The 50-50 argument

by Judith Curry

Pick one:

a)  Warming since 1950 is predominantly (more than 50%)  caused by humans.

b)  Warming since 1950 is predominantly caused by natural processes.

When faced with a choice between a) and b),  I respond:  ‘I can’t choose, since i think the most likely split between natural and anthropogenic causes to recent global warming is about 50-50’.  Gavin thinks I’m ‘making things up’, so I promised yet another post on this topic.

For background and context, see my previous 4 part series Overconfidence in the IPCC’s detection and attribution.

Framing

The IPCC’s AR5 attribution statement:

It is extremely likely that more than half of the observed increase in global average surface temperature from 1951 to 2010 was caused by the anthropogenic increase in greenhouse gas concentrations and other anthropogenic forcings together. The best estimate of the human induced contribution to warming is similar to the observed warming over this period.

I’ve remarked on the ‘most’ (previous incarnation of ‘more than half’, equivalent in meaning) in my Uncertainty Monster paper:

Further, the attribution statement itself is at best imprecise and at worst ambiguous: what does “most” mean – 51% or 99%? 

Whether it is 51% or 99% would seem to make a rather big difference regarding the policy response.  It’s time for climate scientists to refine this range.

I am arguing here that the ‘choice’ regarding attribution shouldn’t be binary, and there should not be a break at 50%; rather we should consider the following terciles for the net anthropogenic contribution to warming since 1950:

  • >66%
  • 33-66%
  • <33%

JC note:  I removed the bounds at 100% and 0% as per a comment from Bart Verheggen.

Hence 50-50 refers to the tercile 33-66% (as the midpoint)

Note:   I am referring only to a period of overall warming, so by definition the cooling argument is eliminated.  Further, I am referring to the NET anthropogenic effect (greenhouse gases + aerosols + etc).   I am looking to compare the relative magnitudes of net anthropogenic contribution with net natural contributions.

Further, by global warming I refer explicitly to the historical record of global average surface temperatures.  Other data sets such as ocean heat content, sea ice extent, whatever, are not sufficiently mature or long-range (see Climate data records: maturity matrix).   Further, the surface temperature is most relevant to climate change impacts, since humans and land ecosystems live on the surface.  I acknowledge that temperature variations can vary over the earth’s surface, and that heat can be stored/released by vertical processes in the atmosphere and ocean.  But the key issue of societal relevance (not to mention the focus of IPCC detection and attribution arguments) is the realization of this heat on the Earth’s surface.

IPCC

Before getting into my 50-50 argument, a brief review of the IPCC perspective on detection and attribution.  For detection, see my post Overconfidence in IPCC’s detection and attribution. Part I.

Let me clarify the distinction between detection and attribution, as used by the IPCC. Detection refers to change above and beyond natural internal variability. Once a change is detected, attribution attempts to identify external drivers of the change.

The reasoning process used by the IPCC in assessing confidence in its attribution statement is described by this statement from the AR4:

“The approaches used in detection and attribution research described above cannot fully account for all uncertainties, and thus ultimately expert judgement is required to give a calibrated assessment of whether a specific cause is responsible for a given climate change. The assessment approach used in this chapter is to consider results from multiple studies using a variety of observational data sets, models, forcings and analysis techniques. The assessment based on these results typically takes into account the number of studies, the extent to which there is consensus among studies on the significance of detection results, the extent to which there is consensus on the consistency between the observed change and the change expected from forcing, the degree of consistency with other types of evidence, the extent to which known uncertainties are accounted for in and between studies, and whether there might be other physically plausible explanations for the given climate change. Having determined a particular likelihood assessment, this was then further downweighted to take into account any remaining uncertainties, such as, for example, structural uncertainties or a limited exploration of possible forcing histories of uncertain forcings. The overall assessment also considers whether several independent lines of evidence strengthen a result.” (IPCC AR4)

I won’t make a judgment here as to how  ‘expert judgment’ and subjective ‘down weighting’ is different from ‘making things up’

AR5 Chapter 10 has a more extensive discussion on the philosophy and methodology of detection and attribution, but the general idea has not really changed from AR4.

In my previous post (related to the AR4), I asked the question: what was the original likelihood assessment from which this apparently minimal downweighting occurred?   The AR5 provides an answer:

The best estimate of the human induced contribution to warming is similar to the observed warming over this period.

So, I interpret this as scything that the IPCC’s best estimate is that 100% of the warming since 1950 is attributable to humans, and they then down weight this to ‘more than half’ to account for various uncertainties.  And then assign an ‘extremely likely’ confidence level to all this.

Making things up, anyone?

I’ve just reread Overconfidence in IPCC’s detection and attribution. Part IV, I recommend that anyone who seriously wants to understand this should read this previous post.  It explains why I think the AR5 detection and attribution reasoning is flawed.

Of particular relevance to the 50-50 argument, the IPCC has failed to convincingly demonstrate ‘detection.’  Because historical records aren’t long enough and paleo reconstructions are not reliable, the climate models ‘detect’ AGW by comparing natural forcing simulations with anthropogenically forced simulations.  When the spectra of the variability of the unforced simulations is compared with the observed spectra of variability, the AR4 simulations show insufficient variability at 40-100 yrs, whereas AR5 simulations show reasonable variability.  The IPCC then regards the divergence between unforced and anthropogenically forced simulations after ~1980 as the heart of the their detection and attribution argument.  See Figure 10.1 from AR5 WGI (a) is with natural and anthropogenic forcing; (b) is without anthropogenic forcing:

Slide1

Note in particular that the models fail to simulate the observed warming between 1910 and 1940.

The glaring flaw in their logic is this.  If you are trying to attribute warming over a short period, e.g. since 1980, detection requires that you explicitly consider the phasing of multidecadal natural internal variability during that period (e.g. AMO, PDO), not just the spectra over a long time period.  Attribution arguments of late 20th century warming have failed to pass the detection threshold which requires accounting for the phasing of the AMO and PDO.  It is typically argued that these oscillations go up and down, in net they are a wash.  Maybe, but they are NOT a wash when you are considering a period of the order, or shorter than, the multidecadal time scales associated with these oscillations.

Further, in the presence of multidecadal oscillations with a nominal 60-80 yr time scale, convincing attribution requires that you can attribute the variability for more than one 60-80 yr period, preferably back to the mid 19th century.  Not being able to address the attribution of change in the early 20th century to my mind precludes any highly confident attribution of change in the late 20th century.

The 50-50 argument

There are multiple lines of evidence supporting the 50-50 (middle tercile) attribution argument.  Here are the major ones, to my mind.

Sensitivity

The 100% anthropogenic attribution from climate models is derived from climate models that have an average equilibrium climate sensitivity (ECS) around 3C.  One of the major findings from AR5 WG1 was the divergence in ECS determined via climate models versus observations.  This divergence led the AR5 to lower the likely bound on ECS to 1.5C (with ECS very unlikely to be below 1C).   Nic Lewis at Climate Dialogue summarizes the observational evidence for ECS between 1.5 and 2C, with transient climate response (TCR) around 1.3C.

Nic Lewis has a comment at BishopHill on this:

The press release for the new study states: “Rapid warming in the last two and a half decades of the 20th century, they proposed in an earlier study, was roughly half due to global warming and half to the natural Atlantic Ocean cycle that kept more heat near the surface.” If only half the warming over 1976-2000 (linear trend 0.18°C/decade) was indeed anthropogenic, and the IPCC AR5 best estimate of the change in anthropogenic forcing over that period (linear trend 0.33Wm-2/decade) is accurate, then the transient climate response (TCR) would be little over 1°C. That is probably going too far, but the 1.3-1.4°C estimate in my and Marcel Crok’s report A Sensitive Matter is certainly supported by Chen and Tung’s findings.

Since the CMIP5 models used by the IPCC on average adequately reproduce observed global warming in the last two and a half decades of the 20th century without any contribution from multidecadal ocean variability, it follows that those models (whose mean TCR is slightly over 1.8°C) must be substantially too sensitive. 

BTW, the longer term anthropogenic warming trends (50, 75 and 100 year) to 2011, after removing the solar, ENSO, volcanic and AMO signals given in Fig. 5 B of Tung’s earlier study (freely accessible via the link), of respectively 0.083, 0.078 and 0.068°C/decade also support low TCR values (varying from 0.91°C to 1.37°C), upon dividing by the linear trends exhibited by the IPCC AR5 best estimate time series for anthropogenic forcing. My own work gives TCR estimates towards the upper end of that range, still far below the average for CMIP5 models.

If true climate sensitivity is only 50-65% of the magnitude that is being simulated by climate models, then it is not unreasonable to infer that attribution of late 20th century warming is not 100% caused by anthropogenic factors, and attribution to  anthropogenic forcing is in the middle tercile (50-50).

The IPCC’s attribution statement does not seem logically consistent with the uncertainty in climate sensitivity.

Climate variability since 1900

From HadCRUT4:

HadCRUT4

The IPCC does not have a convincing explanation for:

  • warming from 1910-1940
  • cooling from 1940-1975
  • hiatus from 1998 to present

The IPCC purports to have a highly confident explanation for the warming since 1950, but it was only during the period 1976-2000 when the global surface temperatures actually increased.

The absence of convincing attribution of periods  other than 1976-present to anthropogenic forcing leaves natural climate variability as the cause – some combination of solar (including solar indirect effects), uncertain volcanic forcing, natural internal (intrinsic variability) and possible unknown unknowns.

A key issue in attribution studies is to provide an answer to the question:  When did anthropogenic global warming begin?  As per the IPCC’s own analyses, significant warming didn’t begin until 1950.  Just the Facts has a good post on this When did anthropogenic global warming begin?

The temperature record since 1900 is often characterized as a staircase, with periods of warming sequentially followed by periods of stasis/cooling.  The stadium wave and Chen and Tung papers, among others, are consistent with the idea that the multidecadal oscillations, when superimposed on an overall warming trend, can account for the overall staircase pattern.

Lets consider the 21st century hiatus.  The continued forcing from CO2 over this period is substantial, not to mention ‘warming in the pipeline’ from late 20th century increase in CO2.  To counter the expected warming from current forcing and the pipeline requires natural variability to effectively be of the same magnitude as the anthropogenic forcing.  This is the rationale that Tung used to justify his 50-50 attribution (see also Tung and Zhou).  The natural variability contribution may not be solely due to internal/intrinsic variability, and there is much speculation related to solar activity.  There are also arguments related to aerosol forcing, which I personally find unconvincing (the topic of a future post).

The IPCC notes overall warming since 1880.  In particular, the period 1910-1940 is a period of warming that is comparable in duration and magnitude to the warming 1976-2000.  Any anthropogenic forcing of that warming is very small (see Figure 10.1 above).  The timing of the early 20th century warming is consistent with the AMO/PDO (e.g. the stadium wave; also noted by Tung and Zhou).  The big unanswered question is:  Why is the period 1940-1970 significantly warmer than say 1880-1910?   Is it the sun?  Is it a longer period ocean oscillation?  Could the same processes causing the early 20th century warming be contributing to the late 20th century warming?

Not only don’t we know the answer to these questions, but no one even seems to be asking them!

Attribution

I am arguing that climate models are not fit for the purpose of detection and attribution of climate change on decadal to multidecadal timescales.  Figure 10.1 speaks for itself in this regard (see figure 11.25 for a zoom in on the recent hiatus).  By ‘fit for purpose’, I am prepared to settle for getting an answer that falls in the right tercile.

The main relevant deficiencies of climate models are:

  • climate sensitivity that appears to be too high, probably associated with problems in the fast thermodynamic feedbacks (water vapor, lapse rate, clouds)
  • failure to simulate the correct network of multidecadal oscillations and their correct phasing
  • substantial uncertainties in aerosol indirect effects
  • unknown and uncertain solar indirect effects

So, how to sort this out and do a more realistic job of detecting climate change and and attributing it to natural variability versus anthropogenic forcing?  Observationally based methods and simple models have been underutilized in this regard.  Of great importance is to consider uncertainties in external forcing in context of attribution uncertainties.

The logic of reasoning about climate uncertainty, is not at all straightforward, as discussed in my paper Reasoning about climate uncertainty.

So, am I ‘making things up’?  Seems to me that I am applying straightforward logic.  Which IMO has been disturbingly absent in attribution arguments, that use  climate models that aren’t fit for purpose, use circular reasoning in detection,  fail to assess the impact of forcing uncertainties on the attribution, and are heavily spiced by expert judgment and subjective downweighting.

50 cartoon

832 responses to “The 50-50 argument

  1. Judith,
    I think I understand the logic of your argument and the physics you rely on to support the logic. Data, however, must count for something and that is what I seem to be missing.

    • Data: therein lies the rub

    • Agree. But I’m not sure the logic is right either.

      Judith talks of considering man’s contribution to global temperature increase in three bands. I don’t think that’s any more helpful than two bands. Surely it is better to work out what man’s and nature’s contributions actually were.

      There is an additional complication : You can’t use the linear logic of working out what man’s contribution was, and then subtracting it from the observed temperature increase in order to estimate nature’s contribution. You can’t even try to work them both out as parts of the whole. Because Earth’s system is non-linear, to work out how man has changed it you have to work out what nature would have done in the absence of man’s contribution, and then compare that with the observed. Take atmospheric CO2 for example : over the man-affected period, man has added twice as much CO2 to the atmosphere as the observed CO2 increase of ~40%. Using the linear logic, man’s contribution has been 200% of the increase, and nature’s -100%. But without man’s contribution, atmospheric CO2 would have increased slightly. Man’s contribution was therefore not 200%, but less than 100%. Quite a difference!

      But now we have a much bigger problem: As Judith pointed out –
      “The IPCC does not have a convincing explanation for:
      – warming from 1910-1940
      – cooling from 1940-1975
      – hiatus from 1998 to present”

      Correct, and disturbing. Nor does it have an exlanation for MWP, Roman WP, Minoan WP, Holocene Optimum, or for the LIA and the other cold periods in between. IOW, the IPCC is totally incapable of working out what nature would have done.

      So, what percentage of the observed warming was man-made? We haven’t even started to find out, because none of the IPCC’s work has been directed towards finding it..

      • Your questions are all resolved when you admit that CO2 has no influence on warming, but is subsumed and subordinated in far more potent and long-lived processes. Mankind’s influence is less than negligible.

      • Wow. Two thumbs up.

      • I applaud Judiths attempt to bring reason. However, I agree more with you that the problem really is that we don’t know. The temperature rise from 1910-1940 was as great as 1975-1998. Based on that alone without knowing what other differences in that period contributed it is apparently possible 100% of the increase is not due to man. Judith uses the AMO/PDO as central lacking elements but there are other factors as you bring up coming from apparent longer term variations. Because these longer term variations are significant enough it is entirely possible that the entire warming from 1910-2014 is basically just natural variability. We don’t know.

        We do know that the CO2 had to add heat but I would like to see a concerted effort to do this from BASIC physics. First, prove that the CO2 is in fact doing what it is supposed to be doing. Concentrate on this follks. Put up a satellite with specific focus on this. We are spending billions and billions on all this research. We claim that CO2 is such a huge problem. Can we not invest in building a satellite highly tuned to watch for CO2, look for all the expected effects? It is not that I doubt the physics but I wonder if we are missing something in how the energy from CO2 is handled by the atmosphere at the very start of the process. We should look at this as basic science. First establish the major points. CO2 downwelling radiation is contributing X energy. Then demonstrate the major “multiplicative” feedback, water vapor is correlated. Forget EVERYTHING ELSE. They are irrelevant if you can’t prove 1 and 2 above. If you can prove 1 and 2 above then I believe you can say that there MUST be some attribution.

        All this fuzzy adding this and that, subjective is as Judith says: Making things up. Until the community can demonstrate unequivocally as a physics professor can show me the laws of motion then this debate cannot end and the ultimate truth is: WE DON’T KNOW.

      • A new CO2 satellite just went up a short time ago
        http://oco.jpl.nasa.gov

  2. How about the simple and highly accurate choice: unknown, insufficient information. Strikes me using probabilities (or more accurately just guesses) more or less plays into the hands of those unable to provide proper support for their theories.

    • Well my point is that the terciles is reasonable precision, and the confidence level in any assessment should not be particularly high.

      • Let us not forget the purpose of this attribution of more than 50% of GW being caused by humans was political, not scientific. It was meant as a handy sound-bite for politicians when formulating policies to cut back fossil fuel use. By discussing it at all in terms of the methodology and plausibility of the answer you are giving it more credence than it deserves. It was an expert judgement from experts working for an organisation set up to prove that humans burning fossil fuels was the cause of global warming, any other explanation would mean the IPCC should cease it’s activities.

        Cessation of the IPCC activities would mean that the money being poured into climate change by governments would dry up as the political wing would have been removed and we’d be left with scientists trying to understand the natural world – never something high on the voters’ list of priorities. Effectively asking scientists involved with the IPCC to provide impartial information that would cast doubt on the human effect on the climate is asking them to take the KoolAid. Now who would do that?

  3. “So, I interpret this as scything that..” ??? So, I interpret this as saying that…

    • Perhaps she means that they’re cutting the grass close to the ground. The problem you get is that a huge windrow forms on your left and has to be carted off somehow, where a higher cut leaves the lawn not visibly cluttered.

  4. Re: 50% -50%.
    Since humans have not stopped their contribution, and there has not been any warming in the last 17-18 years one could conclude that natural warming was falling during the ‘pause’.
    Since all past indications are that natural variability cycle is around 60 years, the 50-50 assumption would cut natural cycle down to about 40-45 years.
    .

    • IMHO it would be a remarkable coincidence if natural variability exactly cancelled out nonlinear anthropogenic contributions for 15-20 years (and counting).

    • I think you have a point, vukcevic. If one third of all human emissions have occurred since 1998 and those emissions have not forced the climate upwards, it is an argument against high figures for sensitivity.

      • Tom

        You seem more sceptical than you were a few years ago
        tonyb

      • Hi Tony

        How are you? I’ve been reading your recent contributions at various points of e-information. Well done!

        I don’t know how to be clearer. I firmly believe we are sleepwalking into a world where dramatically rising emissions cause climate change that will be damaging to us, especially those of us living in the developing world. I think it will hit us around the 2075 time frame and I hope to God the developing world has developed… at least in the resiliency sense of the word.

        I don’t think it will be more than 2C. But 2C is more than enough.

        I sound like a skeptic because I am thoroughly p****d at the scaremongers who have been driving this issue to the point of absurdity. Xtreme weather and methane holes in Siberia. 300 reasons for the pause…

        The truth would be enough if people like Mann, Gleick and the rest of the gnarly buffoons would just shut up. Small chance of that, however.

      • Hi Tom

        Fortunately being so near the excellent Met Office archives and Library AND that this field of research is already a well ploughed field (although mostly forgotten) , it is clear that the idea of weather being AS extreme, let alone MORE extreme than the past can be readily refuted. Unless of course you are only measuring back to 1950, which unfortunately seems to be quite normal these days.

        We are living in benign climate times although of course we should look to the past to see what may come in the future and build in resiliency.

        IF you do write another book with Mosh can you confiscate his phone in case he decides to contribute text to it by that method? His smartphone contributions here are even less comprehensible than his usual ones :)

        All the best

        Tonyb

      • –Hi Tony

        How are you? I’ve been reading your recent contributions at various points of e-information. Well done!

        I don’t know how to be clearer. I firmly believe we are sleepwalking into a world where dramatically rising emissions cause climate change that will be damaging to us, especially those of us living in the developing world. I think it will hit us around the 2075 time frame and I hope to God the developing world has developed… at least in the resiliency sense of the word.

        I don’t think it will be more than 2C. But 2C is more than enough. —

        I don’t think we have increase in global temperature by 2 C by 2075.
        Or if we assume average global temperature is currently 15 C, that by 2075 that average global temperature will be 17 C.
        First there is zero evidence of this happening and second one could assume one will first get 1 C increase in global temperature.
        So if we get 2 C by 2075, when would we get the 1 C increase, would be as late as 2065, or put it somewhere mid way like 2045?
        If we go from 2015 to 2045 and gain 1 C in temperature, then obviously it will at level increasing temperature we have never seen before. Though this also true if it take until 2065 to reach this 1 C increase in global temperature.

        In terms of human beings, most people in the world live in urban areas,
        and most urban areas have already seen such rises of 2 C within a century due to urban heat island effects- so some regions have have as much as 10 C rise in local temperatures due to UHI effects. And another aspect is the rising temperature over last century or so, has not caused increase in hottest days in the world- or hottest place and day in world was set in 1912. And both global warming of 2 C and/or UHI effect could also not change this aspect of making very hot days. Perhaps we will get more hots days, but mostly it’s related to warmer winters and warmer nights.
        In terms of nature, we have had global temperature which have been 2 C warmer. The Climatic Optimum: “By 5000 to 3000 BC average global temperatures reached their maximum level during the Holocene and were 1 to 2 degrees Celsius warmer than they are today. Climatologists call this period either the Climatic Optimum or the Holocene Optimum. ”
        And we could expect similar conditions- so such things as treelines extending further towards the poles as they did during the Climatic Optimum. And seems to me that this large increase of 2 C in global temperatures would probably include arctic polar ice melting in summer,
        so as to allow ice free travel in arctic during most summers. One might also have Antarctic polar ice shrinking rather what doing now, which is expanding at at levels levels recorded.

        If one were to get 2 C by 2075, at the time of 2075 one should not have seen much in terms of sea level rise- though one might expect significant rise in the future if such higher temperature continue for decades into the future. So at 2075 one could have fears of future rise in sea level, but not have gained much in terms of sea level rise.

        It seems if we were to get 2 C by 2075, than we would begin to see some evidence of this possibility long before 2075. So it seems that by say 2050 we would have lots of evidence that this could happen. It could be gradual increase up to 2050 which indicate it, or say dramatic increases starting around 2040. And we could many signs before 2040- such as having an ice free arctic sometime before 2040.
        I think we could have ice free arctic before 2040 even if temperature don’t get as much as 1 C warmer by 2075. And we could get the IPCC future projection being shown to be much closer than what they appear to be now. And can assume we will more and better projections of future temperatures.

        Anyhow, it seems if what think as very unlikely [or impossible] were to occur, that people living in 2040 would see there is a problem and get serious about building and using nuclear energy so as to reduce future CO2 emission. And that before 2075, one could have about 1/2 energy from nuclear energy and not be using coal to generate electrical power.

        And in terms using nuclear energy, it seems currently both China and India and moving in the correct direction, whereas Germany has moved and is moving in the wrong direction.

      • Well, I figure the pause lasts another decade. Then we get some hemming and hawing–rise for a decade, fall for a decade. But by 2050 we are burning through 3,000 quads a year globally, most of it from coal. We get an unlucky combination of natural variability changes and we’re off to the races again. Won’t Gavin and the gang be pleased…

        I’m phrasing it casually just in case someone might mistake the above for a scientific analysis. It ain’t. It’s a scenario. But based on current emissions and growth of energy consumption, I think it’s going to play out that way, give or take a decade.

        Cities are certainly growing. The one I’m in is expected to grow from 23 million now to 50 million by 2050. But Shanghai is developed. Think of Lagos or Kuala Lumpur. Even if immigrants flood those cities, They won’t be living safely removed from precipitation or storm surge.

        Manila is basically at sea level. A pinch of sea level rise, a dash of increased storms (the real thing, not the phoney Xtreme Weather being peddled today) and millions of poor immigrants from the farms and you have a recipe for large scale loss of life and economic hardship for the survivors for decades.

      • But by 2050 we are burning through 3,000 quads a year globally, most of it from coal. We get an unlucky combination of natural variability changes and we’re off to the races again. Won’t Gavin and the gang be pleased…

        I doubt it. There are several factors that mitigate against it:

          •   There are many other good reasons besides climate for moving away from dumping large amounts of fossil carbon into the climate/eco-system when we don’t even know where it’s all going, much less how much damage it’s doing along the way. While arguably none of those reasons, individually or in aggregate, justify killing the Industrial Revolution, a slower process consistent with very rapid roll-out of cheap energy to the non-Western world is certainly indicated.

          •   Methane (e.g. natural gas) is inherently easier to transport and store than coal. IMO, of course. Most importantly, methane at neutral pressure/temperature a thousand meters down in the ocean would be very cheap to transport in pipelines. Big, light, cheap pipelines with automatic shut-off valves that don’t have to handle significant pressures.

        And retrieving it isn’t really any more inherently expensive than mining coal, although the technology for the latter is more mature. Even sea-floor methane hydrate wouldn’t be that big a deal, once the learning curve is past.

          •   Solar energy, especially semi-conductor based, is declining in price exponentially. Although simple, cheap technology for storing the essentially intermittent energy isn’t currently available, rapid progress is being made along many lines.

        One of those lines involves bio-conversion of electrolytic hydrogen and atmospheric CO2 (probably retrieved from the upper ocean) to methane. Such technology, once reasonably mature, would allow the entire infrastructure for storing and transporting natural gas to be redeployed for carbon-neutral methane.

          •   Such technology would involve substantial extraction of CO2 from the atmosphere/upper ocean, reversing the dumping of fossil carbon from the earlier Industrial Revolution. When burned, of course, such carbon would return to the air. But once the technology is mature, diverting carbon from the system for sequestration would probably be much cheaper than any currently projected system of extraction/sequestration.

          •   Such remediation also avoids several risks:

              •   We can’t be certain that it’s the dumping of fossil carbon that’s responsible for increasing atmospheric pCO2. Certainly the smart money would bet that way, but focusing on remediation rather than mitigation would avoid that risk.

              •   Even fossil fuel burning is primarily responsible, we can’t be certain that simply stopping the dumping will allow the atmosphere to “return to equilibrium.” One or more tipping points might have been passed. While remediation might have to work much harder to push the system back over such tipping points, it would have a much better chance of working than mitigation.

              •   We don’t even know for sure that such high levels of CO2 are even anthropogenic, or whether it’s desirable to lower it. Such an approach would allow several more decades for research before any firm decision has to be made.

          •   And generating capacity burning methane is far cheaper than any other option. Especially if you don’t demand high efficiency, such technology is extremely cheap, can be purchased in small sizes suitable for local generation, and can be re-deployed when/if demand changes.

          •   The cost of a general distribution system for methane is orders of magnitude smaller than for major electrical grids, so areas still developing their energy systems can invest in local grids powered by small, re-deployable gas generators using a much cheaper distribution system that can also provide direct gas for heating, cooking, and other such purposes.

        While I wouldn’t go so far as to “confidently predict” that the next half-century or so will see universal deployment of methane technology, it seems like a very good bet. And if it doesn’t, that will probably be because some other very cheap method of storing solar energy shows up and out-competes it.

      • Tom,

        What you are missing in worrying about the year 2075 is the exponential growth in human knowledge. 60 years from now with the technological advances that are inevitable and almost certainly the discovery of new forces, dealing with potential warming will be a trivial issue. Imagine that 30 years ago, someone was given the project of making a computer, radio, clock, tape recorder, telephone and camera in one machine. It would have been an impossible project to actually try do it. Instead different forms of technology independently developed and smart people put together those advances and now we have the Prism 2 phone by T-Mobile that costs $50 and does all those things. If warming is a problem 60 years from now, science and technology will do the same thing to the warming problem that I described as has happened to the proposed engineering problem that I mentioned in this post.

        JD

      • Pandora is just a heartbeat away so…

        http://www.independent.co.uk/news/science/medical-dilemma-of-threeparent-babies-fertility-clinic-investigates-health-of-teenagers-it-helped-to-be-conceived-through-controversial-ivf-technique-9690058.html

        splice them together like he dreamed of, while he was still alive in Brazil. Dsign are perfect world of tomorrow the stars.

      • Naq, As long as humans try to solve problems, Pandora’s box will always be open. You can’t stop it, you can only learn to live with it. Also, please be specific about what is so scary about the specific procedure identified in the link you provided. Needs to be regulated but doesn’t scare me at all. (I am asking about THIS procedure, not a parade of horribles of what it may lead to.)

        JD

      • Tom — I am not trying to start one with this, but I can not understand my error. If a thirty-five yr. crawl of Hadley attains equipoise in 1907, and if thereafter the secular trend is 0.016 F,/yr., & if the 9/97 thru 8/98 increase is 0.55 f., then why would anyone “expect” there not to follow a “pause”?

        I admit to being incurably warmist. So, I look at the above Had-facts, and shrug, well, check with me in 2032. Your tribe (should you be a minimalist) seems to alight upon that 1998 date as if any simple assertion entwined with it makes sense. I don’t know enough math to do so. It’s rather like pondering what happened to the Broncos last January.

      • Tom, you’re building sand castles. Not only is there no contemporary evidence of harm from warming, there aren’t any historical examples. It’s all hand-waving. Greening of arid areas, by contrast, is happening apace. It is to be celebrated and encouraged. Your opposition to it is not appreciated.

  5. I have examined the 50-50 question in some detail previously and debated this issue in a Washington DC Energy Bar Association forum on Feb 12, 2014. In preparation for that program and using the results of Figures 4.4 and 4.5 of the report published on the website of The Right Climate Stuff Research Team:
    http://www.therightclimatestuff.com/BoundingClimateSensitivityForRegDecisions.pdf ,
    I concluded that if one believes there has been no continued natural warming since 1850 from the approx. 1000 year period natural climate cycle that brought us the Roman Warm Period, The Medieval Warm Period and the Little Ice Age, then the carefully worded IPCC AR5 report claim that most of the global warming since 1950 is due to human causes, is TRUE. This conclusion takes into account the approximately 62 year period natural cycle in global average surface temperatures that is obvious in the HadCRUT4 global average surface temperature data, that had a maximum in about 1945 and again in about 2007, and that seems to be the cause of the current “pause” in global average surface temperatures.

    However, as shown in Fig. 4.5 of the above referenced report, if continued natural warming from the 1000 year cycle is still occurring and would be expected to peak about 2100, then most of the warming since 1950 would have to be attributed to natural occurrences and the IPCC AR5 claim would be FALSE. In either case, the transient climate sensitivity to atmospheric CO2 extracted from the HadCRUT4 data is much less than claimed by the IPCC in its range of estimates for Equilibrium Climate Sensitivity (ECS), and much less uncertain than claimed by the IPCC. Climate sensitivity to CO2 used for regulatory purposes should be based on available physical data as demonstrated in the above report, not un-validated climate simulation models.

    • Matthew R Marler

      Harold Doiron: I have examined the 50-50 question in some detail previously

      You reinforce point that Prof Curry made and others have made: conclusions about attribution depend critically on assumptions about natural variability, and knowledge of natural variability is imprecise and uncertain.

      Thanks for a good, succinct post.

      • Agreed. We must first understand the natural climate. See also my above comment August 24, 2014 at 6:49 pm.

    • I do agree with Harold when he says past warming may be due to natural variability. I disagree when he says some of the past warming “might” have been due to manmade CO2.

      Harold considers both cases and I agree with Harold when he says that the future warming by manmade CO2 cannot and will not be dangerous.

    • I should also have made the point that using the same Figures 4.4 and 4.5 from the referenced report, that one can conclude most of the HadCRUT4 global average surface temperature warming observed from 1970 – present was due to NATURAL causes, as 0.3C of the approx. 0.55C warming was due to the 62 year natural cycle with amplitude of +/- 0.15C. This conclusion can be reached without regard to what one assumes about the 1000 year cycle discussed. That is also why I said the AR5 report picking 1950 until publication of the AR5 report to discuss attributes of warming was carefully (selectively) worded.

      • Harold Doiron I take the 0.25 Deg C not attributable to natural variability was caused by green house gases and other effects? I mention greenhouse gases because I noticed methane concentration did increase rather fast until the 1990’s. I wouldn’t limit the discussion to CO2.

  6. Time For An Ob

    It’s kindofa strange argument because Gavin would probably not only agree but INSIST that the cooling since 2001 is entirely natural variability.

    • It’s not surprising, really, given Gavin’s priors on the two possibilities: he has a prior for anthropogenic warming of 100%. Thus, any warming must necessarily by anthropogenic and any cooling must be natural variation.

      Of course, if Gavin had even a glimmer of knowledge of statistics, he would acknowledge his priors. But he either (a) does not understand stats at all, or (b) lies about his priors, either to us or to himself.

      • Doug Proctor

        Gavin has many dogs in this fight. He resigned his GISS position at the critical juncture where his anti-fossil fuel position could be challenged within his department; he no longer HAS to critically justify what he thinks.

        Schmidt has staked out position, prestige and his financial legacy on CAGW being true. He has taken up the moral position, also. As such any ambiguity should fall to the CAGW position, the fallback being the noble cause is supported. Like Erhlich, he no longer has to demonstrate rightness, just good intentions.

        An interesting change of goals while others change the goalposts.

  7. Steven Mosher

    Terciles is nice
    Believer. Lukewarmer. Denialist
    Or the other way round.
    Depending on whether we are talking about
    Non anthro or anthro.

    • So more than 66% is Believer, and not greater than 33% is the Denier and not more than 66% or less than 33% is the Lukewarmer.

      That seems a very narrow range [or box] of beliefs.
      Of course the range of believers extend higher than 100%- something like the idea we would be in a Little ice age temperature, if not for CO2 emission. Or from 1950 without CO2 we would be as much say 1 C cooler- so one say as upper range of around 300%.
      Then in terms of Denier, I suppose some think CO2 causes cooling, which follows that following 1950, we could have even higher temperature if not for higher CO2- or less than 0%, though I can’t say I heard Denier express
      how much warmer to could have been without CO2 levels rising.
      One could say Denier tend to be satisfied to say CO2 has little or no effect upon global temperature, whereas Believers are tend to impatient for their world which might become 10 C warmer.
      But in comparison to range of beliefs, the Lukewarmer would confined to very small box of possibility. It seems such classification tends favor the idea that Lukewarmer are the only ones who actually looking at the data.
      Though a *darker side* of Lukewarmers could be they they a group which just don’t care very much about this whole global warming issue.

      • Surely “denier” would have to be o% anthro by definition. You can’t deny something a little bit….

  8. Judith Curry

    Several of my personal observations on:

    “So, am I ‘making things up’? Seems to me that I am applying straightforward logic. Which IMO has been disturbingly absent in attribution arguments, that use climate models that aren’t fit for purpose, use circular reasoning in detection, fail to assess the impact of forcing uncertainties on the attribution, and are heavily spiced by expert judgment and subjective down weighting.”

    I believe that the period 1910 – 1940 is being paid attention to, although not loudly announced. I say this because of the constant adjustments made to the temperature records, decreasing 1910 – 1940 and raising 1970’s to 2000.

    “Expert Opinion” is dependent upon who is selecting the experts. Really the same weakness that Bayesian analysis has, experts assign a probability. Its clear that M & M were not chosen when their analysis differed markedly from the prevailing viewpoint.

    I am amazed that you still care what Gavin does or does not think/say.

    “The best estimate of the human induced contribution to warming is similar to the observed warming over this period.”

    A little editing is needed: “Our best guess….” for The best estimate

    I have been in sponsored meetings where an “answer” was required before we left the room. Somewhere around 4:30 PM there as a rush to judgement and an answer was produced. Uncertainty, caveats, nuances were “gone with the wind.” The final details were left to staff and an single individual to make the whole thing appear presentable. This is my impression of the IPPC process. The USA Government and others care deeply about this “answer” that is best characterized as agreed upon “group ignorance” for public consumption.

    “I am arguing that climate models are not fit for the purpose of detection and attribution of climate change on decadal to multidecadal timescales.”

    Attribution can only be assigned once one understands the system, then make a comparison with the results in hand. First things first. Understand the system, in this case, the climate system. Then one can begin to ascribe components to the observation. The IPPC mandate was totally idiotic. The cart way before the horse.

    When I realized that Nic Lewis was trying to assess surface temperature data during and after the transition from thermometers to electronic recordings and there had been only one station that had an overlap of the two monitoring systems and that was looked at 20 years retrospectively, I thought, what a colossal waste of Lewis’s good brain power. And this type of data set is the bedrock of climate science? Giver me a break.

    • “Attribution can only be assigned once one understands the system, then make a comparison with the results in hand. First things first. Understand the system, in this case, the climate system. Then one can begin to ascribe components to the observation. The IPPC mandate was totally idiotic. The cart way before the horse.”

      Exactly.

    • Judith won’t ‘make a judgement as to how ‘expert judgement’ and subjective ‘down weighting’ is different from ‘making things up.’
      Hmm … those anthropogenically forced model simulations sure
      sound anecdotal ter serfs.

  9. Its Sunday and I am in moderation. I might go for a walk or something or maybe wait until Monday rolls around.

    Too many of your own quotes I presume.

    • No idea why most posts land in moderation, apologies!

    • I just don’t get the tendency for people to get snarky about such things, as if Climate Etc. is a five star hotel and you don’t like the room service.. Sense of entitlement much?

      • I have waited 4 hours and started wondering if the dog ate my post. I don’t think a 4 hrs wait wondering if I should repost is unreasonable. What do you propose? Wait 4 hrs and repost?

      • Seems like the dog ate it, I don’t see anything in moderation or spam? Apologies.

  10. Judith,

    Thanks for your explanation. I’ll try to respond in more detail later, but I’d like to note that the anthropogenic contribution is not necessarily bounded at 100%, since natural factors could in theory have contributed a cooling effect (also in a period of net warming; that does not negate the cooling argument).

    Your statement in the uncertainty monster paper was in response to AR4, which in contrast to AR5 was about the effect of anthropogenic GHG only (rather than the net anthropogenic effect). Since aerosol cause a net cooling, the total contribution of all other factors besides aerosols must have been larger than 100%. This is one of the focus areas of our recent climate survey paper in ES&T (http://pubs.acs.org/doi/abs/10.1021/es501998e).

    Furthermore, you say:
    “It’s time for climate scientists to refine this range.”

    The last line of the AR5 quote you give says:
    “The best estimate of the human induced contribution to warming is similar to the observed warming over this period.”

    In other words, the best estimate according to AR5 is around 100% of the observed warming being human induced. That is consistent with the underlying literature and by inspecting the relative magnitudes (and sign!) of the various radiative forcings.

    On the one hand you say that scientists need to refine (presumably narrow) the range, but otoh you often argue that reality is even more uncertain than this statement allows for (ie the range needs to be widened). Which of the two are you arguing for, or am I missing something?

    • Bart, I am asking you consider how much is anthropogenic and how much is natural. Add together the GHG and the aerosols, then compare with natural variability. If this sum is greater than 100%, then you are by default positing natural cooling, which is something that also needs to be understood. And while you are at it, pls explain the warming 1910-1940.

      My point is that it is not useful to have an extremely high confidence level for a very broad range. Working to clarify this should be a high priority. It is intellectually lazy (not to mention not very useful to policy makers) to maintain such a large range 51-99% with very high confidence. If the uncertainty really is that great as to how much humans are contributing to warming, then drop the confidence level.

      UPDATE: I changed the main post to remove the 0 and 100% bounds. Eliminates Bart’s criticism, but doesn’t change my argument.

      • Bart won’t answer regarding the warming 1910 to 1940 as I have asked him that as well.

        Mind you it would be good to have his explanation for the warming 1700 to 1740 that so surprised Phil jones. Indeed an explanation for all noticeable periods of warming or cooling over the past 2000 years would be useful.

        Tonyb

      • I’ll settle for 1910 to 1940, since the duration and magnitude is similar to late 20th century warming and the observations are pretty solid (although somewhat of a moving target with all the ‘homogenization’, etc.)

      • > Eliminates Bart’s criticism, but doesn’t change my argument.

        Cosmetically, perhaps, but let’s emphasize Bart’s main point:

        Since aerosol cause a net cooling, the total contribution of all other factors besides aerosols must have been larger than 100%.

        NG said the same thing.

        This has nothing to do with the inexactitude of including “1” in the probability space.

        ***

        Also, I fail to see how Judy’s response answers Bart’s question:

        On the one hand you say that scientists need to refine (presumably narrow) the range, but otoh you often argue that reality is even more uncertain than this statement allows for (ie the range needs to be widened). Which of the two are you arguing for, or am I missing something?

        Perhaps this ought to be clarified by stating once and for all under what uncertainty conditions it would be justified to insert confidence levels at all.

        ***

        It is be very easy to condemn any insertion of confidence levels post hoc. It is so easy that we can surmise that Mr. T is a very, very sharp shooter.

      • Ok, here is my concern re precision (narrowing range) vs overconfidence. The IPCC has focused on increasing confidence, with no change to the range. In order to address the range issue, they need to more seriously address natural variability, which they seem loathe to do (takes the focus away from GHG).

      • Shall I tell Phil jones (and Briffa I think) that his observations of 1710 to 1740 Are not solid or do you want to do it? ;)
        Tonyb

      • ha ha :)

      • > In order to address the range issue, they need to more seriously address natural variability, which they seem loathe to do (takes the focus away from GHG).

        Remind me where “more seriously” is defined, Judy. If it is undefined, it can be trivially applied to any kind of treatment of natural variability. For some, very little is ever serious enough. And that’s just considering Mama Bear: if we add Papa Bear, we could create a Procrustean bed by rejecting anything that would be “too” serious.

        So to the question of identifying the uncertainty conditions under which we can insert confidence intervals, still unanswered, we now need an explicit statement of what it would take to be considered “more serious”, and of course the criteriology on which this judgement is based.

        Lots of uncertainties in the moral of Goldilocks’ story.

      • Judith, you ask Bart to “consider how much is anthropogenic and how much is natural. Add together the GHG and the aerosols, then compare with natural variability. If this sum is greater than 100%, then you are by default positing natural cooling,”.

        No, that’s not right. Please see my above comment of August 24, 2014 at 6:49 pm and the comments of various others who have been saying the same thing: You have to know what the climate would have done naturally, in order to know how man has changed it. It’s a non-linear system. You can’t subtract an estimated man-made component from observed climate in order to estimate nature’s contribution. You have to compare what nature would have done and the observed climate in order to see how man has altered it. It’s a non-linear system, so the linear logic of “If this sum is greater than 100%” does not work.

        Let us suppose that global temperature in a given period increased by 0.5 deg, and that without man’s contribution the increase would have been 0.4 to 0.5 deg, then man’s contribution, regardless of any GHG or aerosol calculation, is 0.1 deg to 0 deg. Of course, this calculation can’t be done, because no-one knows how the natural climate works, and a large part of the reason for that is that the IPCC has been looking at the wrong things.

      • Judith,

        Thanks for your update. In this comment though you still refer to “51-99%”, so you still seem to assume a plateau where there is none (or perhaps it was a typo?).

        Regarding your criticism of the broadness of the IPCC range (“more than half”), I concur. See also what Gavin wrote about that in his RC post, quoted by Willard: “For instance, it might well have been worthwhile to add a statement about the likely range of the anthropogenic trends (i.e 80-120% of the actual trend or similar), so that a better picture of the appropriate distribution could be given ”
        In our recent ES&T paper we also criticize the AR4 attribution statement for only giving a lower limit, which is far removed from the best estimate. (Though the best estimate is given in the report as well; just not in the quintessential phrase “most of the …”).

        I’m puzzled about your position on internal variability though. You seemed surprised that I consider the possibility that Int Var may have had a cooling influence over the past decades. On the other hand you seem to think that the amplitude of Int Var is very large. But apparently in only one direction (namely, that of warming). That’s really odd to me, as if you cut off the entire (equally broad) probability distribution on the cooling side. If you argue that since it’s been observed to warm, it makes sense to only consider Int Var to have been warming, that would be affirming the consequent. It may be a valid reasoning if you knew all other potential warming factors to be absent or (together with other cooling factors) averaging out to zero. That is clearly not the case however, so the argument that “therefore Int Var must have caused warming” is not supported. It may as well have caused cooling, thus counteracting part of the GHG warming. In the last ~15 years or so that’s probably been the case for example.

      • Bart, regarding 51-99%, any common understanding of the word ‘most’ stops at something less than 100%.

        My whole point is that if you posit a cooling effect for natural internal variability to explain the hiatus, associated with a multidecadal oscillation, then the flip side is a warming effect for natural internal variability prior to the cooling.

        Over multiple centuries, all of this might be a wash, but not for multi-decadal periods

        One more point regarding the logic of capping at 0 and 100%. If it is cooling, then you assign 0. If warming is more than 100% then you assign 100. I think this is a better way to communicate the overall issue to the public, but having no cap allows you to parse the details of the relative contributions.

      • Steven Mosher

        “So to the question of identifying the uncertainty conditions under which we can insert confidence intervals, still unanswered, we now need an explicit statement of what it would take to be considered “more serious”, and of course the criteriology on which this judgement is based.”

        More serious. we know it when we see it.

        willard playing dumb.

        However, I will give a definition, an operational on.

        Over the course of the history of the IPCC many hours of CPU time have been dedicated to quantifying the effects of anthro forcing at the behest of the IPCC whose founding documents suggest that study be focused on this area

        An effort at understanding natural variation will be More serious when the
        CPU time spent understanding natural variability is equal to the CPU
        time spent to understand anthro forcing.

        The effort will be more serious when people develop a weighting scheme to discount or eliminate models that cannot replicate natural variability in frequency and amplitude.

        The effort will be more serious when they use the right solar series.

        Shall I go on?

        The effort will be more serious when ALL THE STEPS and ALL the calculations used to make statements are

        1. transparent
        2. traceable.

      • > The effort will be more serious when ALL THE STEPS and ALL the calculations used to make statements are 1. transparent; 2. traceable.

        This is supposed to specify:

        Ok, here is my concern re precision (narrowing range) vs overconfidence. The IPCC has focused on increasing confidence, with no change to the range. In order to address the range issue, they need to more seriously address natural variability, which they seem loathe to do (takes the focus away from GHG).

        http://judithcurry.com/2014/08/24/the-50-50-argument/#comment-620844

        How do transparent and traceable statements seriously address natural variability?

        Good effort to peddle own’s one pet topic, though.

    • So Bart where are we now? 450% of climate is due to CO2? That is pretty much what it will take to get to the high end estimates. You can generally stay inside the 100% boundary until you realize mistakes, underestimates or over-estimates, then you can throttle up over that pesky 100%. Since climate is a boundary value problem, try pretending that 0 and 100% are the boundaries.

    • Matthew R Marler

      Bart Verheggen: I’ll try to respond in more detail later, but I’d like to note that the anthropogenic contribution is not necessarily bounded at 100%, since natural factors could in theory have contributed a cooling effect (also in a period of net warming; that does not negate the cooling argument).

      Attribution of effects to CO2 depend heavily on models (mathematical and conceptual) of natural variability. When you respond in more detail later, it will help if you tell us your model (or possible models) of climate variability over the Holocene era; or perhaps why you think some earlier swings in climate are of little relevance; or exactly what model you use in your attribution, if not what I have outlined.

      In other words, the best estimate according to AR5 is around 100% of the observed warming being human induced. That is consistent with the underlying literature and by inspecting the relative magnitudes (and sign!) of the various radiative forcings.

      Put differently, exactly what model of natural variation supports such an attribution, and how does it fit with everything else that is known about natural variation?

    • Bart Verheggen: “… the anthropogenic contribution is not necessarily bounded at 100%”

      This has not been well communicated (I have been called upon to explain it a few times!). Because it is interpreted as saying “100% of observed warming is *GHG* induced”

      To communicate this statement more clearly requires a broadening of what we present as “human induced” and a more explicit statement of the (cooling) influence of anthropogenic aerosols.

      Part of the problem is UNFCCC’s wording which, for mitigation policy purposes, focuses on GHGs. It does not seek an international framework for “net anthropogenic forcing.”

      1. (b) “Formulate, implement, publish and regularly update
      national and, where appropriate, regional programmes
      containing measures to mitigate climate change by
      addressing anthropogenic emissions by sources and
      removals by sinks of all greenhouse gases not
      controlled by the Montreal Protocol, and measures to
      facilitate adequate adaptation to climate change;”
      (c) “Promote and cooperate in the development,
      application and diffusion, including transfer, of
      technologies, practices and processes that control,
      reduce or prevent anthropogenic emissions of
      greenhouse gases …”

      Whereas IPCC’s remit is (supposed to be) a broader consideration of climate science.

      • Wrhoward, most of the problem is that the UNFCCC – as per your quote – did not seek better understanding of drivers of climate, but assumed that CAGW existed and that corrective action was needed. This drove the whole exercise off track, if they had merely sought better understanding, much of the work and argument of the last 30 years might have been avoided, and we might have years ago had a somewhat accurate indication of the whether or not AGW was occurring, and its magnitude. The UNFCCC was directing “solutions” to the “problem” in a particular direction without having done any of the work necessary as a foundation.

      • Sure looks like a policy looking for justification.

      • Faustino, +1.

        Imagine if the NIH had decided that stress was the primary cause of ulcers and set off the research in that direction… oh, wait.

    • Temperature for the past ten thousand years has been bounded in very tight bounds. Modern temperatures are well inside the same bounds. Natural Variability can and does explain the bounding. Study and understand natural variability and get off of the Flawed, so called, Consensus Science. More and more actual data does show that snowfall and temperature and Albedo are inside normal bounds and that really shows that the Consensus Alarmist Theory is not valid.

    • Bart, I’m just a spectator and a kibitzer, but it seems to me the IPCC could use better graphics. If you want me to send you a few examples I can (I used to prepare power point shows for a huge multinational’s management).

      By the way, I copied your data from a newspaper article, mangled it and graphed it, and showed it with three Mexican wrestlers I labeled using “deniers”, “moderates” and “extremists”.

  11. Readers also liked:

    Why does the IPCC conclude that the long-term rise is caused by man? The primary logic is simple, really. Of all the things driving long-term changes in the climate system, the biggest by far over the past 60 years is greenhouse gases. Second on the list is particle pollution, or aerosols, which partly counteract the greenhouse gases. Over the past 60 years, natural forcings (sun, volcanoes) have also had a cooling effect. So arguments over the relative importance of different kinds of forcing don’t really matter for explaining the past 60 years of temperature rise: the only large one on the positive side of the ledger is greenhouse gases.

    Of course, it’s not enough to say that greenhouse gases point temperature in the right direction. The magnitudes have to match, also. Here, too, the hiatus increases confidence that there’s not some unknown but significant positive forcing agent other than greenhouse gases that’s driving temperature. The smaller the rate of warming, the smaller the possibility that a separate, additional cause of warming is being missed, and that, therefore, greenhouse gases account for most or all of the total amount of warming.

    […]

    If, over 60 years, natural variability averages out to zero, it doesn’t matter how strong natural variability is compared to man-made climate change, what’s left over is the man-made part. Thus the IPCC can and should consider it to be extremely likely that human influence dominates the net rise in temperature over the past 60 years.

    http://climatechangenationalforum.org/your-logic-escapes-me-by-john-nielsen-gammon/

    • Remind me of how well JNG’s argument works for the warming 1910-1940?

      This really makes my head hurt:

      “Here, too, the hiatus increases confidence that there’s not some unknown but significant positive forcing agent other than greenhouse gases that’s driving temperature. The smaller the rate of warming, the smaller the possibility that a separate, additional cause of warming is being missed, and that, therefore, greenhouse gases account for most or all of the total amount of warming.”

      • Ask NG, and take one ibuprofen.

      • From 1910 to 1940 the sun went from a sunspot lull like the current one, to its most active sunspot cycles of the century, a sign of high activity. A significant amount of the 1910-1940 warming can be explained by 0.1-0.2 C from the sun with the rest from CO2. The role of the sun should not be ignored either in 1910 or now given its likely role in the LIA that most would accept.

      • Well this is news since AR5 (see figure 10.1). Solar forcing for the early warming period is not at all agreed upon.

      • There are long-standing estimates around that put the TSI increase at a very significant 1 W/m2 in that period (0.2 W/m2 forcing). As a forcing that is like 10 ppm CO2 in that period, which is significant compared to the anthropogenic changes prior to 1940. Some even including Camp and Tung have said that the 11-year cycle with similar TSI swings can produce 0.2 C variations. It is within the range of possibility. More study is needed, but the sun is important and can’t be dismissed for 1910-1940. Part of the LIA recovery could be considered to include 1910-1940, because it was only after 1940 that the sun reached its recent levels exceeding anything back to 1750, but after 1950 it has declined a bit especially since 2000.

      • nottawa rafter

        Jim D flips flops. It is not the sun when it suits his purpose. But when it suits his purpose all of a sudden Mr Sol comes to the rescue. I guess in climate science we can have it both ways. Just make it up as you go along, Jim, and hope no one notices.

      • notty, I only mention the sun because there have been studies, and its variability has been estimated to include this kind of effect. Especially pertinent to that period is that the sunspots tripled, which should focus in on this as a factor, at least. I understand why the “skeptics” need 1910-1940 to be unexplainable by credible forcing factors, however.

      • > I understand why the “skeptics” need 1910-1940 to be unexplainable by credible forcing factors, however.

        Why, Jim D?

      • willard, they have to posit that if there is an unexplained warming from 1910-1940, that unexplained thing could again be affecting the temperature now. Having an explanation leads to a testable hypothesis, so if I say we can explain it with a moderate solar forcing change within expectations, they realize that can’t be used for the post-1950 period, so they would prefer it not to be solar. It is quite a complex chain of things that leads them to want no testable explanation or to reject testable ones.

      • From 1910 to 1940 the sun went from a sunspot lull like the current one, to its most active sunspot cycles of the century

        Twaddle.

        http://sidc.oma.be/silso/yearlyssnplot

      • OK, that graph seems to support what I said.

      • Nope you said 1910-1940,the graph says otherwise.

      • ie More study is needed, but the sun is important and can’t be dismissed for 1910-1940

      • The sunspots increased from 1910 to 1940, and continued increasing to 1960. There was a significant part of the gradient from 1910 to 1940. Maybe you want to split hairs.

      • Thanks, Jim D.

        Appealing to ignorance is appealing.
        Indirect appeals are even more so.

      • They increased 1900-60. Dipped some in the 70, but remained above the mid 1800s, well above 1910-40s, until 2000 and then dipped a little (not as much as 70s) around 2000 and only now are near late 1800 lu.

        k

      • “Here, too, the hiatus increases confidence that there’s not some unknown but significant positive forcing agent other than greenhouse gases that’s driving temperature.

        this is a really good time to read Pope’s Climate Theory

        Look at the NEW Short Version

      • Steven Mosher

        When Leif finishes his work the new solar series has a good chance of creating headaches for the GCMS..

        If they choose to use it.

    • Matthew R Marler

      willard(@ nevaudit) : If, over 60 years, natural variability averages out to zero,

      Well sure. In light of the full record of climate variability (thermometry, reconstructions, etc) how likely is it that natural climate variability has averaged out to 0 over any particular 60 year period, like say 1954-2014?

      • > willard(@ nevaudit) : If, over 60 years, natural variability averages out to zero,

        Stop putting words in my mouth, MattStat.

      • Matthew R Marler

        willard(@nevaudit): Stop putting words in my mouth, MattStat.

        I quoted exactly an assumption that you made and asked whether it was likely true in a particular case, or any case that satisfied it.

      • > I quoted exactly an assumption that you made

        This is incorrect on two counts. It was a counterfactual, not and assumption. NG made that counterfactual, not me.

        Exactness may not imply correctness.

      • Steven Mosher

        matthew willard quoted NG.

        Not because he believed NG, but rather just to annoy
        Now if you agreed with NG, he would say nothing.

        Let’s ask willard directly.

        Willard. direct question:

        Does natural variability average out to zero over any 60 year period?

        And dont make stuff up.

        assign probabilities.. show you are more serious.

      • Matthew R Marler

        willard(@nevaudit): This is incorrect on two counts. It was a counterfactual, not and assumption. NG made that counterfactual, not me.

        You quoted him in bold face without a hint of disagreement. And, a counterfactual can be an assumption for a derivation, as it was in that case. but there was no hint in the quote or in your posting of the quote that it was intended as a counterfactual.

        What I wrote about it (after quoting your post exactly) applies equally well (or poorly perhaps) no matter who wrote it first. If in the future you would like to dispute NG on that, you might cite my comment (either as mine or as something you agree with).

        Readers also liked:

        Imagine our surprise when, after that introduction, you disavowed what you quoted in bold face. Who would have guessed that you did not like it?

      • > [A] counterfactual can be an assumption for a derivation, as it was in that case.

        We could say that a counterfactual contains an assumption, but I’d rather say it simply contains an antecedent. Here’s NG’s counterfactual:

        If, over 60 years, natural variability averages out to zero, it doesn’t matter how strong natural variability is compared to man-made climate change, what’s left over is the man-made part.

        This assumption is not only NG’s, but Judy’s:

        Suppose we make a generous assumption for the role of natural variability. Suppose we assume that the stadium wave hypothesis is correct. As Curry alludes to, the stadium wave hypothesis posits that there is a regular, propagating, approximately 60-year oscillation in the climate system that, among other things, affects global temperatures. Let’s suppose that it has a pronounced effect, as big an effect as Curry thinks it might have, and is thus responsible not just for the present hiatus but also the hiatus centered on the 1950s.

        http://climatechangenationalforum.org/your-logic-escapes-me-by-john-nielsen-gammon/

        Burdening NG with a consequence of Judy’s stadium wave hypothesis might be quite suboptimal.

        ***

        > You quoted him in bold face without a hint of disagreement.

        My beliefs about NG’s claims are irrelevant to the fact that I’m not the one who made them, but NG. If MattStat has a problem with NG’s claims, he can find him. NG can answer questions for himself.

        Meanwhile, let MattStat JAQ off to his heart’s content.

      • Matthew R Marler

        willard(@nevaudit): Meanwhile, let MattStat JAQ off to his heart’s content.

        I am sure everyone recognizes how clever that was.

        I think you missed the point that I was criticizing a text, not an author.

      • > I think you missed the point that I was criticizing a text, not an author.

        The past tense may take into account MattStat’s remark about cleverness, and that’s without mentioning the previous comments, where readers are supposed to see I’m disavowing words I put in bold.

        Anyway.

        Let’s recall what MattStat may refer to as a “criticism”:

        willard(@ nevaudit) : If, over 60 years, natural variability averages out to zero,

        Well sure. In light of the full record of climate variability (thermometry, reconstructions, etc) how likely is it that natural climate variability has averaged out to 0 over any particular 60 year period, like say 1954-2014?

        Not only have I not authored this ” assumption,” but it follows from the logic behind the stadium hypothesis, a logic that still escapes NG.

        MattStat may need to ask Judy that question. Or is it a criticism?

        Overburdening others with commitments they don’t have is a common ClimateBall ™ move.

      • Matthew R Marler

        Willard(@nevaudit): Not only have I not authored this ” assumption,” but it follows from the logic behind the stadium hypothesis, a logic that still escapes NG.

        OK, you did not author it. You merely quoted it. I think you have established that. Do you have an opinion with respect to its accuracy?

    • “Here, too, the hiatus increases confidence that there’s not some unknown but significant positive forcing agent other than greenhouse gases that’s driving temperature. The smaller the rate of warming, the smaller the possibility that a separate, additional cause of warming is being missed, and that, therefore, greenhouse gases account for most or all of the total amount of warming”.

      So, the further the observations diverge from the theory, the more sure you can be that the theory is correct. Nice!

      Clearly, someone is in denial. But strangely, it is not the AGW ‘denialists’.

      • thisisnotgoodtogo

        “The smaller the rate of warming, the smaller the possibility that a separate, additional cause of warming is being missed”

        Isn’t that as cute as can be?
        On the other hand, there is the assertion that since warming was great, then that excludes any natural cause.

        They must have more than two sides of the mouth to speak out of.

        What’ll it be next?

    • The smaller the rate of warming, the smaller the possibility that a separate, additional cause of warming is being missed, and that, therefore, greenhouse gases account for most or all of the total amount of warming

      And so the less we have to worry about it.

    • willard, 8/24/14 @ 2:05 pm re what Readers also liked: [3 paragraphs attributed to Nielsen-Gammon on 1/22/2014].

      0. For the record, these paragraphs were covered the next day on Climate Etc., “The logic(?) of the IPCC’s attribution statement”.

      1. Why does the IPCC conclude that the long-term rise is caused by man?

      The question is psychological, not scientific. A question that can be answered with fact is when did that happen, and the answer throws a lot of light on the why. The UN established IPCC in 1988 and its charter was “to assess the state of existing knowledge about climate change: its science, the environmental, economic and social impacts and possible response strategies.” Instead, IPCC rewrote its own charter to be

      to assess on a comprehensive, objective, open and transparent basis the scientific, technical and socio-economic information relevant to understanding the scientific basis of risk of human-induced climate change, its potential impacts and options for adaptation and mitigation. Bold added, Principles Governing IPCC Work, 10/1/1998.

      Somewhere in its first decade and before even its Third Assessment Report, IPCC inserted the assumption that “human-induced climate change” exists, and so elevated that conjecture above any “comprehensive, objective, open and transparent” investigation.

      2. Of all the things driving long-term changes in the climate system, the biggest by far over the past 60 years is greenhouse gases.

      This is a statement about IPCC’s attribution, not about science, and it is a double nonsequitur to the initial statement quoted, first overtly re man, second covertly re the warming effects of man’s CO2 emissions. More importantly, IPCC has made no attempt to validate that Cause & Effect conjecture using facts. For that it must show causality, the principle in science that a Cause must precede its Effects. As shown next, the facts show that causation, the axiom in science that every effect has a cause, is in the opposite direction of the 60 year statement.

      Water vapor and atmospheric CO2 overwhelmingly dominant the greenhouse effect. Even IPCC models use thermodynamics, and in particular the Clausius-Clapeyron relation, to model water vapor as following temperature, not leading it. And in AR4 FAQ 6.1, IPCC timidly admits that CO2 lags temperature by “some hundreds of years” (actually about a millennium) in the ice core record. The dominant GHGs are factual effects of temperature, not causes, regardless of what the anyone makes his GCM do.

      3. there’s not some unknown but significant positive forcing agent other than greenhouse gases that’s driving temperature.

      Oh but indeed there is! It’s the Sun. IPCC claims the variability of the Sun is too small for its modeling, but IPCC dismissed the report by Stott et al. (2003) on the existence of an unknown amplifier in the atmosphere, later confirmed by Tung et al. (2008). IPCC also overlooked the rapid, positive feedback of cloud cover to solar radiation because it has never been able to model clouds dynamically. Because cloud cover gates the Sun on and off, it is the most powerful feedback in climate, positive with respect to solar variability, and negative with respect to warming from any cause. The GCMs omit this dominant dual feedback.

      4. If, over 60 years, natural variability averages out to zero, it doesn’t matter how strong natural variability is compared to man-made climate change, what’s left over is the man-made part.

      At the outset and following Revelle, IPCC just assumed that man caused global warming, and to prove it, IPCC zeroed out all natural effects in its GCMs. It then attributed to man all the subsequent climate changes that it could make happen in models. Natural effects continue their ways in the real world, supplying data to be misattributed in the GCMs.

      Does natural variability average out to zero? Here’s the test: pick two points at random on any paleo temperature record. The temperature averages out to zero with the probability that the two points are the same. Those records can’t resolve a 60 year span, so for the 60 year conjecture, pick one point on a HadCRUT temperature record and another 60 years away. What are the chances the two temperatures are the same? The chances are not too good for Nielsen-Gammon’s ever popular, unscientific rationalizations.

      • David L. Hagen 8/26/14 @ 4:20 pm said, For greater modeling accuracy, see Clausius-Clapeyron equation and saturation vapour pressure: simple theory reconciled with practice [link]

        Thanks for the link to the nice work by Koutsoyiannis, but for climate this is picking the flyspecks out of the pepper to some high power.

        Climatology has yet to model climate to the first significant figure, and it is never going to get there with the radiative forcing paradigm (the GCMs). The problem is not accuracy, but wholesale omission of major parameters in the climate system. Perhaps most important of those is cloud cover. As the climate warms, water vapor increases in the atmosphere according to the C-C equation. The GCMs make that happen. In fact positive water vapor feedback to the CO2 greenhouse effect is essential for the models to exhibit a frightening amount of warming just over the horizon. Be that as it may, the models do not increase cloud cover when they increase humidity, so miss this powerful negative feedback that mitigates warming.

        The humidity in the IPCC climate model depends on the saturation vapor pressure, and Koutsoyiannis’s improvement is much less than 10%, and in many cases a tenth or less of that. To debunk IPCC on cloud cover feedback, the sign of the slope of the C-C equation is sufficient. That tells us that as temperature increases, water vapor increases, cloud cover increases, cloud albedo increases, and TSI at the surface is turned down. The effect is not in the GCMs.

        And it’s not going to be fixed by IPCC. That’s because it wipes out IPCC’s version of its charter: to frighten policymakers with the effects of man on climate.

    • David L. Hagen

      curryja and willard
      HockeySchtick posts: “New paper finds large volcanic eruptions only cause 3-5 years of cooling; Hansen claims 20+ years”

      a third paper published this week demonstrates that radiative imbalance from large volcanic eruptions resolves within ~2 years, not 20+ years as claimed by James Hansen as his excuse for the 18 year “pause” in global warming. This means that volcanic aerosols have minimal long-term cooling effects and therefore, the warming effect of CO2 has to be much lower than assumed in Hansen’s climate models and thus climate sensitivity estimates must be lowered even further.

      Linking to:
      Wahl et al. Late Winter Temperature Response to Large Tropical Volcanic Eruptions in Temperate Western North America: Relationship to ENSO Phases Global and Planetary Change Available online 23 August 2014

  12. Hank Zentgraf

    Judith, your arguments appear sound to me. I hope Gavin responds.

  13. If we look at the apparent very strong correlation between NH temperatures and the AMO cycle…

    http://www.woodfortrees.org/plot/hadcrut4nh/from:1850/mean:12/detrend:0.8/plot/esrl-amo/from:1850/mean:12

    it provides very strong evidence that much of the temperature variations observed from 1900-2014 are due to the AMO. It also would suggest that, absent extensive temperature adjustments by the record keepers we quite likely are in for some actual cooling over the next couple of decades. I think what happens over the next ten years will be quite informative. If temperatures start climbing again for the next decade… maybe there is some merit for TCR>1C. If temperatures actually decline, even a little, then TCR almost has to be <1C. This clearly argues that policies to mitigate AGW should not be enacted for at least the next decade… CANCEL all regulations that demonize CO2 for now. So far the increase in CO2 has been net beneficial…. increased crop yields and perhaps a slight increase in temperatures that are actually net beneficial since the temps of the LIA are without doubt not desirable.

  14. Judith,

    Brilliant post. I think Gavin & co are probably relying on the obscure reasoning behind the anthropogenic “fingerprinting” analysis summarized in Figure 10.5, where Natural + Internal variation are shown as negligible while ANT fully explains all the observed temperature change. Quite how the error bar on ANT is smaller than GHG and OA is still a mystery to me.

    AR5 goes on to say :

    The observed recent warming hiatus, defined as the reduction in GMST trend during 1998–2012 as compared to the trend during 1951–2012, is attributable in roughly equal measure to a cooling contribution from internal variability and a reduced trend in external forcing (expert judgement, medium confidence).The forcing trend reduction is primarily due to a negative forcing trend from both volcanic eruptions and the downward phase of the solar cycle. However, there is low confidence in quantifying the role of forcing trend in causing the hiatus because of uncertainty in the magnitude of the volcanic forcing trends and low confidence in the aerosol forcing trend. Many factors, in addition to GHGs, including changes in tropospheric and stratospheric aerosols, stratospheric water vapour, and solar output, as well as internal modes of variability, contribute to the year-to-year and decade- to-decade variability of GMST.

    The Atlantic Multi-decadal Oscillation (AMO) could be a confounding influence but studies that find a significant role for the AMO show that this does not project strongly onto 1951–2010 temperature trends.

    That is their story and they will no doubt stick to it !

    Fig 10.5 is the crucial result for the attribution statement which I strongly suspect can be shown to be erroneous.

  15. In response to Willard, I believe the next 15 years (1970-2030) will be much better in determining the AGW component to the warming than using the 1940-2000 cycle. There were quite extensive temperature corrections applied to the 1940s data which result in lowering the temperatures of that era. These correction MAY have been valid, but it does bring into doubt just how accurate we know the temperatures of that part of the AMO cycle. So far, if this current line of reasoning is correct in accounting for the cessation of warming, the data from 2000-2014 would be more in line that those earlier corrections were overstated.

  16. Those who like terciles may also like:

    The rule of Three is a writing principle that suggests that things that come in threes are inherently funnier, more satisfying, or more effective than other numbers of things.[citation needed] The reader or audience of this form of text is also more likely to consume information if it is written in groups of threes. From slogans (“Go, fight, win!”) to films, many things are structured in threes. Examples include The Three Stooges, Three Little Pigs, Three Billy Goats Gruff, Goldilocks and the Three Bears and the Three Musketeers.

    http://en.wikipedia.org/wiki/Rule_of_three_(writing)

    See also:

    In a desolate Western ghost town during the American Civil War, Mexican bandit Tuco Ramirez (“The Ugly”) narrowly escapes three bounty hunters, killing two and wounding a third, Elam. Miles away, Angel Eyes (“The Bad”) interrogates former Confederate soldier Stevens about Jackson, a fugitive now calling himself “Bill Carson”, who has information about a cache of Confederate gold. The interrogation concludes with Angel Eyes killing Stevens and his eldest son. He soon collects his fee from his employer, another Confederate soldier named Baker, and then sadistically kills him as well.

    Tuco is rescued from three more bounty hunters by “Blondie” (“The Good”). However, Blondie delivers him for the $2,000 reward. As Tuco is about to be hanged, Blondie surprises the authorities and frees Tuco at gunpoint. The two escape and split the reward money, beginning a partnership and lucrative money-making scheme. Eventually Blondie, weary of Tuco’s complaints about profit share, abandons him penniless in the desert. Tuco survives and tracks Blondie to a hotel in a town being abandoned by Confederate troops. Tuco tries to force Blondie to hang himself, but when Union shells destroy the hotel, Blondie escapes.

    http://en.wikipedia.org/wiki/The_Good,_the_Bad_and_the_Ugly

    • In the post-modern world we live in three is the perfect number. Gone is the binary view of good/evil, black/white, yes/no.

      I’m happy to have the third option in the multiple choice question “Is the end of the world nigh?”
      A) yes
      B) no
      C) maybe ( or if you prefer dont know)

      • Since there is no empirical knowledge as justified true belief anymore, HR, either your three choices are all versions of “don’t know” and “maybe”, or you can have only possible answer: C. This has nothing to do with the conjecture that a tripartition would best appeal to postmodern sensibilities. Neither does Al Gore, although we can suspect that his fatness could lend an infinite partition.

    • thisisnotgoodtogo

      Michael Mann’s tree ring circus!

    • So Willard, which Musketeer are you?

      Pathetic?

  17. The argument can’t be both ways. If co2 is a driver of temperatures, then why the pause? Not only up until the warmest year on record has co2 levels increased, but every year since large amounts have been constantly added. At that point it becomes what percentage of the warming is due to AGW, and will it result in a disaster. If other factors overwhelm the co2 signal, then the significance is greatly reduced. This cannot be a valid theory 1) the math won’t let it be anything other than co2, 2) the record they have produced depends on the relationship of co2 and temperature. 3) AGW cannot produce a prediction either backwards or forwards. None of the models came close to predicting a pause. If they cherry pick dates during the time of most complete data, they still fail. 4) The arguments change every year to keep the theory alive, and 5) long term trends are made up of shorter term ones. They aren’t able to go 3, 6 months or even a year out.

    50 -50? No, the IPCC put themselves out there as certain nearly 100% of warming is caused by man.

    When they first did the measurement of incoming and outing heat, at the time 240/w/m^2 were being retained. Since that time I would think that with the co2 that’s been added that the amount of heat retained would have been increased per w/m^2 (since in their view the TSI is stable). The amount of heat build up would have to be more than enough to verify somewhere during the past (depending on where you start) 10, 13 16 or 18 years ago. That’s a lot of energy. Think about when co2 levels were lower and the energy income and outgo were balanced. (if that’s ever the case) . When you look at the graph, what pops out at you? That’s right the co2 and temperature are in sync. Did the IPCC change that analysis?

    Just to head off a possible debate about water vapor, that is one of the key arguments. Warmer air holds more moisture, and when it rains or snows the energy is released. But according to AGW theory that energy is retained. How does it continue to snow when the energy is retained and every day the heat content continues to grow?

    The argument about half the warming due to the oceans warming is a red herring. On one of the other posts, if the total increase is 0.5 C and half is 0.25 C, then as someone retorted back that the 0.25 is imbedded and the 0.7 C increase since 1950 is all AGW. Stair stepping and other arguments just like this one are just a cover for the deficiencies in AGW theory.

    (I don’t mean your article about the 50 -50 Judith, I agree with it)

  18. Hi Judy

    You wrote

    “But the key issue of societal relevance (not to mention the focus of IPCC detection and attribution arguments) is the realization of this heat on the Earth’s surface.”

    I disagree. What is more important is how major large scale atmospheric and ocean circulations are altered in response to human and natural climate forcings and feedbacks. It is these circulation features, which as you know, determine locations of drought, floods, tracks of tropical cyclones, etc.

    I discussed this, for instance, in my posts

    http://pielkeclimatesci.wordpress.com/2009/02/26/the-human-effect-on-the-climate-system-involves-a-diverse-set-of-heterogeneous-climate-forcings-a-focus-on-carbon-dioxide-is-too-narrow/

    http://pielkeclimatesci.wordpress.com/2008/11/11/what-is-the-importance-to-climate-of-heterogeneous-spatial-trends-in-tropospheric-temperatures/

    http://pielkeclimatesci.wordpress.com/2005/07/28/what-is-the-importance-to-climate-of-heteorgenous-spatial-trends-in-tropospheric-temperatures/

    For example, as I wrote

    “The 2005 National Research Council report concluded that:

    “regional variations in radiative forcing may have important regional and global climate implications that are not resolved by the concept of global mean radiative forcing.”

    The question you are asking

    a) Warming since 1950 is predominantly (more than 50%) caused by humans.

    b) Warming since 1950 is predominantly caused by natural processes.

    is not the socially or environmentally most important issue (and indeed, the assessment of heat changes must focus on the oceans regardless of the length of record),

    A more important question, in my view, is

    “Are long term trends and variations in

    a) atmospheric and ocean circulation patterns since 1950 predominantly (more than 50%) caused by humans.

    or are long term trends and variations in

    b) atmospheric and ocean circulation patterns since 1950 predominantly caused by natural processes.

    Roger Sr.

    • Roger, the bottom line is that we have no decent observations of ocean or atmospheric circulation patterns prior to 1950. How oceanic and atmospheric circulation patterns translate into things that matter directly to society (e.g. surface climate and weather) requires longer data sets that allows us to understand how the major multidecadal modes translate into atmospheric circulation patterns and surface climate.

    • Matthew R Marler

      Roger A Pielke, Sr. I disagree. What is more important is how major large scale atmospheric and ocean circulations are altered in response to human and natural climate forcings and feedbacks. It is these circulation features, which as you know, determine locations of drought, floods, tracks of tropical cyclones, etc.

      Are not all those other things important (beyond the curiosities of the big bang and distant galaxies) because they explain the surface events? It seems to me that your disagreement reinforces Prof Curry’s point.

    • What is more important is how major large scale atmospheric and ocean circulations are altered in response to human and natural climate forcings and feedbacks. It is these circulation features, which as you know, determine locations of drought, floods, tracks of tropical cyclones, etc.

      Not only “forcings and feedbacks”, but other boundary conditions in general. It’s important to remember that the overall behavior of a hyper-complex non-linear system isn’t necessarily linear (“Duh!”). It’s quite feasible that a very small increase in pCO2 could drive the system past a “tipping point” where the general behavior would change. It’s also possible that the change would involve dramatic rearrangement of climatic regions while the “global average temperature” remains effectively unchanged. (IIRC you’ve pointed this out, although I don’t have links.)

      But AFAIK this could easily be true of any other boundary condition. For instance, the destruction of a single mountain peak such as Mt. St. Helens:

      The removal of the north side of the mountain (13% of the cone’s volume) reduced St. Helens’ height by about 1,280 feet (390 m) and left a crater 1 to 2 miles (2 to 3 km) wide and 2,100 feet (640 m) deep with its north end open in a huge breach.

      This could have affected the general circulation patterns, through reduction of the local “turbulent friction” on the boundary layer. Or some type of change to the nature of its effect on passing storm systems. Unlikely in any particular case, But not impossible, given our current knowledge of how global circulation patterns react to the relief of continental landforms.

  19. For CO2 increasing from 310 ppm to 400 ppm and the temperature increasing by 0.7 C since 1950, the Lewis transient sensitivity of 1.3 C per doubling gives 0.45 C that is certainly more than half and so even that supports the IPCC wording. He also had to assume very small aerosol effects to get his number. It is very difficult to say 50/50 is a mid-point estimate when it even low-balls Lewis’s number which is near 65/35. More standard attributions suggest that aerosols and other GHGs more or less cancel in the forcing so that you can derive a TCR near 2 C per CO2 doubling from these numbers.

    • On top of this, I would say that natural variability can be either sign since 1950. There is no reason to assert a positive value of several tenths of a degree which is what a 50/50 attribution implicitly does.

      • And when one considers the ocean already contains 50 times more CO2 than atmosphere

        Elsewhere the figure of 4000 times was given.

      • And when one considers the ocean already contains 50 times more CO2 than atmosphere

        See here.

    • Matthew R Marler

      Jim D: For CO2 increasing from 310 ppm to 400 ppm and the temperature increasing by 0.7 C since 1950, the Lewis transient sensitivity of 1.3 C per doubling gives 0.45 C that is certainly more than half and so even that supports the IPCC wording.

      0.45/0.70 = 64%, a “middle tercile” estimate. Do you think Prof Curry’s terciles are an improvement over the binary classification?

      • 64% makes the IPCC right. Is that wording not what the original debate was about? Their attribution encompasses Lewis who would also say “most” with quite a lot of certainty given the margin between 64% and 50%.

      • Matthew R Marler

        Jim D: Is that wording not what the original debate was about?

        Prof Curry’s question was whether the original debate can meaningfully be made more refined. A 49 percenter and a 51 percenter have more in common with each other than a 51 percenter and a 99 percenter, but are made to seem in conflict with each other. Isn’t a more refined classification better?

        It has been pointed out that some people called “deniers” are better labeled “lukewarmers” — they believe that CO2 has effects, but not the large effects claimed by the “alarmists”. Having 3 classes instead of 2 gets to the heart of the debate better, I think.

        Personally I think that quartiles would be better. I think that if there were quartiles, we would find that not many climate scientists believe that humans are responsible for 75% or more of the mean temperature increase since 1940 (almost for sure nowhere close to 97%). But perhaps terciles are enough. K. K. Tong of the recent AGW-saving THC mechanism for carrying the missing heat into the deeps is in the middle tercile. Near the end of his good book “Principles of Planetary Climate”, Raymond T. Pierrehumbert posits a value of 2C for the equilibrium climate sensitivity to a doubling of CO2 concentration; that puts him in the middle tercile, I think. The TCS estimate of under 1.5C by Isaac Held and others is also a middle tercile candidate.

      • Mathew Marler, it would be most sensible for people to have central estimates and ranges. Most of the 97% would have a range that includes 100%, because that is entirely possible just from a moderate 2 C per doubling sensitivity. It is even within Lewis’s range of TCR (0.9-2.0 C).

      • Matthew R Marler

        Jim D: Mathew Marler, it would be most sensible for people to have central estimates and ranges. Most of the 97% would have a range that includes 100%, because that is entirely possible just from a moderate 2 C per doubling sensitivity. It is even within Lewis’s range of TCR (0.9-2.0 C).

        I am guessing that you do not think the proposed classification scheme is an improvement.

      • Matthew M, no, having boundaries is not good unless you allow people to choose more than one range to cover their uncertainty.

      • JimD, “Well, it seems gbaikie and captd prefer to change the subject rather than defend Salby, where does that leave us?”

        If you have a link to a recent Salby paper on CO2, then I may be able to defend or not Salby’s theory. The actual subject should be atmospheric CO2 concentration and changes in ocean pH caused by atmospheric CO2 and vice versa.

        Stott, as I mentioned has a number of papers published and is one of many that noted CO2 tends to lag “GMST” which is becoming a questionable metric. Stott also noted that upwelling deep water in the Antarctic doesn’t appear to be the glacial/interglacial CO2 trigger. Since there is about a 80ppm change in atmospheric CO2 that lags “GMST” and that doesn’t appears to be due to southern hemisphere variations, the THC and NH sea ice extent could be the link between the lag of CO2 to Temperature.

        Nailing down what all impacts atmospheric CO2 when, is likely to be a fairly wicked problem, so I doubt that Salby, Stott or anyone else has all the answers, but there is definite evidence that more than just GMST and burning dead dinosaurs are involved.

      • David L. Hagen

        curryja
        For your post on Salby, you may find interesting to add some of the analysis of CO2 variations by Fred H. Haynie (formerly with the EPA).
        Quantifying the Anthropogenic Contribution to the Global Background Level of Atmospheric CO2
        His previous analysis with further detail is posted at:
        The Future of Global Climate Change, Fiction and Facts
        http://www.kidswincom.net/climate.pdf

      • Curryja “I have a forthcoming post on salby. If anyone has debunking links, i would appreciate seeing these.”

        On 8/19 at Lucia’s I asked whether Salby’s work was decent science. http://rankexploits.com/musings/2014/back-from-vacation-open-thread/ A debunking link that was unanswered from Dewitt Payne was this http://www.ferdinand-engelbeen.be/klimaat/co2_origin.html

        I don’t feel competent to judge Salby’s work and will look forward to your post.

    • Jim D, even if you are correct, and I don’t think you are, what contribution of the 90 ppm is man?

      • I would guess 90% with the rest due to the feedback of the warming ocean/biosphere to warmer temperatures.

      • JimD, I will look for the ref., but I recall the man-part of the 90ppm to be only 10 ppm or so, rest natural.

      • Bob, that might be the much debunked Salby.

      • Jimd

        Were those that debunked Salby capable of debunking him? Perhaps you could provide a link.

        Tonyb

      • I have a forthcoming post on salby. If anyone has debunking links, i would appreciate seeing these.

      • tonyb, you can choose to believe Salby, but you need to read about the carbon cycle on which he is woefully uninformed. I also challenge you to understand how Salby gets to his conclusion, which, much like Lewis, is rather abstracted from real notions that anyone can explain to Joe Public.

      • And I have a forthcoming paper with Nic Lewis, which should be very understandable to Joe Public

      • Jimd

        I said nothing about believing Salby I just asked to see links that debunked him. Seems Judith is interested to. If you would like to provide some links for her that would be good. Just be aware that if you post too many links they will go into moderation.

        Tonyb

      • Judith

        There is a long running thread on Salby at the bishops that might be of interest to you

        http://bishophill.squarespace.com/discussion/post/2398783

        Tonyb

      • Another recent thread is here
        https://andthentheresphysics.wordpress.com/2014/08/21/salby-again/
        I would go further and say the oceans are acidifying and therefore can’t be the source of the CO2, and therefore Salby is wrong. Clearly the oceans and atmosphere are both getting the CO2 from elsewhere: that being from fossil-fuel burning.

      • I read ATTP on salby, his response is pretty thin gruel

      • Jimd

        The oceans outgas 7 ppm of co2 for every one degree rise in its temperature. Are you claiming that is no longer happening?

        Tonyb

      • Jim D,Salby is a powerful intellect. don’t be so quick to dismiss him. I know the extremes do, but you shouldn’t. Let it play out, follow the data. The data speaks for itself.

      • It is common sense that if Man puts x amount of CO2 into the air, and the CO2 amount in the air goes up by x/2 while the ocean acidifies, this is cause and effect in its plainest exposition. What nonsense are these people suggesting happened to the manmade CO2? Someone needs to explain Salby in plain English. He’s kidding you people, and is probably surprised to have a following.

      • tonyb, the numbers you suggest of 7 ppm per degree (or I would say 10-15 ppm per degree including the biosphere) are OK and sane, but that is not at all what Salby is saying. He is saying all 120 ppm came out as a result of the warming of less than a degree(!). Do you agree with that? Note that outgassing of 90 ppm occurred as the last Ice Age ended and that was from warming of 6-8 C. These numbers fit with chemical equiibrium arguments.

      • –It is common sense that if Man puts x amount of CO2 into the air, and the CO2 amount in the air goes up by x/2 while the ocean acidifies, this is cause and effect in its plainest exposition. —

        And when ocean “naturally” breathes in and out about 100 GT per year, it’s also acidifying and de-acidifying, also?

        And when one considers the ocean already contains 50 times more CO2 than atmosphere or say more than 50 trillion tonnes of CO2, what effect would their be if during a brief period of time [say any where within a week or month or even a year] one could add, say .1 trillion tonnes to this existing 50 trillion tonnes CO2 then what in terms acidifying occurs in such a body?

      • gbaikie, the famous Keeling curve shows the natural annual part, and it is nothing like the background trend that accelerates in what must be a dumbfounding correlation to emission rates for you.

      • Tony,
        If 1 degree leads to 7 ppm rise, how many degrees the oceans must warm to raise concentration by 120 ppm?

      • I just read the post about Salby linked to above, and I have to say, I don’t get it. It doesn’t tell me what Salby’s position is or why that position is wrong.

        I’ve never paid attention to the Salby discussions, but I have to assume there are better sources to use.

      • > I just read the post about Salby linked to above, and I have to say, I don’t get it.

        One hypothesis is that it makes no sense.

        There are other hypotheses.

      • “What nonsense are these people suggesting happened to the manmade CO2?”
        ““Somewhere on earth, on land, one-quarter of all our carbon emissions released through fossil fuel emissions is disappearing,” said David Crisp, a senior research scientist at NASA’s Jet Propulsion Laboratory. “We can’t identify the processes responsible for this. Wouldn’t it be nice to know where?””
        http://www.nytimes.com/2014/06/30/science/nasa-launching-satellite-to-track-carbon.html?_r=0
        The accounting for CO2 seems broke. 10 percent of we lost it, might be acceptable.

      • @Jim D | August 24, 2014 at 6:29 pm |

        It is common sense that if Man puts x amount of CO2 into the air, and the CO2 amount in the air goes up by x/2 while the ocean acidifies, this is cause and effect in its plainest exposition.

        Common nonsense. The pH follows the atmospheric pCO2. How does the total amount of organic carbon in the ocean compare to the total (organic and inorganic) in the atmosphere? How does it compare to the anthropogenic contribution? How does (our best estimate) of total land organic carbon compare to those two values?

        Your anti-scientific sound-text-bytes aren’t even worth paying attention to until you address the disgusting trick done to Salby. Explain it, repudiate it, or be associated with something that wouldn’t have any reason if Salby’s work could be repudiated on scientific grounds.

      • AK, OK, so a rise the surface ocean pH is due to the atmosphere having more CO2, you agree, but if that CO2 left the ocean the pH should have risen like with a fizzy drink going flat. OK, so that doesn’t make sense to you, but maybe you would care to explain the correlation between the Keeling curve and emissions being 0.9988.
        http://www.ferdinand-engelbeen.be/klimaat/klim_img/emissions.gif

      • @Jim D…

        […] but if that CO2 left the ocean the pH should have risen like with a fizzy drink going flat.

        No. The pH follows the atmospheric pCO2, as I said.

        […] maybe you would care to explain the correlation between the Keeling curve and emissions being 0.9988.

        No, I’m waiting to see Salby’s explanation. Which people you associate yourself with have been sabotaging. So he’s right until proven wrong, and nothing you say is worth listening to until you repudiate that sabotage.

        BTW, I dug up some numbers for you, since I suppose you wouldn’t bother with order-of-magnitude considerations.

      • I look forwards to seeing if Salby addresses the correlation with emissions or just ignores it. I think Salby is playing a practical joke on the skeptics as his presentation is quite inscrutable to anyone except possibly himself. Also, you don’t seem to get that if the ocean is losing CO2 to the air it will get less acidic. As it is, both the air and ocean are gaining carbon, and there is an obvious reason for that.

      • –Jim D | August 24, 2014 at 6:54 pm |

        gbaikie, the famous Keeling curve shows the natural annual part, and it is nothing like the background trend that accelerates in what must be a dumbfounding correlation to emission rates for you.–

        Not for me.
        But maybe it’s lefty disease of projection, that is troubling you.

        You have heard about the concept [or silly idea] that CO2 emission from fossil fuel use would at some point would reach a saturation point?
        It seems to me the famous Keeling curve and China exceeding US CO2 emission and reaching towards doubling US fossil fuel emission has demonstrated a problem with the “idea”.

        Find the very dramatic increase in yearly Chinese fossil fuel emission in the famous curve.
        http://en.wikipedia.org/wiki/List_of_countries_by_carbon_dioxide_emissions#mediaviewer/File:Carbon_dioxide_emissions_due_to_consumption_in_China.png

      • JimD, “Also, you don’t seem to get that if the ocean is losing CO2 to the air it will get less acidic. As it is, both the air and ocean are gaining carbon, and there is an obvious reason for that.”

        Not necessarily. The deeper ocean has a lower pH and changes in the rate and location of upwelling can increase the average pH at the surface. while either releasing CO2 to or reducing the rate of CO2 uptake from the atmosphere. What happen in the Pacific Northwest for example. Lowell Stott was doing some research on the subject.

      • captd, so Salby has some intricate mechanism whereby the ocean absorbs the manmade CO2, sequesters it to the deep, and replaces it with proportional amounts of its own CO2 that it puts back into the atmosphere. In fact the ocean is so good at mimicking emissions that it even doubled its rate of CO2 production at the same time as man did. Nature sure is doing a good impression of Man. Ridiculousness abounds around Salby.

      • JimD, “captd, so Salby has some intricate mechanism whereby the ocean absorbs the manmade CO2”

        I haven’t read squat published by Salby, Stott on the other had has a few very interesting papers. Since you indicated that the oceans giving up CO2 “HAD” to increase pH, I thought you might want to consider your comment a little more carefully. Climate Science looks to be a tad more complex than you seem to think.

      • Well, it seems gbaikie and captd prefer to change the subject rather than defend Salby, where does that leave us?

      • **Jim D | August 24, 2014 at 10:14 pm |

        Well, it seems gbaikie and captd prefer to change the subject rather than defend Salby, where does that leave us?**

        Well:
        –curryja | August 24, 2014 at 8:59 pm | Reply

        I stated a few comments back that I am planning a future thread on salby–

        Perhaps at such a future thread, we could talk about something specific regarding what salby says.
        And who knows, maybe salby could be around to defend himself.

      • Salby’s argument is that CO2 level in the atmosphere is fixed by global temperature. So it doesn’t matter if you try to emit more, you can’t change CO2 level that way. The excess will just filter out. Similarly if you try to absorb more, it will fill up faster, always to a level determined by temperature.

        So human emissions have simply coincided – by sheer fluke – to a period of warming which has driven up CO2 level up anyway. Those CO2 levels have contributed to the warming itself, but humans have not contributed to either.

        The main problem with the argument is that it is BS.

      • In significant part, however, CO2 is controlled by Global Temperature, as it is in the Proxy Record.” Murray Salby

        The seething resentments and free invention all seems fundamentally at odds with the what has been said – what I know of it.

        ‘Ecosystem warming experiments, modelling analyses, and fundamental biokinetics all suggest that’ the statement above is indubitably correct.

      • Salby’s argument is that CO2 level in the atmosphere is fixed by global temperature. So it doesn’t matter if you try to emit more, you can’t change CO2 level that way. The excess will just filter out. Similarly if you try to absorb more, it will fill up faster, always to a level determined by temperature.

        Straw Man Alert!

      • I wouldn’t call Salby’s argument a strawman, but it is certainly absurd.

      • Steven Mosher

        “And I have a forthcoming paper with Nic Lewis, which should be very understandable to Joe Public”

        congrats

      • I wouldn’t call Salby’s argument a strawman, but it is certainly absurd.

        Yours is the straw man. You clearly don’t have the faintest idea what Salby’s argument is. So you description of “absurd” is ignorant drivel.

      • Salby’s argument, as I have explained, is that CO2 level in the atmosphere is fixed by global temperature. So it doesn’t matter if you try to emit more, you can’t change CO2 level that way.

        Sorry to have explained it in such a clear way that anyone can understand.

      • Matthew R Marler

        Jim D: It is common sense that if Man puts x amount of CO2 into the air, and the CO2 amount in the air goes up by x/2 while the ocean acidifies, this is cause and effect in its plainest exposition. What nonsense are these people suggesting happened to the manmade CO2?

        I agree with you there. Even if all of the increase in CO2 is anthropogenic, the atmospheric increase will be faster in warm weather than in cold weather, because in cold weather the rate of dissolution into ocean water is greater than in warm weather.Salby’s argument on this point is at best incomplete and inconclusive. I have repeated this point farther down, in response to Rob Ellison.

      • Salby’s argument, as I have explained, is that CO2 level in the atmosphere is fixed by global temperature. So it doesn’t matter if you try to emit more, you can’t change CO2 level that way.

        No, that isn’t Salby’s argument. It’s a straw man made up by you.

        Sorry to have explained it in such a clear way that anyone can understand.

        The problem is that’s NOT Salby’s argument.

      • Matthew R Marler

        markus: Salby’s argument, as I have explained, is that CO2 level in the atmosphere is fixed by global temperature. So it doesn’t matter if you try to emit more, you can’t change CO2 level that way.

        Salby’s argument is at best incomplete and probably wrong. It is certainly possible to pump CO2 into the atmosphere faster than the oceans and biosphere and rocks can absorb it all. All of the evidence taken together supports the idea that humans have been doing that, more than it supports the idea that all (or even most) of the CO2 increase is independent of human fossil fuel use.

      • The increase in CO2 in the atmosphere related to temperature is from biological sources – and not primarily from lower solubility in warmer oceans. This seems fairly obvious and uncontroversial. At least to other than the oblivious few. Nor is anyone suggesting that anthropogenic emissions are not happening.

        Discussion of Salby seems to inevitably take on a surreal aspect that should be fascinating in a dedicated post.

      • Matthew R Marler

        Rob Ellison: Discussion of Salby seems to inevitably take on a surreal aspect that should be fascinating in a dedicated post.

        That was why I referred to his textbook. He cites the outgassing of Co2 from oceans on p. 68, and in a talk of his that has circulated. Also on p. 68 he cites the decomposition of biological matter. He further down says that the dependence of CO2 on temperature is poorly understood. Taken all together, the dependence of measured CO2 in the atmosphere on temperature does not rule out a mostly fossil fuel source of the increasing CO2.

      • The two studies I link below together suggest an increase from soils and tropical vegetation of 70% of anthropogenic emissions.

      • Matthew R Marler

        Brandon Shollenberger: I’ve never paid attention to the Salby discussions, but I have to assume there are better sources to use.

        check out his textbook.

      • Matthew R Marler, textbooks are generally too much of a pain to track down for a topic I have little interest in. That’s especially true since many of them can’t be accessed without paying money.

      • Matthew R Marler

        Brandon Shollenberger: a topic I have little interest in.

        I missed your lack of interest in Salby. Sorry.

        As to cost: check out the book, if you can.

      • Matthew R Marler, no prob. I’m not opposed to learning more about the topic. I just haven’t seen anything about it thus far that has caught my attention. That puts it in the category of “things I’ll check out if it’s convenient.” If I ever happen to see that book, I’ll be happy to read what it has to say. The same is true if I ever see a post giving a good overview of the subject. I just don’t intend to look too hard for such.

        In the meantime, I figure if people on either side of dispute want me to understand their position, they can write an overview which actually explains matters. If they choose not to, instead going with posts and comments like what I saw at Ander’s blog, I’m going to stay uninterested.

      • On 8/19 at Lucia’s I asked whether Salby’s work was decent science. http://rankexploits.com/musings/2014/back-from-vacation-open-thread/ A debunking link that was unanswered from Dewitt Payne was this http://www.ferdinand-engelbeen.be/klimaat/co2_origin.html

        I don’t feel competent to judge Salby’s work and will look forward to your post.

        Placed this link in the wrong spot previously.

        JD

    • Jim D:

      The straight CO2 no feedback of 1.1 K per doubling yields 0.35… exactly 50%

      Of course, this assumes all other things being equal and/or cancelling each other out.

      Looking at 1910 to 1970 delta CO2 is 20-ppm and the delta T is 0.3K. Using 1.3 per double yields 0.1K indicating 0.2K from “other”. If the other is “natural recovery from LIA, it’s at a rate of 0.67K/century. This assumes aerosols have no effects.

      Assuming the pause continues to 2030 the 1970 to 2030 delta T is 0.7K and CO2 is 95ppmv. Using Nic’s 1.3/double yields 0.44K which is the same as the 1950 to 2014. However, if Natural = 0.67K/century, then 0.4K is natural and 0.3K is CO2 which indicates a TCS of 0.9K/double.

      In any event, all of these calcs are B S because we don’t really understand the sum total of past/present and future aerosol effects nor of CO2 feedbacks nor of the combo of CO2 feedbacks with changing aerosols nor of natural low frequency climatic variation.

      These are the main data/knowledge gaps that makes the 50/50 argument rather pointless.

      While climate scientists work on filling these gaps, no regret policy actions seems appropriate and relatively uncontroversial.

      • You only get low sensitivities like Lewis by assuming aerosols have not done much to reduce CO2/GHG effects since the industrial era began. There are observations and scientific ideas that conflict with that assumption.
        50/50 also assumes that whatever else is happening is a warming of an unspecified type that contributes 0.35 C positive net. This is not an uncertain natural variability argument that would also allow for an equal negative value and just broaden the distribution in both directions. It is explicitly saying that 0.35 C of the warming since 1950 is not CO2, but something as yet unknown or unhypothesized and three times larger than the PDO and AMO, but clearly not those either as they just cancel themselves over 60 years. It is very hard to understand this level of certainty in something unknown.

      • If we find more and more gaps, Howard, will we find lower and lower hanging fruits?

      • Willard:

        No. The objective is to find the higher hanging fruit that does the most damage. As you could ferret out from RUd’s “post” there is a lot of uncertainty regarding potential species/habitat (including Humans!) impacts from the warming already in the pipeline. Obviously, we cannot address all of these uncertain concerns. Improving the regional accuracy of GCMs will help solve a number of problems, including impacts. Right now, there is no evidence that we understand the problem sufficiently to be that specific in targeting.

      • Jim D

        I agree that the IPCC consensus may be underestimating aerosol cooling. However, the opposite could be true as well. Atmospheric aerosol science is pretty thin, including their role in low-level (warming) and high-level (cooling) cloud development, PM agglomeration, PM and VOC oxidation, condensation and precipitation effecting albedo. In addition, there is a very interesting biological component to aerosols that is not well understood. One thing to note, carbon black is not the only aerosol that changes albedo.

        IMO, this is a huge, low-hanging data gap that needs a lot more work. Implementing aspects of the no-regrets policy is one way to perturb the system to get a better handle on what is going on.

      • Steven Mosher

        “You only get high sensitivities …..

      • Howard,

        I’m not sure the objective should be to find the higher hanging fruit that does the most damage, and to pick the lowest hanging ones while we’re seeking for that optimal fruit. I’m a fan of satisficing:

        http://en.wikipedia.org/wiki/Satisficing

        High enough fruits that do big enough damage are good enough for me.

        Since we’re waiting for Godot in Judy’s thread dedicated to her 99-1 argument, I’ll agree with you that the water problem is quite high indeed.

  20. The competent questions to ask expert or layman alike come in two flavors: what do the models predict, and how have the models been validated they been validated.

  21. Matthew R Marler

    Prof. Curry, that was a good post.

    As to making things up (expert judgment?), how about a prior density on climate sensitivity (to a doubling of CO2 concentration) that is uniform on (0, 8) or (0,12)? Has that “made stuff up”?

  22. stevefitzpatrick

    Judith,
    ” I won’t make a judgment here as to how ‘expert judgment’ and subjective ‘down weighting’ is different from ‘making things up'”

    I very nearly snarfed my beverage when I read this. Let me help you: it is very little more than making things up.

    On a more serious note, I think we need to not consider the apparent ~60 year cycle in the temperature history, and instead accept that a conservative case is for all warming since the mid 19th century was due to human forcing. Yes, it may in fact be less than that, but even considering all net warming over ~160 years is due to human forcing, the sensitivity consistent with our best estimates of current forcing is a conservative estimate for public policy… the sensitivity may be lower, but it is unlikely to be much higher. As Nic Lewis (and others) have shown, the best empirical estimate of sensitivity, based on all observed warming, is low enough that it is impossible to currently justify expensive mitigation policy.

    Anything you write which supports a lack of need for draconian action will continue to cause loud squeals from advocate climate scientists, as Gavin so promptly showed via his comment. The disagreement is essentially political/moral/philosophical, and compromise on these is very difficult.

  23. Danley Wolfe

    Judith, the cartoon is perfect right on target ! I believe this thing illustrates the problem of the consensus argument, and more generally the IPCC approach to the stated crisis (sic) of rising global mean (land/water) temperature. If the observable outcome (temperature increase, independent variable) is the result of a) manmade forcings plus b) non manmade forcings; and if admittedly non manmade forcings are not well enough to well embody them in the models (scenario or what if sensitivity models not forecasting models), the answer (by definition) it’s not possible to put a number on the probability / likelihood of manmade causes. “Why is this hard to understand? Counter arguments claiming to be able to do so are opinions not backed by the science. Taking averages of multiple models and mentioning averages and variances is pretty much nonsense.. statistical statements about data is ok but statistical statements about forecast model outputs is nutso weird especially when the models do not explain back cast history. Asking individuals their opinion on this question is irrelevant. Depends on who you ask, what their vested interested is, whether they are competent to opine on this question… and worse, opinion polls for the same reason …. how was the question asked, who was in the poll, what is their competence to answer, etc. Compare this with the Einstein and Bohr debate on wave vs. particle theory: in this case a) real data supported both theories, b) both theories are required to explain real life phenomena, c) Bohr and Einstein were civilized and took genuinely reasoned arguments in support of their positions, and they in fact highly respected each other (which you certainly do not see on global warming, d) and so it goes to this day. This says that neither wave or particle theory is wrong and they are two ways of explaining different manifestations of the same thing. In the case of global warming thinking people would agree BOTH manmade and non manmade forcings are at work (including, and especially negative feedbacks). We do not have enough understanding of the non manmades, but someone is asking what our opinion is on the manmade. Huh?

  24. In response to Jim D, if TCR is near 2C, then you have a very big problem explaining the lack of warming 2000-2014 as the AGW component should be completely swamping the non AGW cooling component.
    If you want to base your entire analysis based on a data set that shows the most warming 1950-2000 and ignore the problems… lack of current warming and possibly overcorrected data in the 1940s, I find it illogical to claim that there is 95% certainty that TCR is that high.

    • A TCR based on 1950-2000 would have been over 2.5 C per doubling, so 2 C already accounts for the cooling due to this phase of natural variation. Overall natural variations of annual averages have not strayed more than 0.1 C away from the rising line given by a 2 C sensitivity.

      • Analyzing the data this way glosses over the fact that there currently has been no warming 2000-2014. Even at TC=2, the lack of warming this century is totally inconsistent. It seems you are pretending there is no pause in warming at the moment. At TC=2.5, it is even worse….. but still at TC=2, it does not square with no warming for 15+ yrs.

      • It is natural variations plus some solar decline. It adds up to a couple tenths of a degree at most. These have occurred throughout the record and the current one is nothing statistically different, and not much in the multi-degree warming picture that is predicted.

      • Also, it appears based on this graph, that the warming 1950-2000 is closer to 0.4 C, while the warming 1970-2000 is where the 0.7C comes from. Thus, this fact alone cuts the TC you list nearly in half, and indicates that the Ocean cycle variation is much larger than the 0.1C you claim.

        http://www.woodfortrees.org/plot/hadcrut4nh/from:1850/mean:12/detrend:0.8/plot/esrl-amo/from:1850/mean:12

      • 0.7 C comes from fitting a linear trend starting at 1950 and multiplying this fit by the number of years for that trend. For 2014 it comes out at 0.7 plus or minus depending whether you use GISTEMP or HADCRUT4. This method avoids problems with endpoints and is quite robust.

  25. There is a crucial aspect missing in this 50:50 approach:
    Let go back to 2006, one year before AR4 in 2007: Open still
    was the question, on how much the EARTH ORBIT contributes
    to global warming……. In this year, the lead authors of wg1, AR4
    had a grand meeting and they colluded to throw the Earth Orbit
    out of the warming causes and decided to KEEP THE LID on
    the Earth orbit influence.. As this decision was made, they
    gratulated themselves and danced “Full of Joy” (according to an
    participant)…
    For this reason, only tropospheric and Sun-related causes
    are being put forward…..clearly misleading you and you are stuck
    with the 50:50 question without an answer….JS.

    • The Milankovitch cycle has a negative trend favoring Arctic ice expansion in this phase. This is noteworthy only for its inconsistency with the current trends there.

      • which is why you will see an increased trend in arctic ice extent over the next 20 years plus,along with net cooling of the northern hemisphere,though by your account of the oceans sequestration of CO2 ,ocean acidification will go through the roof at the same time.

  26. All the net warming since 1880 has been caused by humans, with aCO2 leading the way. That is a no-brainer.

    • Then the IPCC has no brains, since as per fig 10.1, with natural forcing, they cannot explain warming from 1910-1940

      • The AR5 states:

        In conclusion, the early 20th century warming is very
        unlikely to be due to internal variability alone. It remains difficult to quantify the contribution to this
        warming from internal variability, natural forcing and anthropogenic forcing, due to forcing and response
        uncertainties and incomplete observational coverage.

      • Oh, then they didn’t account for the log sensitivity to CO2 properly, and they didn’t include the LOD variant of the stadium wave as a natural variation. At the end of the complete time span, the LOD returns to a zero compensation level.

        If you do all that, it is straightforward to see that it is all aCO2
        http://imageshack.com/a/img812/74/abh.gif

      • Matthew R Marler

        WebHubTelescope: All the net warming since 1880 has been caused by humans, with aCO2 leading the way. That is a no-brainer.

        What other anthropogenic influences have you included in your model?

        How exactly can you tell that all of the other possible influences have balanced out? Is that the part of your modeling process where you used no brains? (sorry, that’s too obvious a joke to avoid. You kind of set yourself up.)

      • I said aCO2 leading the way. The contribution of CO2 may in fact be greater than 100% and aerosols act to reduce the effective contribution to the 100% evel.

    • So are you saying that any increase of co2 over the turn of he century base of 300ppm will result in warming? If so, surely we can ‘t live on this planet as we will always cause warming.

      Tony

    • I think this was meant as sarcasm or something.

    • “Then the IPCC has no brains”
      Oh Dear Judith, that must mean that Webby doesn’t either.

    • nottawa rafter

      That’s right Web, just ignore the last 10,000 years. Those that value science can’t do it. But for those needing simple answers go for it.

      • The last 10,000 years have a significant ENSO component. And that is known to have bounded limits and reverts to a mean that is zero. Same is true of TSI variation, with little estimated impact. Volcanos come and go but also revert to zero over the long term. What is left is the stadium wave which has a +/- 0.1 C variation over the last 100 years, largely compensated out.

        As scientists and engineers, you really ought to understand the definition and meaning of “compensation”. And no, that does not represent your paycheck.

    • Web: If you are correct, then the aCO2 effects are not linear due to the 1910-1970 CO2/Temp relationship if there is no net natural Temp increase and everything else is a wash.

      lets assume
      delta T = Log(10)DeltaCO2 yields a CO2 doubling of 2.4K, which is close to IPCC midpoint

      Our current delta T from CO2 would be 2.1K Since the actual delta T is 0.8K, then for the non-linear model to work, current aerosols are cooling by 1.3K

      However, IPCC essentially claims that anthro aerosols cancel out the all the other non-CO2 LLGHGs, leaving aCO2 the proxy for net AGW.

      Therefore, your 100% anthro attribution hypothesis can only be true if 1) aCO2 effects are not linear and 2) IPCC underestimates anthro aerosol effects

      Not saying you are wrong, but maybe you could explain how your hypothesis fits with the aCO2 and Temp records which we can agree are the most reliable data we have.

      Thanks!

    • if you have no brains .

    • Matthew R Marler

      WebHubTelescopeAll the net warming since 1880 has been caused by humans, with aCO2 leading the way. That is a no-brainer.

      Try to express what you are asking mathematically. That’s what I do, work on solving homework problems. If you can’t do that much, you will be left behind.

      Mathematically, then, how much of the warming since 1880 has been caused by humans by mechanisms other than anthropogenic CO2? You evaded tonyb’s response to your assertion of “all the net warming since 1880”; if the warming of the late 19th century was caused by CO2, then 300ppm causes net warming, and the “350ppm” goal is useless.

      • Marler, you must be dense. All of the net warming since 1880 is attributable to man-made causes.

      • Matthew R Marler

        WebHubTelescope: All of the net warming since 1880 is attributable to man-made causes.

        Are you totally uninterested in quantifying how much is due to CO2 and how much to other causes? You have been repeatedly asked. Clearly you are not obliged to answer, but you don’t seem to have understood the question.

      • Marler, The net warming from 1880 to now is 100% due to man-made forcing, following the growth of aCO2 to well above a 0.99 correlation coefficient.

        I don’t know where you have gone wrong because you have not shown your work anywhere. Do you not understand what the word net means in this context?

      • WebHubTelescope (@WHUT) commented on The 50-50 argument.

        “Marler, The net warming from 1880 to now is 100% due to man-made forcing, following the growth of aCO2 to well above a 0.99 correlation coefficient.”

        Lol!!!!!!!!!!

      • Matthew R Marler

        WebHubTelescope: Do you not understand what the word net means in this context?

        Sure. It means that in your csalt model all of the diverse human impacts are confounded in the CO2 term, so that you overestimate the effect of CO2 itself.


      • Matthew R Marler | August 27, 2014 at 1:42 pm |

        Sure. It means that in your csalt model all of the diverse human impacts are confounded in the CO2 term, so that you overestimate the effect of CO2 its

        Matthew “Warmist” Marler, And if those will still be there as CO2 continues to grow?
        Then CO2 then acts as a proxy for all of man’s effects.

      • Matthew R Marler

        WebHubTelescope: Then CO2 then acts as a proxy for all of man’s effects.

        I have agreed with that several times already. How much of warming is attributable to factors other than CO2? Those factors will persist if anthropogenic CO2 is reduced, so your model overestimates the amount of temperature reduction that might be achieved by reduction in CO2.

        Are you not interested in separating CO2 effects from the other effects of which it is a proxy?


      • Are you not interested in separating CO2 effects from the other effects of which it is a proxy?

        Why don’t you effin lift a pen and try doing it yourself ? They all show the same rapid increase over the industrial age. Knock yourself out.

        It’s tiresome slogging through your concern-trollish responses.

    • ‘All the net warming since 1880 has been caused by humans, with aCO2 leading the way.’

      That is a correct statement.
      But only 75% of the warming from 1950 to 2010 was caused by humans. CMIP5 are too sensitive to CO2 and TCR is actually about 1.5C.

    • WebHubTelescope, 8/24/14 @ 3:45 pm asserted, All the net warming since 1880 has been caused by humans, with aCO2 leading the way. That is a no-brainer.

      The statement may be true in the GCMs, but not in the real climate. The notion is in the GCMs by design. IPCC shows Policymakers how the process works in AR4, Figure SPM.1, p. 3, where modern instrument data for CO2, CH4, and N2O blend smoothly into ice core data (by a process called chartjunk and a corollary of Mann’s calibration trick to “hide the decline”).

      All this is to support this conclusion:

      The understanding of anthropogenic warming and cooling influences on climate has improved since the TAR, leading to very high confidence that the global average net effect of human activities since 1750 has been one of warming, … .

      (Keep moving folks. Nothing of concern was happening between 1750 and 1880.)

      It’s chartjunk because, for one, experimental data from different sources never match so neatly. For a second reason, the ice core data are averages over the ice closure time, sometimes several millennia, while the collection time for instrument data is a minute or less. Consequently, the ice core data are heavily low-pass filtered, and correspondingly heavily attenuated, compared to instrument data. Calibrating the two into agreement on the average might be OK, if revealed, but the slopes of the two should not match.

      In system modeling theory, such models are known as small signal models. They are supposed to represent changes which are rapid with respect to the background so that the background may be assumed constant. That’s OK. The no-brainer part is that when the models fail, that is, are unable accurately to predict anything of significance, the investigator should realize that the small signal assumption has failed.

      All this is just the tip of the ice core. If CO2 is causing warming, it must lead the warming. Instead, it lags the warming in the ice core record, and lags by a millennium. IPCC doesn’t know about the leads and lags of causality. The Sun drives climate change, but IPCC models it as constant so its small signal models might have a chance to work. In fact, the atmosphere (i.e., cloud cover) amplifies solar variation, but IPCC models cloud cover as constant so its small signal models might work. When climate temperature changes, the CO2 content of the atmosphere follows by Henry’s Law. When IPCC uncovered the effects of Henry’s Law in its attempt to resurrect the Revelle Factor, IPCC hid the data “in order not to confuse the reader”, and so its small signal models might have a chance to work.

  27. Curious George

    We simply don’t know enough to answer the 50-50 question with even an appearance of certainty. But you can accept bets.

  28. Reblogged this on Bob Tisdale – Climate Observations and commented:
    Judith, thanks for making this a separate thread. It’s an extremely important topic. The Gavins of this world will fight you tooth and nail on this, because they have tuned their models to a naturally occurring upswing in the surface temperatures–regardless of whether that upswing was caused by ENSO, the AMO, or other factors. Therefore, the Gavins of the world have likely doubled the expected warming, climate sensitivity, etc.

    • Matthew R Marler

      Baart Verheggen, quoted by willard(@nevaudit):

      .@curryja’s answer to @climateofgavin seems to come down to the old “uncertainty = ignorance” fallacy. No argumentation, no quantification.
      7:05 AM – 22 Aug 2014

      Clearly that is false.

      • The ongoing discussion, MattStat. The ongoing discussion.

        In that discussion, we find a link to an old 2012 article:

        In summary then, the IPCC AR4 statement was a fair, even conservative, assessment. There is an unfortunate tendency to reify the particular statements made by IPCC, since there were clearly other correct statements that could have been made. For instance, it might well have been worthwhile to add a statement about the likely range of the anthropogenic trends (i.e 80-120% of the actual trend or similar), so that a better picture of the appropriate distribution could be given (see Huber and Knutti, 2011) for examples). But claims that the statement was unsupported, or that it demonstrated that IPCC was ignoring uncertainty are simply untenable.

        http://www.realclimate.org/index.php/archives/2012/01/the-ar4-attribution-statement

        Our emphasis to make sure everyone took their ibuprofen.

        In that context, the use of the concept of “reification” is quite an understatement.

      • Perhaps Bart will be kind enough to tweet his explanation of the 1910 to 1940 warming. Or even better he might turn up here again and answer it.

        Tonyb

      • tonyb, 1910 to 1940 was due to aerosols and solar throttling up to 200% doncha know. Back then aerosols were a positive forcing, now of course they are negative. It really looks like leaded gasoline may have had some impact on the science as well during the previous hiatus.

      • Captain

        Can you pop it through a model and confirm the day, month and year when aerosols changed from a positive to a negative forcing?

        Perhaps it was about the same time that heat decided to go only into the sea instead of the sea AND the land whilst cleverly bypassing all the temperature buoys.

        Tonyb

      • Matthew R Marler

        willard (@nevaudit) : In summary then, the IPCC AR4 statement was a fair, even conservative, assessment. There is an unfortunate tendency to reify the particular statements made by IPCC, since there were clearly other correct statements that could have been made. For instance, it might well have been worthwhile to add a statement about the likely range of the anthropogenic trends (i.e 80-120% of the actual trend or similar), so that a better picture of the appropriate distribution could be given (see Huber and Knutti, 2011) for examples). But claims that the statement was unsupported, or that it demonstrated that IPCC was ignoring uncertainty are simply untenable.

        Nevertheless, the sentence by Bart Verheggen that I quoted was false. That something else he wrote somewhere else was true does not change the fact that the quoted sentence was false.

      • tonyb, It was April 19, 1950. There was a big headline in the papers that CO2 had just taken over. It is known as bicycle day in some academic circles.

      • > That something else he wrote somewhere else was true does not change the fact that the quoted sentence was false.

        That changes the relevance of the “quoted by willard” bit quite a lot. I quoted the first tweet of that exchange.

        You’re entitled to claim that Bart’s tweet is false without identifying which bit is wrong, without excluding which bit is not, without justification whatsoever, without even considering the timeline, or even the “seems” at the beginning.

        If you can remind me of a quantification somewhere, that’d be nice.

      • Matthew R Marler

        willard(@nevaudit): You’re entitled to claim that Bart’s tweet is false without identifying which bit is wrong, without excluding which bit is not, without justification whatsoever, without even considering the timeline, or even the “seems” at the beginning.

        I thought so too. You prefer to take some part out of context that, out of context and without punctuation, might not be false?

        Is this “enough” quantitation, or do you require “more”: The 100% anthropogenic attribution from climate models is derived from climate models that have an average equilibrium climate sensitivity (ECS) around 3C. One of the major findings from AR5 WG1 was the divergence in ECS determined via climate models versus observations. This divergence led the AR5 to lower the likely bound on ECS to 1.5C (with ECS very unlikely to be below 1C). Nic Lewis at Climate Dialogue summarizes the observational evidence for ECS between 1.5 and 2C, with transient climate response (TCR) around 1.3C.

        Or were you requiring a derivation of something new?

      • > Or were you requiring a derivation of something new?

        Something related to the 50-50 argument might have been nice.

        The topic of BartV’s comment, the one MattStat dismissed as false without even stating what was false.

      • Steven Mosher

        barts answer
        No argumentation, no quantification. mere assertion.

        wait for willard to call him out

      • Steven Mosher

        willard trying to be clever

        “The ongoing discussion, MattStat. The ongoing discussion.”

        Bart starts with a conclusion. Judith’s argument “comes down to”
        uncertainty = ignorance with NO argumentation.

        Not, faulty argumentation.
        Not, specious argumentation,
        Not incomplete, Not faulty, not inconclusive, but rather
        No argumentation

        Well this is false. As a conclusion summarizing the issues discussed,
        this is false. No “on going discussion” will turn Judiths argumentation
        into a LACK of argumentation. No on going discussion even on that focuses on specific issues will render her whole position as one
        without argument.

        Willard knows this. And if it were Judith taking this position against gavin or Bart, he would be all over it.

        But he chooses not to be all over it.

      • Matthew R Marler

        Steven Mosher: willard trying to be clever

        That’s a good post.

      • Steven Mosher

        whats worse Matthew is that willard tries to get you to specify which part
        of barts assertion is false

        “seems to come down to the old “uncertainty = ignorance” fallacy. No argumentation, no quantification.”

        Bart argues
        1. That her entire position comes down to ‘uncertainty = ignorance”
        That’s false.
        2 That she makes no argument.
        That’s false.
        Then willard focuses on the ‘quantification’ issue.
        Here we a case where Judith has done some quantification. Clearly not as much quantification as the IPCC, but clearly some. The minute she puts the range’s down she is quantifying. Now we may take issue with her quantification. We may call it wrong, imprecise, lacking, unclear, not well thought out, not complete, we can use many words to describe it.
        No quantification, however is false.

        Then you will see willard shift downstream to the “on going conversation”
        and here he would try to find one area where there was no quantification.
        one can do this with any dialogue. In this way he avoids calling Bart to account for the very kind of argumentation that he calls others to account for.

        The IPCC account of attribution, NG’s account, Bart’s account, gavin’s account, Judith’s account, are all short on rigor, transparency, repeatability, and traceability. tweeting about the topic is part of the problem.

      • > Bart starts with a conclusion. Judith’s argument “comes down to”
        uncertainty = ignorance with NO argumentation.

        Here’s the first sentence:

        @curryja’s answer to @climateofgavin seems to come down to the old “uncertainty = ignorance” fallacy.

        Notice what Mosphit added, and what he subtracted.

        It’s now considered to be a conclusion, which means there should be an argument. The “NO argumentation” has been added to that “conclusion”, as if the fact that there would be no argumentation would lead us to infer that Judy’s 99-1 argument conflated ignorance and uncertainty.

        The word “seems” has been omitted. This reinforces the idea that BartV’s tweet is a “conclusion”. The two sentences have been merged together, creating the impression that they were the same “conclusion”, one we can reject in one go by saying that “it” is false.

        The “no quantification” too has been omitted, for obvious reasons.

  29. Readers might also like the opinion of an old regular of Judy’s, Pekka Pirilä:

    I just noticed that Judith Curry keeps stubbornly the line that even over the 60 year period from 1950 less than 50% AGW is as likely as more than 50%. I have argued against that so many times there that I have to figure out something new to say before I comment there.

    http://andthentheresphysics.wordpress.com/2014/08/22/a-hiatus-in-some-peoples-skepticism/#comment-29671

    • Well that whole thread made me want to pop more ibuprofen, but earlier in the comments Pekka says this:

      ‘When the statement concerns specifically the average surface temperatures of the latest 2.5 decades of 20th century, I do believe that 50% natural variability is very well within the limits of uncertainty, not even close the edge of the plausible range. There are some questions on, how to define that, but at least many of the possible definitions support that claim, if not all.’

      WHich is essentially what I am saying.

      • So, let me get this straight, Judy: since you’re betting on the lowest bound of the attribution problem justified disingenuousness can buy. In other words, you’ve just transposed the lukewarm gambit (usually applied to climate sensitivity) to the attribution problem. Am I right?

        If I am, well played!

      • It is just mathematics. Natural variability from decade to decade can be 0.2 C. CO2 can warm by 0.15-0.2 C per decade in the last few decades. In any two decades therefore you are comparing 0.2 C with 0.3-0.4 C, so there is a possibility of 50%. As you get to 6 decades since 1950, you still have that 0.2 C but are now comparing it with 0.7 C. 50% becomes less likely with longer time-spans.

      • 60 years is 2.4 times 25 years. That makes all the difference, as AGW can be isolated only as a smooth deterministic trend, not quite linear, but smooth anyway.

      • Likely smooth and likely small.
        ==========

      • I think I must have written ‘last quarter of the last century’ on lucia’s blackboard at least a hundred times.
        =============

      • A good rule of thumb is: don’t trust anything less than 30 years when it comes to climate change factors, otherwise you are just looking at irrelevant noise.

      • I don’t regard this as a useful rule of thumb; in fact it is this kind of thinking that has led to the IPCC detection failure. We need to understand the decadal to centennial modes of natural climate variability. there is nothing magical about 30 yrs; in fact 30 yrs is nominally half of an AMO cycle, so that period can be particularly misleading.

      • thisisnotgoodtogo

        It’s fine if you’re all thumbs…eh, Jim D?

      • thisisnotgoodtogo

        “Natural variability from decade to decade can be 0.2 C.”
        If you say so, JimD!
        So that covers about 1.2 degrees rise since 1950?

      • I am saying yes, use 60 years or centuries, but not shorter than 30 years. Decadal natural variations are similar to the expected CO2 signal, making this a tough scale to decipher anything on. It has led to a lot of arguments about decadal noise that do nothing to address the long view, and actually distract from it. We have a long-term record and there is no reason to focus on short periods, especially one of multiple pauses in the longer record that just happens to be the most recent, but is not statistically different.

      • thisisnogood, it is a 0.2 C amplitude of noise around a long-term mean, so your 1.2 C is several standard deviations and would require an explanation, just as 0.7 C is in reality. Lovejoy went into this, saying for century scales 0.8 C is four standard deviations, making it improbably a natural variation with something like 99.9% certainty.

      • Dismal accounting from Jimbo as usual.

        The increase between 1944 and 1998 was some 0.4 degrees C. This assumes that the warm and cool periods in the interval exactly cancelled out.

        So let’s assume it was all anthropogenic. What does that imply? An increase of 0.4 degrees C at some 40% of the way to CO2 doubling. This is such a simple and obvious accounting. Why do they seem incapable of it?

      • Rob Ellison, but oddly you get 0.7 C if you end in the current year instead of 1998. Must be all those intervening warm years shifting the trend up during the so-called pause.

      • Year____Anomaly
        1944____0.150
        1998 ____0.531
        2013____0.487

        http://www.metoffice.gov.uk/hadobs/hadcrut4/data/current/time_series/HadCRUT.4.2.0.0.annual_ns_avg.txt

        Not sure how Jimbo gets 2014 temps – creative accounting possibly.

        Let’s compare it to the Swanson graph from realclimate.

        http://watertechbyrie.files.wordpress.com/2014/06/swanson-realclimate.png

        The 1998 ‘overshooting’ has decades to work it’s way through the system yet. Decades of non-warming or even cooling are much more likely than not. .

      • thisisnotgoodtogo

        Jim D said
        “Natural variability from decade to decade can be 0.2 C. ”
        Oh, sure, but can it be more ?

        Oh, no, you say. “It is just mathematics.”

        No, JimD it is not just mathematics. It’s the multiproxy reconstructions.

        ‘To assess the natural variability before much human interference, the new study uses “multi-proxy climate reconstructions” developed by scientists in recent years to estimate historical temperatures, as well as fluctuation-analysis techniques from nonlinear geophysics. The climate reconstructions take into account a variety of gauges found in nature, such as tree rings, ice cores, and lake sediments. And the fluctuation-analysis techniques make it possible to understand the temperature variations over wide ranges of time scales.”

        And there’s the laugh. Thanks again, JimD!
        Shaun Lovejoy does it good for you.

      • Matthew R Marler

        Jim D: A good rule of thumb is: don’t trust anything less than 30 years when it comes to climate change factors, otherwise you are just looking at irrelevant noise.

        Well it is a “rule of thumb”, not anything firm. The alarmists started to ignore it regularly in the early 80s, pretty much destroying it. A more justifiable figure is the 17 year epoch shown by Santer, but change-finding algorithms can sometimes find changes with shorter or longer epochs between changes (but as usual, there isn’t sufficient evidence to rule out complicated background noise that affect the detection of the change points; an not enough to specify the shape of the signal in between change points [quadratic vs linear, for example]). In the 20th century the warming occurred in steps, within intervals shorter than 30 (e.g. 1978-1998) years, so there is a case to be made that there has been no change in climate since the beginning of the recovery from the Little Ice Age.

        If the hiatus continues for a while, we may be able to say that the climate changed in 1998 or thereabouts. Or, with proper mechanisms, it didn’t change really and the Earth is still warming as it always has since the end of the LIA, or changes may be identified ad hoc dependent on when certain records were started, the mechanisms not having existed before then.

        The “rule of thumb” did not gain prominence until the surface temperature record flattened out, and by then it had been ignored by AGW alarmists for 2 decades.

        A better rule of thumb is not to trust any claims of climate change, since the course of the climate absent changes of the sort posited now and then is not known. Every claim presupposes something about processes, without much evidence for the presupposition.

      • Choosing the published works of Lovejoy over someone calling themself thisisnogood on the webosphere with no supporting evidence, just intermixed nonsequiturs and denials, is an easy decision.

      • I don’t think many agreed with Santer’s 17 years either. It requires a much stronger CO2 signal to be statistically certain at 17 years, and perhaps that is what he had in mind, but 0.2 C per decade isn’t going to show up well in 17 years, being only a standard deviation or two larger than the noise, which may offset it in some decades. When it reaches 0.3 C per decade, 17 years may become sufficient, but not yet.

      • I don’t believe anyone knows exactly what percentage of the warming from 1976-1998 was anthropogenic as opposed to natural variability.

        It is important enough to micro-scrutinize a temperature record that is obviously too short–if sensitivity is high. If it is not, then we can hypothesize now, measure later. If it is high, then we work with the time series we have, not the one we wish we had.

        Whether or not previous warming is anthropogenic, whether or not sensitivity is high, we can’t put the issue to bed while emissions are increasing as dramatically as they are now and as hyper-dramatically as they are expected to going forward.

        So this isn’t a parlor game. Gotcha garbage from both sides notwithstanding, this is an issue that is serious and worthy of our A game.

      • > I don’t believe anyone knows exactly what percentage of the warming from 1976-1998 was anthropogenic as opposed to natural variability.

        But for another timespan, it’s 50-50.

        That ought to convey our inexact ignorance more properly.

      • Matthew R Marler

        Jim D: , but 0.2 C per decade isn’t going to show up well in 17 years, being only a standard deviation or two larger than the noise, which may offset it in some decades.

        That’s the way it is with power analyses: Santer et al showed that 17 years was the minimal length of time to achieve a specified power against a specified change. There is no guarantee that 17 years will be either necessary or sufficient to detect a change. Still, that is more analysis than has ever been adduced in support of the 30year rule of thumb, which has never been respected anayway.

        I am glad that you mentioned that the noise may be greater than its average value in some epochs. That is why claims that the noise will balance out in some specific time frame are vacuous. Autocorrelated noise is even less intuitive, as it will generally remain above or below its average value for longer periods of time than independent noise.

      • Steven Mosher

        ” In other words, you’ve just transposed the lukewarm gambit (usually applied to climate sensitivity) to the attribution problem. Am I right?”

        there is no transposition. They are variables in the same damn equation you, dolt.

      • Steven Mosher

        “A good rule of thumb is: don’t trust anything less than 30 years when it comes to climate change factors, otherwise you are just looking at irrelevant noise.”

        so when a volcano supresses temperatures for a couple years you are looking at noise?

        if the climate warmed by 3C next year, we would think nothing of it?
        or if it cooled by 10 C that would just be noise.

        noise is choice. that is, you see weird data and assume it is noise.
        others see weird data and try to explain it.

        The fundamental issue is that on its face you cant tell how to respond.

      • > there is no transposition. They are variables in the same damn equation you, dolt.

        The classical variation of the lukewarm gambit is a way to finesse toward the lowest climate sensitivity justified disingenuousness one can buy. Judy’s 99-1 argument is more general than that. It solves the overall attribution problem. It thus extends the usual variation.

        What is being transposed is the strategy: to finesse toward the lowest attribution statement justified disingenuousness can buy.

        In any case, Moshpit’s argument has no merit. A King’s Indian defence, can transpose in a Benoni. The game remains the same: Chess.

      • The best way to show that 60-year averaging removes noise and leaves a signal is this. This signal is remarkably like one expected from the way CO2 rises with an increasing gradient. It is hard to make a case for a natural process also having this effect on the temperature.
        http://www.woodfortrees.org/plot/hadcrut4gl/mean:720

      • Jim D:

        Choosing the published works of Lovejoy over someone calling themself thisisnogood…

        And Curry vs Jim D?

      • willard, you prove here that you know just as much about lukewarmers and their ideas as you do about most subjects upon which you pontificate.

        Mosher is a lukewarmer. I am a lukewarmer. What you say about the position and its advocates is not true. Stephen tells you this. I tell you this. You ignore us and continue to create word games to hide this.

        Why am I less than surprised?

      • Steven Mosher

        note that willard does not address the argument.

        Historically the development of the lukewarmer position BEGAN
        with attribution assignments. with luke warmers taking a middle position.

        Later On Lucia’s I cashed this SAME statment into a prediction.

        Your a lukewarmer if you think the future warming will be less than .2C

        Again i was challenged so I chased the SAME position out into a statement about sensitivity

        Now one is able to do this because sensitivity DEPENDS upon deltaT

        and deltaT has two components natural and anthro

        So its SIMPLE math to express the same idea in different metrics

        And what is that idea? what is that idea in a nutshell?

        The IPCC says X.. we think less than X, but we are not denialist nuts

        who think zero. pretty effin simple.

        Now HERE is the trick. I’ve explained this trick, this gimmick before.
        the gimmick in the lukewarmer position is that we dont foreground the fat tail. our estimate is smack dab on top of the consensus estimate.
        we just think fear monger with a bogus fat tail is well fear mongering.

        Consequently people like Shemp, err willard, argue that we are arguing for no action

        WRONG AGAIN. the argument is quite different. the argument is that policy can and probably should be divorced from the science. there are things we can do and should do, regardless of the science argument.
        and, further that ANY policy even c02 taxes are consistent with the lukewarmer position on the science.. which WHY i refuse Tom when he asks me to write a policy book. the luke warmer position can be cahsed out into any damn policy you like.

        So Shemp is wrong.

      • But we still should have written that book.

      • Steven Mosher

        ha ya.

        I would say that with some of Zeke’s recent and forthcoming work on NG,
        that some sort of policy framework could be laid out.

        still Im more of a general principles kind of person

      • I would say […] that some sort of policy framework could be laid out.

        Wish I had time to write a book. For that matter, if I already had one published like yours, I’d make the time. ‘Course, any book I wrote wouldn’t be the same as yours, but here’re some suggestions:

        •     Looking at the linear response, assuming the new best estimates of “Transient Climate Response”, it’s very hard to demonstrate significant harm from BAU before the end of this century. What are the chances that natural technological development won’t have solved the problem before it becomes a problem.

        •     When it comes to non-linear responses, the “fat tail” degenerates into a bunch of very low probability responses, some of them potentially very disastrous. (Thus supporting your statement that “the luke warmer position can be cahsed [sic] out into any damn policy you like.”)

        •     When you add in the potential for similar non-linear responses not associate with climate, such as catastrophic eco-system reorganization simply from the higher pCO2, that increases the impact (on policy) of that “bunch of very low probability responses, some of them potentially very disastrous.”

        •     Policy would then, presumably, depend on:

            •     How much you’re willing to impact the economy to protect from “very low probability responses, some of them potentially very disastrous”, and…:

            •     How you define “low-regrets”. I.E. if you regard world government with sweeping bureaucratic micro-management as a good thing, the sort of “solutions” we’ve been hearing since Kyoto will be “low-regrets”. Same for making energy 5-10 times as expensive, with “energy welfare” for low-income people managed by that bureaucracy. For those who regard such things as a very bad thing™ (which, AFAIK would include most libertarians), such policy responses are “very high-regrets”!

      • phatboy, you will notice that the stadium wave paper did not make a case for a 60-year trend, rather a 60-year repeat of a cycle. I have not yet seen any paper make a case for a 60-year trend due to anything other than CO2, or even a fraction of it, and from the figure I posted, you can see why no one tries to even make a case, because the 60-year trend looks so obviously like CO2 did it.

      • No Jim D, I’m talking about your double standards.
        You appeal to whichever authority suits you, and denigrate those which don’t.

  30. A thought occured to me that should add further uncertainty. Namely, two solar cycles of the same size could have entirely different effects on the earth. Since many of the coronal mass ejections miss the earth entirely and some glance across while others have near direct hits, there could be a situation of the sunspots widely effecting the earth while others that have very little effect. Is this incorrect?

    • –A thought occured to me that should add further uncertainty. Namely, two solar cycles of the same size could have entirely different effects on the earth. Since many of the coronal mass ejections miss the earth entirely and some glance across while others have near direct hits, there could be a situation of the sunspots widely effecting the earth while others that have very little effect. Is this incorrect?–

      It’s not known what the effects upon global temperatures that are related to Earth being hit by a CME. Generally speaking, a very small effect could be an accurate enough assessment. I don’t know. but as wild guess perhaps a CME could effect Earth ozone layer?? But in any case, CME are largely about a large magnetic “blast bubble” which deforms and shakes our magnetosphere. In analogy of a car crash totaling a car, CME can “momentarily” total our magnetosphere. Or they are capable of really smacking around and/or delivering knock out punch to our magnetosphere.

      CME do other things like sweep up the particles of solar wind- or they reduce the density of sun’s very large and tedious “atmosphere”. By which I mean the Sun atmosphere which extend beyond Pluto or all way out to the heliopause:
      “The heliopause is the theoretical boundary where the Sun’s solar wind is stopped by the interstellar medium; where the solar wind’s strength is no longer great enough to push back the stellar winds of the surrounding stars. The crossing of the heliopause should be signaled by a sharp drop in the temperature of charged particles….In the fall of 2013, NASA announced that Voyager 1 had crossed the heliopause as of August 25, 2012. This was at a distance of 121 AU (18 billion km) from the Sun”
      http://en.wikipedia.org/wiki/Heliopause_%28astronomy%29#Heliopause
      One go over to space weather site:
      http://www.spaceweather.com/
      And on upper left they give solar wind speed and it’s density. Currently
      Solar wind: speed: 276.4 km/sec
      density: 4.2 protons/cm^3
      And this varies daily.
      So I say range could be anywhere from 2 to 8 protons/cm^3
      and velocity 200 to 800 km/sec.
      We current at solar Max- the second peak of somewhat unusual double peaked Solar Max. Which is one weakest Solar Max we have had in quite a while and will probably continue for more than a year longer.

      As for general point of same two types cycle having different effects, this seem reasonable for numerous reasons.

      • Thanks for that answer. I have been looking at # of sunspots as an indication of sun strength not solar wind. So that helps. I thought we were most recently past the second peak of this solar cycle? I also have been looking for other websites since Hathaway recently got transferred from Marshall. I found Solarham and this one (space weather) looks good too. Thanks for the link. I see I need to study up a little more to get the general idea of solar. I copied and pasted all the info on solar from AR5 but I still haven’t referenced the papers.

      • Gb, I think you meant “tenuous” atmosphere, rather than “tedious’. Perhaps you were thinking of some repetitive posters when you made that error.

  31. Updated AMS polling results paper released today:

    Climate Change Nonsensus: Only 52% of meteorologists think global warming is mostly man-made

    http://hockeyschtick.blogspot.com/2014/08/climate-change-nonsensus-only-52-of.html

    They apparently didn’t define what “mostly” means in the polling questions, and find a significant political i.e. non-scientific bias on opinions among other interesting findings and biases.

    • Thanks Schtick, I had a post on this previously
      http://judithcurry.com/2013/11/10/the-52-consensus/

      • Oops –

        This was supposed to be in bold:

        This result is contrary to that found by Kahan et al. (2012b), in which members of the public with greater scientific literacy viewed climate change as a slightly less serious risk.

    • Interesting what HS didn’t mention:

      We found that perceived scientific consensus, political ideology, expertise, and perceived conflict are each, to greater or lesser degrees, associated with AMS members’ views of global warming. Before considering implications of those findings, however, readers should consider two methodological issues that could have affected the accuracy of our results.

      […]

      We found that perceived scientific consensus was the factor most strongly associated with AMS members’ views about global warming. This suggests that scientists’ thinking on scientific topics may be subject to the same kinds of social normative influences that affect the general public. Rather than rationally weighing the evidence and deciding for themselves, as would be expected under more traditional ideas of scientific judgment, scientists may also use the views of a relevant peer group as a social cue for forming their own views.

      […]

      Political ideology was the factor next most strongly associated with meteorologists’ views about global warming. This also goes against the idea of scientists’ opinions being entirely based on objective analysis of the evidence and concurs with previous studies that have shown scientists’ opinions on topics to vary along with their political orientation (Nisbet 2011; Rosenberg et al. 2010).

      We found expertise to be positively associated with meteorologists’ views about global warming,…

      While we found that higher expertise was associated with a greater likelihood of viewing global warming as real and harmful, this relationship was less strong than for political ideology and perceived consensus. <strongThis result is contrary to that found by Kahan et al. (2012b), in which members of the public with greater scientific literacy viewed climate change as a slightly less serious risk.

      That last part, in bold, is particularly interesting. Why?

      Because when Judith wrote a post about Kahan’s study,she skipped right over the main finding of the study (that views on climate change are associated with political ideology/world view), and wrote about the relatively insignificant finding from the study – that “skeptics” tended to score slightly higher on an assessment of “scientific literacy.” I’m ;left to wonder if, since Judith seems to think that any association between scientific literacy and views on climate change is interesting enough to comment on, she might discuss the contradiction between the AMS’s survey and Kahan’s study?

      She might be particularly interested in this aspect of the discussion on the AMS survey:

      The difference between the two studies is likely explained by the different measures of expertise. As opposed to comprehension of rudimentary scientific facts, knowledge acquired via graduate-level training and publishing in climate science does appear to increase the likelihood of viewing global warming as real, human caused, and harmful, if other factors are held constant.

      What do you say, Judith?

      • Joshua, you probably can guess by now that the standard answer to that is peer pressure, even if the poll is anonymous.

      • Jim D –

        First, even though the response rate to our survey was well within the normative range, nearly three-quarters of the AMS members invited to participate did not do so. This raises the possibility that our respondents may not accurately represent the views of the broader AMS membership. It is plausible, for example, that AMS members skeptical of global warming may have been less likely than the average member to respond, potentially by virtue of feeling marginalized within their professional society as a result of the views on the issue. Conversely, it is also plausible that skeptical members may have been more likely than the average member to respond, due to a desire to use the opportunity to have their views recognized by AMS leadership and other members.

      • Yes, self-selecting surveys have those caveats.

      • 25% response rate for a B2B survey is not uncommon or disqualifying. Depends of course on whether some were more likely than others to not bother with the survey.

      • I have knowledge obtained from graduate level training Josh, and it was sufficient to smell the BS of much of the alarmist community.

        But then I don’t disbelieve in AGW. Thanks to my training I simply think there is more we don’t know than what we do and have to thus wonder why certainty and consensus get pushed so hard.

        Ok Josh, you can go back to tossing crabapples at Dr Curry.

    • After reading through the poll and the supplementary material, I could not find the breakout for the percentage of people surveyed who thought the warming was going to be catastrophic. Interesting they did not find that of interest to reveal.

  32. Judith, you write “by global warming I refer explicitly to the historical record of global average surface temperatures. Other data sets such as ocean heat content, sea ice extent, whatever, are not sufficiently mature or long-range … Further, the surface temperature is most relevant to climate change impacts, since humans and land ecosystems live on the surface.”

    I would add to this that policymakers have adopted global average surface temperature as a policy target. Namely the 2° “guardrail”. They have not adopted policy targets based on other manifestations of anthropogenic climate change.

    They have not set policy targets based on threshold changes in ocean heat content, ice sheet mass balance, etc.

    • Will, thanks for this one.

    • The 2C target was, of course, purely for presentational and scarifying purposes, and had no substantive basis, as the originator of it admitted in an interview with Der Spiegel (I’ve got a copy somewhere). It is not a basis on which I would make policy.

    • This seems highly relevant to this discussion. As well as trying to be a statement of scientific fact the IPCC also needs to be a jumping off point for policymakers. It had occured to me that a statement saying most warming is anthro with a high degree of certainty is more user friendly for policy then one that narrows in on the higher end of anthro attribution but with the need to explain the sources of the greater uncertainties.

      In some senses it seems like judiths and the IPCC statements are the flip sides of the same coin. I like the idea though that Judiths approach might put the emphasis on solving the unknowns. Webhub aside, who seems to think he’s already solved the problem, I think most on this blog would like a better quantification of the role of climate dynamics on the SAT evolution over the last century or so.

  33. IPCC’s AR5 uncertainty framework is also muddled. The problem is the phrases “quantified measures of uncertainty” and “expert judgment” are used in the same sentence. You can have “quantified measures” or you can have “expert judgment”, not both, IMO.

    ” this WGI Technical Summary and the WGI Summary for Policymakers rely on two metrics for communicating the degree of certainty in key findings, which is based on author teams’ evaluations of underlying scientific understanding:”

    “Confidence in the validity of a finding, based on the type, amount, quality, and consistency of evidence (e.g., mechanistic understanding, theory, data, models, expert judgment) and the degree of agreement. Confidence is expressed qualitatively.”

    “Quantified measures of uncertainty in a finding expressed probabilistically (based on statistical analysis of observations or model results, or expert judgment).”

    They further note:

    “The confidence metric provides a qualitative synthesis of an author team’s judgment about the validity of a finding, as determined through evaluation of evidence and agreement. If uncertainties can be quantified probabilistically, an author team can characterize a finding using the calibrated likelihood language or a more precise presentation of probability. Unless otherwise indicated, high or very high confidence is associated with findings for which an author team has assigned a likelihood term.”

    • a.k.a ‘making things up’

      • I should also add I think “expert judgment” can be a useful vehicle for policy advice to governments. So I’m not completely against “expert judgement” or “expert elicitation” in and of themselves.

        The problem comes in presenting these as “quantitative.” This confusion leads to reports in the media like “Scientists 95% certain …”

      • > You can have “quantified measures” or you can have “expert judgment”, not both, IMO.

        As the Most Important Man in the World would say, “I do not always say I believe that P, but when I do, it’s because P stands on its own.”

        Such claim is so strong that one could use it in an argument to reject just about any use of modality in expressing an epistemic state. In fact, it would undermine any kind of measurement whatsoever, since being measured still implies being measured by someone.

        In other news, the kilogram has been losing weight:

        http://www.npr.org/templates/story/story.php?storyId=112003322

    • Curious George

      [You can have “quantified measures” or you can have “expert judgment”, not both.] Surely IPCC has both: if a panel of 30 “experts” votes 29 to 1, they get a 97% confidence level.

      What a tradition! Lying once started is difficult to stop.

      • [Will] You can have “quantified measures” or you can have “expert judgment”, not both, IMO.

        [Judy] I think the most likely split between natural and anthropogenic causes to recent global warming is about 50-50.

  34. “I won’t make a judgment here as to how ‘expert judgment’ and subjective ‘down weighting’ is different from ‘making things up’”

    I will, as a voter. There is no difference. ‘Expert judgment,’ ‘down weighting,’ ‘most/more than half.’and ‘calibrated assessment’ are not terms of science. They are political terms dressed up as science.

    Why don’t the solons of the IPCC prescribe some more specific limit to ‘more than half?’ Two reasons:

    1. They don’t have to. The term is intended for use in political propaganda. Precision is irrelevant.

    2. They can’t. They have no clue, and if they gave a more precise number, the question of how they reached it would be harder to fudge.

    I think adding ‘calibrated assessment’ to ‘expert judgment’ shows quite clearly how they are trying to dress their political conclusions up to look ‘sciency.’ What does one use to calibrate an ‘expert judgment?’ And what is the unit of measure? What increments of vanity are we talking about here?

    • increments of vanity . . . love it :)

    • increments of vanity . . . love it :)

      JC comments: There are some important insights in this piece. The most important insight IMO is that the study shows that skepticism at the individual level is more likely among scientifically literate and numerate individuals.

      • Joshua, do you think that all beliefs in science are politically motivated?
        Do you think beliefs in fetal neurodevelopment have a similar political footprint as climate change?
        Or funding for the space program?
        What about mitigation? Do you think those on the right are less likely to support building more nuclear power plants than the left?

    • Where’s the quantification of <50% ??

      Does it rely mostly on 'expert judgement' ?

  35. Hi Judy

    I agree with you that

    “Roger, the bottom line is that we have no decent observations of ocean or atmospheric circulation patterns prior to 1950.”

    In fact, I conclude that we have inadequate observations of ocean or atmospheric circulation patterns until after the development of global satellite converge (~1979). However, since the more recent time is when the CO2 levels were higher, if there is a signal, that is the time period to examine,

    Falling back on the surface temperatures as the metric for the most societal relevant climate metric, even if its period of record is longer, is not a reason to focus on it, if it does not serve the purpose of telling us if humans are significantly altering these circulation patterns, and thus the weather and ocean conditions that matter the most in terms of the impacts on water resources, food, energy, human health and ecosystem function.

    Roger Sr.

  36. P.S. I do agree with you also that the policymakers (and Gavin) have made the global average surface temperature anomaly the primary climate metric to show the human influence on the climate system. My point is that is a misguided and scientifically flawed approach.

    The 2C threshold itself is an absurd simplification of what actually dominates climatic effects. Even the meaning of 2C is poorly described [e.g. the temperature at what level near the surface (2m, etc)?; the mean or the maximum daily?, etc).

  37. Three new studies demonstrate climate sensitivity to CO2 is very low

    http://hockeyschtick.blogspot.com/2014/08/three-new-studies-demonstrate-climate.html

    As climate researcher Paul “Chip” Knappenberger pointed out in a tweet this week, two new studies provide a double-whammy to climate alarm because 1) man-made aerosols have been found to have minimal cooling effects and 2) at least 50% of recent global warming is not anthropogenic. Therefore, the possible role of CO2 in causing global warming has to be far less than previously assumed, and the “climate sensitivity” to doubled CO2 levels therefore very low…

  38. David in Cal

    The per cent of warming since 1950 due to man’s activity is (presumably) a single, unknown number. So, what does it mean to apply a probability estimate to a constant? First of all, this is a personal probability. It measures a individual’s degree of belief. It could be different for different people. This probability has no physical meaning.

    Savage’s classic “Foundations of Statistics” offers a definition. A personal (or Bayesian) probability represents the odds at which one would take either side of a bet. E.g., if a scientist thinks it’s 95% likely that man’s activity contributed over half of the warming since 1950, he’d be willing to bet his own money either way if the odds were set at 19 to 1.

    Now we reach the joke. Savage’s definition is based on the individual having a financial stake in being right. However, that’s not at all the case for climatologists. They have a financial stake in estimating a high degree of climate risk, regardless of what figure actually turns out to be right.

  39. If, over 60 years, natural variability averages out to zero, it doesn’t matter how strong natural variability is compared to man-made climate change, what’s left over is the man-made part. Thus the IPCC can and should consider it to be extremely likely that human influence dominates the net rise in temperature over the past 60 years.

    The warming and cooling regimes in the 20th century have been precisely identified. Cooling from 1944 – warming from 1976 to 1998.

    If we assume with John Nielsen-Gammon that ‘natural variability’ averages out to zero since 1944 – then the rate of increase is 0.07 degree C/decade. Or some 0.381 degrees C in total. As most of the CO2 increase in the atmosphere happened after 1944 – we are entitled to infer that the impact of anthropogenic greenhouse gases on surface temperature is not all that significant.

    A similar result can be obtained by excluding the noisy bifurcations (dragon-kings) at climate transition periods – 1976/1977 and 1998/2001. As Kyle Swanson did at realclimate.

    https://watertechbyrie.files.wordpress.com/2014/06/swanson-realclimate.png

    It begs the question of whether natural variability does average to zero between 1944 and 1998. If we extrapolate the idea of surface warming associated with El Nino and cooling with La Nina – the picture changes with El Nino dominance in the 20th century following centennial La Nina dominance.

    https://watertechbyrie.files.wordpress.com/2014/06/vance2012-antartica-law-dome-ice-core-salt-content.png

    It has intriguing echoes of the cosmogenic isotope record and suggests a top down UV/ozone mechanism for multi-decadal – and longer term – changes in the frequency and intensity of ENSO events. The source of these changes must be somewhere – and ‘sloshing’ is utterly unconvincing for these low frequency shifts.

    Indeed – with ENSO we can go much further back in the Holocene with high resolution proxies. Moy et al (2002) present the record of sedimentation shown above which is strongly influenced by ENSO variability. It is based on the presence of greater and less red sediment in a lake core. More sedimentation is associated with El Niño. It has continuous high resolution coverage over 12,000 years. It shows periods of high and low ENSO activity alternating with a period of about 2,000 years. There was a shift from La Niña dominance to El Niño dominance some 5,000 years ago that was identified by Tsonis (2009) as a chaotic bifurcation – and is associated with the drying of the Sahel. There is a period around 3,500 years ago of high ENSO activity associated with the demise of the Minoan civilisation (Tsonis et al, 2010). It shows ENSO variability considerably in excess of that seen in the modern period.

    http://watertechbyrie.files.wordpress.com/2014/06/moys-20022.png

    In this UV/ozone theory of ENSO – low solar UV activity results in a more negative Southern Annular Mode spinning up the South Pacific gyre and biasing the system to more frequent and intense La Nina. The same effect in the northern hemisphere drives more or less cold upwelling in the north east Pacific. The periodicities are no coincidence.

  40. Put me down for (b).

    Really people, you don’t want permanent glacial advance. You don’t even want a permanent 17th century. Brrr.

    Admittedly, warmer isn’t good for everyone – California’s drought of the Medieval Warming is kinda terrifing – but you’re bound to have these warm patches in your holocene. Just don’t take them for granted.

  41. David L. Hagen

    Less than 50%
    Some researchers are finding less than 50:50. e.g.:
    Nicola Scafetta, “Comment on “Tiny warming of residual anthropogenic CO2” International Journal of Modern Physics B Vol. 28, No. 20 (2014) 1475001 (2 pages)

    t in Refs. 4 and 5 . . .I argue that at least 50% of the warming observed since 1850 could be attributed to a set of decadal, multi-decadal (20 and 60 year), secular and millennial natural oscillations.

    4. N. Scafetta, J. Atmos. Sol.-Terr. Phys. 80, 124 (2012).
    5. N. Scafetta, Earth-Sci. Rev. 126, 321 (2013).
    (Though note that is from 1850.)
    Astronomical Climate model forecast vs. IPCC Scafetta’s model appears to show substantially better skill than the IPCC’s.

    The IPCC’s severe “Illusions in Regression Analysis”
    J. Scott Armstrong (2012)
    “the more complex the regression, the more skeptical I am” (Friedman and Schwartz 1991).

    “Fit implies accuracy” illusion: Analysts assume that models with a better fit provide more accurate forecasts. This ignores the research showing that fit bears little relationship to ex ante forecast accuracy, especially for time series.
    Typically, fit improves as complexity increases, while ex ante forecast accuracy decreases – a conclusion that Zellner (2001) traced back to Sir Harold Jeffreys in the 1930s. . . .
    Tom used standard procedures when starting with 31 observations and 30 potential variables.. . .The final regression had eight variables and an R-square (adjusted for degrees of freedom) of 0.85 Not bad, considering that the data were from Rand’s book of random numbers (Armstrong 1970). . . .
    Studies have continued to find the fit is not a good way to assess predictive ability (e.g., Pant and Starbuck 1990).

    Severe Type B Error
    Rather than being normally distributed about the actual temperature trends, >95% of the IPCC’s 34 year projections are severely biased too hot.

    Low sensitivity likely
    The very high complexity of IPCC Global Climate Models with Armstrong’s findings infer that the IPCC’s >95% confidence in >50% anthropogenic is “an illusion”. Combining with the severe Type B errors and Scafetta’s models etc. I consequently expect the sensitivity to be in the lowest tercile. i.e. < 33%.

  42. By the way, I skimmed the comments on that post, and I saw this:

    Another issue that was presented all around as soon as Salby started to present his claims is that his point was totally moot. He got rid of the trend by detrending the data. That’s how simple his error was.

    I don’t know if this is true or not. What I do know is it is strikingly similar to what we saw in a guest post on this site a few years ago. In that post, Richard Tol argued a paper downplaying human contributions to global warming was complete bunk because:

    As their method, LLE use detrended fluctuation analysis (DFA). DFA is a perfectly respectable method to estimate the correlation function, power spectrum and Hurst exponent in one go.

    So far so good. Unfortunately, fluctuation analysis does not work on trending variables. Therefore, LLE use DETRENDED fluctuation analysis. That is, they first fit a polynomial of order two to the data, remove this trend, and study the deviations from the trend.

    Having removed the trend from their data, LLE cannot answer the question: What caused the warming? They eliminated from their analysis the very thing in which they are interested.

    Which as I pointed out many times in the comments section of that (and at least one other) post, was complete nonsensical. Tol’s description of the methodology Ludecke et al used was completely wrong, and he repeatedly demonstrated he didn’t know what he was talking about. The use of DFA to calculate hurst coefficients was in no way inappropriate, and the fact it has the word “detrended” in it does not mean the authors “eliminated from their analysis the very thing in which they are interested.”

    I can’t say I know whether or not the same thing is true in regards for what Salby did. All I do know is it is impossible for me to take criticisms seriously when they are in this same form. If someone truly did something inappropriate, you need to show what part of their analysis is wrong. You can’t just wave your hands and say they “got rid of the trend” “in which they are interested.”

    Because as Richard Tol’s post shows, sometimes people will claim such fundamental flaws exist by just making things up.

    • Oops. This comment was supposed to be a follow-up to a comment I made in a discussion upthread.

    • Brandon, consider giving it a rest. Being Captain Ahab regarding Tol isn’t really a productive use of your intellect, which I consider high. Consider the example here of someone who is obsessed with Judith. Do you really want to go there?

      • Call him Ishmael.

      • Tom Fuller, you should try not to jump to conclusions. That I provided an example from Richard Tol’s guest post here has nothing to do with any other issues I have with him or what he’s done. I use the examples I know of when they are approriate. I know of no other example of behavior so similar to what was said about Salby’s work. If somebody other than Tol had written those incredibly stupid things criticizing Ludecke et al’s work in a guest post here, I’d have quoted them instead.

        The truth is I hadn’t even given a thought to my recent commentary regarding Richard Tol when writing the comment you’re responding to. I’m not remotely obsessed with him, and if I criticize him often, it’s only because people like you refuse to apply the same standards to him that you apply to others. If people would just agree about basic points that they themselves had repeatedly made, the subject would get resolved.

        Here’s something you should consider. I have repeatedly used Michael Mann, John Cook and others as examples in the same way I used Richard Tol above. I have repeatedly criticized them, writing far more about them than I have Tol. You’ve never suggested I’m obsessed with them. In fact, the only people who have ever claimed I am obsessed with Michael Mann or John Cook are their defenders.

        I write five times as much about John Cook as Richard Tol and ten times as much about Michael Mann. Exactly what am I supposed to be obsessed with?

      • Steven Mosher

        tom,

        some people listen to understand
        some people listen to reply

        it’s not hard to see who is who. sometimes there are two dwarfs
        sometimes there are three stooges. and sometimes 4 when willard shows up.. lets call him shemp

      • Brandon Shollenberger (9:37 pm):

        Tom Fuller, you should try not to jump to conclusions. That I provided an example from Richard Tol’s guest post here has nothing to do with any other issues I have with him or what he’s done.

        I trust Brandon on that. (Mention of Ahab always recalls Micaiah, delightfully sarcastic prophet. Brandon plays it straighter than that.) Like Steve McIntyre I’ve parked the earlier stuff about Tol but I trust the integrity. Lack of obsession is harder to detect. On a climate blog?!

      • Steven Mosher

        “Tom Fuller, you should try not to jump to conclusions. That I provided an example from Richard Tol’s guest post here has nothing to do with any other issues I have with him or what he’s done.”

        All we have to judge is your behavior. The simplest explanation is you chose an example about Tol, because it is related to issues you
        have with him.

        It’s easy to prove otherwise. Show the other examples you considered and explain why the Tol example was the best.

        You have an issue with Tol, that’s cool. denying it is funny, almost Joshua like.

      • Steven Mosher:

        It’s easy to prove otherwise. Show the other examples you considered and explain why the Tol example was the best.

        I can’t think of a single example that would have fit well at all. I’m sure there may be some out there somewhere, but I doubt many are in guest posts at this blog. Of any guest posts here with examples that might have fit, I’d wager I wasn’t involved with them.

        You have an issue with Tol, that’s cool. denying it is funny, almost Joshua like.

        For someone who has said he believes me to be a liar, multiple times, you seem to have little interest in what I actually say. I’ve never denied having an issue with Richard Tol. I never would. It’s obvious I do. Just like it’s obvious I have issues with John Cook, Michael Mann and many other people.

        Not only have I not denied having issues with these people, I’ve openly discussed having issues with them. The only thing I denied is that I used Richard Tol’s stupid remarks as an example of a particular sort of behavior because of any issues I have with him. I didn’t. I just used the best example I had.

        Here’s a simple explanation. When I want to provide examples of inappropriate behavior, the people who consistently exhibit such behavior will tend to provide most of the examples. I take issue with people who consistently behave in inappropriate ways. That means I will have issues with most people I use in examples.

  43. Jeff Melcher

    Dr Curry, may I pick (a) with a revision?

    a) Warming since 1950 is predominantly (more than 50%) caused by human — land use changes.

    Overgrazing, deforestation, soot, delpletion of fisheries, urbanization… I’m prepared to accept a lot of responsibility (>51%) for changes (good and bad) to the climate, but I’m a lot less willing to accept the one-knob hypothesis that CO2 dunnitall. In consequence I’m very UNWILLING and UNLIKELY (<33%) to support policy and tax structures that address CO2 while allowing other climate-affecting activities to continue.

    • that is far too sensible a post for an attribution debate.

    • +100!

    • +2

    • Though, deforestation may reduce gat, and increase land temp.

    • Steven Mosher

      “I’m prepared to accept a lot of responsibility (>51%) for changes (good and bad) to the climate, but I’m a lot less willing to accept the one-knob hypothesis that CO2 dunnitall.”

      there is no one knob hypothesis for modern changes.

      • Mosher also said later (6:27 pm):

        In the modern era if you want to see all the knobs read the IPCC.

        The only people who believe in a one knob theory are people who believe their opponents believe in a one knob theory.

        Fair point (that I’m also using to test a GreaseMonkey script). But the ‘attribution’ argument often seems to suggest that increased atmospheric CO2 is the only influence worth studying. Seems to. Like so much else in the climate debate the way it’s framed to policy makers and in public discourse matters greatly too.

    • This is far too sensible to be included in the discussion.

      Land use decisions tend to be local. Far harder to impose top down division making on something like that.

  44. Alexander Biggs

    ” Not being able to address the attribution of change in the early 20th century to my mind precludes any highly confident attribution of change in the late 20th century.”

    Yes, indeed. The latter change is just a lagged version of the earlier change. Anyone with a knowledge of system dynamics can easily spot that. Of corse the IPCC were in denial of the earlier change. so would not spot it, would they? The HadCrut 4 results above make all this clear.

    Where I part company with Judith is in the attribution of changes to the AMO and PDO. The main unpredictable force in the southern hemisphere is ENSO. but ENSO is not cyclical because it has no definite period, but Enso has to be top of the list of natural forces, Californian farmers would not deny the NH effects of ENSO. So a good model needs a dose of ENSO, though we don’t know how to simulate it, yet.

    • Matthew R Marler

      Alexander Biggs: but ENSO is not cyclical because it has no definite period, but Enso has to be top of the list of natural forces,

      Why some writers insist that a process can not be cyclical if it does not have a fixed period I have never understood. For an obvious counter example, consider an automobile engine, which clearly has a cycle, but almost never a fixed period; even with cruise control the engine speed is not constant so there is no fixed period. Nothing in nature has a period that is fixed to an exact amount, but cycles are everywhere; as in the life cycle of butterflies.

      • Alexander Biggs

        Mathew: A car engine is a man-made object designed to operate over a range of rpm, nature could never provide anything like an internal combustion engine. On the other hand nature can provide repetitive evends with a strict cycle, like day and night. Anything with mass and elasticity in a gravitational field can vibrate or oscillate

      • Matthew R Marler

        Alexander Biggs: Mathew: A car engine is a man-made object designed to operate over a range of rpm, nature could never provide anything like an internal combustion engine. On the other hand nature can provide repetitive evends with a strict cycle, like day and night. Anything with mass and elasticity in a gravitational field can vibrate or oscillate

        That does not justify a claim that any natural cycle has to have a fixed period, or the consequent that anything natural without a fixed period can’t be cyclic.

  45. This topic brings up a couple things which always bugged me. For instance, the Skeptical Science “consensus” paper said one of its “consensus” categories was:

    1 Explicitly endorses and quantifies AGW as 50+%

    However, it examined papers back to 1991. Suppose a paper in 1991 said humans are responsible for 50+% of the observed warming. Suppose another paper in 2014 said humans are responsible for 50+% of the observed warming. How can we hope to compare these claims when practically all the variables used for them are different? The amount of warming, amounts of various forcings and time elapsed are all different. You can’t sensibly compare things like that. Fortunately, the IPCC AR5 has improved and does give a specific period (1951 to 2010).

    Another issue I have is how can anyone say humans are responsible for 100+% of the observed warming? That doesn’t make sense. You can’t cause more of something than actually happens. If there is only one degree of warming, humans did not cause two degrees of warming. That’s simply nonsensical.

    That is easily seen if we consider a different situation. Suppose you have a bathtub with water in it. You unplug the drain so water starts draining out, but at the same time, you turn on the faucet. After 30 seconds, the water level drops by a foot. You calculate how much water the faucet adds, and you find six inches of water were added. Can you then say:

    The faucet caused -200% the observed drop in water level!

    No! That’s just silly. The faucet didn’t cause any drop in the water level.

    If we accepted that sort of terminology, we’d get all sorts of silly things. For instance, if the drain was partially clogged and the water level only dropped six inches, that -200% decrease in water level would suddenly become a -100% decrease.

    And what if the drain was really clogged? Suppose water drained out of the tub at the same rate the faucet added water. Since the total change in water level is 0, we’d say the faucet caused a 6 inch/0 inch change in water level. That’d mean the faucet was responsible for an infinite amount of the observed change in water level!

    Using percentages to measure attribution is silly. We could wind up saying humans are responsible for 400% of the warming for one decade, 10% of the warming of the next decade and -200% of the one after that.

    • Matthew R Marler

      Brandon Schollenberger: Another issue I have is how can anyone say humans are responsible for 100+% of the observed warming? That doesn’t make sense. You can’t cause more of something than actually happens. If there is only one degree of warming, humans did not cause two degrees of warming. That’s simply nonsensical.

      I agree.

      What was intended, I guess, is that CO2 increase by itself would have produced more warming than was observed, but that atmospheric aerosols reduced the warming below what would have been due to CO2 alone.

      • I’m not sure about that. I’ve seen lots of people make comments attributing 100+% of the observed warming to humans, and they’ve pretty much all done so while claiming the “pause” is artificial – that the true amount of warming is being concealed by various factors (such as natural cycles or surface temperatures being a poor proxy for global warming).

  46. TSI stayed high until towards the end of the century – funny that.

    https://watertechbyrie.files.wordpress.com/2014/06/tsi-reconstruction.png

    • Yes, but this is like ice core and other proxies. They likely show some relative changes, but there are probable processess that filter data and resolution that declines over time and is wished away by spurious stats.

      5

  47. Some Numbers for Reviewers of Salby’s Work

    From Wiki Carbon pools in the major reservoirs on earth (gigatons):

    Atmosphere 720

    Oceans (total) 38,400

      Total inorganic 37,400

      Total organic 1,000

      Surface layer 670

      Deep layer 36,730

    Lithosphere

      Sedimentary carbonates > 60,000,000

      Kerogens 15,000,000

    Terrestrial biosphere (total) 2,000

      Living biomass 600 – 1,000

      Dead biomass 1,200

    Aquatic (non-marine) biosphere 1 – 2

    Fossil fuels (total) 4,130

      Coal 3,510

      Oil 230

      Gas 140

      Other (peat) 250

    For comparison, Warmist organization CO2now.org says annual anthropogenic CO2 emissions are a little under 10 gigatons/year.

  48. Judith –

    I just read this comment from Brandon:

    All I do know is it is impossible for me to take criticisms seriously when they are in this same form. If someone truly did something inappropriate, you need to show what part of their analysis is wrong.

    and I found it quite interesting, because it immediately led me to thinking about your comment from above:

    ==> “I read ATTP on salby, his response is pretty thin gruel.”

    Now I assume that you want Brandon, and folks like him, to take your criticisms seriously – but Brandon knows that’s impossible because if Anders truly did something in appropriate (in his discussion of Salby), you need to show what part of his analysis is wrong.

    So Judith – perhaps you could describe what aspect(s) of Anders’ analysis of Salby’s arguments was wrong? I’m sure that quite a few folks would like to see you weigh in with some discussion of substance w/r/t Sably’s theories. It would be great if you could lend your expertise to the discussion.

    As far as I know, you’ve never actually said whether you think Salby’s theory has merit or not. Which is it? Do you think his theory has merit? If not, which aspect(s) are you in disagreement with?

    • I stated a few comments back that I am planning a future thread on salby

      • I look forward to it.

      • Leaving aside the fact you had already said you plan to make a post about this topic, Joshua’s comment is stupid. What you did (calling a response “thin gruel”) is a far cry from what I discussed (saying a person did something inappropriate in their analysis).

        Joshua’s comment was just another case of him drawing a false equivalence to act as though there was a contradiction where there was none. You shouldn’t encourage that sort of behavior by responding to it as though he made a fair comment. That’s what makes trolling so common here.

      • Brandon –

        Brandon Shollenberger
        July 13, 2014 at 5:34 pm
        “… but I am going to stop responding.”

        I apologize for once again, forcing you to waste your time. I realize that you have no decision-making power over whether you read my comments and/or respond – and I take advantage of that to make you do things against your will.

        Such are the ways of the evil troll.

      • > What you did (calling a response “thin gruel”) is a far cry from what I discussed (saying a person did something inappropriate in their analysis).

        Citation needed for the “what I discussed”.

        In any case, if Joshua’s point is to remind Brandon of his moderation policy:

        Also, as a moderation policy, I do not allow claims to be challenged yet remain unsubstantiated.

        http://hiizuru.wordpress.com/2014/02/05/sock-puppetry/#comment-171

        all Joshua needs for this policy to be triggered both by Judy’s “gruel” claim and Brandon’s claim, whatever this claim might be, is to challenge both.

      • You and your readers might be interested in my 900-word critique of Salby’s 4/18/13 talk at Helmut Schmidt University, available online. The critique first appeared as a comment on Pierre Gosselin’s blog NoTricksZone on 4/7/2013, reprinted there as a post on 6/9/2013.

        http://notrickszone.com/2013/06/19/reader-jeff-glassman-comments-on-murry-salby-and-co2-climate-forcing/

      • got it, thx

      • Jeff Glassman

        Very interesting response. I would be intrigued to hear JimD’s reaction to it (and Webby’s) Hopefully Judith will also see it.

        I am doubtful about the ice core records for co2 values. They seem to have been at similar levels to today in the recent past but it is difficult to explore this aspect without people invoking Ernst Beck.
        tonyb

      • Climatereason, 8/25/14 @ 2:59 pm: I am doubtful about the ice core records for co2 values. They seem to have been at similar levels to today in the recent past but it is difficult to explore this aspect without people invoking Ernst Beck. tonyb

        First and notwithstanding any other considerations, we can rely on the ice core data to debunk IPCC until IPCC retracts the data.

        Second, the ice core data are certainly suspect when the ice age is shorter than the closure time. For Vostok, that means data are suspect if less than about 1000 years old, but the samples are about 1500 years apart. Other cites are not so lucky.

        Third, the Vostok CO2 and air temperature records tend to confirm one another, under the assumption that the Antarctic air temperature follows the sea surface temperature. The confirmation comes from Henry’s Law and the shape of Henry’s Coefficient for CO2 in water.

        Fourth, an apparent problem with ice core CO2 not matching MLO data has two origins. One is that the Keeling Curve is a manufactured curve with a reconstituted mean and variability, coupled with the fact that MLO is in the plume of major CO2 outgassing from the Eastern Equatorial Pacific, and the plume likely wanders across the island with the prevailing wind. MLO CO2 is a regional effect that IPCC erases by calibrating all stations to that “master time series”.

        The second aspect is that the MLO samples data in one minute or less, while Vostok CO2 is open for over half a millennium or so. In other words, Vostok CO2 is heavily filtered compared to MLO, both being low pass filters, and the data would be rejected if the means of the two records matched. Did Ernst Beck take low pass filtering into consideration?

      • Climatereason, 8/25/14 @ 2:59 pm: PS:

        A fifth reason for liking the ice core CO2 record is that it has tons of character to its shape. It does what objective theory says it should.

      • As opposed to the much higher resolution stomatal record that has higher peaks and greater variability.

        ttp://watertechbyrie.files.wordpress.com/2014/06/steinthorsdottir_co2_stomata_2013_zps0180f088.png

      • “an apparent problem with ice core CO2 not matching MLO data has two origins. One is that the Keeling Curve is a manufactured curve with a reconstituted mean and variability, coupled with the fact that MLO is in the plume of major CO2 outgassing from the Eastern Equatorial Pacific, and the plume likely wanders across the island with the prevailing wind. MLO CO2 is a regional effect that IPCC erases by calibrating all stations to that “master time series”.”

        Sorry, these statements are simply not correct.

        The highest-resolution ice-core CO2 record, Law Dome, the CO2 record (MacFarling-Meure et al., 2006) provides independent validation of the Mauna Loa record where the two overlap in time.

        The same decadal trends in CO2 are measured in the atmosphere all over the globe – Alaska, the South Pole, Tasmania, and many places in between, so local or regional sources (upwelling, volcanic) of CO2 cannot explain them.
        go to

        http://cdiac.ornl.gov/trends/co2/

        and look at the data yourself.

        See also
        Keeling, C. D., 1993, Global observations of atmospheric CO2, in Heimann, M., ed., The Global Carbon Cycle, New York, Springer-Verlag, p. 1-31.

        Keeling, C. D., and Whorf, T. P., 2005, Atmospheric CO2 records from sites in the SIO air sampling network, Trends: A Compendium of Data on Global Change, Oak Ridge, TN, Carbon Dioxide Information Analysis Center, Oak Ridge National Laboratory.

        MacFarling Meure, C., Etheridge, D., Trudinger, C., Steele, P., Langenfelds, R., van Ommen, T., Smith, A., and Elkins, J., 2006, Law Dome CO2, CH4 and N2O ice core records extended to 2000 years BP: Geophysical Research Letters, v. 33, p. L14810.

      • In fact Josh is so looking forward to it he’s been out all day with his little red wagon collecting a fresh supply of crabapples.

      • “an apparent problem with ice core CO2 not matching MLO data has two origins. One is that the Keeling Curve is a manufactured curve with a reconstituted mean and variability, coupled with the fact that MLO is in the plume of major CO2 outgassing from the Eastern Equatorial Pacific, and the plume likely wanders across the island with the prevailing wind. MLO CO2 is a regional effect that IPCC erases by calibrating all stations to that “master time series”.”

        Sorry, these statements are simply not correct.

        The highest-resolution ice-core CO2 record, Law Dome, the CO2 record (MacFarling-Meure et al., 2006) provides independent validation of the observational record where the two overlap in time.

        The same decadal trends in CO2 are measured in the atmosphere all over the globe – Alaska, the South Pole, Tasmania, and many places in between, so local or regional sources (upwelling, volcanic) of CO2 cannot explain them.

        I recommend looking at the data yourselves:
        http://cdiac.ornl.gov/trends/co2/

        See also
        Keeling, C. D., 1993, Global observations of atmospheric CO2, in Heimann, M., ed., The Global Carbon Cycle, New York, Springer-Verlag, p. 1-31.

        Keeling, C. D., and Whorf, T. P., 2005, Atmospheric CO2 records from sites in the SIO air sampling network, Trends: A Compendium of Data on Global Change, Oak Ridge, TN, Carbon Dioxide Information Analysis Center, Oak Ridge National Laboratory.

        MacFarling Meure, C., Etheridge, D., Trudinger, C., Steele, P., Langenfelds, R., van Ommen, T., Smith, A., and Elkins, J., 2006, Law Dome CO2, CH4 and N2O ice core records extended to 2000 years BP: Geophysical Research Letters, v. 33, p. L14810.

      • I have just looked again at Salby’s 2013 Hamburg video (1 hour), and there are places where he just jumps to conclusions that don’t stand close scrutiny.
        1. That paleo data smooths the CO2 record, therefore there MUST have been large unseen swings – no it doesn’t prove that.
        2. That because the derivative of CO2 in the modern record correlates with temperature, you can derive the CO2 from the temperature – well, yes, but the constant of integration is important and includes the anthropogenic part that he never shows on the same scale as his natural inferred source.
        This correlation has been brought up before and is just as easily explained as the natural sink being less effective in warmer years. The dominant source is anthropogenic and that is smooth which is why the background CO2 rise is so uniform, but that’s in Salby’s constant of integration that he kind of hides.
        He is a smooth operator in his presentation style with long pauses for effect, but there are also hidden things between the lines.

      • In significant part, however, CO2 is controlled by Global Temperature, as it is in the Proxy Record.” Murray Salby

        Tendentious narrative notwithstanding.

        ‘Ecosystem warming experiments, modelling analyses, and fundamental biokinetics all suggest that’ the statement above is indubitably correct.

      • “A fifth reason for liking the ice core CO2 record is that it has tons of character to its shape. It does what objective theory says it should.

        Rob Ellison | August 25, 2014 at 6:54 pm |
        As opposed to the much higher resolution stomatal record that has higher peaks and greater variability.

        ttp://watertechbyrie.files.wordpress.com/2014/06/steinthorsdottir_co2_stomata_2013_zps0180f088.png”

        A bit higher resolution. I think the figure you have linked to is from

        Steinthorsdottir, M., B. Wohlfarth, M. E. Kylander, M. Blaauw, and P. J. Reimer (2013), Stomatal proxy record of CO2 concentrations from the last termination suggests an important role for CO2 at climate change transitions, Quat. Sci. Rev., 68(0), 43-58, doi:10.1016/j.quascirev.2013.02.003.

        My back-of-envelope average delta-t for the stomatal proxy CO2 is ~ 56 years over the span they cover with 14C: 13790 – 11871 calendar yrs BP

        For EPICA Dome C the average Delta-t is about 75 years for approx. the same time span. The Dome C ice core CO2 is more direct than stomatal proxy CO2 so to be preferred as an estimate of paleo-CO2.

        see

        Parrenin, F., V. Masson-Delmotte, P. Köhler, D. Raynaud, D. Paillard, J. Schwander, C. Barbante, A. Landais, A. Wegner, and J. Jouzel (2013), Synchronous Change of Atmospheric CO2 and Antarctic Temperature During the Last Deglacial Warming, Science, 339(6123), 1060-1063, doi:10.1126/science.1226368.

        (the data is in the Supplemental Materials ; I don’t think behind a paywall. But let me know and I’ll get you the data for both papers)

        Funny thing is that Steinthorsdottir et al. are actually making a case for a stronger role in climate for CO2:

        “The prevalent explanation for the main climate forcer during the Last Termination being ocean circulation patterns needs to re-examined, and a larger role for atmospheric [CO2] considered.”

        The newer WAIS ice core record will provide a higher-resolution CO2 record than EPICA Dome C and the Steinthorsdottir stomatal proxy:

        High Resolution CO2 Reconstructions from the WAIS Divide Ice Core

        Marcott, S. A.; Bauska, T. K.; Sowers, T. A.; Edwards, J. S.; Buizert, C.; Kalk, M.; Brook, E.
        American Geophysical Union, Fall Meeting 2013, abstract #PP21E-02

        “A clear connection exists between atmospheric greenhouse gases, climate, and ice sheet volume during glacial-interglacial cycles. Establishing the role of carbon dioxide (CO2), both as a feedback and forcing, during the most recent glacial and deglacial periods provides an excellent opportunity for understanding how this connection operates. To do this, a precise, high-resolution, well-dated record of atmospheric CO2 is a prerequisite. We will present a carbon dioxide record from 40-35 and 28-9 ka from the last glacial and deglacial periods from a new ice core from West Antarctica with an average sampling resolution of 25-50 yrs. Our record shows that CO2 variations during the glacial period have a clear relationship with abrupt climate changes in the Northern Hemisphere that continues into the deglacial period. In addition, instead of being gradual (several millennia), nearly half of the ~85ppm rise in CO2 during the deglaciation occurred in three abrupt 10-15ppm steps that took place in less than 100-200 yrs and were followed by concentration plateaus. Each transition was synchronous with abrupt changes in methane (CH4), suggesting a rapid reorganization of the carbon cycle. These rapid changes in atmospheric CO2 and CH4 concentrations are also recorded during the Heinrich Stadials of MIS 3, demonstrating an important mechanism that operates on centennial time scales during the glacial and deglaciation, which may point to important thresholds in the global carbon cycle. We will present our most recent results and newest interpretation.”

        Cheers.

      • “an apparent problem with ice core CO2 not matching MLO data has two origins. One is that the Keeling Curve is a manufactured curve with a reconstituted mean and variability, coupled with the fact that MLO is in the plume of major CO2 outgassing from the Eastern Equatorial Pacific, and the plume likely wanders across the island with the prevailing wind. MLO CO2 is a regional effect that IPCC erases by calibrating all stations to that “master time series.”

        The ice-core CO2 record at Law Dome (MacFarling-Meure et al., 2006) provides independent validation of the observational record where the two overlap in time (see also Ahn, et al., 2012).

        The same decadal trends in CO2 are measured in the atmosphere all over the globe – Alaska, the South Pole, Tasmania, and many places in between, so local or regional sources (upwelling, volcanic) of CO2 cannot explain them.

        I recommend looking at the data:

        http://cdiac.ornl.gov/trends/co2/

        See:

        Ahn, J., E. J. Brook, L. Mitchell, J. Rosen, J. R. McConnell, K. Taylor, D. Etheridge, and M. Rubino (2012), Atmospheric CO2 over the last 1000 years: A high-resolution record from the West Antarctic Ice Sheet (WAIS) Divide ice core, Global Biogeochem. Cycles, 26(2), GB2027, doi:10.1029/2011GB004247.

        Keeling, C. D., 1993, Global observations of atmospheric CO2, in Heimann, M., ed., The Global Carbon Cycle, New York, Springer-Verlag, p. 1-31.

        Keeling, C. D., and Whorf, T. P., 2005, Atmospheric CO2 records from sites in the SIO air sampling network, Trends: A Compendium of Data on Global Change, Oak Ridge, TN, Carbon Dioxide Information Analysis Center, Oak Ridge National Laboratory.

        MacFarling Meure, C., Etheridge, D., Trudinger, C., Steele, P., Langenfelds, R., van Ommen, T., Smith, A., and Elkins, J., 2006, Law Dome CO2, CH4 and N2O ice core records extended to 2000 years BP: Geophysical Research Letters, v. 33, p. L14810.

      • Wrhoward, 8/25/14 @ 7:47 pm, corrected 8/26/14 @ 12:45 am, makes a sweeping accusation that the statements in my fourth reason for having confidence in ice core data “are simply not correct”. He provides no evidence for my observation that the Keeling Curve is a manufactured curve as I described. Nor that MLO is not in the plume of the EEP degassing. Nor that that the plume wanders over Hawaii.

        He claims,

        The highest-resolution ice-core CO2 record, Law Dome, the CO2 record (MacFarling-Meure et al., 2006) provides independent validation of the observational record where the two overlap in time.

        These do not address the issue of the distrust in ice core data resulting from the mismatch between the Vostok records and the Keeling Curve. A search of MacFarling Meure et al. produced no hits on Keeling, Mauna, MLO, or “the CO2 record”.

        Wrhoward claims,

        The same decadal trends in CO2 are measured in the atmosphere all over the globe – Alaska, the South Pole, Tasmania, and many places in between, so local or regional sources (upwelling, volcanic) of CO2 cannot explain them.

        Because records have the same decadal trends is good evidence that they do not match in the mean, which is the problem at hand.

        Secondly, IPCC applies “calibration procedures within and between monitoring networks”. (TAR, p. 211). That’s not in general objectionable for scientific purposes, but records calibrated into agreement cannot be used to support any claim that what is being recorded is a uniform global phenomenon. The information needed is in the calibration data, which are not published.

        Furthermore, until proved otherwise, investigators may be assumed to have used similar calibration techniques to bring ice core records from various locations into agreement.

        Wrhoward says,

        I recommend looking at the data yourselves:

        http://cdiac.ornl.gov/trends/co2/

        First, you need to quote from your references so the reader doesn’t have to search for what you think you may have found, and then determine whether your interpretation was correct. Second, you need to site to the page or paragraph. Your cdiac link is an index. It’s not even on the subject.

        You say, See also [¶] Keeling, C.D 1993… [¶]Keeling, C.D. and Whorf, T.P., 2005 …, [¶] MacFarling Meure, C [et al.] 2006 … .”

        I saw the references, and have them in hand. Now what fascinated you about them? Provide quotations to support your argument.

        I stand by my comments.

      • David L. Hagen

        Jeff Glassman & wrhoward
        See links above to Fred H. Haynie, for his blog and earlier <a href=presentation.
        He provides detailed analysis of CO2 trends, especially interesting the variations from south to north pole.
        Like Salby, he finds CO2 dominated by natural sources.

      • David L. Hagen, 8/26/14 @ 2:56 pm said, Haynie … [l]ike Salby, he finds CO2 dominated by natural sources.

        Can’t tell if you think of that as positive or negative. However, Salby got the right, or at least a better, answer, but for the wrong reasons. His right answer, he claims, didn’t help his career. His wrong reasons doesn’t help science debunk the AGW movement.

    • I am still not completely clear exactly what the details of Salby’s theory (theories?) are. Is there any actual document, published or not, in which Salby makes his case scientifically in one place?

      I might be in a better position judge the merits or not of his ideas if I had that.

      Anyone?

      • Not a complete document, AFAIK. There are several presentations on YouTube, but the ones I’ve seen involve a number of separate points not clearly distinguished. And references are hard to check. etc.

        Best if his theories are published, IMO. If the various fanatics who are sabotaging him can be made to stop. Of course, the very fact of that sabotage carries a message.

      • David L. Hagen

        wrhoward
        You will find preliminary info in Salby’s 2012 edition of Physics of the Atmosphere and Climate
        17 Influence of the ocean 533
        17.3 Role in the carbon cycle 544

        For his recent work, Salby is trying to get past the climate gatekeepers.
        Best I have found are his presentations with some posted slides. and his presentations Murry Salby CO2 e.g. his 18 April 2013 Hamburg presentation

        For an evaluation of Salby equations, see
        A comparison of Gösta Pettersson’s carbon cycle model with observations, By Pehr Björnbom
        Page 10 addresses Salby’s equations.

        According to this, Murry Salby’s equation may be seen as an incomplete variant of equation (13) neglecting the two first terms. It is not unlikely that the two first terms in equation (13) temporarily describe a curve of a similar form as the third term. That would explain why Murry Salby’s equation gives a good fit to observational data. However, the complete equations (9) and (13), unlike Murry Salby’s equation (11), show that anthropogenic emissions have an impact on the carbon dioxide mixing ratio. Although the results of Salby and Titova (2013) may not give an accurate picture of the the impact of anthropogenic emissions they support the results from the Pettersson model.

        (His posts on Murry Salby)

      • I have had a look at a couple of his presentations. Based on that the only conclusion that I can draw is that he has nothing publishable in a properly peer reviewed journal. If he has, nobody can prevent him from publishing it somewhere. That way he has the perfect possibility of proving all us wrong, who presently believe that there’s nothing.

        As long as he has not brought to public anything of substance we can only continue to believe that he has nothing to present, except empty words.

      • I have not paid much attention to Salby’s presentations at all. However – there are many other sources and ‘ecosystem warming experiments, modelling analyses and fundamental biokinetics’ all suggest that natural CO2 flux should change significantly with climate. Some 5Pg C/year increase in recent times from a couple of references I give below.

        From this we would presume that Pekka’s understanding in this area is superficial at best.

  49. 50-50 in this context would be that alarmists now are willing to say–e.g., …it’s even money we’re wrong to believe all global warming since 1950 is mostly caused by human activity. That’s a bit like J-P Sartre saying, …Lenin was an antidemocratic despot but it’s even money communism under Stalin will mostly be good for the people of the USSR and the EU would be wise to follow a similar course.

  50. John Smith (it's my real name)

    Dr. Curry,
    Enjoyed this article. Thanks again from “Joe Public.”
    Particularly your clarifying (for me) that surface temp averages count.
    My CAGW friends yell at me and say “surface temps don’t really mean anything.”
    May I tell them that you, not the Koch brothers, are warping my feeble mind?

  51. I thought you had a (guest) post on this before. It’s the wrong question, isn’t it? If the beginning point of attribution starts at the highest temperature point in the natural cycle, then the amount of warming due to anthro will always be 100% or greater. If it starts at the lowest point, then anthro will be greater than 0 but less than 100. Let’s say (for arguments sake) that 1945 was the highest naturally achievable earth temperature without anthro form now until eternity. 100% of warming since 1945 is man made, at least (if nature is now cooling, it could be 125%).

    On the other hand, take 1910 as a low point, and the start of the attribution period. Let’s also assume 100% of warming since 1945 is man made. Now, anthro contributes maybe 40% of warming since 1910.

    Great, with the same question you get an answer of (say) 40% to 125% based on your starting point. Or, go back to the ice age (I think temps were 2 degrees colder still), and you have 18% of warming due to Anthro.

    A better question is how many degrees “C”, though even that isn’t the right question.

    The right question is what is the cost of what this anthro warming is going to do beyond what the costs would otherwise be. Hard, yes, and how many degrees “C” seems like a reasonable substitute, something folks can grasp.

    Anyway, apologies for being a stick in the mud on this, but it seems to me the question is not the right one. The attribution question is an advocacy question, and it ought to be exposed as one.

  52. http://watertechbyrie.files.wordpress.com/2014/06/carbonflowchart-ucla_zps640921ed.png

    This is vastly different to the IPCC cartoon linked to at ATTP. The carbon cycle is biologically mediated – temp changes lead to changes in uptake and respiration of CO2. Higher temps result in more CO2 in the atmosphere from both breakdown of soil carbon stores and from vegetation digestion. In volumes that rival anthropogenic emissions.

    e.g. http://environmentportal.in/files/Temperature%20associated%20increases%20in%20the%20global%20soil.pdfhttp://www.csiro.au/Portals/Media/Tropical-ecosystems-regulate-variations-in-Earths-carbon-dioxide-levels.aspx

    It makes for substantial changes in atmospheric concentration that don’t seem captured by the ice cores record.

    https://watertechbyrie.files.wordpress.com/2014/06/steinthorsdottir_co2_stomata_2013_zps0180f088.png

    Assuming that natural fluxes equal out is a zombie meme.

    • Fossil limestone is actually degraded in nature. If you have ever been in limestone country, you can see that roots have made their way through the rock. I believe this has been accomplished by organic acids. However it happens, the limestone is gone and the roots are in it. Therefore, it’s now CO2.

    • i.e. SALBY SEEMS 100% RIGHT AND THE MANY VOICES CLAMOURING UTTERLY MISGUIDED


      • Rob Ellison | August 24, 2014 at 11:51 pm
        i.e. SALBY SEEMS 100% RIGHT AND THE MANY VOICES CLAMOURING UTTERLY MISGUIDED

        This statement by the Aussie is exhibit A to show that he is not able to think logically.

        If one agrees with Salby’s conjecture that the excess CO2 is naturally occurring, then you can make no claims about aCO2 as a GHG apart from dismissing the theory completely.

        This places the Aussie in the most isolated minority that can’t even accept a TCR of 1.3C.

      • If one agrees with Salby’s conjecture that the excess CO2 is naturally occurring, then you can make no claims about aCO2 as a GHG apart from dismissing the theory completely.

        Actually, that’s not true. If the pCO2 has been bouncing around sometimes reaching values higher than today, there could well be some tendency for higher pCO2 to correlate with higher temps. In a very complex way. Whether or not there actually is such a correlation would depend on details of pCO2 and temperature, both of which are pretty much unknown. If you accept Salby’s hypothesis.

      • The annual CO2 rise is correlated 0.9988 with emissions, and these have both almost tripled since the Keeling curve started. Call it coincidence if you want.

      • ‘In significant part, however, CO2 is controlled by Global Temperature, as it is in the Proxy Record.” Murray Salby

        CO2 clearly follows temperature – as is seen in the statistical analysis of Ole Humlum and in the paleoclimatic record.

        It is something shown in the two studies linked to above. From the soil emissions study.

        ‘Soil respiration, RS, the flux of microbially and plant-respired carbon dioxide (CO2) from the soil surface to the atmosphere, is the second-largest terrestrial carbon flux. However, the dynamics of RS are not well understood and the global flux remains poorly constrained. Ecosystem warming experiments,
        modelling analyses, and fundamental biokinetics all suggest that RS should change with climate.’

        And has in fact increased by some 20% of current anthropogenic emissions according to the study.

        Salby’s message – what there is of it – seems restrained and well supported by theory, experiment and data. But the mere mention of the name appears to send them into seething gales of resentment, innuendo and disparagement.

        Tony suggested that webby has an intellect. It seems to me that intellect requires a breadth of culture. History, philosophy, literature, economics, maths, multiple sciences and a facility with modern cultural forms being a minimum for an intelligent discourse. More to the point – it requires being able to argue a cogent point that doesn’t consist entirely of aggression and abuse. Webby seems sadly lacking in any of these qualities.

      • Jimbo’s point would be true if the increase was entirely temperature modulated.

        The question de jour is how much of the warming was natural.

      • CO2 follows temperature in the Ice Age recovery too. You will find this in textbooks and talks by climate scientists (e.g. see Richard Alley at the AGU). It’s true. This is the response of water to warming. It is as much as 10 ppm per degree, not 100 ppm per degree, which is what Salby has to resort to. Skeptics wrongly think that just because CO2 follows temperature in paleoclimate, it can’t be the other way around. However, that is also illustrated in paleoclimate. E. g. following volcanic CO2 release periods, you get warming, but somehow these same skeptics who use paleoclimate as an example don’t seem to know this part. Nor that the last 50 million years has had CO2 going down due to geological sequestering and this has corresponded to cooling, another example of CO2 changes leading temperature.

      • Biology and not chemistry Jimbo – as everything I have said or linked to attests.

        Webby rather proves my point resorting to US cultural stereotypes rather than any cogent argument. Something that is utterly lacking in favour of clumsy and contrived jibes.

        I could do my poor boy routine. I left school at 15 – the product of a long line of poor white trash. My education began with a facility with reading and writing and a Henry Miller novel discovered at a railway station bookstall. I followed every thread of those voluminous and immensely erudite works through countless bookstores and libraries.

        I finished high school after sitting an entrance test and doing 3 years in 8 months at a trade school – and am always grateful. Ultimately – I studied civil engineering and then environmental science – part time and by working long hours every week. Both of these are broadly interdisciplinary fields. Physical sciences – physics, chemistry, geology, biology, hydrology, fluvial geomorphology as well as maths, environmental policy and economics both of the traditional and environmental varieties. I could do my poor boy routine – but in Australia they would just laugh at me.

        All there is from webbly – objectivlely – is an endless stream of seething resentment and irrationality aimed at what? Refuting my detailed argument that ecosystem ‘warming experiments, modelling analyses, and fundamental biokinetics all suggest that RS should change with climate?’

      • So we relentlessly get to the stage of webbly comment disappearing leaving out of context replies.

        There really should be more of it – automatic, a matter of course, much more often than not. Is there much of a point to any of the calumny he broadcasts habitually Judy?

      • Rob Ellison | August 25, 2014 at 1:15 am |
        “CO2 clearly follows temperature – as is seen in the statistical analysis of Ole Humlum and in the paleoclimatic record. ”

        How do the ‘skeptics’; reconcile this with the current ‘pause’/ ‘hiatus’?
        Has CO2 not increased over the last 16 years??

      • Matthew R Marler

        Rob Ellison: ‘In significant part, however, CO2 is controlled by Global Temperature, as it is in the Proxy Record.” Murray Salby

        CO2 clearly follows temperature – as is seen in the statistical analysis of Ole Humlum and in the paleoclimatic record.

        Unfortunately, the record over the last century is ambiguous, that is having at least 2 disparate explanations. Even if all of the increased CO2 were anthropogenic, the rate of dissolution of CO2 into ocean would be temperature dependent; hence the atmospheric concentration would increase more in warm weather (lower rate of dissolution) than in cool weather (higher rate of dissolution.) The association of CO2 increase with temperature since 1980 is displayed on P 67 (figure 1.43) of his textbook Physics of the Atmosphere and Climate, Cambridge University Press, 2012.

        The association of CO2 change with isotope ratios (same figures) is likewise explained even if most of CO2 increase is anthropogenic. Outgassing and dissolution both occur continuously at the ocean surface. In warm weather, the ratio of outgassing to dissolution is slightly higher than in cool weather, so the overall isotope ratio of the exchange changes.

        Unless something more quantitative and accurate than these correlations has been published, I don’t think Salby’s evidence permits a conclusion that most of CO2 increase is independent of human activity. Human CO2 emissions can be estimated from human fossil fuel consumption, and there has been enough of an increase in fossil fuel consumption to produce the observed increase in atmospheric CO2. The evidence for a natural source of the CO2 increase is much weaker than that.

      • WebHubTelescope


        How do the ‘skeptics’; reconcile this with the current ‘pause’/ ‘hiatus’?
        Has CO2 not increased over the last 16 years??

        Michael, This is considered good uncertainty. They don’t know why CO2 has increased over the last 16 years even though the temperature has “paused”. This adds to the overall uncertainty. They don’t distinguish between uncertainty in dimwit theories vs uncertainties in other aspects.

        Any uncertainty is good as it feeds the Uncertainty Monster. The ingredients of Monster Chow are varied portions of Fear, Uncertainty, and Doubt.

        Rob Ellison is uncertain whether he is a cartoon character or not. That is also good uncertainty. Skeptics are confused by this and it adds to the uncertainty.

      • Better watch it webbly or you will be disappeared yet again. I don’t suppose it matters to you much. Each comment is much like another. Tired and clumsy jibes in place of rational discourse, seething resentment in place of actual knowledge, fantastic rants in place of cogent thought. Each to their strengths I suppose.

        The two studies I link to show an increase in CO2 respiration form soils and tropical vegetation that total 70% of anthropogenic emissions. These alternatives sources are biological. and not chemical and due to solubility. This seems quite a difficult point for some – as we keep returning to this idea of lower solubility in a warmer ocean as the source of CO2. It occurs but is relatively minor. But it is in fact simple – the carbon cycle is biologically mediated and to a lessor extent chemical reactions. Write that down. Have a look at the pathways I started with.

        ‘Ecosystem warming experiments, modelling analyses, and fundamental biokinetics all suggest’ that CO2 increases in a warmer environment. Surely this is obvious to any but the recalcitrantly oblivious few.

        As I think I said quite clearly – the increase is in ‘significant part’ temperature dependent. How significant and what the natural warming was are reasonable questions for a scientific realist. Although it seems to send alarmists into paroxysms of seething resentment and misrepresentation.

        It seems a simple argument – backed by mainstream science. From personal circumstances –

        http://watertechbyrie.files.wordpress.com/2014/06/cam00003.jpg

        – I have less patience than ever for stubborn obtuseness. Less so for clumsy and repetitive jibes. Read the damn links before making id_ot comment.

      • Michael, their answer to that would be lag time.

      • The Aussie pulls the poor boy sympathy card by posting a pic of himself (?) under duress — note the parenthetical QUESTION MARK representing the UNCERTAINTY MONSTER.

        Is this place a klown show or what?

      • God only knows what his problem is. Seething resentment, an inability to frame an argument that isn’t clumsy and repetitive abuse, opportunistic disparagement in a bad case of bad faith, noisy prattling and preening informed by superficial knowledge and astonishingly silly assumptions?

        He does math and you don’t? I do maths and modeling. What he does is curve fitting to data series. Something that is always an utterly pointless exercise. It operates by the presumption that he can fool the mathematically naïve into believing that scaling silly assumptions to a data series reveals fundamental physical relationships. It doesn’t. What it reveals is silly assumptions that are galaxies away from describing the physical states of an immensely complex system.

        Example – a periodic function plus a linear trend define surface temperatures. Not even close – but there is an utter futility in attempting to educate the webbly.

        For years I have tried to dissuade from following me around making the same pointless jibes. I have complained – his comments routinely disappear – but he always pops up with the same opportunistic nonsense that goes such a long way to making this site much less than it could be. There is no possibility of any wit, humour or wisdom emerging when his habitual and response is too call you all clowns.

      • Let me correct my typos.

        I don’t do deliberate dishonesty – if I say something you can be assured that it is as true as I can be. I don’t really understand any other way of operating.

        God only knows what the webbly’s problem is. Seething resentment, an inability to frame an argument that isn’t clumsy and repetitive abuse, opportunistic disparagement in a bad case of bad faith, noisy prattling and preening informed by superficial knowledge and astonishingly silly assumptions? All for what? A showcase for delusion fantasies about how superior he is to you and me?

        He does math and you don’t? I do maths and modeling. What he does is curve fitting to data series. Something that is always an utterly pointless exercise. It operates by the presumption that he can fool the mathematically naïve into believing that scaling silly assumptions to a data series reveals fundamental physical relationships. It doesn’t. What it reveals is silly assumptions that are galaxies away from describing the physical states of an immensely complex system.

        Example – a periodic function plus a linear trend define surface temperatures. Not even close – but there is an utter futility in attempting to educate the webbly.

        For years I have tried to dissuade him from following me around making the same pointless jibes. I have complained – his comments routinely disappear – but he always pops up again with the same opportunistic nonsense that goes such a long way to making this site much less than it could be. It is an utter distraction and a complete waste of time.

        The sadness is that there is no possibility of any wit, humour or wisdom emerging when his habitual response is to call you all clowns.

      • Rob Ellison | August 24, 2014 at 11:51 pm
        i.e. SALBY SEEMS 100% RIGHT AND THE MANY VOICES CLAMOURING UTTERLY MISGUIDED

        Rob Ellison | August 26, 2014 at 4:02 pm |
        I have not paid much attention to Salby’s presentations at all.

      • ‘In significant part, however, CO2 is controlled by Global Temperature, as it is in the Proxy Record.” Murray Salby

        There is no contradiction to saying that Salby and that I don’t give much weight to such blogospheric manifestations. It is 100% right – as I show by reference to actual science.

        Is that sad little cut and paste all that you are capable of?

        Salby is obviously a cause for seething resentment from the Borg collective. The discussion needs to be broadened and have some real substance.

      • I have not paid much attention to Salby’s presentations at all. However – there are many other sources and ‘ecosystem warming experiments, modelling analyses and fundamental biokinetics’ all suggest that natural CO2 flux should change significantly with climate. Some 5Pg C/year increase in recent times from a couple of references I give below.

        Is the full quote – i.e. in context.

      • wrhoward | August 27, 2014 at 1:58 am |

        Rob Ellison | August 24, 2014 at 11:51 pm
        i.e. SALBY SEEMS 100% RIGHT AND THE MANY VOICES CLAMOURING UTTERLY MISGUIDED

        Rob Ellison | August 26, 2014 at 4:02 pm |
        I have not paid much attention to Salby’s presentations at all.

        Good, Keep on pointing out how the Aussie contradicts himself.

        The sad part is that he pulls out the sob stories such as leaving school at 15 and including a pic of himself in a leg cast so we can feel sympathy for his plight.

        Too bad that the Aussie can’t figure out that science doesn’t care about the cards he has been dealt. It’s harsh that way.

      • There is no contradiction as seems evident from what I said. The science I referenced is consistent with what Salby said – the science is what is important and not a random video presentation or 2.

        Webby was whining that I was some privileged twerp. I am far from that.

        And I am laid up again with my foot – it gives me both time to comment (as well as watching Sherlock Holmes on Youtube) and impatience at clueless twits who are incapable of coherent, substantive and coherent argument.

      • Matthew R Marler

        WebHubTelescope: Rob Ellison is uncertain whether he is a cartoon character or not. That is also good uncertainty. Skeptics are confused by this and it adds to the uncertainty.

        It is a shame that you camouflage your occasional good points among this vast quantity of persiflage. It is really tedious and time consuming to slog through it all day after day, looking for the rare nuts of insight.

    • I like it that I am still called Chief – Cecil would be so proud.

      In the absence of any rational or civilised discourse – or even any basic interpersonal fairness or honesty – I should just call it a day.

    • Matthew R Marler

      Rob Ellison: e.g. http://environmentportal.in/files/Temperature%20associated%20increases%20in%20the%20global%20soil.pdfhttp://www.csiro.au/Portals/Media/Tropical-ecosystems-regulate-variations-in-Earths-carbon-dioxide-levels.aspx

      Thank you for the links.

      From the second: a temperature anomaly of just 1ºC (in near surface air temperatures in the tropics) leads to a 3.5-Petagram (billion tonnes of carbon) anomaly in the annual CO2 growth rate, on average. This is the equivalent of 1/3 of the annual global emissions from the combustion of fossil fuels and deforestation together.

      OK, but there has not been a 1C increase since WWII, so that is not a large contribution compared to fossil fuel burning.

      From the first: The S1 data imply that RS is responding to climate anomalies on the local scale. Climate is only one of many factors controlling
      decomposition and RS (ref. 10), but this raises the question of the
      integrated global effect of these changes. We calculated RS over the
      time period covered by these data by using the basic model (model B)
      to predict grid-cell RS across the entire terrestrial land surface. We
      estimate that the annual global RS in 2008 was 98 6 12 PgC, or 85 PgC if agricultural areas are excluded, and is increasing at 0.1PgC yr 21
      (0.1% yr 21 ; Fig. 2). The 0.1Pg Cyr21 increase from 1989 to 2008 was significant ( t 18 5 5.2,P,0.001), and a grid-cell-matched,two-sided
      t -test confirmed (t 60,843 52 129.0, P 0.001)that the computed 2008 global flux was significantly higher than that for 989. This annual global
      RS value is 20–30% higher than previous 3,8,15 estimates. It is, however, consistent with a previous global calculation f the heterotrophic soil flux
      23, given the general heterotrophic contri-bution to RS (ref. 24). The interannual variability of annual global RS was 1.5PgC, similar to that found in an earlier modelling study 8

      Some translation/typesetting errors, but those together suggest that anthropogenic CO2 is the dominant source of CO2 increase.

      Is there more?

      • It seems there has been a 1 degree change in surface temperature since 1900.

        The increase from soils is 1.5 PgC – some 20% of human emissions. The increase from tropical vegetation is 3.5 PgC.

        I never said it was dominant – merely significant. Read harder as they say Matthew.

      • Actually – the increase from soils is only from 1989.

      • Matthew R Marler

        Rob Ellison: I never said it was dominant – merely significant. Read harder as they say Matthew.

        True. You said that the cited sources contributed 70% as much CO2 as human. But you also said that Salby was 100% correct. If human sources are greater than natural sources, then Salby isn’t 100% correct.

        So one was forced to guess a bit as to your intended meaning. I put more weight on what you wrote in caps. Looks like I was wrong.

      • Does Salby insist that natural changes are dominant in the 20th century? Or are you relying on popular strawmen?

        Other sources seem far more relevant to my mind – but the statement that – in significant part – CO2 follows global temps seems entirely justified by experiment, modeling and fundamental biokinetics. .

      • Matthew R Marler

        Rob Ellison: Or are you relying on popular strawmen?

        I cited his textbook and his oral presentation that circulated on the internet. He has argued that the correlation of CO2 change with temperature shows that the increase can not be man-made; but the correlation can have multiple causes and can exist even if the CO2 increase is mostly man-made.

        Are you still confident that Salby is 100% correct?

      • I have quoted from the closing minutes of the Hamburg address – please feel free to provide a similar quote or I will be entitled to believe that you are full of it.

      • Matthew R Marler

        Rob Ellison: I have quoted from the closing minutes of the Hamburg address – please feel free to provide a similar quote or I will be entitled to believe that you are full of it.

        You are entitle to your beliefs about me in any case. At this time, I prefer to think that Salby has been unclear as to whether he thinks the present evidence shows the majority of atmospheric CO2 to have been of natural origin.

        Here is what you quoted: ‘In significant part, however, CO2 is controlled by Global Temperature, as it is in the Proxy Record.” Murray Salby

        There is no contradiction to saying that Salby and that I don’t give much weight to such blogospheric manifestations. It is 100% right – as I show by reference to actual science.

        Note that “controlled by” is ambiguous, as I wrote. It could mean that the measured CO2 increase is dependent on temperature even if almost all of the increase in CO2 comes from burning fossil fuel. Or it could mean that almost all of the increase in CO2 is independent of fossil fuels. Both are possible in light of actual science.

        If, as suggested by the studies you linked to, natural sources contribute 70% as much CO2 to the atmosphere as burning of fossil fuels, then 60% of the annual increase in atmospheric CO2 is from the burning of fossil fuel. That still leaves room for CO2 to be “controlled by Global Temperature” “in significant part”.

      • It could mean dicksquat Matthew – as your circumlocutions seem to.

    • Dr. Curry, maybe you could interject. What has been the cause of the rise in atmospheric CO2? Could this be another 50/50 argument?

    • ‘In significant part, however, CO2 is controlled by Global Temperature, as it is in the Proxy Record.” Murray Salby

      There is no contradiction to saying that Salby and that I don’t give much weight to such blogospheric manifestations. It is 100% right – as I show by reference to actual science.

      Is that trivial cut and paste all that you are capable of?

      Salby is obviously a cause for seething resentment from the Borg collective. The discussion needs to be broadened and have some real substance.

  53. Industrial aerosols appear to be a wash. There is no evidence of regional cooling from increases in asian aerosols so it is logical to conclude that black carbon and sulfates balance out.

    50% of the late 20th century warming appears to have been caused by ocean oscillations. These oscillations are superimposed on a long term trend of increasing poleward ocean heat transport.

    All of the warming since the LIA can easily be explained by increases in poleward ocean heat transport. While it seems safe to conclude that at least 50% was due to short term oscillations in ocean heat transport, it is impossible to determine how much was caused by the long term trend in poleaward heat transport until such time as it reverses as it may currently be in the process of doing.

    Anthropogenic warming is most likely to be less than the 33% mark in the multiple choice test.

  54. From the EPA’s Endangerment Finding:

    “Most of the observed increase in global average temperatures since the mid-20th century is very likely due to the observed increase in anthropogenic GHG concentrations. Climate model simulations suggest natural forcing alone (i.e., changes in solar irradiance) cannot explain the observed warming.”

    http://www.epa.gov/climatechange/Downloads/endangerment/Endangerment_TSD.pdf

    Judith, would you mind asking the EPA to revisit the scientific basis for their finding?

  55. Willis Eschenbach

    Judith, thanks for an interesting post. However, I couldn’t follow your logic. It seems to me you skipped a step. You say:

    Let me clarify the distinction between detection and attribution, as used by the IPCC. Detection refers to change above and beyond natural internal variability. Once a change is detected, attribution attempts to identify external drivers of the change.

    Now, the questions you posed are questions of attribution, viz:

    a) Warming since 1950 is predominantly (more than 50%) caused by humans.

    b) Warming since 1950 is predominantly caused by natural processes.

    You say that your estimate of the attribution is 50% nature and 50% nurture (actually 33% to 66%). My question is … the attribution of what, exactly?

    According to your quote above, detection precedes attribution. And in your words,

    Of particular relevance to the 50-50 argument, the IPCC has failed to convincingly demonstrate ‘detection.’

    So … what have you detected, and how did you detect it, that leads you to any attribution? In other words, exactly where in the global temperature record is the portion that, in your words, is “above and beyond natural internal variability”?

    Best regards,

    w.

    • @ Willis Echenbach

      ” Detection refers to change above and beyond natural internal variability.”

      I’m with you on this one Willis.

      Convince me that anyone has detected a ‘change’ above and beyond natural variability and then we’ll discuss attribution.

      Climate Science proclaimed attribution ex cathedra and then proceeded to spend billions of dollars searching, so far unsuccessfully, for the unnatural change requiring the aforementioned attribution.

      Frankly, the whole procedure doesn’t appear all that scientifical to me.

  56. Climate change, which includes global warming is ALL caused by natural drivers.

    Two natural drivers have been identified that explain measured average global temperatures since before 1900 with R^2>0.9 (95% correlation) and credible values back to 1610. Global Warming ended before 2001. The current trend is down.

    The two natural drivers, method, equation, data sources, history (hind cast to 1610) and predictions (to 2037) are provided at http://agwunveiled.blogspot.com and references.

  57. We are 95% certain that the number is from 51 to 99. This could be problematic. I could say that Procter and Gamble’s has a net worth of from $51 billion to $99 billion. What could you do with that information? If you were to loan them money or buy their stock, you’d argue for the low value. If you were selling your stock in them or they were trying to borrow money, the high value would be used. Both sides would be better served by tightening the range. I find no inherent utility in picking a range of roughly X to 2X. Though I am not speaking for CPAs, a goal might be to say with 95% certainity that the answer is 100 +- 5. Why 5%? A 5% difference in net worth or net income usually will not be the cause of a business failure. In limited cases it will though. Better than 5% (say within 3%) involves additional auditing costs. At some point dollars spent on auditing accomplish less and less. Getting the error down to 1% might be prohibitively expensive versus the value of doing that. So CPAs like to say we are 95% certain we are within about 5% of the answer. This information is supposed to be useful to management and shareholders. The broad range of 51-99 may have limited use but it isn’t so much a ‘what we know statement’. It’s more of a ‘what we don’t know statement’. A go back and do more work statement.

  58. What was done, was to take a large number of models that could not reasonably simulate known patterns of natural behaviour (such as ENSO, the Pacific Decadal Oscillation, the Atlantic Multidecadal Oscillation), claim that such models nonetheless accurately depicted natural internal climate variability, and use the fact that these models could not replicate the warming episode from the mid seventies through the mid nineties, to argue that forcing was necessary and that the forcing must have been due to man.
    The argument makes arguments in support of intelligent design sound rigorous by comparison. It constitutes a rejection of scientific logic, while widely put forward as being ‘demanded’ by science.

    http://climateconferences.heartland.org/richard-lindzen-iccc3/

  59. While I have a lot of sympathy with the overall thrust of Dr. Curry’s post, I’m going to suggest that 33-66% still isn’t a useful metric, because it’s likely that 33% vs 66% still has profound policy implications.

    To be useful, I think science is going to have to cut that one in half again, 33-49% and 50-66%.

    I won’t insist on those numbers at all for the split, but I do think 33-66% still is too much uncertainty for the degree of opportunity cost associated if science accurately hits the target range but is off within the range near the margin.

  60. Pingback: Climate Nonsensus: Only Half Of U.S. Meteorologists Think Global Warming Is Man-Made | The Global Warming Policy Foundation (GWPF)

  61. –curryja | August 24, 2014 at 8:59 pm | Reply

    “I stated a few comments back that I am planning a future thread on salby–

    Perhaps at such a future thread, we could talk about something specific regarding what salby says. And who knows, maybe salby could be around to defend himself.”

    I’d be happy to have an exchange with Prof Salby. I addressed his hypothesis, as best I could understand it (there seems to be no publication?) in comments following my guest post on “consensus.”

  62. Thank you, Prof Curry, for a clear, well reasoned, logical and forceful summary of the case. When all the dust has settled, and whether the Global Warming advocates prove right or wrong, your place will be among the few who kept to the values of reason and science, and followed them wherever they lead.

  63. Pingback: Judith Curry: The 50-50 Argument | The Global Warming Policy Foundation (GWPF)

  64. Causes of the pause only some of the 40
    1. There is no pause
    2. Low solar activity
    3. The heat is in the oceans
    4. The Pacific decadal oscillation (PDO) has been mostly negative
    5. the 60–70-year Atlantic multidecadal oscillation may have a similar effect
    6. Stratospheric water vapor decreasing temperature
    7. Chinese coal the increased burning of coal in China is producing aerosols
    8. The Pacific and the La-Niña-like decadal cooling.
    9. Stadium waves
    10. Arctic stations the pause is an artefact of poor spatial sampling
    10. Pacific trade winds . It is contended that there has been a strengthening
    11. Pacific trade winds that weak trade winds are responsible
    12. Trade winds are not varying
    13. Volcanoes
    14. Aerosols other
    15. A coincidence!
    16 Natural variation Warmists and Skeptics united saying “we do not know!”
    I believe there would be 40 causes put forward and would be happy for others to add the ones I have missed.
    When there are possibly 40 causes of the pause I find it a bit hard to believe that natural variation” can be said to be only balancing human anthropogenic warming. If natural variation had gone the other way we would all be here saying man’s emissions are cooling the planet.

    Lets face it, if there are 40 causes for a pause then humans could only be responsible for 2.5 % of any warming that occurs.
    Sitting on the fence with a middle thirtle?
    No put it in the lowest, < 5%
    Admit we do not know and hence 50% is a stab in the dark

    • Steven Mosher

      we believe in one knob.

      • The CAGWer apostles’ Creed:

        I believe in the CO2 knob, the Father of all climate, Creator of Earthly warmth; and in Global Warming, its mythical son: That was conceived by the Holy Hansen, born of the IPCC, suffered under Anthony Watts, was crucified by Mark Steyn, died of the pause and was buried. It descended into PR hell; the third decade It rose again from the dead; Surface temps ascended into El Nino, are seated at the right hand of Barack the Obama; from thence they shall come to judge the coal and the oil and the gas. I believe in the Hockey Stick, the Holy Warmist Church, the communion of “Climate Scientists”, the banning of fossil fuels, the resurrection of Copenhagen, and decarbonization everlasting. Amen.

      • In the name of the Fossil, the Sun, and the back infrared radiation.

      • Say Jim2,
        quite kim-like.

      • Our EPA, who art in Washington, hallowed be thy name. Thy regulations come, thy will be done, outside the beltway as it is not within the beltway. Give us this day our daily tax increase and do not forgive our footprints as we forgive the footprints of China. And lead us not into temptation of prosperity, but deliver us from economics.

    • The pause is weather and nothing to do with the trajectory of climate over the current millennium.

  65. Put it at some warming – and recognize that small changes in control variables in a coupled, nonlinear system brings with it a spectrum of risk from negligible to severe.

  66. The status of ‘expert’, really subjective, judgement is nicely illustrated by the fiasco with Bayesian priors for the estimation of ECS. This seems lucidly, and accessibly, described by Annan and Hargreaves(2009). The fact that ‘experts’ thought any value between 0C and 20C(one paper) or 0C-10C(another paper) was equally likely for ECS is ‘beyond belief’. Even accounting for some statistical naivety, these ranges betray alarmist prejudice in what purports to be expert judgement. Financial theory is often maligned, but it does at least recognize that subjective/expert expectations depend partly upon a person’s preferences. This remains true, even when different peoples’ ‘estimates’ are combined (as in market prices). Not really a sound basis for scientific attribution?

  67. I still find it very interesting that these temperature graphs show 1800’s until now. So are our scientists telling us that our temperature measuring devices were accurate back then as they are today? I very much doubt that. How can a device back then compare to our recent ones that measure temperatures to several decimal places. Plus what about those early urban recording areas that are now contained in cities. Are these same scientists also telling us that urban temperatures recorded back in the 1800’s are in any way comparable to today’s city temperatures? Yes they are! They are using a fair bit of poetic licensing as far as I’m concerned.

  68. Given the present state of the science, I can’t see how anyone can argue for 50-50, 80-20, 20-80, or almost any other range,.

    Gavin is a strong believer in the power of the expert and since his experts say high degree of human influence he follows like a sheep, barely conscious of his own bias. The same, however, could also be said for those on the other side of the argument.

    Obviously something in the middle range is the most likely but this is largely a judgment call based more on common sense than hard science.

    • It’s an unfortunate fact that the more biased people are, the less likely they are to acknowledge, or even to be aware of, their own biases, and the more likely they are to dismiss any counter-arguments.

    • … barely conscious of his own baas ….

      On that bleat, goodnight.

    • @ James Cross

      “Obviously something in the middle range is the most likely but this is largely a judgment call based more on common sense than hard science.”

      Actually, until there is some empirical evidence that the climate is doing something outside its range over the the last 2-3k years, it is not obvious that the range of human influence is more than academically different from zero.

  69. “Nic Lewis at Climate Dialogue summarizes the observational evidence for ECS between 1.5 and 2C, with transient climate response (TCR) around 1.3C.”

    Nic Lewis also shows the anthropogenic warming since 1950 is about +0.7C (ghg+aerosol forcing of 2wm-2 since 1950 and 1.3C TCR)

    +0.7C is ALL of the warming since 1950.

    Come on lets at least mention the manmade warming estimate his numbers produce shall we! It refutes 50/50.

  70. I have been told by others that Three Card Monte, was a game of chance & chance, where the odds were almost 50-50 depending upon your luck. I found out quickly he could not be trusted. I stopped playing. What experience did you have when you played Three Card Monte? The odds are greater than 50% you no longer play the game with strangers today.

  71. Since the published GAT’s show global warming that neither the daily min nor daily max temps measurements show, and that GCM’s are tuned to show a matching trend.

    The annual average of the difference in day to day min and max temps.
    http://content.science20.com/files/images/GB%20Mn%20Mx%20Diff_1.png

    I think that makes all of the warming man made, right?

  72. I’d give it better than 50-50 that talking about surface temperature without at least a footnote to UHI — the Urban Heat Island effect — says a lot more about the lack of integrity of modern climate research that anything else.

  73. Now that they have followers in Western cities, ignoring ISIS when they believe “Zionism is Nazism” would be foolhardy. But, what would ISIS say about “Climatism”?

  74. Pingback: The core of the climate debate: how much of the past warming did we cause? | Fabius Maximus

  75. Judith
    I agree with you that the IPCC models are not useful for detecting the effect of Anthropogenic CO2 because they are tuned to too short a period.
    Unless the range and causes of natural variation, as seen in the natural temperature quasi-periodicities, are known within reasonably narrow limits it is simply not possible to even begin to estimate the effect of anthropogenic CO2 on climate. In fact, the IPCC recognizes this point.
    The key factor in making CO2 emission control policy and the basis for the WG2 and 3 sections of AR5 is the climate sensitivity to CO2. By AR5 – WG1 the IPCC itself is saying: (Section 9.7.3.3)
    “The assessed literature suggests that the range of climate sensitivities and transient responses covered by CMIP3/5 cannot be narrowed significantly by constraining the models with observations of the mean climate and variability, consistent with the difficulty of constraining the cloud feedbacks from observations ”
    In plain English, this means that the IPCC contributors have no idea what the climate sensitivity is. Therefore, there is no credible basis for the WG 2 and 3 reports, and the Government policy makers have no empirical scientific basis for the entire UNFCCC process and their economically destructive climate and energy policies.
    The key natural variation in the temperature data is the 960-80 year quasi millennial periodicity illustrated in Figs 5 – 9 at
    http://climatesense-norpag.blogspot.com
    Unless this is included in any semi-empirical model we cannot begin to understand what is going on .
    The same posts provides estimates of a possible coming cooling based on the reasonable supposition that the current temperature peak is a more or less synchronous peak in the 60 and 960 year quasi- periodicities.
    The chief uncertainties in these forecasts are the exact timing and amplitude of the 960 year periodicity and the variable lag times between the solar activity driver peaks and their appearance in the climate data in different regions.
    Obviously anthropogenic CO2 must have some effect on climate. At this time there is no empirical reason to suppose that it is of anything other than minor significance.

  76. “Gavin thinks I’m ‘making things up’, so I promised yet another post on this topic.”

    If anyone would know about ‘making things up’, I rather think that would be Gavin…

    He is a ‘professional’, after all.

  77. Steven Mosher (11:36 am):

    I have a forthcoming paper with Nic Lewis, which should be very understandable to Joe Public

    I didn’t spot that. Thanks.

  78. David Springer

    Global average temperature is not robust enough pre-satellite era to answer that question.

  79. When does the technical insider community stop focusing on “if” and “how” stuff is “just making stuff up” and simply acknowledge that’s always been the case and get to assigning reasons why they make stuff up???

    Without that conclusion the public is simply being deceived in another way; “It’s Colonel Mustard in the library with a wrench” without ever knowing why. Everyone here knows why even if they are in constant testimonial denial as to the political I.D. of the warming agenda’s core support.

    It’s why stuff is made up and the willing affiliates eager to believe anything supporting the warming meme that is the real story at this point. It’s called a logical conclusion.

  80. The Washington Post writes about the Certainty of climate change. It is a shame they do not know about the Uncertainty Monster.

    http://www.washingtonpost.com/opinions/the-countrys-sinking-climate-debate/2014/08/24/d4d4aeca-29ff-11e4-86ca-6f03cbd15c1a_story.html

    • It’s never about “knowing” but the political expediency of believing what fills the agenda. In the case of the Washington Post its a foregone conclusion, 100% statism, 100% of the time.

  81. http://www.woodfortrees.org/plot/hadcrut3vgl/from:1905/to:1956/plot/hadcrut3vgl/from:1957/to:2008

    one of these is no CO2, one is all CO2, totally obvious and plenty of data to promote any and all attribution claims…../sarc

  82. Having only just gotten to this most interesting and thought provoking post, a meta analysis comment on the extensive comments. Attribution seems to be a real ‘litmus test’. It brought out expected perspectives from all of the expected usual commenters, at least as I mentally categorize them without having done a large research study on same. Which itself suggests how much ‘momentum’ and how little the rational approach ‘conclusions follow from facts, and when facts change so should conclusions’ (to paraphrase IIRC Keynes) enters the dialog even at ClimateEtc. Rather like Mann on hockey sticks or EPA on carbon pollution endangerment findings. One suspects none of this will move Gavin an iota cause if it did he might be expelled from the church of warmunism. Besides, he is probably too busy further homogenizing the 1930’s down and the ‘pause’ up, changing temperature facts to fit his conclusion rather than vice versa.

    Put differently, attribution proves to be a good experimental method to show how much of the climate debate is political rather than scientific in any Feynman sense. Politics involves vested interests, belief systems, and Weltanschauen, all immune in the short run to facts. But not in the long run, since facts are stubborn things that do not go away easily once revealed. Like the pause, the warming from 1910 to 1940, and Climatereason’s longer qualitative historical perspectives.

    • That’s an optimistic thought; “facts are stubborn things”. The history of post WW2 science, it’s link to ever growing political and ideological subjugation didn’t start or end with global warming agendas. This is all just a snap shot of the deterioration into post normal science.

      We’re generations away from the broad political establishment and it’s media operatives acknowledging the warming agenda was political fraud and excess supported by like minded academics and the many tools that believe in ever larger state size and authority.

      Dr. Curry’s post is positive but it remains quibbling since the core political acknowledgement is clearly missing. Most thinking people understand what the IPCC agenda is, it’s only intense political correctness that prevents even the conversation among the technocrats like Dr. Curry. The core warming movement was and is politically corrupt, science to rationalize central planning agendas. It’s been this way Dr. Curry’;s entire career so this seems to me the longest Road to Damascus in history of logical conversions. The endless nuance with the greenshirt fringe is in fact counter productive.

  83. 50-50?

    Actually, there is growing evidence that the true anthropogenic contribution to Global Warming is asymptotically approaching 100%.

    Nothing to do with ACO2 of course, but the predictable result of giving progressives access to computers, pencils, and billions of dollars and charging them to ‘come back with your fossil fuel catastrophe shields or on them’.

    • “Klimate Klown Klan”

      I for one am glad for the dissenters on this blog (although I’m not always crazy about the tone of some). Without some stimulation and controversy it would be less interesting.
      And I like to ‘know my enemy’ for those debates that come up on the issues in ‘real life’ ;)

  84. “there is no one knob hypothesis for modern changes”

    LOL– seems to believe he knows what everyone else believes. There are lots of nutty beliefs- keep reading the comments here and you will come to understand what you wrote is incorrect.

    • Steven Mosher

      The Control knob hypothesis has to do with explaining the entire historical record. It states EXPLICITLY that C02 is not the only knob.
      In the modern era if you want to see all the knobs read the IPCC.

      The only people who believe in a one knob theory are people who believe their opponents believe in a one knob theory.

      But go ahead, find the published scientific theory that posits c02 as the one knob.

      you might find sun cranks on the web who argue that.
      you might find nuts who grunt “natural variability” is one knob..

      besides that.. not much

      • I thought aerosols was the control knob.

      • Aerosols are the catch all for those things unexplained. If you can’t answer the question just chant aerosols work in mysterious ways and all will be well. They are also great for tuning models if you should ever be in need of a better picture.

      • David Springer

        Mosher is wrong again. Some things never change.

      • @ Steven Mosher

        “You might find nuts who grunt “natural variability” is one knob..”

        Hi Mosh

        ‘Natural variability adequately explains observed climate variability.’ is a theory.

        Like all theories, it is subject to falsification by observation. Specifically, by observations demonstrating that modern climate has moved outside its historical range.

        What observed climate data falsifies the natural variability theory?

        ‘ACO2 is causing the Temperature of the Earth to rise (climate to change, climate to become ‘weird’, whatever) at an unprecedented rate that will prove catastrophic to the biosphere at large unless coordinated government action is taken to curb the use of fossil fuels.’ is apparently NOT a theory as it is NOT falsifiable. EVERY noteworthy ‘climate event’, hot, cold, wet, dry, polar ice, no polar ice, hurricanes, no hurricanes, tornados, no tornados, drouth, flood, snow, no snow, TOE rise, TOE fall, TOE flat, increases in kidney stones (true cite), ad infinitum, are ALL cited as confirmation of the ACO2………..what?

        So I ‘grunt’ that I continue to believe that theories(?) which are confirmed by any and all observations and which are being supported by attempting to prosecute or ruin professionally anyone who challenges them were most likely developed for purposes other than explaining the workings of nature.

      • “But go ahead, find the published scientific theory that posits c02 as the one knob.”
        Dessler.

      • Real But Exaggerated

        Kind of ‘everyone is right’ here:

        Lacis and also Alley https://www.youtube.com/watch?v=RffPSrRpq_g_
        call CO2 the BIGGEST ( not lone ) control knob.

        The press, for all their ignorance, shortens things to THE control knob.

        But since there is a negative trend to temperature since 2001, we know that CO2 is not the biggest control knob for that duration ( 13 years ).

        Will it be for 14 years? That’s why we watch.

      • Steven Mosher

        Sorry Bob

        “‘Natural variability adequately explains observed climate variability.’ is a theory.”

        It is not a theory.

        A) it’s not quantifed
        B) it makes no prediction
        C) it doesnt not explain X in terms of Y, that is, it lacks causality

        lets start with C.

        We can proceed by example. Suppose I record your weight from
        the age of 45 to 60. at 45 you weigh 220lbs and then for the next
        15 years your weight moves up and down, down to 200, up to 205,
        down to 195, up to 210, and so forth and over the last 2 years it
        held steady at 218.

        Suppose you went to the doctor and he looked at your record.
        You ask him the question: Doc, why does my weight go up and down
        and he said.. “natural variability” has he explained anything to you?
        No, he has just given a NAME to the phenomena. What he has said
        is that he cannot explain the changes.

        Now suppose you visit a second doctor. And he asks you for a
        record of how much you ate and how much your exercised. You give him
        the record.

        He then constructs a formula with a left hand side and a right hand side.
        on the left he puts “weight gain” in pounds. On the right he puts
        calories consumed from food and calories expended by exercise.
        And he shows you how excess calories get transformed into pounds
        thats pounds on the left explained by calories on the right. This is
        an explanation. One thing causes another thing.

        When you say that “natural varaition” causes or explains the variation
        in temperature, you havent explained anything. Your like the first doctor
        who says… “well weight goes up and down”

        But you also see that the fact that your weight doesnt move outside
        the boundaries of the past, that there is Still something to explain.
        what is explained is the WHY of the movement. Nothing requires
        that the change be unprecedeneted.

        Lets go to B. the explanation of natural variability makes no prediction.
        What does the theory predict for the next 10 years? given a past
        where the world was a snowball and much cooler, given a past when
        there were allegators at the north pole, What EXACTLY does the
        theory predict for the next 10, 20, 30 years? Does it predict
        that the world will stay within a 10C band? with zero increase and zero
        decrease? Thats easy to test. Move back to 1900 and apply the
        same predictive logic.

        Now to A.

        The theory that natural variability “explains” the Current temperature
        or that natural variability explains the cooling in the LIA or the warming
        in the Holocene lacks any quantification. To show quantification
        you need to show actual numbers.

        Here your last paragraph is most telling

        “Like all theories, it is subject to falsification by observation. Specifically, by observations demonstrating that modern climate has moved outside its historical range.”

        The problem with this is that you havent defined “historical range”
        I define the historical range as 1850 to 1900. Guess what?
        temperature moved outside that. You object, and say the historical
        range is 1000 to 1900? Well, how did you decide that this is the right
        range? Further, even if the temperature moved outside this range,
        you could point further back and say.. well it was warmer 20 million
        years ago. And suppose the sun increased in brightness and the
        planet warmed by 15C. warmer than it had ever been. You’s still
        call that “natural” variability.

        The problem with the un precedented argument is this. Even if
        the temperature is un precedented, that really tells us nothing about
        Why. and Why is what we are after. Likewise, even if the temperature
        change is SMALL ( like after a volcano ) we can STILL ask and answer
        the why question. Imagine this. Imagine there is a volcano and the world
        cools by 1 C. Do you explain that by saying
        “well, the change is small, its been cool before, its been cooler before
        therefore, there is nothing to explain because the change is within historical boundaries? Or do you say this small change can be attributed
        to the volcano. Suppose, the clouds increase and temperature falls.
        Do you say “nothing here to explain, its all natural variability, well within
        the historical ranges” or do you say temperature drop, although small, can be explained by increased clouds.

        The unprecedent argument from both sides holds no water. What we want to do is explain the observed change from 1850 to today in physical
        terms. We want temperature in C on the left hand side and forcing (for example) Natural variability doesnt do that as a theory.

      • Natural variation is just an observable phenomenon, that’s all.

        Evidently, some of you prefer to deny it.

        Andrew

      • Steven Mosher

        “Aerosols are the catch all for those things unexplained. If you can’t answer the question just chant aerosols work in mysterious ways and all will be well. They are also great for tuning models if you should ever be in need of a better picture.”

        yup.

      • Steven Mosher

        Lacis and also Alley https://www.youtube.com/watch?v=RffPSrRpq_g_
        call CO2 the BIGGEST ( not lone ) control knob.”

        Gosh somebody who doesnt turn their opponents theory into a cartoon.

        The one knob theory is a cartoon version of the actual science.

        guys. read more, watch more, comment less

      • Mosh says. ;

        ‘Read more comment less,’

        Coming from someone who occupies 8 of the last 9 ‘ most recent comments” on the side bar we can conclude that Americans can do irony very well.

        Have you seen the latest thread relating to the comments on climate models by Dr Richard Betts over at WUWT?

        Tonyb

      • Matthew R Marler

        Rob Ellison: You’re kidding right?

        Mosher is correct. The paper in Science that introduced the “control knob” theory asserted that CO2 is necessary to keep the climate warm enough that all of the other knobs to have effects. The “control knob” analogy is not that useful for predicting the effects of future CO2 increases, but that is a different issue from what the authors wrote and that Mosher characterized correctly.

      • Tonyb
        Very funny. Thanks for that.
        Scott

      • Steven Mosher

        tony
        “Have you seen the latest thread relating to the comments on climate models by Dr Richard Betts over at WUWT?”

        yes, I could not have written it better.

        1. this subthread is about the control knob theory. I suggest you read
        THE SCIENCE before commenting.
        2. Betts position is one I have already articulated, in fact I take
        a stronger stance. We dont need climate models to set policy.
        energy balance tells you all you need to know.

        suggest you read more of what I have written.

      • Steven Mosher,
        You don’t use models in your Best analyses?

      • Steve, the hypothesis that atmospheric CO2 is the major determinant of the Earths temperature over the last half billion years is widely propagated.
        Want a link to RC?

      • I assume Mathew is talking ‘condensing’ and ‘non-condensing’ gases. Water vapour and clouds are feedbacks in the CO2 control knob theory that are slaved to CO2.

        http://www.giss.nasa.gov/research/briefs/lacis_01/fig1.gif

        ‘The numerical climate experiment described in Fig. 2. demonstrates the fundamental radiative forcing role of the non-condensing GHGs, and the feedback (only) role of water vapor and clouds. This climate modeling experiment was performed using the GISS ModelE general circulation coupled atmosphere-ocean climate model by zeroing out all of the non-condensing greenhouse gases. Doing this removed the radiative forcing that sustains the temperature support for water vapor and cloud feedbacks, causing rapid condensation and precipitation of water vapor from the atmosphere, collapsing the terrestrial greenhouse effect, and plunging the Earth into an icebound state.’

        ‘Other’ forcings aren’t all that significant it seems.