3.5 million subsea volcanoes; there are many other examples of unquantified but potentially substantial natural forcings), still less to estimate not only the extent but the phases of synoptic variability, notably the phases of the Pacific Decadal and other ocean oscillations. It is evident, for instance, that the three warming periods since 1850 each coincided with positive or warming phases of the Pacific Decadal Oscillation index.

        Lovejoy’s second diagram perpetrates another elementary logical fallacy: that of petitio principii, the begging-the-question or circular argument. He assumes what he says he is “proving”. He begins a priori with the assumption, which may be true or false, that the main reason for the global warming of the 20th century was anthropogenic, and then declares
        that the residuals either side of his trend-line are the result of natural variability while the trend itself is not: therefore, the trend is anthropogenic. There is no basis in statistics for torturing innocent residuals in this way, for residuals simply reflect variability without telling us anything about why the variability arises. And there is certainly no basis in logic for perpetrating such a petitio principii.

        To justify his breach of elementary logic, he says: “The difference (residues) between the actual temperature and the anthropogenic part is the natural variability, which is plotted in Figure 1b. We can confirm that this is reasonable since the average amplitude of the residues (±0.109°C) winds up being virtually the same as the errors in 1-year global climate models…”. Correlation is again assumed necessarily to entail causation.

        He goes on: “So knowing only the slope [of the trend-line of temperature change against the logarithm of the proportionate change in CO2 concentration since pre-industrial times] and the global annual CO2, we could predict the global temperature for the next year
        to this accuracy. Clearly, this residue must be close to the true natural variability.”

        Here, the petitio principii is again relied on. Lovejoy starts with the assumption he is attempting to prove, then says all fluctuations other than his “anthropogenic” trend-line must be natural, with the implication that, therefore, the trend-line is indeed anthropogenic.

        Next, Lovejoy reiterates an error he perpetrated in the first of his papers attempting to prove Man is to blame for what little warming occurred in the 20th century. He says his analysis took no account of volcanic or solar activity, but remains unaware of the uncertainties that these and many other systematic or synoptic natural forcings introduce to
        the calculation. There were, for instance, three major volcanic eruptions in the late 20th century: el Chichon, Agung, and Pinatubo, since when there has been no major eruption. In fact, a period of a quarter of a century without a very large eruption is quite rare in recent history. As for solar activity, Solanki (2005) says that the period of 70 years from 1925-1995 was a near-record high for solar activity since the end of the last Ice Age 11,700 years ago.

        Lovejoy assumes that because solar activity has been declining since it peaked in 1960 and yet the world warmed during the positive PDO phase from 1976-1998 the Sun did not contribute to 20th-century warming. He is entirely unaware of the numerous papers that reproduce the temperatures since 1950 with great precision using solely the time-integral of solar activity as the driver of climate. Now, I do not warrant that those papers are true: however, they use methodology very similar to that of Lovejoy, but come to precisely the opposite conclusion. In both approaches, it is the methodology that is inadequate, for it is
        mere curve-fitting.

        Next, Lovejoy makes another statistically absurd assertion: “Applying the usual statistical approach—the bell curve—to these data leads to the conclusion that the chance of a 1 C° fluctuation over 125 years being natural is in the range of 1 in 100,000 to 1 in 3,000,000,” which, allowing for “non-linear geophysics”, he somewhat arbitrarily cuts to 1 in 1000. Let us go back less than three 125-year periods in the temperature record. The cooling of 1645-1693, and the warming of 1694-1733, were both very substantially greater than a 1 C° fluctuation. Besides, the warming periods 1860-1880 and 1910-1940 both occurred before Man could have had much influence. Lovejoy’s analysis simply takes no account of the substantial and startling discrepancy between the supposedly CO2-driven warming rates before and after 1950.

        Next, Lovejoy once again tortures the poor, innocent residuals, so as to justify his assertion that the inconvenient Pause in global warming since 1997 (he dates it from 1998) “is actually a natural cooling event sufficiently large (≈0.3°C) that it has masked the more or less equal anthropogenic warming over the period”. Now, this assertion may or may not be true. Since it is difficult to distinguish natural from anthropogenic causes in the present limited state of knowledge of the climate, and may always be difficult given that the climate behaves as a chaotic object (a complication of which Lovejoy seems blissfully unaware), it is not legitimate to rule out the possibility that there would have been an unusually strong cooling but for manmade warming, which has offset it.

        However, as the NOAA State of the Climate report in 2008 said, a period of more than 15 years without global warming would indicate a discrepancy between models’ predictions and observed reality. The Pause has now endured for 18 years 8 months, according to RSS, or 18 years 5 months, according to UAH. The three longest-standing terrestrial tamperature datasets all used to show the Pause, but in the last year or so, in the run-up
        to Paris, all have been revised with the effect of disappearing the Pause, which, however, endures in the RSS and UAH satellite datasets and, of course, in the temperature anomalies in the upper ocean strata during the entire 11-year ARGO record.

        Whether or not the Pause is a natural offsetting of what would otherwise have been global warming, Lovejoy’s reason for asserting that that is what it is is unsatisfactory. For, on his figure 1b, he draws two flagrantly incorrect trend lines, that are not linear-regression
        trends but join-the-dots lines between local minima and maxima, and then says: “Although this cooling is somewhat unusual, it is not rare: statistical analysis shows that similar 15-year coolings have a natural return period of 20–50 years. Additionally, in this case, the cooling immediately follows the even larger pre-pause warming event (1992–1998; Figure 1b). That is, the pause is no more than a return to the mean; it can be accurately hindcast.”

        The correct analysis, insofar as any analysis relying on the repeatedly-altered and heavily
        politicized Hansen/Schmidt GISS temperature database can be called “correct”, is to determine the least-squares trend on the entire period from 1992-date. That shows warming at 1.9 C°/century equivalent (compared with 1.1 C°/century equivalent for RSS). It is in the nature of residuals in a least-squares trend analysis that they will lie either side of the trend-line. But what is evident even in the GISS graph is that there was fairly rapid warming up to 1998 and a much reduced warming rate thereafter, though the anthropogenic forcings after 1998 are of course substantially greater than the forcings before it.

        The fact that Lovejoy realizes his own argument is insubstantial may be deduced from his reliance on the self-evidently nonsensical tampering by Karl et al., who concluded on the basis of no warming of the lower troposphere and no warming of the surface strata of the ocean that the surface between them was, by some magical process that defies the mere tedious laws of thermodynamics, nevertheless warming. Karl’s heroically absurd paper has rightly come in for criticism from both sides of the climate divide.

        Lovejoy concludes with the usual cloying and wearisome pietisms: the debate is over, the science is settled, it’s time for closure, nothing to see here, move along, move right
        along, pay no attention to the man behind the curtain. Believers have been telling us the debate is over for 25 years, and yet the debate continues.

        His fundamental error is that of apriorism. He starts by desiring a particular outcome and tortures the data until he gets it. The only way to prevent such prejudice is to eschew hindcasts in favour of making predictions. Then it will be possible to verify who is right.

        My own prediction, in Monckton of Brenchley (2013), Science Bulletin vol. 60 no. 1, on the basis of a simple but not inelegant zero-dimensional model, is that there will be less than 1 K global warming by 2100. If the warming is that slow, it will not prove to be a problem even in the longer term. But my prediction is based not on fiddling with past data to see if I can curve-fit a function to it: it is based on understanding the fundamental equations of radiative transfer, of radiative forcing and of temperature feedback system gain, which provide the three principal inputs to the central equation of climate sensitivity – an equation that you will not see whole and entire anywhere in any document of the IPCC.

        Interestingly, if one plugs in the CMIP5 central estimate of the temperature-feedback sum into the fundamental equation of climate sensitivity, using the forcing of around 3 Watts per square meter that IPCC expects this century on the RCP 6.0 business-almost-as-usual scenario, making due allowance for the fact that only two-thirds of equilibrium warming will arise within a century of the forcing that triggered it, and that the forcing itself is projected to arise near-linearly throughout the century rather than all up front, one would expect just 0.5 K global warming in the rest of the century. And that is mainstream climate science.

        Our descendants, reviewing these exchanges, will know which of us was right.

        • Robert

          Good excuse..”…but I’m quite certain that Eos is not open to any but a single, narrow viewpoint on the climate. So, if I …”

          • Tyler Durden

            My climate models predict…, err I mean project that one day Robert will insult the wrong person who will proceed to cut off his tiny balls and shove them down his skinny throat. And the world will be a better place thereafter.

        • Robert

          Evidence?
          Gone missing…
          Something 7th graders are taught not to do.

          “… to 95% confidence its
          assertion to the effect that recent warming is mostly manmade. However, the IPCC’s flagrant misuse of statistical confidence intervals as a purported gauge of what is no more than an unquantifiable opinion not at all strongly supported in the reviewed journals ..”

        • Robert

          Funny how an article length comment wasn’t sent it for possible publication……

          No. Not funny.

          • Craig King

            Seriously, is that the best you can do to point out where, if at all, Moncton is incorrect?

  • monckton

    Mr Lovejoy has written a statistically questionable posting that would not have passed peer review. The relationship between CO2 concentration change and temperature change is not linear but logarithmic. No trouble has been taken to draw a proper distinction between natural and anthropogenic influences. Correlation has been assumed to imply causation (which in logic does not necessarily follow). The absence of correlation between the one-third of all forcings that have arisen in the past 18 years 8 months and the total absence of warming over the same period has been glossed over, though in logic absence of correlation necessarily implies absence of causation. The use of the term “denialist”, with its deliberate and malevolent overtones of pejorative comparison with Holocaust denial is unacceptable and unworthy of the American Geophysical Union. If this is the intellectual height of the believers’ case, then the climate scare is over.

    • jack dale

      That would be Dr. Lovejoy, a physicist at a prestigious university.

      Scientometrics data from Google Scholar:

      Sept. 25, 2015 All Since 2010

      Citations11227 3798

      h-index53 31

      i10-index168 107

      His latest publication:

      Proving anthropogenic global warming and disproving
      natural warming:
      determinism and stochasticity

      can be found on his web site.

    • Constant Gardener

      Monckers is as much an expert on climate science as Dame Edna is an expert on womanhood. They are both amusing fakes.

      Monkers, the Dame Edna of climate science.

  • monckton

    The hate-speech term “denialist”, used by the appalling Lovejoy, is a deliberately, maliciously loaded hate-speech term. Its use, of course, betrays the abject desperation – now bordering on panic – of the climate-Communist faction as its wilfully destructive climate fraud becomes exposed for the hollow but profitable sham that it is.

    No global warming for 18 years 8 months (RSS), or 18 yeas 5 months (UAH). Warming at half the central prediction of IPCC (1990) on the three principal terrestrial datasets. No warming of the ocean surface at all (ARGO) during the entire 11-year record, and such warming as is evident is coming up from below, contrary to the official theory. Meanwhile, the economic cost of measures to make global warming go away continues to cause destruction and death worldwide, particularly in countries that desperately need cheap, reliable, base-load coal-fired electricity. The climate Communists ought to be ashamed of themselves: instead, just as with the millions they killed with their ban even on the indoor use of DDT, they don’t care how many they kill.

    • Robert

      “The climate Communists…”

    • Robert

      So much science…. /s

      “…climate-Communist faction as its wilfully destructive climate fraud …”

    • Robert

      Why? Fits to the basic definition

      Definition of denialist in English:
      noun

      A person who does not acknowledge the truth of a concept or proposition that is supported by the majority of scientific or historical evidence; a denier:
      the small minority of very vocal climate change denialists
      [AS MODIFIER]: the denialist view’

      OED definition

      “The hate-speech term “denialist”, used by the appalling Lovejoy, …”

      • monckton

        Don’t be pathetically disingenuous.

        Global warming continues to be more evident by its absence than by its presence. Get over it.

  • I already answered this on Judith’s blog.
    It represents a basic misunderstanding of what I have done. There is no dismissal of evidence of solar or volcanic forcings, their effects are statistically included in calculating the probabilities. I simply showed that the return period for the observed industrial period change of about 0.9oC was longer than a thousand years. This statistic includes the changes due to volcanism and solar variations.

    In ref. L1 it was even checked that the solar and volcanic statistics since 1880 are of exactly the same type as the pre-industrial solar and volcanic statistics with the amplitudes of the variations within expected random variation.

  • Robert

    S. Lovejoy has written a thorough explanation walking through multiple lines of evidence showing just how thin the denialist position is.

    I also appreciate that S. Lovejoy used the best posible term labeling those fervent blog followers.

    Thank you for the time and effort it takes to craft a thorough piece such as this.

    • John WB

      It’s just a pity that he clearly doesn’t understand the correct statistical tests which, when applied, render his conclusions nonsense.

      • Robert

        Send in a rejoinder….

      • jack dale

        Maybe you could respond to some of his papers posted at the physics department at McGill.

        His latest publication:

        Proving anthropogenic global warming and disproving
        natural warming:
        determinism and stochasticity

        can be found on his web site.

        • Craig King

          How would that change SL’s obvious statistics illiteracy?

  • When there are two hypotheses and one can be rejected, that’s closure. Unless you prose a third such as divine intervention.

    • John WB

      With statements like that, history will not be kind to you Lovejoy, particularly when your use of statistics is so abjectly poor that your conclusions fall apart on first reading.

    • Robert

      The denialists are already claiming devine intervention through the hail mary pass of monckton claiming undersea volcanoes.

      Thanks for taking the time to respond to the various spurious claims with more clear science. That just reinforces your main thesis.

  • Tyler Durden

    Here is my take.

    (1) The author shows that there is correlation between CO2 rise and temperature rise. Agreed. However corelation does not equal causation.

    (2) The author tries to show that there is no other possible explanation for the 1C (actually closer to 0.9C) rise in the last 125 years, which implies causation. This seems to be a weak argument. Questions: Where does your number of 0.1C for historical standard deviation of global temperature come from? This seems much lower than I would expect. I have doubts about our ability to measure this value with any accuracy. This 0.1 standard deviation is the key to the entire line of reasoning. The author will need to provide a lot more detail on where this came from to provide a convincing argument. Don’t tell me it was Mann’s hockey stick.

    (3) At 2.3C increase per CO2 doubling, I agree that the pause does not yet disprove CO2 warming. However, the pause does make a strong case that sensitivities much higher than 2.3, say 3.0C, are highly unlikely. The higher the sensitivity, the less chance there is for an extended pause.

    Prof Lovejoy, where did you come up with the historical 0.1C standard deviation value?

    • 1) There is no need to assume causation. All that this plot is needed for is to estimate the total change since 1880. We then estimate the probability of the change.

      2) You misunderstood: causation is not important for the argument. My argument is essentially classical statistical testing: I make a statistical hypothsis, in this case that there is a natural change of 0.9oC (whether you take 0.9 or 1oC doesn’t change the conclusions.) and then I show that the probability is so small that the hypothesis can be discarded. It only rejects natural variability, it doesn’t prove causality. I calculate the probabilities
      The 0.1oC number comes from pre-industrial multiproxies over 125 year periods, see the references if you want the details. It is also the standard deviation of the residuals.

      3) The pause is nearly perfectly predicted (hindcast), see the references. If there had been no pause, we could soon have statistically rejected the anthropogenic warming theory.

      • Tyler Durden

        The entire basis of your argument depends on your 0.1C standard deviation, generated from “pre-industrial multiproxies”. What happens to your argument if that standard deviation is instead 0.5C? It goes up in smoke, that’s what. Pre-industrial multiproxies sounds like a synonym for pile of dung, but I will go check your references for the details just to find out. The fact that you won’t just tell me makes it smell even more like a pile of dung.

      • Tyler Durden

        Prof Lovejoy, I can find nothing in your references that would give a 0.1C standard deviation of temperature in preindustrial times. Here is a quote from your article:

        “L1 used preindustrial temperature series drawing on several sources”

        Please provide detail on your “several sources” that you refer to. Thank you.

  • M​a​r​k S​h​o​r​e

    It’s surprising that EOS has drawn many of the same ignorant commenters that one finds at the likes of Watts Up With That or Judith Curry’s Climate Etc. blog. Perhaps the latter’s reference to Dr. Lovejoy’s commentary here has drawn them to an AGU website that they otherwise never would have frequented.

    Any, nice article with an interesting and novel presentation using T vs. log CO2.

    • Yes, it the denizens of Judith Curry’s Climate Etc. blog.

      • Larry Evans

        Judith Curry? You mean Dr. Judith Curry, former chair of the School of Earth and Atmospheric Sciences at the Georgia Institute of Technology?

        Ya…she doesn’t have anything to contribute.

    • CB

      “It’s surprising that EOS has drawn many of the same ignorant commenters that one finds at the likes of Watts Up With That or Judith Curry’s Climate Etc. blog.”

      They are organising.

      They’ve attacked a site called Eco Watch too.

      There’s at least one paid fossil prostitute here…

      “Christopher Monckton was a speaker at the Heartland Institute’s 7th International Conference on Climate Change (ICCC7). DeSmogBlog researched the co-sponsors behind Heartland’s ICCC7 and found that they had collectively received over $67 million from ExxonMobil, the Koch Brothers and the conservative Scaife family foundations.”

      (Desmog Dossiers, “Christopher Monckton”)

  • Craig King

    So you claim a logarithmic effect, CO2 saturation, can have a linear effect on temperature? You seem confused.

    • This was proposed by Arhhenius in 1896 and is the basis of all CO2 climate sensitivity estimates (that’s why one expects the same temperature increase very time the CO2 doubles). It may not be trivial, but it certainly isn’t confusing!

  • volker_lives

    The radiative transfer argument from CO2 and other greenhouse gases is fine – the question is the (equilibrium!) climate sensitivity. In effect (simplifying), this is the slope of your regression line. Whether it is an accurate representation of the data is therefore fundamental. It is not. Remarkably figure 1b actually makes this clear. The line really only fits the period 1950-2000. Handwaving about low resolution proxies as justification for passing off this serious deficiency as natural variation is only going to convince the disciples.
    I should add I have read (well, skimmed) a couple of your papers from 2014 on these matters.

  • volker_lives

    Prof Lovejoy seems something of a statistical methods denier. The residuals (or residues as he calls them) from a fitted regression are not there as an all-purpose model variable, the way they are used in climate research. They are there to assess whether the model fits the data. Figure 1b shows the model fit is poor before 1950 (large residuals, both plus and minus). Kudos on the foreshortening of this period in figure 1a by the way, to disguise the lack of fit? Only in an ideological science is the model deemed so perfect that it does not require empirical verification using standard statistical techniques.

    • odin2

      Lysenko science at its best.

      • CB

        “Lysenko science at its best.”

        …is what you’re engaging in.

        Is it likely all scientists on Earth have been wrong for over a century?

        What do you think?

        “The heat-trapping nature of carbon dioxide and other gases was demonstrated in the mid-19th century”

        (NASA, “Climate change: How do we know?”)

        • A Human

          To be fair, not every single scientist over the past century agrees with the consensus on the greenhouse function of the atmosphere. Before I say this, I want to make ABSOLUTELY CLEAR that I do NOT agree with the person who I will speak of’s position on this, in fact, I think that he ought to stop blackening our camp with all the controversy he has brought about. His name is Tim Ball. (Start Sarcasm) I am sure that you know who he is and that you have a billion links proving that everything he says is false because X oil company funded him and he fudged his credentials, and he spoke at one of Heartland’s conferences on climate change, etc. (End Sarcasm) However, he does have a Ph.D. in something and was a professor in the Department of Geography at the University of Winnipeg, so I believe we can consider him a scientist who disagrees with the consensus (as he is one of the “Sky Dragon Slayers”, among other things.)

          Again, I disagree with him on his position on the greenhouse effect, to avoid any confusion or strawman arguments. I agree with you alarmists that it exists and that because of it, Earth is an inhabitable place.

          I will sincerely appreciate this does not turn into an ad hominem echo chamber, so please forgive me if I have offended anyone in any way and spare me the trouble of attempting to rebut what may arise as a result of my comment.

          • CB

            “not every single scientist over the past century agrees with the consensus on the greenhouse function of the atmosphere.”

            lol!

            Really?

            …and what do these alleged “skeptical” scientists believe?

            If the only way the Earth has of cooling down is emitting infrared radiation…

            …and if greenhouse gasses absorb infrared radiation.

            How could greenhouse gasses not warm the planet?

            “While the dominant gases of the atmosphere (nitrogen and oxygen) are transparent to infrared, the so-called greenhouse gasses, primarily water vapor (H₂O), CO₂, and methane (CH₄), absorb some of the infrared radiation. They collect this heat energy and hold it in the atmosphere, delaying its passage back out of the atmosphere.”

            (Columbia University “The Greenhouse Effect and Global Warming”)

            • A Human

              I honestly do not know and consider their opinions, as I said before, as a stain on skeptic’s reputations. It is understandable why alarmists consider so many skeptics fools in view of how some of us truly act like it. I do agree with Columbia’s assessment, (though the explanation is simplified somewhat for the laymen) but to answer your “Really”, the answer is, unfortunately, yes.

              • CB

                “I honestly do not know”

                …so you don’t know what these alleged scientists believe, you’re just blindly repeating their claims…

                Is that skeptical behaviour?

                …or something else?

    • This is science not statistics. The scientific underpinnings are:

      a) The science going back to Arhhenius in 1896 predicts that CO2 radiative forcing is a logarithmic function of CO2 concentration.
      b) The
      small magnitude of this forcing in relation to overall solar forcing (less than
      1%) implies that it’s effect on temperature is roughly linear.
      c) All anthropogenic effects are are highly
      correlated with CO2 emissions due to the global economy.

      Taken together, these three justify the interpretation of the residuals as the natural
      variability. Statistical comparisons with pre-industrial multiproxies – over scales ranging from years to a century – show that the statics of the 1880- 2004 residuals are very close to the pre-industrial
      residuals (from 1500-1900). This is a statistical confirmation of the the theoretical prediction.

      This is science – empirically testing specific hypotheses – it is not just statistics.

      • monckton

        The current hiatus of a quarter of a century in statistically-significant global warming differs from previous periods of little or no temperature change in that the anthropogenic forcings in the 25 years since the IPCC’s First Assessment Report in 1990 account for more than half of all industrial-era anthropogenic forcings – and yet not little global warming has resulted. The correlation between economic growth and temperature change has accordingly broken down, as IPCC has recognized in its important admission that 111 of 114 climate models had over-predicted the global warming rate.

        IPCC, recognizing the growing discrepancy between its predictions and the less exciting observed reality, has all but halved its medium-term warming projections. It ought also to have substantially cut its longer-term or equilibrium projections, since the CMIP5 models, also recognizing the impact of the hiatus, now cluster (with the exception of a single outlier) around a temperature-feedback sum one-quarter below the CMIP3 central estimate.

        The effect of this one change is to reduce the central estimate of equilibrium sensitivity from 3.3 to 2.2 K per CO2 doubling. Even this may not be a sufficient reduction: for, in Moscow recently, Professor Ray Bates, one of half a dozen physicists who understand the mathematics of feedback amplification or attenuation as applied to the climate object, gave a talk concluding that temperature feedbacks are likely to be net-negative, and that climate sensitivity must be <0.4 K at CO2 doubling.

        For these and many other reasons, one should not make the unwise assumption that a correlation (even where it properly existed) necessarily implies causation. On the current state of the evidence, one would expect little anthropogenic warming by 2100.

        • Monkton:
          The current hiatus of a quarter of a century in statistically-significant
          global warming differs from previous periods of little or no temperature change
          in that the anthropogenic forcings in the 25 years since the IPCC’s First
          Assessment Report in 1990 account for more than half of all industrial-era
          anthropogenic forcings – and yet not little global warming has resulted. The
          correlation between economic growth and temperature change has accordingly
          broken down, as IPCC has recognized in its important admission that 111 of 114
          climate models had over-predicted the global warming rate.

          SL: these numbers are not quite right,
          and by cherry picking the start and end points we can get quite different
          results. For example, from Fig. 1a we
          can see that over the period 1990-2012, the log2 CO2 has
          increased from 0.34 to 0.48 so that the forcing has increased by
          (0.48-0.34)/0.34 or 41% (your best case). The temperature
          has increased by (1.02-0.84)/0.84 = 21%. However, had we instead taken the period
          1992-2011, then the numbers would have been an increase in the forcing by 0.14/0.35= 40% but with a temperature change
          of 0.47/0.65= 72%. In order to get a
          meaningful result, we need to use the entire curve in the figure, not just
          cherry picking convenient end points: a regression analysis. That is what my analysis is based on.

          Monkton:
          IPCC, recognizing the growing discrepancy between its predictions and the
          less exciting observed reality, has all but halved its medium-term warming
          projections. It ought also to have substantially cut its longer-term or
          equilibrium projections, since the CMIP5 models, also recognizing the impact of
          the hiatus, now cluster (with the exception of a single outlier) around a
          temperature-feedback sum one-quarter below the CMIP3 central estimate.

          SL: The fact that the pause can be
          accurately hindcast using stochastic models (i.e. without GCM’s) shows that the
          problem is that the GCM’s were overpredicting the temperature, it has nothing
          to do with a flaw in the anthropogenic warming hypothesis.

          Monkton:
          The effect of this one change is to reduce the central estimate of
          equilibrium sensitivity from 3.3 to 2.2 K per CO2 doubling. Even this may not
          be a sufficient reduction: for, in Moscow recently, Professor Ray Bates, one of
          half a dozen physicists who understand the mathematics of feedback
          amplification or attenuation as applied to the climate object, gave a talk
          concluding that temperature feedbacks are likely to be net-negative, and that
          climate sensitivity must be <0.4 K at CO2 doubling.

          For these and many other reasons, one should not make the unwise assumption
          that a correlation (even where it properly existed) necessarily implies
          causation. On the current state of the evidence, one would expect little
          anthropogenic warming by 2100.

          SL: My analysis does not assume that
          correlation implies causation. For the
          basic statistical test (ref. L1), figure 1a
          is only used to estimate the overall change in temperature since 1880. The residuals – again without assuming causation – are also
          used to hindcast the pause in ref. L3.

          • monckton

            Ross McKitrick, in a talk late last year, said there had been no statistically-significant warming for 26 years on the RSS dataset. That takes us back before the IPCC’s First Assessment Report, which, like it or not, was published in 1990. That is not a “cherry-picked” date, unless the IPCC “cherry-picked” it. It is the date of publication.

            In the report of that date, IPCC made the first of its overblown predictions of global temperature change. Specifically, it predicted 1 [0.7, 1.5] K near-linear warming to 2025. Naturally, one must make allowance for natural variability either side of this interval: but, on the RSS dataset, only 0.27 K warming has occurred over the quarter-century to September 2015, using a linear-regression analysis over the entire period.

            The decadal warming rate would thus have to increase at least fivefold over the next ten years compared with the past 25 years in order to reach 1 K warming. IPCC’s prediction was wildly overdone, which is why IPCC has now been compelled to reduce its medium-term warming predictions by almost half. Shamefully, it has refused to reduce its longer-term predictions to match.

            It is no doubt all very interesting that the Pause “can be hindcast by stochastic models”. But almost no models did what would have been not only interesting but useful: to forecast it.

            We are agreed that a substantial fraction (Mr Lovejoy says more than 40%, I say more than 50%) of the anthropogenic forcing since 1750 (which arises not only from CO2 but from many other causes) has occurred since 1990, and yet, on the satellite datasets at any rate, no statistically-significant warming has resulted. No surprise, then, that the French Computation Society has published a paper saying that models are valueless when applied to the question how much global warming we may expect. And modeling is what the Society’s members specialize in.

            Finally, Mr Lovejoy now says, more than a little disingenuously, that his analysis does not assume that correlation necessarily implies causation. Yet his opinion piece suggested a direct, linear correlation between change in CO2 concentration and change in temperature. That, so it seemed to me, was the main point of his scientific argument, though his concession that the CO2 forcing function is of logarithmic and not of linear shape is welcome.

            The point, however, is that the rapidly-rising anthropogenic forcings have not – for about a quarter of a century – been reflected in rapidly-rising temperature. The absence of correlation between forcings and temperature change necessarily implies absence of causation of the latter by the former.

            Accordingly my conclusion stands: that, given the substantial reduction in the central estimate of the feedback sum between the CMIP3 and CMIP5 models, taken with the fact that only two-thirds of equilibrium warming will arise over a century, and that the 2.75 W m/2 forcing predicted by the IPCC on the “business-almost-as-usual” RCP 6.0 scenario is predicted to arise in near-linear increments over the rest of the century, mainstream climate science leads us to expect only a harmless and beneficial 0.5 K global warming in the 21st century. That is the inconvenient truth.

            And that is one of many reasons why hate-speech terms like “denialist” should not be directed at those of us who are asking legitimate scientific questions such as these.

            • jack dale

              What the heck is the “French Computation Society”? If you mean Société de Calcul Mathématique SA, that is private held corporation.

              SCM was born in 1987, as a non profit organisation
              (“Association Loi 1901”, under the French law).
              It was created by a University professor,
              Dr. Bernard Beauzamy.

              It became a commercial company in 1995.
              “Société Anonyme” means “Corp.”
              Capital 56 200 Euros.
              RCS Paris B 399 991 041.
              Code APE 7129 Z.

              Beauzamy’s claims have been refuted years ago.

          • Robert

            Thank you for your service above and beyond in responding to denialists!

  • John WB

    I’ve no idea who this clown Lovejoy is, but his grasp of the data is shaky to say the least. It would take far too long to list all the falsehoods, errors and omissions in the article but the most obvious and glaring problem with the analysis relates to the fact that around 45% of the warming since 1880 had taken place before the addition of man made CO2 into the atmosphere.

    Jesus how did this get printed.

    • BlueScreenOfDeath

      Quite.

      • CB

        “Quite.”

        Whose grasp of the data is shaky at best?

        Is it Dr. Lovejoy’s?

        “The year 2014 now ranks as the warmest on record since 1880, according to an analysis by NASA scientists.”

        (NASA, “NASA, NOAA Find 2014 Warmest Year in Modern Record”, January 16, 2015)

        • Larry Evans

          38% chance, that is.

          • CB

            “38% chance”

            Yup. We know you like to spread misinformation about probability distributions.

            Is there a year more likely than 2014 to have been the warmest on record?

            Which year was that?

            If you don’t know, how could you possibly know scientists are wrong?

            “2015 will very likely beat 2014 as the warmest year”

            (Scientific American, “2015 May Just Be Hottest Year on Record”, By Andrea Thompson, August 20, 2015)

            • BlueScreenOfDeath

              More utter drivel.

            • John WB

              According to the more reliable NASA satellite datasets 1998 was the warmest in recent history followed by 2010. 2014 ranked 5th in in the last twenty years.

        • BlueScreenOfDeath

          Utter drivel.

          As I rather think you are well aware.

    • M​a​r​k S​h​o​r​e

      You have no idea who Lovejoy is but you feel free to comment on a climate article without checking any of his publications or past work?

      Well, nobody ever claimed you deniers were fixated on data or factual analysis.

      • John WB

        I don’t need to know who Lovejoy is to know the claims in this article are statistical nonsense. I did scan some of his other work but unfortunately none of it was any help in rescuing what is a completely inept article.

        Despite what you claim data is the only thing I am interested in, which is why I can confidently say I am surprised this nonsense ever got printed. It wouldn’t pass high school grade statistics.

      • CB

        “nobody ever claimed you deniers were fixated on data or factual analysis.”

        lol! Well they do, of course… but their word isn’t worth so much…

        Given that their well-being is at stake, I’d suggest their lack of interest in what is true hints at a suicidal dimension of the mental illness they seem to suffer from.

        “The continent of Antarctica has been losing about 134 billion metric tons of ice per year since 2002, while the Greenland ice sheet has been losing an estimated 287 billion metric tons per year.”

        (NASA Global Climate Change, “Vital Signs of the Planet: Land Ice”)

      • monckton

        I ken fine who Lovejoy is. He is not good at the mathematics and statistics of climate.

        • CB

          “He is not good at the mathematics and statistics of climate.”

          You are describing someone very specifically.

          Who is the person you’re describing, Mr. Christopher Monckton?

          “we estimate a 97% probability that 2015 will become the warmest year on record.”

          (NOAA Climate, “Somewhat. Very. Extremely. How likely is it that 2015 will be the new warmest year on record?”, Arguez et al, Thursday, September 17, 2015)

    • monckton

      Lovejoy’s piece got printed because it reflects the Party Line. It is remarkably poor statistics, and its language is the language of hate-speech. No respectable journal would have given it space.

      • Robert

        Why tone down your claims? Usualy, it is “paid troll” and “Climate Communist “.

        “Party Line”

        • CB

          lol! I dunno, I think the “hate-speech” line is pretty extreme.

          The laws of physics are so hateful! /s

          lol!

          “Without greenhouse gases, Earth would be a frozen -18 degrees Celsius (0 degrees Fahrenheit).”

          (NASA Earth Observatory, “Effects of Changing the Carbon Cycle”)

          • Robert

            After a well referenced article on the science, we get the science deniers wo a hint of irony showing us their science-free arguments…

            • CB

              “we get the science deniers wo a hint of irony showing us their science-free arguments”

              In a way, it showcases the disconnect between people like Shaun who actually care what’s true, and the Climate Denier clowns down here in the peanut gallery who just don’t.

              His article is way too dense for any of them to comprehend, of course, though I think he’s onto something in proving their fantasies wrong.

              The only thing I would add (and do add) is a Socratic approach to the matter.

              Has there really been a global conspiracy to convince people that greenhouse gasses warm the planet when they really don’t? Has that conspiracy really gone on for centuries?

              Ask them to supply the likelihood of their own wacky claims being true and I think the fibrillation that ensues can be quite effective in swaying public opinion…

              • Robert

                Given the demographics for denialists, I sometimes worry that pushing some of them might make”fibrillation” an issue…

                • CB

                  “Given the demographics for denialists, I sometimes worry that pushing some of them might make”fibrillation” an issue…”

                  lol!

                  Whatever gets the job done, right?

                  I was being metaphorical, of course, but I would believe they do get physically worked up by having their dishonesty challenged!

                  That’s a choice they make.

                  No one’s forcing them to double down on dishonesty.

                  Life really is easier when you stop lying… and turn off Fox News!

                  (Forbes: Kenneth Rapoza, “Fox News Viewers Uninformed, NPR Listeners Not, Poll Suggests”, Nov 21, 2011)

      • Elizabeth

        Oh, please! “hate speech”? I don’t fully understand the statistics in the first half of the article, but the probability part was quite clear. Whatever he said, the tone of the article was not in the least inflammatory.
        It occurs to me that he can afford to take a measured, non-provocative approach because his argument is sound. It is only those who are desperately trying to prove an unprovable point who have to resort to name-calling, and slurs about someone’s lack of credentials. PhD in Physics or MA in Classics? Hmmmm……

    • jack dale

      Had you bothered to read through the article.

      S. Lovejoy, Department of Physics, McGill University, Montreal, Quebec, Canada

      His CV is available.

    • monckton

      JohnWB is right. Lovejoy is not really familiar with the physics of climate and his papers tend to overestimate Man’s influence and to claim certainty where none in truth exists.

  • Curious from Cleathropes

    I would not make any attempt to categorise people into groups since this just creates an “us against them” mentallity. E.g Certain papers have suggested that unknown natural variations represent a significant portion of the measured increase in temperatures obversed since 1900 (ref 1, ref 2 etc.). This paper demonstrates that by analysing CO2 forcing versus temperature . . . Etc.

    To me you make a compelling case and the fact stand by themselves.

    Regards

  • Curious from Cleathropes

    Good article but what a shame the author felt the need to categorise people as “denialists”, which in my opinion took this from being an A+ to a B-! The facts should present them selves and if you feel the need to start calling people with different ideas names this will always negatively affect your credibility.

    Such a shame . . .

    • The nonstandard term “denialist” (see the reference to Gillespie) was used specifically in an attempt to be as neutral as possible. What term would you use?

      • BlueScreenOfDeath

        “The nonstandard term “denialist”… was used specifically in an attempt to be as neutral as possible”

        Drivel.

        It is as you are certainly well aware pejorative, a corruption of “deniers” with its connotation of Holocaust denial and conspiracy belief in general, and its use to insult a very large proportion of the population who do not “deny” that the climate changes, nor that a certain portion of this change is anthropogenic does you no favours and lays you open to the same disrespect you have shown to that large section of the population.

        The acceptable term is sceptics (or skeptiks if you are resident in the USA), as it is very clear to any person with a solid scientific background that climate science is by no means settled.

        Aside from that, I have seldom read such a load of scientifically and statistically illiterate donkey droppings in my life.

        As the pause/plateau/hiatus continues with no sign of termination you lot are clearly getting desperate. Scared of losing your seats on the AGW gravy train? You should be.

        • M​a​r​k S​h​o​r​e

          My preferred term is ‘willfully ignorant Dunning-Kruger dolts’, but that’s quite long and I find many deniers dislike it as well.

          There’s just no pleasing some people.

      • odin2

        You lack self awareness.

      • justinburch505

        It’s a pejorative designed to put anyone who questions Big Green in the same despicable class as Holocaust denier and you know it. You can play with words and quote others as much as you want but to call any scientist who disagrees with you a despicable person on a par with a antiSemitic Holocaust denier and to claim there is no more debate in the science of climate change simply indicates you are an arrogant ass, regardless of the state of the science.

      • monckton

        Mr Lovejoy was wrong to use the loaded term “Denialist” with its deliberate and malevolent overtones of pejorative comparison with Holocaust denial. Those of us who publish research questioning the extent and cost of anthropogenic warming do so on the basis of mainstream scientific arguments. We are “questioners”, or, in al-Haytham’s phrase, “seekers after truth”. Perhaps one might call those who accept the Party Line on climate “believers”.

        Al-Haytham, celebrated in the East as the founder of the scientific method, wrote that the seeker after truth does not place his faith in any mere “consensus”, however venerable or widespread. Instead, he checks and checks and checks again. “The road to the truth,” wrote al-Haytham, “is long and hard, but that is the road we must follow.” Questioners, then, are squarely in the tradition of the scientific method; believers, on the other hand, seem to repudiate the role of uncertainty in science.

        Arrhenius, for instance, wrote in 1896 that a CO2 doubling would cause 4-8 K global warming. Then, instead of proclaiming his finding to be unquestionable truth and declaring any questioners to be “denialists”, he thought again and, in 1906, wrote a second paper, this time published in German, which is why so few believers have come across it:

        In aenliche Weise berechne ich, dass eine Verminderung des Kohlensaueregehalts zur haelfte oder eine Zunahme desselben auf den doppelten Betrag Temperaturaenderungen von minus 1,5 beziehungsweise plus 1,6 grad Celsius entsprechen wuerde.

        “Likewise I calculate that a reduction of CO2 concentration by half or an increase of the same by double would cause -1.5 and +1.6 degrees Celsius degrees of temperature change respectively.”

        So let us have no more hate-speech about “denialists”. In Scotland and in Austria, such language constitutes a criminal offense. Use of such terms cheapens what is already a shaky argument, statistically speaking. Best to keep the politics out of science.

        • Robert

          Claimed. With no evidence. Read a dictionary.
          “pejorative comparison “

        • Monkton:
          Mr Lovejoy was wrong to use the loaded term “Denialist” with its
          deliberate and malevolent overtones of pejorative comparison with Holocaust
          denial. Those of us who publish research questioning the extent and cost of
          anthropogenic warming do so on the basis of mainstream scientific arguments. We
          are “questioners”, or, in al-Haytham’s phrase, “seekers after
          truth”. Perhaps one might call those who accept the Party Line on climate
          “believers”.

          SL: As you know, denialist is a
          neologism, it is an attempt to be neutral to avoid using the loaded terms
          skeptic and denier.

          Monkton:
          Arrhenius, for instance, wrote in 1896 that a CO2 doubling would cause 4-8 K
          global warming. Then, instead of proclaiming his finding to be unquestionable
          truth and declaring any questioners to be “denialists”, he thought
          again and, in 1906, wrote a second paper, this time published in German, which
          is why so few believers have come across it:

          In aenliche Weise berechne ich, dass eine Verminderung des
          Kohlensaueregehalts zur haelfte oder eine Zunahme desselben auf den doppelten
          Betrag Temperaturaenderungen von minus 1,5 beziehungsweise plus 1,6 grad
          Celsius entsprechen wuerde.

          “Likewise I calculate that a reduction of CO2 concentration by half or
          an increase of the same by double would cause -1.5 and +1.6 degrees Celsius
          degrees of temperature change respectively.”

          SL: Thanks for the history of science,
          it is interesting even if not relevant!

          Monkton:
          So let us have no more hate-speech about “denialists”. In Scotland
          and in Austria, such language constitutes a criminal offense. Use of such terms
          cheapens what is already a shaky argument, statistically speaking. Best to keep
          the politics out of science.

          SL: Considering that the term denialist was invented in an attempt to
          be neutral I would be surprised if anyone would classify it as hate
          speech. Certainly the accusation rings
          false coming from someone who termed my paper (L1) “a mephitic ectoplasmic
          emanation of the forces of darkness”. Aren’t
          you being little over-sensitive?

          • monckton

            If Mr Lovejoy really thinks “denialist” is a “neutral” world, he must be even farther to the hard Left than one had imagined. Bad science combined with bad language: not an appealing or useful combination.

          • monckton

            “Denialist” is no better than “denier”: it is a maliciously pejorative comparison with Holocaust denial. It is not to be used again. I hope that, on behalf of questioners of the Party Line, I have made that clear.

            The relevance of the reference to Arrhenius, as should have been obvious, is that Arrhenius was aware of the possibility that he might be wrong, a possibility that believers who use words such as “denialists” of those who question their credo seem unable even to contemplate.

            • jack dale

              Here is what as a Holocaust survivor,Micha Tomkiewicz, has to say about your whining.

              I had originally planned to make my next post a continuation of the last one, and call it “Proof, Part 2.” However, my last blog post stirred up a lot of debate and reaction, including recognition from New York Times environmental reporter/blogger Andrew Revkin. So, I thought I’d take a slight detour and address some of the issues raised by that post.

              Many thoughtful comments on this blog (thanks!!) have focused on my so-called “dragging” the Holocaust into the climate change debate. The claims were that I am “cheapening” the Holocaust, that I am not able to distinguish between deniers and skeptics and/or that I am accusing climate change deniers of using “Nazi methods” simply by using the term deniers in the context of climate change.

              First of all, I could not and would not “cheapen” a genocide that killed most of my family and deprived me of my childhood between the Warsaw Ghetto and Bergen-Belsen. I was born three months before the start of this genocide in which we were targeted for annihilation because we belonged to a group that the Germans did not think had a right to exist.

              But, of course, I am using the term “denier” to make a point. In 1933, very few people believed that Hitler would seriously try to accomplish what he preached and almost no one could imagine the consequences of his deadly reign. Although there was evidence available – Hitler was clear about what he wanted to do in Mein Kampf – why did people not pay attention? These “deniers” might as well have been called skeptics in their day.

              I make my “climate change denier” claim for one reason. It’s easy today to teach students to condemn the Holocaust, but it’s much more difficult to teach them how to try to prevent future genocides. There are different kinds of genocides and they don’t repeat themselves; they come to us in different ways. I am not suggesting that the Holocaust is just like climate change. But what I am suggesting is that it’s hard to see a genocide – any genocide – coming. The future is hard to predict, but we can see this one coming. This genocide is of our own making, and it will effect everyone, not just one group or country.

              Even if people don’t believe this or are skeptical – remember Germany as Hitler came to power – why don’t we act now? Why wait? And what, exactly, are we waiting for anyway? Are we waiting for “the answer?” Since, as I’d said earlier, the future is not totally predictable, we may never get “the answer.”

              I don’t want my grandchildren to die in a climate change genocide that we could have helped head off because we were waiting for some unattainable certainty about climate change.

              The preventive actions that need to be undertaken are outlined in various credible scientific reports and will be expanded upon right here in the near future. They will have to be applied on a multigenerational time scale (End of Now in my book- see first blog).

              These actions that we can take now are not meant to be “the answer” to a certain scenario. They were always meant to be an insurance policy that we can afford to pay and that we must pay. In my opinion, most of those actions can be summarized like this: at a minimum, we must require that by the “end of now” (my grandchildren’s life-span), half of our global energy use must not result in the emission of greenhouse gases to the atmosphere and fossil fuels must not be coal based. (There’s more on all of that in my book.)

              Ultimately, my main objective in “dragging” the Holocaust into this debate is that, in my opinion, long-term solutions to our climate change problem can only be attained through the educational system.

              Holocaust studies and commemorations are now widespread. Here’s just one example – “United Nations General Assembly resolution 60/7 on Holocaust remembrance called for the establishment a programme of outreach on the subject of the ‘Holocaust and the United Nations’ and measures to mobilize civil society for Holocaust remembrance and education in order to help to prevent future acts of genocide.” Millions of children, mainly in Europe, North America, Australia, Israel, and even in China study the events. Holocaust museums are opening in places that are not directly connected with the event.

              A valid question, one that probably only a person with a background similar to mine can ask is, why? The UN resolution provides a reasonable response – “to prevent future acts of genocide.” The Spanish-American philosopher George Santayana wrote that, “Those who cannot remember the past are condemned to repeat it,” to which the English writer and cartoonist Max Beerbohm replied, “History does not repeat itself. The Historians repeat one another.”

              Teaching the Holocaust to achieve this objective requires not only the study of past events, but it also must attempt to analyze future situations that might lead to genocides – man-on-man and self-inflicted – through destruction of the physical environment.

              I belong to the last generation of Holocaust survivors. The interest in study of the Holocaust is increasing, and the demand for people like me to appear before school children to tell our stories and answer their questions, is increasing. This is an opportunity that I choose to use to remind everybody within our reach that we need to pay attention to the prevention of future genocides through analysis of situations that might lead to one.

        • jack dale

          ” using the Holocaust itself to score rhetorical points is a slimy tactic, and it is insulting to those who survived the Holocaust to raise petty disputes to the level of the worst crime in history.”

          • monckton

            Don’t whine. The author of the head posting uses the hate-speech term “denialist”. If you can’t take it, don’t dish it out.

            • jack dale

              You are the slimy whiner. Follow your own advise – hypocrite.

              • monckton

                Don’t whine. You’re paid to be an effective little Climate Communist, not to whine.

                • jack dale

                  Thanks for thinking that my posts have some value. Yours have none.

                • monckton

                  Dale’s posts are not effective. He is taking money from his climate-Communist paymasters under false pretenses.

                  Meanwhile, the world continues to fail to warm at anything like the predicted rate. Despite all the whining trolls, the scientific case for alarm recedes and collapses.

                • Robert

                  “… climate-Communist paymasters …”

          • monckton

            In that event, the use of the word “denialist” or “denier” should be banned on this and all websites.

      • monckton

        The term “denialist” is a hate-speech term and it is altogether unacceptable. It has deliberate and malevolent overtones of comparison with Holocaust denial. It should be banned by the AGU.

        • jack dale

          No – “denialist” describes you perfectly. Ask Carl Mears.

          Stp whining about and accept what you are.

        • Robert

          Why? Fits to the basic definition
          Definition of denialist in English:
          noun
          A person who does not acknowledge the truth of a concept or proposition that is supported by the majority of scientific or historical evidence; a denier:
          the small minority of very vocal climate change denialists
          [AS MODIFIER]: the denialist view’
          OED definition

          • monckton

            Don’t be disingenuous.

        • Mobius Loop

          And on the subject of hate speech, here one again are some of the insults an unhappy Monckton chucks out of the pram.

          – yah-boo
          – grunting
          – yahoos
          – shrieking
          – poison pen attacking
          – paid trolling
          – childish
          – climate communist

          • monckton

            In fact and in law, an anonymous person has no legitimate claim that he has been insulted. The small nest of childish, grunting, yah-boo-shrieking, paid climate-Communist trolls here, who are ignorant, hate-filled well-known regulars poisonously and daily infesting and infecting multiple sites where otherwise an intelligent conversation about the climate might be possible, treat any commenter with vicious discourtesy and savagery. If it were only I who attracted their small-mindedness – gnats buzzing futilely around the flame of truth – I’d be worried.

            As it is, the moderators of this site have yet to learn the simple rule, gradually being implemented elsewhere, that either commenters must have the guts to say exactly who they are or they must be banned from making ad-hominem attacks. The application of this rule has vastly improved the quality of other sites, where the paid extremists can no longer poison the well with their hate speech because if they did so everyone would know who they were.

            Their despicable technique, invented by those who established the totalitarian regime that led to the Second World War, is calculated to drive away all who would otherwise have the courage to speak out and oppose the profiteers of doom.

            Mainstream science would lead us to expect no more than 0.5 Celsius degrees of global warming by 2100. Mainstream economics demonstrates that making global warming go away by mitigation today is 10-100 times costlier than letting it happen and paying the cost of adaptation to its net-adverse consequences (make that 1000 times costlier given that global warming is not occurring – and on mainstream-science considerations is not expected to occur – at anything like the once-predicted rate.

            Furthermore, policies that prevent or delay the introduction of cheap, reliable, easy-maintenance coal-fired power for third world countries whose populations lack electricity are a significant, serious and growing cause of death among the world’s poorest.

  • Roger Clifton

    The article argues that any increase in GHGs leads to a proportional increase in temperature. It follows that there is no sustainable level of emissions. Rather than “reduce” global emissions, we must eliminate them.

    • Dandersan

      Eliminate CO2 means eliminating life on earth!

      • Roger Clifton

        There is a world of difference between the “rate of emissions”, that is of fossil carbon, and the “levels of GHGs” that warm the world. The (rate of) emissions is the rate of increase of greenhouse gases. People who claim that we only need to “reduce” to some sustainable rate of emission are under the wilful delusion that there is a restoring force that increases to return GHGs to some God-ordained level. The only thing resembling that is the weathering of rock, but that process takes hundreds of thousands of years not decades. The only sustainable rate of emissions is zero; we must eliminate global emissions of fossil carbon.

        • Robert

          Thanks for pointing out how the commentor tried to change the argument to fit a standard denialist talking point.

    • Spongsdad

      And how precisely do we do that? Should we all stop breathing, perhaps? Your “logic” suggests that an increase in global population would necessarily lead to an increase in emissions

  • hippecampre

    What a moron.

  • akbetts

    Thank- you, Sean, this is a helpful analysis!