Santer on timescales of temperature trends

by Judith Curry

Santer et al. have a new paper in press entitled “Separating Signal and Noise in Atmospheric Temperature Changes: The Importance of Time Scale.”

Separating Signal and Noise in Atmospheric Temperature Changes: The Importance of TimescaleJ. Geophys. Res., doi:10.1029/2011JD016263, in press.

B.D. Santer, Carl A. Mears, C. Doutriaux, Peter Martin Caldwell, Peter J. Gleckler, Tom M.L. Wigley, Susan Solomon, Nathan Gillett, Detelina P. Ivanova, Thomas R Karl, John R. Lanzante, Gerald A. Meehl, Peter A. Stott, Karl E Taylor, Peter Thorne, Michael F Wehner, Frank J. Wentz.

Abstract.  We compare global-scale changes in satellite estimates of the temperature of the lower troposphere (TLT) with model simulations of forced and unforced TLT changes. While previous work has focused on a single period of record, we select analysis timescales ranging from 10 to 32 years, and then compare all possible observed TLT trends on each timescale with corresponding multi-model distributions of forced and unforced trends. We use observed estimates of the signal component of TLT changes and model estimates of climate noise to calculate timescale-dependent signal-to-noise ratios (S/N). These ratios are small (less than 1) on the 10-year timescale, increasing to more than 3.9 for 32-year trends. This large change in S/N is primarily due to a decrease in the amplitude of internally generated variability with increasing trend length. Because of the pronounced effect of interannual noise on decadal trends, a multi-model ensemble of anthropogenically-forced simulations displays many 10-year periods with little warming. A single decade of observational TLT data is therefore inadequate for identifying a slowly evolving anthropogenic warming signal. Our results show that temperature records of at least 17 years in length are required for identifying human effects on global-mean tropospheric temperature.

Key Points

  • Models run with human forcing can produce 10-year periods with little warming
  • S/N ratios for tropospheric temp. are ~1 for 10-yr trends, ~4 for 32-yr trends
  • Trends >17 yrs are required for identifying human effects on tropospheric temp.

The paper is not available online, but Pielke Sr. has posted some excerpts on his blog, some of which are reproduced below:

From the conclusions:

We relied on control runs from the CMIP-3 multi-model archive for our estimates of climate noise. Estimates of externally forced climate-change signals were obtained from three different sets of satellite-based observations and from CMIP-3 simulations of 20th and 21st-century climate change. In contrast to almost all previous work, we compared modeled and observed TLT changes on multiple timescales (using maximally overlapping trends) rather than over a single period of record. For timescales less than the record length, this strategy reduces the impact of climate noise on estimates of the signal component of observed (and simulated) temperature trends. The fact that our pf′ values (even for 30-year TLT trends) are sensitive to the addition of a single year of observational data indicates the dangers of ignoring the effects of interannual variability on signal estimates, as was done, for example, in Douglass et al. [2007].

Because of the large effect of year-to-year variability on decadal trends, roughly 10% of the 10-year TLT trends in the 20CEN/A1B runs are less than zero (Figure 4A). This result shows that anthropogenically forced models can replicate the recent muted warming of the surface [Easterling et al., 2009; Knight et al., 2009] and the lower troposphere. Claims that minimal warming over a single decade undermine findings of a slowly-evolving externally-forced warming signal [e.g., as in Investor’s Business Daily, 2008; Happer, 2010] are simply incorrect.

On all timescales examined here, the TLT trends in the observational satellite datasets are not statistically unusual relative to model-based distributions of externally forced TLT trends. While this consistency is encouraging, it should be qualified by noting that: 1) The multi-model average TLT trend is always larger than the average observed TLT trend; 2) As the trend fitting period increases, values of pf decline, indicating that average observed trends are increasingly more unusual with respect to the multi-model distribution of forced trends. Possible explanations for these results include the neglect of negative forcings in many of the CMIP-3 simulations of forced climate change ), omission of recent temporal changes in solar and volcanic forcing [Wigley, 2010; Kaufmann et al., 2011; Vernier et al., 2011; Solomon et al., 2011], forcing discontinuities at the ‘splice points’ between CMIP-3 simulations of 20th and 21st century climate change [Arblaster et al., 2011], model response errors, residual observational errors [Mears et al., 2011b], and an unusual manifestation of natural internal variability in the observations (see Figure 7A).

JC comment:  Note that the CMIP3 simulations were the basis for the “very likely” in the attribution statement, which was the subject of the uncertainty monster post.

Although we considered three different observational estimates of TLT changes (and one observational estimate of SST changes), our analysis does not comprehensively explore the impact of data uncertainties on model evaluation.

In summary, because of the effects of natural internal climate variability, we do not expect each year to be inexorably warmer than the preceding year, or each decade to be warmer than the last decade, even in the presence of strong anthropogenic forcing of the climate system. The clear message from our signal-to-noise analysis is that multi-decadal records are required for identifying human effects on tropospheric temperature. Minimal warming over a single decade does not disprove the existence of a slowly-evolving anthropogenic warming signal.

Pielke Sr only has minor criticisms of the paper.  Looks like the editor doesn’t need to resign over this one :)

How well do CMIP3 models do in simulating natural internal variability?

Lets take a look at Fig. 9.7 in the IPCC AR4 WGI Report:

Figure 9.7

Figure 9.7. Comparison of variability as a function of time scale of annual global mean temperatures (°C2 yr–1) from the observed record (Hadley Centre/Climatic Research Unit gridded surface temperature data set (HadCRUT3), Brohan et al., 2006) and from AOGCM simulations including both anthropogenic and natural forcings. All power spectra are estimated using a Tukey-Hanning filter of width 97 years. The model spectra displayed are the averages of the individual spectra estimated from individual ensemble members. The same 58 simulations and 14 models are used as in Figure 9.5a. All models simulate variability on decadal time scales and longer that is consistent with observations at the 10% significance level. Further details of the method of calculating the spectra are given in the Supplementary Material, Appendix 9.C.

The point I want to make (and I made this point point in the Uncertainty Monster paper) is  globally, the modeled spectral density of the variability, when compared with observations, is too high for periods of ~ 8-17 years, and too low for periods of 40-70 years.   Because this is a log-log scale, it is somewhat difficult to eyeball this, and one might argue that this is all within the range of uncertainty of the climate models and the climate models and observations agree ‘ok.’

In the context of Santer et al.’s conclusions regarding “Trends >17 yrs are required for identifying human effects on tropospheric temp.”, they might be in store for a surprise if the cool phase of PDO (nominally of 60 year period) persists for 30 years.  The model’s failure to capture the observed level of power in the periods 8-17 years and 40-70 years has biased Santer et al.’s conclusion towards the low end of the spectrum.

JC conclusion.  Santer et al. have laid down the gauntlet with this paper in terms of providing a method for falsifying climate  model simulations for the purpose of attribution of 20th and early 21st century temperature variations.  It would be interesting to see the same study conducted for the CMIP5 simulations, but I suspect that there might not be much of a change.

So, what are your bets for the duration of the current period of “minimal warming” ?

353 responses to “Santer on timescales of temperature trends

  1. Time is important for sure. What goes around comes around all over again—e.g.: BOOMS–> tulip bubble, dot-com bubble, housing bubble, silver bubble, gold bubble; BUSTS–> ’29, ’87, ’00; BANK FAILURES–> ’30s, ‘80s, ’08; HYSTERICAL FEAR OF GLOBAL COOLING–> ‘70s; SUPERSTITIOUS FEAR OF AGW–> ’90’s…

    • Very timely …

      timely = ‘subjective’ experience
      (independent experiences are reconnected by reminiscence across a timely interval)

      timeless = ‘objective’ experience
      (All experiences are viewed as timeless and stable in their granular isolation)

      Not being argumentative here, just pointing out that there two approaches to continuity/discontinuity

      ‘Subjective’ = reconnecting independent discontinuous objects
      ‘Objective’ = maintain a continuum of isolated and robust objects

      One approach isn’t better nor worse than the other. Most of all, it gets hugely confusing when the fundamental distinction between ‘subjective experience’ and ‘objective experience’ either gets forgotten or fails to get noticed at the outset.

      • Obviously the IPCC would have everyone believe it is ‘very likely’—i.e., there is a ‘greater than 90 percent likelihood’—that America is destroying the world with global warming caused by human CO2 emitted from American tailpipes. Naturally, the Official Science of the government science authoritarians like at the EPA already has been falsified by reality because human CO2 has gone up whereas global temperatures have gone down. Interestingly and even the IPCC has admitted temperatures have plateaued.

      • As I intoned in my previous response, it is crucially important to identify and separate ‘subjective’ and ‘objective’ assertions.

        The predominate misunderstanding and route to failure in all this ‘climate business’ arises from:

        a) the confusion that comes of subjective experience.
        b) the inherent difficulty in remembering or recalling the (subjective) context

        I do NOT suggest that ‘subjective’ or ‘objective’ appreciation is inferior or superior. They are different things, each with advantage and limitation.

        If anything there is too much emphasis placed on the ‘objective’ viewpoint. That’s because everyone is a sucker for a sure bet. A clearly presented ‘objective’ argument is convincing to subjective and objective thinker alike.

        Subjective arguments are diminished and dismissed as soon as they are recognized as being ‘subjective’, specifically because those arguments are recognized as being subjective. Hence ‘subjective’ arguments automatically become imbued, entangled and discharged precisely because they are ‘subjective’ arguments. … Yuk.

        I’m not trying to be pedantic or argumentative here. ‘Subjectivity’ is a very difficult and confusing topic. For example ….your very own assertion is to claim that the IPCC is being ‘subjective’.

        Obviously the IPCC would have everyone believe it is ‘very likely’—i.e., there is a ‘greater than 90 percent likelihood’—that America is destroying the world with global warming caused by human CO2 emitted from American tailpipes.

        By golly [*] your are correct there! The IPCC couldn’t possibly be more if they had tried to be such. That’s because they are deliberately trying as hard as humanly possible to be subjectively manipulative. They have been exceedingly effective and successful at doing exactly such a thing.

        Your very own response is essentially a re-action to being handed a subjective stinker and being told to eat it whole and without garnish.

        You know when you are being given a truckload of crap. You sir, are the lucky recipient of a freight car full of crap. Enjoy it, make use of it or curse it … Like it, lump it or dump it. That’s how it is. Goodbye

        In essence you have used your subjective sensibility to recognize that you have been handed a load of ‘subjective’ crap. You don’t like that …

        Your response amounts to saying … My ‘subjective’ sensibility suggests that I am being fed dubious SubjectiveNonsense
        To add insult to the injury, you get ridiculed for possessing worthless delusional subjective sensibility.

        ‘Subjectivity’ is one massive confusing problem. Please don’t blame the objective people of the world for that. They have their hands full, avoiding terminal HeadUpAz blind sightedness.

        As difficult and confusing as the topic of subjectivity might be, it isn’t the objective thinker’s strong suit.

        Be subjective. Use the sensibility that you know and have good reason to trust. Just don’t forget the skill is ‘subjective’ and it has worth and pertinence all of it’s own.

        I apologize if I have inadvertently offended or flustered you. .. Sincerely that is not my intention. I am on your side.

        [*] By Golly …
        By Gollywog … [blush] .. another inadvertent subjective throwback to the past. Never realized that before just now.

      • When you fully understand the scientific method you will realize that the issue of “subjectivity” has everything to do with the honor of the scientist and nothing to do with the method. That is not to say that some scientists eschew subjectivity and still reach erroneous conclusions. For example, no matter how strong the relationship or your belief may be it still is not correct to conclude that marriage is the leading cause of divorce.

        As Koutsoyiannis et al. have said that, “falsifiability is an essential element of science (Popper, 1983), the scientific basis of climatic predictions may be disputed on the grounds that they are not falsifiable or verifiable at present. Such a critique may arise from the argument that we need to wait several decades before we will know how reliable the predictions may be. However, we maintain that elements of falsifiability already exist. These should be traced in at least two directions: in the very structure and core hypotheses of GCMs and the related modelling practices, and in the agreement of model results in past periods with reality (hindcasting or retrodiction).”

        heverunderstand why s

  2. Interesting.

    The 17-year figure startled me when I started noticing it myself, too, on the data.

    Still, I think the odds of getting people to stop wasting our time with sub-17-year trend analyses infinitessimal.

    • Also:
      “Trends >17 yrs are required for identifying human effects on tropospheric temp.”

      Says nothing about using shorter periods to rule out estimates of warming that are above the canonical 2C per century.

      • Steven Mosher

        You’ll have to expand on your mathematics and reasoning on that assertion.

        As it pretty much says exactly that shorter periods can’t be used for squat.

        At least not by honest brokers.

      • Bruce

        Most of the models show several 10 year periods of cooling, generally between 5 and 17 such periods over the total runs.

        You can look that up for yourself.

        It was previously much-discussed here on a couple of old threads.

      • Not much of an answer. Did Santer archive his data?

      • Bruce

        Not much of an answer given because it’s not much of a challenge to look up the model runs for yourself and count downward 10-year trends.

        Or to Google, if your Google-fu is strong.

        It’d be a worthwhile education.

        I mean, it was good for me when I did it for myself from nothing.

      • Bart, I’m not going to do your research for you. You made a claim.

        At least Mosher pointed out the A1B model predicts anywhere from -.2C to .6C. Kind of a joke really.

        A .8C spread in predictions for just 10 years is kind of like a casino gambling putting a chip on every number in roulette.

      • actually not bart.

        What it says that trends longer than 17 years are required to identify the human contribution. It says nothing about testing the magnitude of hypothesized warming trends

        A simple thought experiment will show you how shorter trends can be used for other purposes.

        If the hypothesis is that warming will increase at 1C per decade, and if we observe a cooling of -20C in 10 years, then we can conclude that the estimate of 1 per decade is high.

      • Steven Mosher

        Your example would be pretty exactly what we couldn’t conclude.

        Were the hypothesis that warming will increase at least 1C/decade averaged over a millennium at 95% confidence, nineteen times in twenty, given the noise in the signal, all other things being equal, we’d first need 17 years at least to get some kinda sketchy data, and then could begin calculating from the set of subsequent running or independent 17 year spans (a different calculation for each, depending on the PDF) the probability that a -20C decade would be consistent with a +1C/decade hypothesis.

        This is simple accept/reject testing.

        One outlier means nothing; the more extreme the outlier, the less likely it is to reflect on the regular modality of the system.

        If each of the subsequent 20 independent decades were on average a 2C rise, for example, our confidence in the hypothesis would be extremely high.

        Loosey goosey made up nonsense parameters that allow infinite degrees of ambiguity mean nothing.

      • “averaged over a millennium”

        The ultimate con.

        Warmenista: “Nyahh nyahh. You can’t prove us wrong for a 1000 years.”

      • Bruce

        I don’t like the way the mathematics of Las Vegas house odds, federal taxes, or calorie intake work either.

        Doesn’t mean gamblers aren’t losers, taxpayers don’t have to pay what they owe, or deep fried Krispy Kreme cheeseburgers don’t make you fat.

        If you’re choosing the battlefield, don’t choose one that you can’t be right on for several hundred years.

        I certainly don’t like the AGW+/- argument for just this reason.

        But it’s fun to kibbitz with those chronologially-challenged obsessives who do.

      • The trouble with it cooling .05C since 2001 it that it is agreed that black carbon from China/India is causing more warming than their should be.

        Which means it is actually cooling MORE than .05C and in fact, it may have been cooling for way longer than the 13 year flatline.

        And if warmenistas are right about the .2C per decade warming caused by CO2, then maybe it even cooled by .3C over the last 10 years and only man’s black carbon, CO2, NOx etc all kept us from the next little ice age.

      • Bart R says

        “I don’t like the way the mathematics of Las Vegas house odds, federal taxes, or calorie intake work either.”

        What utter nonsense. Which number a ball falls into on a roulette wheel is a random event. Whether the temperature rises or falls is dependent on the natural laws of nature and nothing else. Trying to say that the current decade of cooling can be explained by such an analysis is nothing but a con job. The temps are not random events.

        Steve M. showed Santer to be unethical when he showed that Santer’s analysis of the accuracy of GCM’s was flawed. Santer had a decade of data (the present decade) that he could have included in his analysis, but he knew that including the recent flat-lining, dropping, of temps would give a result that he didn’t want the world to know about. Steve showed that the models are predicting too high a temperature rise by as much as 400%. Santer knew this but chose to hide the fact.

        You can see how your google-fu is working and look that one up. Can be found at climateaudit.com

        Anyone with the common sense of a dog realizes that the failure of temps to rise since 1998 is a BIG problem for the Gores of the world. This is just a poor attempt at trying to prove that it doesn’t mean that we are all going to die from CAGW. Nothing to see here, move along. Record high temps will be here shortly!

      • Whether the temperature rises or falls is dependent on the natural laws of nature and nothing else.

        You must be a conservative. Who else would divide the laws of nature into the natural and unnatural ones? Conservatives approve of some things nature does but are very disapproving of others, such as the prevalence of homosexuality in many species.

        Just kidding. More seriously, do you really believe that 7 billion humans can have no influence whatsoever on the temperature of the planet? Would this be equally true if there were a thousand times that many humans, or a million? At what level of population would you accept that humans can impact the planet’s temperature by say half a degree, when a single person can raise the temperature of a light bulb 5000 degrees just by throwing a switch?

      • Vaughn,

        What if there a thousand time less people? Would there still be an influence?

      • You mean 7 million people instead of 7 billion?

        That would depend. If all 7 million were flying daily between continents, the impact could be even greater than what we’re seeing today.

        If 1 million of them were into planting dirty nuclear bombs in sports stadiums and railroad tunnels, it might be interesting.

        If 100,000 were equipped with nuclear-tipped RPG’s, that could make a difference.

        It all depends on what they’re up to. If the 7 million are living in Fuller domes and surviving on pizzas delivered by camel I very much doubt their impact could compete with El Nino or the Atlantic Mutlidecadal Oscillation. Not by a long shot.

        It all depends.

      • Oh god, is that vrpratt moron back? Pay no attention to his rubbish.

      • Oh yeah, Mr. “no ad hom arguments here”? You’re a fine one to complain about the level of discourse here. Hope you’ve bought your asbestos suit in readiness for t

      • in readiness for the oncoming rise in temperature. Or is asbestos on your naughty list?

    • How to come with 17.

      13 years of no warming plus a fudge factor of 4 to ensure I get in a few more grants before I retire.

    • “The 17-year figure startled me when I started noticing it myself, too, on the data.”

      Amazing! “Using the identified climate signal as our spatiotemporal filter, normalized reconstructed components (RCs) were generated for all indices, each reflecting a multidecadal signal that centers on ~64 years.” Wyatt, Kravstov and Tsonis.

      How can one tell if a 17 year trend is anthropogenic or a pseudo harmonic of a pseudo cycle or would that be quasi-harmonic of a quasi-cyclic oscillation?

      • Dallas

        An intelligent question!

        Given the ontic problem space, we likely can’t tell if any one trend of any size has any particular meaning.

        We can, however, on the data, disqualify trends below a certain length as being meaningful on signal:noise alone.

        After that disqualification, all our other problems remain.

      • “We can, however, on the data, disqualify trends below a certain length as being meaningful on signal:noise alone.” Possibly.

        The quasi-cyclic oscillations are quasi-cyclic due to the degree of synchronization between several oscillations. I would agree with that statement if models reasonably represent or emulate the better known quasi-cycles. Some do fairly well with ENSO, but I not seen any that reasonably well emulate PDO. The impact of PDO may not be well known, but its rough timing is. If it were better emulated, the period 1998 to present could be useful for estimating sensitivity instead of explaining why the models are over estimating sensitivity.

      • Dallas

        These oscillations are also probably dynamically interdependent in an iterated series, making them ergodic, sensitive to initial conditions, and spatio-temporal chaotic.

        At best, we can suggest that signal:noise never falls below some limit; at the current time for the current data, given the current dynamically-dependent parameters of the system, 17 years seems the minimum.

        With multiple external forcings (particulates and CO2 likely the most important, but also land use and ocean harvesting possibly), and at least some of these forcings expected only to grow, it’s unlikely the minimum will decrease, and I expect it to rise again in time.

      • “17 years seems the minimum.” We will know better in a few years. I suspect that a longer period will be needed since this neutral cycle is likely to last and the current increase in forcing due to CO2 is likely producing a small signal. Land use at this point may have a stronger signal than CO2. Which brings me back to my issue with Global versus regional paleo reconstructions. There is a much stronger regional paleo signal that should be compared with regional instrumentation. Zack over at Lucia’s did an AMO versus North Atlantic SST that showed some degree of anthropogenic impact riding on internal oscillation.

        Instead of willy nilly dumping all the paleos in the blender, more focused regional-regional comparisons may be able to reduce required trend lengths.

      • Just what we do not need: regional attribution! But then we already have it in Arctic ice, etc.

      • David, LOL, I would suspect regionally during the regional Medieval Warm Period that Arctic Ice may have experienced an unprecedented melt, at least to the anecdotal Vikings settlers. That regional Sargasso Sea temperature reconstruction seems to indicate things have been happening climate wise in that region. Drought proxies in the US and Mexican deserts indicate climatic things have been happening. These may be meaningless for an accurate “global” temperature determination, but they give some pretty good clues about the internal oscillations.

      • Dallas says: “Some do fairly well with ENSO, but I not seen any that reasonably well emulate PDO. “

        There’s really no reason for models to try to reproduce the PDO, since the PDO does not represent the Sea Surface Temperature anomalies of the North Pacific, north of 20N. In fact, the PDO is inversely related the multidecadal variations of the North Pacific SST anomalies. This is easy to see when we detrend North Pacific SST anomalies and smooth them with a 121-month filter (same method NOAA/ESRL uses for the AMO) and compare it to scaled and inverted PDO data.
        http://i52.tinypic.com/15oz3eo.jpg

        The graph is from this post:
        http://bobtisdale.wordpress.com/2011/06/30/yet-even-more-discussions-about-the-pacific-decadal-oscillation-pdo/

      • Bob Tisdale said, “There’s really no reason for models to try to reproduce the PDO, since the PDO does not represent the Sea Surface Temperature anomalies of the North Pacific, north of 20N.” That is true but no reason for the models not to attempt to emulate the general impact of PDO on climate. The climate shift due to PDO over the oceans may produce little if any change to SST, but that same shift over land masses would produce a sizable change due to the differences in land versus ocean thermal characteristics. Like this year in North America. The increased snowfall provides a stronger high for the longer persistence of the Hadley cell allowing for la nina neutral to a new la nina where less snowfall would tend to reduce the strength of the Hadley cell. That is what climate models should be trying to model.

      • Dallas says: “That is true but no reason for the models not to attempt to emulate the general impact of PDO on climate.”

        Since the PDO is an aftereffect of ENSO, first they’d have to be able to reproduce ENSO. And they aren’t close to doing that.

        Some of the misunderstandings about the PDO are generated by the fact that the PDO data has been standardized, giving it the appearance of a signal that’s comparable in strength to ENSO. But if we compare the 1st Principal Components of Detrended NINO3.4 SST anomalies and the 1st Principal Components of Detrended North Pacific SST anomalies north of 20N (basically the PDO) without standardizing either dataset, we can see that the ENSO signal dwarfs the PDO signal.
        http://i54.tinypic.com/2im3xag.jpg

        I agree, however, that the climate models should be able to reproduce the multidecadal variations in North Pacific, North Atlantic, and NINO3.4 SST anomalies. I’ve recently downloaded and plotted the ensemble members of one of the CMIP5 SST hindcasts and the AMO or ENSO are nonexistent. I’m working on a post about it. And I think I’ll add the North Pacific multidecadal variations as well to highlight another component of the instrument temperature record that’s missing from the hindcast.

        Regards

      • Bob,

        I look forward to reading that post. I was trying to make sense of the PDO a while back. To me it was like a shift indicator with an upper and lower threshold, like two competing variations slightly out of phase. I was thinking that the eastern north pacific and western north pacific where competing variations with the central north pacific along for the ride. Interesting, but too much going on.

        The southern Pacific is kind of boring to watch, but it seems to have a better correlation to solar, very small of course, but a big ocean with a small change can do big things. Do you have data showing the northern versus southern hemisphere ocean heat content? I think that may be useful for predicting things.

  3. “Models run with human forcing can produce 10-year periods with little warming”

    Dog bites man? Could it be that human forcing is so small as we should wonder why agw hysteria and political opportunism ever got this far? I think so.

  4. I’m betting that, whatever the answer is, someone will eventually write a paper stating that the answer +1 will be the ["Trends required for identifying human effects on tropospheric temp.”].

    Furthermore, if we get another warming trend for the next ten years, can we effectively dis-count that also?

    This is yet another example of people trying to provide pseudo-scientific reasons (excuses) why the observed data does not match the modelled theory. Just move the goalposts…

    • Arfur

      They’ve just moved the goalposts from the original 30-year minimum to a 17-year minimum.

      That’s a substantial move closer, not further.

      You’re complaining that the truth is more accessible?

      Oh. Silly of me. Of course you would.

      • I am excited that the truth is more accesible. Bring it on!

      • Edim

        Likely, it’s not going to get much truthier on straightforward brute-force reasoning.

        See Dallas’ intelligent question above for one obstacle.

        Still, the Monster Wranglers ™ have done a significant job, and with a bit more uncertainty-wrestling, it’s possible someday a satisfactory solution will be finessed from this topic.

      • Bart R,

        I realise that sarcasm is an habitual refuge for many posters on this site, so I’ll ignore it. As to your other stuff…

        What original 30-year minimum?
        Closer to what?
        The truth is that I can give you an observed 160-year trend of just 0.06C per decade.
        And its not getting any steeper!
        Why use a 17-year trend now?
        .
        How come no-one explained that we should not be surprised at a thirteen-year ‘no warming’ period when the temperatures were going up? I seem to recall it was all ‘doom and gloom’. That’s what was sold to Joe Public. You guys must be sooooo angry that Gaia isn’t playing ball with your cAGW theory.

        No accelerated warming.
        No accelerated sea level rise.
        Accelerated CO2 increase.
        Hmmm….

      • Arfur

        You’ve misidentified figures of speech.

        This is not uncommon among those who have learned speech from the Internet. My usage was meiosis, not sarcasm.

        I was obviously implying by suggesting lightly that you preferred the truth be less accessible that you clearly prefer deception, as indicated by your heavy-handed assertions from ignorance.

        Sarcasm would’ve been if I’d said, “What a brilliant thing to say, there, Arfur! A picture of honest inquiry you are!”

        Original 30-year minimum? I refer you to the first IPCC Assessment Report (FAR), 1990. (www.ipcc.ch)

        The quality of your objections doesn’t merit more precise reply, as it appears you must be unfamiliar with the entire document, and would benefit from a peruse of it and its following generations. How can you call the play-by-play if you’ve never learned the rules of the game, much less seen the field?

        Closer to what? Well, if we knew what the outcome would be ahead of time, then would we really need to go looking?

        Why 17-years now? Because that’s what the math tells us about the ratio of signal to noise, just as it would for any problem containing a signal-to-noise ratio. Didn’t you read the top of the thread?

        How come no one explained that we should not be surprised? Because we are treated like adults who can think for ourselves, and figure out from being told that observations representing spans shorter than 30-years would be useless that we shouldn’t use 13-year spans. Thirteen being less than thirty.

        And.. I was explaining it. Over and over again. On this blog. To Girma. Who never figured it out.

        Now, I don’t know Joe Public personally, but if he’s mad at what was sold to him, I suggest he take it up with Girma personally, who managed to have his too-short-span views repeated online hundreds of thousands of times. And this Gaia person, I’m also unfamiliar with. However, I should disabuse you of the notion that I have a cAGW theory.

        To me, +/-AGW is a dead end because of the obvious difficulties with resolving the problem; I personally prefer to sidestep +/-AGW in favor of the sufficient grounds of first principle Chaos Theory.

        However, from the point of view of an outsider, the +AGW types are clearly making the far better case, and on the multi-century scale, +cAGW looks like a strong candidate too, as argued by those who back it.

        No accelerated warming? Accelerated CO2 increase?

        Let’s compare, side to side: http://www.woodfortrees.org/plot/esrl-co2/mean:204/offset:-330/scale:0.008/plot/hadcrut3vgl/from:1957/mean:204

        It appears you owe graph paper an apology.

      • Silly me – and there I was trying to determine if the Bart signal to noise ratio – credibility – was at all measurably greater than zero. It slipped into negative territory with cell division – i.e disinformation and big noise.

        This is not the problem with climate change. The problem there is a small signal and big noise – at least initially. We find that the computer generated ‘internal variability’ decreases in amplitude with increasing trend length.

        Do we really believe that that ‘noise’ amplitude decreases with time in a spatio-temporal chaotic system? What is the nature and source of the ‘noise’? Should we believe a 23 year warming interval because it is more than 17 years or disbelieve it because it is less than 30?

        Of course it ceases to be noise if predicted beforehand from physical oceanography – here is my 2007 effort – http://www.americanthinker.com/2007/11/enso_variation_and_global_warm.html. Written after the AR4 totally stuffed up by ignoring what was obvious about decadal variability. I was confidently expecting natural variation to have a higher visibility for years before that.

        There are a couple peer reviewed articles that suggest – as a result of Pacific variability especially – that the world is not warming over the next 10 years (Mochizuki et al 2010, Swanson et al 2009, Tsonis et al 2007, Keenlyside et al 2008).

        What we really have is a signal of natural variability – and a very small and disputed anthropogenic signal.

        The problem with these people – I keep saying – is the AGW version of a spaceship cult. Fitting facts to a theory rather than the other way around.

      • Bart R,

        Well, we have established your level of debate. It’s a shame someone of your obvious intelligence has to resort to such a puerile use of sanctimony but I’ll try not to lower myself to responding in kind – if you don’t mind.

        Actually, my reference to your use of sarcasm was not what you thought it was, but to your final sentence. Be that as it may…

        OK, your 30 year rend reference was from FAR. Now you have given it a reference, I know to which 30-year minimum you were referring.

        “Closer to what? Well, if we knew what the outcome would be ahead of time, then would we really need to go looking?”

        Well, if you don’t know the answer, why ask the rhetorical question in the first place? You stated:
        “That’s a substantial move closer, not further.”
        I repeat, closer to what? You must have had some idea when you wrote it.

        “How come no one explained that we should not be surprised? Because we are treated like adults who can think for ourselves, and figure out from being told that observations representing spans shorter than 30-years would be useless that we shouldn’t use 13-year spans. Thirteen being less than thirty.”

        Now a closer look…
        You have decided that you are happy with Santer’s use of a 17-year minimum based on the S/N. And yet, you also state that, being adults, we can figure out that observations representing spans shorter than 30 years would be useless! Make your mind up. Of course 13 is less than 30. So is 17. So lets see whether the use of a 17 year trend makes any difference, shall we? Seeing as how you like to manufacture woodfortrees graphs to suit your argument…

        http://www.woodfortrees.org/plot/hadcrut3gl/from:1980/to:2010/trend/plot/hadcrut3gl/from:1980/to:2010/plot/hadcrut3gl/from:1993/to:2010/trend

        The same trend! 0.016Cpd. So, now that you prefer the use of 17-year trends (because it is closer to some ‘truth’ of your own choosing), we only have another 3.5 years to go before we reach a point where you will be happy to use the 17 year trend from 1998. How confident are you that it will show either an accelerated warming or even a warming at all? To beat 0.16Cpd, we will have to witness a 0.67C increase in the next 3.5 years! If we don’t see that increase, will you then assert that your 17-year minimum trend is still valid?
        .
        I also note you have ignored my point about the 0.06Cpd trend over 160 years. If you are happy for a 17-year minimum trend length, surely you are happy at a trend of 160 years? Yes?
        .
        Now to your woodfortrees graph…
        You have had to use a 17-year smoothing to make your point. Well done. Anyone who has to do that to a graph displays insecurity regarding his case. The start date of 1965 is curious. Could it be that you wished to cherry-pick the warming period of ca1970 to 1998? Why did you not include the warming period (of roughly equal dimensions) of 1910 to 1943? Did the CO2 data not match up that well? Oh, and of course, the use of 17-year smoothing will nicely (partially) remove the embarrassing (for the warmists) lack of increase after 1998.

        Bart, you are erudite and bright. You also argue from a belief in the efficacy of the radiative forcing theory leading to cAGW. Someone with your intellect should at least try to be objective. Instead of cherry-picking your trend length, use the overall trend since accurate data began (according to the IPCC). Explain why the overall trend today is far lower now than it was in 1878 and slightly lower than 1998. If those that believe in cAGW are correct, then the overall trend WILL HAVE to start increasing. You must realize this. If the trend does not increase, then the theory is wrong.

        I have to disagree with your statement about cAGW being a strong candidate.

        I also suggest that you owe logic an apology.

      • @Arfur Bryant: Bart R: Well, we have established your level of debate. It’s a shame someone of your obvious intelligence has to resort to such a puerile use of sanctimony but I’ll try not to lower myself to responding in kind – if you don’t mind.

        Try not to? You just did, Arfur. Well lowered.

      • @Arfur: I also suggest that you owe logic an apology.

        When A suggests that B apologize to C, there is the tacit assumption that A is acquainted with C. This is demonstrably not the case here.

      • Chief

        Let’s play a game.

        One of these things is not like the others.

        http://www.woodfortrees.org/plot/esrl-co2/mean:360/offset:-336/scale:0.009/plot/hadcrut3vgl/from:1958/mean:360/plot/jisao-pdo/from:1958/mean:360/offset:-0.01/scale:0.5

        Red, Green, Blue.

        Can you guess which one before I end my song?

        Sure, we have more problems than just signal:noise.

        However, signal:noise is a fairly elementary step.

        Whereas the noise of unwarranted analyses, that’s signal-free.

      • Chief

        I think it hilarious, however it is a valid way to compare too little poor information to too little poor information.

        Smooth by 30-year mean to eliminate noise in the original, and perform the same smoothing so all curves may be compared as like-to-like.

        Offset subsequent curves to bring all curves to the range of the original comparator.

        Scale to bring all subsequent curves to the span of the original comparator.

        I recognise PDO is not ENSO, indeed they have a somewhat inverse relationship; however given how strongly connected they are, any ENSO signal significant enough to influence global temperature trends ought survive in PDO.. which clearly there is no sign of at all.

        The curves that fit are CO2 and temperature.

        It appears suggestive that at first CO2 leads temperature rise, and then temperature rise begins to lead CO2 rise. It could be just an artifact of the data; it could indicate positive feedback.

        It could all be coincidence.

        However, it suggests anyone claiming no connection of CO2 to temperature is flat out blind to fact.

        As would anyone claiming a dominant ENSO-global temperature contribution on the scale of the influence of CO2 in the long term.

      • Chief

        A picture is worth a thousand words.

        http://www.woodfortrees.org/plot/jisao-pdo/mean:360/plot/hadcrut3vgl/mean:360/from:1915/scale:1.6/plot/esrl-co2/mean:360/offset:-337/scale:0.015

        Can’t prove AGW beyond doubt, but does disprove you very persuasively.

      • Arfur

        per http://judithcurry.com/2011/09/12/santer-on-timescales-of-temperature-trends/#comment-111789

        I can’t claim to being terribly bright. I’m here, aren’t I? Also, as to erudite, that’s a term rendered moot by Google.

        Oh. My last line was, and remains, sincere. I suggest you reappraise my level of debate and peg it somewhat lower.

        As 17 is shorter than 30, we are nearer the limit of determining salient conclusions pertaining +/-AGW, by now being able to approach answers to statistical problems possibly as much as 43% sooner with some level of veracity.

        Though, as these are statistics about largely linear questions in a nonlinear system, that approach is of somewhat dubious merit.

        So I do not know, nor do I endorse predetermining the answer, though I admit it takes a fine lunacy to fail to recognise the strength of the +AGW argument, just as much as it takes some stubborn streak to continue on +/-AGW at all when there is a satisfactory result to be had from more reliable analyses in the Chaos Theory realm.

        This is like watching two men arguing what side of the ship is leaking when they’ve got a hoist that will raise them, ship and all, above the water. Fascinating, but pointless.

        Now, as to 30 and 17.

        30 comes from FAR, you recognise the reference, therefore must know its basis. 17 is from Santer et al. (well, also from the data, you could find it yourself using Santer’s or other methods).

        As Santer came out two decades after FAR, hard to fault the use of 30 prior to Santer; likewise 30 remains a better basis for comparison, Santer’s merely found the present s:n span for the data. If you call that ‘happy’ considering the ample conditions and contraindications above, more power to you. If you call it ‘prefer’ then you’re just being a simpleton.

        Looking at your graph and its hamfisted trend lines, you confirm you’re one of those accelerationists or predictionists who think the climate like a billiard table with one ball that must be pocketed on one shot.

        The post-1993 period has seen a number of strange events come together, from ENSO (which, though it’s hardly all Chief claims, is not nothing) to particulate levels to the Arctic thaw and so on.

        So it seems we run into one of two equally likely perspectives on data in this range of time that both fit the observations better than your inflated claims: a) uncertainty tells statisticians to say “19 times out of 20″ after their PDFs, and we’re at that 1 in 20 exception; b) did you miss the part about bifurcation in dynamically complex chaotic systems?!

        “To beat 0.16Cpd, we will have to witness a 0.67C increase in the next 3.5 years!”

        May as well say if the coin comes up heads on the first toss, it’s two-headed.

        Silly meaningless argument betraying utter failure to apprehend probability you have there.

        Yes, Arfur, I ignore much of what you say. In case no one has told you yet — though I cannot imagine it likely — most of what you say is worth ignoring.

      • Bart R,

        So, just to get this straight, you ignore the 160-year trend in favour of a 17-year trend?

        By your argument, we should accept – in 3.5 years – the 17-year trend starting in 1998 as an efficient indicator of whether or not the cAGW theory is valid.

        I do hope you are still around so that we may discuss it again…
        .
        Do you actually believe that there is some sort of scientific justification for your belief in the radiative forcing theory of significant or catastrophic AGW?
        .
        The global temperature – as far as it can be measured – has increased about 0.8C in 160 years since the start of accurate data recording (according to the IPCC). Those same datasets indicate that the gt today is about 0.3C less than it was in 1998. These are facts, Bart, or as close as the cAGW debate allows. Your acceptance of a 17-year minimum trend is likely to leave you in an uncomfortable debating position if the current lack of warming continues for a few years. Similarly, your logic of reducing the 30-year to 17-year as an advancement ["As 17 is shorter than 30, we are nearer the limit of determining salient conclusions pertaining +/-AGW, by now being able to approach answers to statistical problems possibly as much as 43% sooner with some level of veracity."] would lead to the logical conclusion that someone may soon come up with an even shorter “minimum trend length”.

        Bring it on and be careful what you wish for…
        .
        Please note I refuse to play your snark game. In spite of our opposing views, I do try to find respect for those opposing views even when they are not backed up with evidence.

      • I do try to find respect for those opposing views even when they are not backed up with evidence.

        Shove it, Arfur. Your BS on this blog is getting old.

      • Chief

        For you, I’ve Girma’d your PDO curve to make it look like it means something.

        http://www.woodfortrees.org/plot/jisao-pdo/mean:360/detrend:-3/plot/hadcrut3vgl/mean:360/from:1915/scale:4.9/offset:2/plot/esrl-co2/mean:360/offset:-298/scale:0.05

        Doesn’t that make you feel better?

      • It is not my PDO curve at all – you are just playing with yourself. I can see no point in bothering with you at all – but you insist on stalking me for some reason only you know in your madness.

        http://www.realclimate.org/index.php/archives/2009/07/warminginterrupted-much-ado-about-natural-variability/

        http://i1114.photobucket.com/albums/k538/Chief_Hydrologist/Wong2006figure7.gif

      • you insist on stalking me for some reason only you know in your madness.

        We bystanders know why he’s “stalking” you, CH, if that’s the word for it. If he’s mad, that’s understandable, anyone with half a brain would be driven mad by your non sequiturs.

      • Vaughan,

        You are a serial pest.

        Cheers

      • Arfur

        per http://judithcurry.com/2011/09/12/santer-on-timescales-of-temperature-trends/#comment-112113

        (As an aside, for those wondering at Chief’s dismay and Vaughan Pratt’s chagrin at Chief, the red-blue-green graphs suggests CO2 is two or more orders of magnitude better at explaining temperature rise than ENSO on timescales exceeding six decades. Given that Chief’s bet the farm, or at least his Hydrological credibility, on ENSO over AGW, it’s a significant blow to the core of his being. And it’s in such a methodologically solid form that anyone seeing Chief’s reaction might feel the same disgust as they would at a grown man throwing a temper tantrum like a toddler.)

        Do I ignore the 160-year trend?

        Not at all.

        I favor the greater data over the lesser, so long as the analysis is valid.

        Which is why I ignore your claims pertaining the 160-year trend, Arfur. They are invalid.

        Let’s look at the logic of claiming that what I’ve said implies that cAGW might have an ‘efficient indicator’ as reflected in 3.5 years..

        No, let’s not, it’s too offensive to reason on too many levels and in too many ways to allow your words-in-the-mouth straw man inversions to stand as anything but worth ignoring, except to revile in disgust.

        17 years is just a current signal:noise minimum timespan for the data. It’s an indication that looking at shorter spans is meaningless. It allows one to say about spans as short as 17 years that they may have some meaning much of the time for some uses.

        It doesn’t flip a switch and suspend logic because some scientist has invoked a mystic number that by repeating you can use in voodoo rituals to get science to do what you want. It is what it is, no more and no less.

        All this superstitious claptrap you toss around by investing the number with extraneous properties pulled out of your butt is mere annoyance.

        As the timespan is a property of the data, it is subject to change if the data changes in some ways. It’s unlikely to become shorter than 17 years in my opinion, and more likely to become longer over time.

        Persisting in engaging ‘since 1998′ trends ignores the very straightforward and simple logic that a trend less than 17 years long has too much noise to be meaningful.

        There’s no “as close as the cAGW debate allows” at all on your favorite year.

        It’s not allowed. Not because it’s cAGW, or Climate, or Science, but because of rather simple math.

        Even if there were 3.5 or 26.5 years of substantial cooling from today on, as a simple mathematical fact, there would be no proof or disproof of AGW in simple temperature trends; that has nothing to do with signal:noise, however, but with concepts like predicate probability and what can and cannot constitute a statistic called the Confidence Interval (http://en.wikipedia.org/wiki/Confidence_interval).

        The data too limited and the system too complex for this type of analysis to give much clarity. (Though I admit to being surprised by just how much good analysis some have accomplished, they still have a ways to go at great expense in time and effort.)

        Which is why I prefer to look at the whole +/-AGW discussion as merely of academic interest.

        The real and valid discussion is about perturbation and ergodicity, I think. There is the possibility of gathering useful information and making good surmise, such as will satisfy the needs of policy in terms of risk analysis in this arena.

        As for my blatant snarking, I do it in part for the purpose of avoiding sanctimony – the practice of appearing on the surface respectful or pleasant while harboring disguised foulness.

        Odd that I’ve achieved both snark and sanctimony at the same time somehow. Perhaps the words do not mean what I think they mean?

  5. AGW theory isn’t science: it’s more social than science and ‘very likely’ a mass social delusion. GCMs have no predictive ability whatsoever. The reasons for that are obvious and in fact, the logic is undeniable.

    According to the IPCC, ‘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.’ Obviously they have hoisted themselves with their own petard and their theory has blown up between their legs.

    The Earth has been in a cooling trend for a decade, a trend that Dr. Ball points out is ‘a trend that began in the Southern Hemisphere 10 years earlier.’ Using their own logic, based on what they believe is ‘very likely,’ the IPCC thought there was a ‘greater than 90 percent likelihood’ that global warming was caused by human CO2. Their ‘science’ has already been falsified by reality because human CO2 has gone up whereas global temperatures have gone down.

    GCMs fail because the IPCC and the model-makers refuse to admit that changes in solar activity have a significant effect on climate change. They simply do not acknowledge that it’s the sun, stupid.

    • Waggie

      How hard is signal-to-noise for you to grasp?

      If you’re expressing opinions about the globe, then the phrase “cooling trend for a decade” is meaningless.

      Other than meaning you can’t do math.

  6. This reminds me of a conversation I had with a Japanese executive many moons ago as to why his business plan didn’t show a profit for 22 years.

    His answer was simple, he was going to retire in 21 years.

    How long until Santer retires?

  7. Seems they’ve decided just in time that global warming doesn’t necessarily mean, you know, that the globe is actually warming..

  8. So, what are your bets for the duration of the current period of “minimal warming” ?

    Very droll.

    The authors have done half of a job. Next half: how long a duration do we have to observe to have at least an 80% of detecting the man-made warming, according to those models? This is an estimate of statistical power. If the models all produce 40-70 yr period oscillations, and if those oscillations are out of phase, model to model, then the answer might be indeterminate from the models, or else a very long duration (maybe hundreds of years.) If so, even a 40-year period with next to no warming would not definitively rule out AGW.

    • I agree, the whole thing is indeterminate from the models

      • Judith

        Wagathon said something very interesting above which is worth a paper in itself;

        “AGW theory isn’t science: it’s more social than science and ‘very likely’ a mass social delusion.”

        Some say that it has already become post normal which is intriguing as it seemed to have bypassed the stage of actually proving things beyond doubt. Therefore I wondered if there is a scientific definition of science and whether climate science does indeed fulfill all the criteria or whether it more closely fits the other states that Wagathon identified such as it being a mass social delusion .

        Tonyb

    • MattStat

      Thank you. Well said.

      Could you elaborate?

    • Re MattStatIf so, even a 40-year period with next to no warming would not definitively rule out AGW.

      Did you just switch the Null Hypothesis to AGW exists and science must now prove it does not?

      • Stephen: Did you just switch the Null Hypothesis to AGW exists and science must now prove it does not?

        Not exactly. What I did exactly was two things: (1) I suggested that a power analysis ought to be performed; (2) I inferred from what Judith wrote that no matter what happens in the next 40 years, it will be compatible with at least one of the simulations (or else the 40-70 year period oscillations would be in synchrony and clearly non-zero over the time span.)

        Next, to elaborate on your idea, if the Null Hypothesis is switched to the claim that AGW exists, the simulation results show (or probably show, I have not yet seen the complete paper), that it will be nearly impossible for any actual data to reject the null hypothesis at one of the conventional levels before 2050 or thereabout. Another way to say this is (again based only on the abstract), the authors have made a case that the AGW theory is not testable even in principle, as it is represented by those models.

        However, if someone were to put prior probabilities on those models, someone with great authority, then we could at least accumulate the posterior probabilities year by year, and see which models become the least supported. I said someone with “great authority” because there are likely to be many priors, and there will always be at least one model that can not be rejected because some group gave it a 99% prior probability.

  9. AGW True Believers continue to refuse to admit a single fact that is contrary to their Warmanist belief system. The truth is not their friend. Science is not their ally. Logic is their enemy.

     “Climate prediction is hard, half of the variability in the climate system is not predictable, so we don’t expect to do terrifically well,” and, “The weather is not predictable beyond a week or two.” (Dr. Jim Renwick)

     Dr. Hans von Storch described GCMs as ‘Quatsch.’ McShane and Wyner demonstrated yet again that MBH98/99/08 (aka, the ‘hockey stick’ graph) is a proven scientific fraud, observing that, “it is hard to argue that a procedure is truly skillful if it cannot consistently outperform noise–no matter how artfully structured.”

    • Wagathon

      Why do you keep confusing explicitly non-predictive models in an inherently unpredictable system with predictions?

      And.. relevance?

      • Question: Are AGW witchdoctors’ predictions of catastrophe based on the casting of chicken bones, numerology, tarot cards or some other for of jigger-pokery quackery?

        Answer: All of the above. It is the opinion, for example, of three of Japan’s leading scientists is that Climate science amounts to ‘ancient astrology’ and that climate change is the result of `natural cycles’ not `human industrial activity.’ Kanya Kusano wrote that the IPCC’s “conclusion that from now on atmospheric temperatures are likely to show a continuous, monotonic increase, should be perceived as an improvable hypothesis.” Shunichi Akasofu stated that, “We should be cautious, IPCC’s theory that atmospheric temperature has risen since 2000 in correspondence with CO2 is nothing but a hypothesis,” and cautioned that, “Before anyone noticed, this hypothesis has been substituted for truth… The opinion that great disaster will really happen must be broken.”

      • Wagathon

        Continuous monotonic increase?

        Bwhahahaha.

        Yes, we can dismiss anyone who uses that phrase about climate on spans averaged under 30 years out of hand, and even 40 year or more non-increasing spans wouldn’t invalidate even a sharply increasing trend.

        Which, as I’m not a +/-AGWer, couldn’t care less personally.

        However, with all due respect the good doctors, neither being a Dr. nor being Japanese imbues one with such magickal powers as to unseat mathematics, statistics, or physics.

        Which indicate that dismissal of the associated Risk is simply an error of reasoning.

      • The lesson of the McShane and Wyner chalkboard squeak heard ’round the world is not that M&W debunked yet again the MBH98/99/08 `hockey stick’ hoax-graph. Scrutinizing the uninspiring statistics of Mann and his sycophants’ silly-science has become a fun pastime for geeks. The math is not debatable: The more interesting finding was that there is absolutely no ‘signal’ in Mann’s proxy data. The ‘consensus’ is shot and the Medium has become the Message: all who claim there is a consensus of opinion pointing to humans as the cause of global are simply outing themselves as science pariahs.

      • Raving @ Bart R

        Never understood the painfully awkward Japanese need to avoid speaking of ‘unpleasantness’ in regard to Fukushima. Some comment somewhere on the ‘Web’ recently explained it convincingly … (paraphrased) …

        The Japanese strongly avoid mention of ‘ill fortune’. When such unpleasantness does get mentioned, it invites a tsunami of curmudgeons

        As for …

        neither being a Dr. … imbues one with such magickal powers as to unseat mathematics, statistics, or physics.

        Math/stats/phys is intensely preoccupied with “truth seeking” and “truth improvement”.

        Speaking crudely, … All thoughts about exploring “What we don’t know regarding that which is unknown?” were abandoned in the commitment to pursue “What we do know about that which is already known?”

        The hardship of uncovering meaningful worth in uncertainty by way of the pursuit of truthfulness is starkly revealed by the following irony. …

        The term “Bayesian”, which displaced “inverse probability”, was in fact introduced by R. A. Fisher as a derogatory term.

        For me, it isn’t about attacking math/stats/phys. Rather is is about struggling to ascertain where the math/stats/phys is appropriate and where the math/stats/phys is a blind sighted and extremely enticing tempest in a teacup.

    • Did you mean to say the truth is not their trend:-)

  10. “Models run with human forcing can produce 10-year periods with little warming”

    2001 – 2011 = .5C/century cooling

    http://www.woodfortrees.org/plot/hadcrut3gl/from:2001/plot/hadcrut3gl/from:2001/trend

    Which model shows .5C/century cooling as opposed to “little warming”?

    • What part of 17 years do you not understand?

      • It would appear the most recent 10 of ‘em.

      • 17 years is for human caused warming. 10 years of “little warming” is NOT “10 years of cooling”.

        I’m surmising that 10 years is enough to find non-human cooling.

      • “Trends >17 yrs”

        Which part of the open-endeness of “>” do you not understand ?
        Abritrary time-grabs are just par for the circus. If one pre-chosen time grab doesn’t work, why then, just choose another – preferably open-ended to avoid accountability

        CH seems to be correct – chaotic non-linear rules, predictions are pointless

    • Bruce the data that show trends LESS THAN what we have observed have been listed for aquite some time on Lucia’s

      http://rankexploits.com/musings/2011/where-is-the-trend-relative-to-all-runs/

      3.7% of model trends fall below the observed Hadley trend.
      7% fall below the observed NOAA trend
      15.5% fall below the observed GISTemp trend.

      Some model runs do show trends that are less than the observed trends.

      • “3.7% of model trends fall below the observed Hadley trend.”

        So the shotgun they were using to cover the whole target with pellets was missing ONE pellet?

        Very droll.

      • John Carpenter

        What’s amusing is you asked a question and then got an answer you never expected.

      • The answer was even funnier than I expected.

        I mean, when the model can produce predictions of -.2C to .6C over 10 years you might as well be flipping coins.

      • steven mosher

        Just a question (and not a “trick” one):

        If 15.5% of model runs fall below the observed GISTemp trend, does this mean that 84.5% of model runs are at or above the GISTemp trend?

        Wouldn’t 50-50 have been a better target?

        Max

  11. Dear Dr. Curry:
    Tropical temperature trend (say 32⁰N) is about equal to the weighted average temperature trend. Dr. Christy’s conclusion of 0.09⁰C±0.03⁰C /decade is in line with my theoretical projection completed in 2007. You will find that the present trend was projected at about 0.07⁰C /decade. Please see Table-1, page 58, and Table-5, page 60 of my book. Also, please see Table-5A page 44 of Article-12, Earth’s Magic.

    My bet for the current period is that the temperature trend will follow the path projected in my work, of course depending on the trend in the concentration of carbon dioxide, which varies with the state of the economy. Since I live in Las Vegas Area at this time, let’s make it the Las Vegas’s way. I’m willing to bet money, if that is OK with you Dr. Curry.

  12. Did the period that indicated great global warming as a crisis in 1998 last 17 years?
    How is 0 year for the 17 year period determined?
    What about 16 years or 18 years?
    How many years of data would it take to support the idea of the world climate facing a crisis?
    How many to falsify the claim?

  13. Dr. Curry writes “So, what are your bets for the duration of the current period of “minimal warming” ?”

    My bet is that the current period of minimal warming will turn into a period of actual cooling; possibly before 2020. Livingston and Penn’s trend line for sunspots to disappear is still holding up, and if this continues then the odds are that the coming Eddy solar magnetic grand minimum will be a Maunder type; with all that that implies. The predicitons of Smith el al, Science August 2007 will be shown to be completely wrong.

    As others have already noted, climate models have absolutely no predictiive ability at all, so the whole exercise is a complete and utter waste of time and effort.

  14. “If so, even a 40-year period with next to no warming would not definitively rule out AGW.”

    Clever isn’t it, this unfalsifiable hypothesis business. Heads I win, tails you lose, and don’t let the door hit you in the ass on your way out the door.

  15. Headpost: “So, what are your bets for the duration of the current period of “minimal warming” ?”

    100+ years, if the definition of “minimal warming” is less than 0.2 C/ decade. :)

    My other bet is that ocean heat content will be the key metric that finally really tells us the extent of global warming. We have pretty good current data on OHC, reasonably accurate data back to around 2003/2004. The ocean does a nice job of integrating the radiative imbalance, making the separation of short term and long term trends easier (note that I didn’t say separation of long term trends from noise — ENSO and other cycles like that are signals in their own right. Just of different timeframes).

  16. I simply can’t understand this statement: “This large change in S/N is primarily due to a decrease in the amplitude of internally generated variability with increasing trend length.” but this is completely at odds with the graph of climate noise/variability which shows that internally generated variability increases with increasing length.

  17. Two points. First, funny how we didn’t see predictions of ten year periods without warming until AFTER we had a ten year period without warming. Since when did science start making predictions about what has already happened? Is there a paper published before 2001 that predicted ten year periods without warming?

    Second point. What we have here is a basic failure to understand probability. We didn’t get a ten year period without warming – we got THE FIRST ten year period without warming. The proper question would be, what are the odds of getting a ten year period without warming during the FIRST TEN YEARS?

    The second point is an egregious failure of basic probability theory. The first is post-hoc Cover-Your-Ass-ing. It’s hard to decide which is worse.

    • MarkB,
      You are making a very interesting point. With most prophecies, the prophets are very careful to either make the prophecies far in the future, or ‘discover’ the prophecy after the event being predicted takes place.
      So we are at about year 13 since 1998.

    • Second point. What we have here is a basic failure to understand probability. We didn’t get a ten year period without warming – we got THE FIRST ten year period without warming. The proper question would be, what are the odds of getting a ten year period without warming during the FIRST TEN YEARS?

      Perhaps the proper question ought to be “What are the odds of a second successive ten year period without warming?”. Here’s hoping I’m still alive to watch them wriggle!

  18. Judith Curry says “Pielke Sr only has minor criticisms of the paper. Looks like the editor doesn’t need to resign over this one :)”

    Au contraire, one of the reasons given by Wagner for his resignation was that Spencer and Braswell failed to cite prior relevant papers. Pielke Sr. notes that Santer et et et et al failed to cite or discuss Christy et al , 2010: “What do observational datasets say about modeled tropospheric temperature trends since 1979?”

    Has anyone heard of resignations in AGU leadership and/or Journal of Geophysical Research editors?

    • Maybe Wagner really resigned because he got a better job offer? [Or maybe the act of resigning, itself, was based on an offer too good to turn down?]

      Let’s see where he pops up.

      • These editorial jobs are not usually paid positions. As an academic one does this for free because of the prestige associated with editor positions.

      • Open-access journals are really commercial enterprises that take advantage of the system. All the editors volunteer, there is minimal review and editing, and the article processing fees are often $1000 per article. They then have dozens of categories, some of the newer volumes with $0 teaser rates. When scientists start publishing at the teaser rates, then they jack up the processing charge and it gets locked in.

  19. Mark,

    All very nicely said. Thank you. That second point is especially damning it seems to me. Moreover it looks likely that the next ten years will see cooling, and the decade after that even more cooling with the AMO switching from warm to cold. And God only knows where we’ll be if another Dalton minimum kicks in.

  20. Regarding short time period analyses. Does a model that shows high climate sensitivity have the same behavior and likelihood as one with low sensitivity? I would think that the high-warming models would be more likely to show this, and as such Mosher is right that you can reach some conclusions about which side of 3C is the better bet.

    Santer says 17 years. Is it right that the current situation is no signal since 1998? That is 13 years. Sounds like a 4-5 year window for the planet to exhibit the signal or science must be reevaluated, right?

  21. Hey Dr. C.
    I just had a thought (I know. You’re right. Rare occurence.) But I often wonder about the backgrounds of many of the regular poster here. Would you consider a thread wherein those who wanted to could post a little bit about themselves?

  22. One should not forget the fact that if we have 13 years of no warming so far, it doesn’t necessarily take 17 more years of no warming to get to the 30 years of no warming. If the cooling in this decade is sufficient, we can have 30 years of no warming in only 9 years (2020). Hypothetically.

  23. Spectral analysis, unless properly understood may lead to very misleading conclusions, here are shown four essential things one needs to be aware of all the time:
    http://www.vukcevic.talktalk.net/SR.gif
    On the other hand there are again unnoticeable data curiosities, this graph shows an unusual configuration within one of the top five temperature data sets used by the climate scientists in their calculations, predictions and computer models.
    http://www.vukcevic.talktalk.net/Data.htm

  24. “Trends >17 yrs are required for identifying human effects on tropospheric temp.”,

    Hmm the first non trivial problem then arises ie the shelf life of the satellite observations and instrumental intercalibration (5-10yr) eg Ruzmaiken and Feynman (2009)

    Unambiguous determination of trends is the central theme of climate change studies. A promising way to validate and quantify a warming trend of few degrees on a time scale of a century, predicted by climate models, is the use of measurements provided by satellites. However, climate variables, such as temperature and concentration of water vapor in the Earth’s atmosphere, are noisy and subject to seasonal and interannual variabilities. The lifetime of any single satellite is relatively short ( 5–10 years) and producing long-term data records by using successive satellite introduces inter-calibration problems. Standard methods of trend determination, such as the least square fit of a linear trend, require sufficiently long time series and thus are not effective for the analysis
    of satellite data. Here, we applied the Empirical Mode Decomposition (EMD) and find it to be more efficient in the search for climate trends in the relatively short time series provided by satellites. We give examples of climate time series analyses using the EMD and discuss the problems we encounter in calculation and interpretation of trends
    extracted from the data limited in time extent.

  25. Thanks Hunter. I’ll check it out. As to your comments above, the trend of course s to get less and less specific as prediction after prediction bites the dust. I wasn’t hearing ANYONE on that side predicting more cold and more snow until we started to get more cold and more snow. Then of course they started to fall all over themselves in a blatantly post hoc attempt to rewrite history.

    The term I’m hearing more and more lately is “global weirding.” The first time I saw it was about a year and a half ago I think, in a Thomas Friedman NYT’s column. Since then, it’s gotten fairly popular for obvious reasons. I doubt it’s possible to come up with a more unfalsifiable prediction than that of increasing weirdness.

    • pokerguy,
      This is like finding out that significant parts of the old testament Prophets were written after the predictions in them took place.
      At least with religious prophecies one can make a legitimate argument that a major purpose of them is to provide teachings.

      • Teachings from a lack of truth!

        Good call.

        Roy Weiler

      • Roy,
        The larger lessons are what makes those stories valuable.
        And even if they are written conveniently after the events, they can still tell a worthwhile history.
        AGW is much the same:
        The lessons that will remain are to be good to the environment, steward resources carefully, be thoughtful.
        The means to the story- CO2 obsession, apocalyptic claptrap, fear and guilt, are unworthy.

      • Yeah…not in this case so much. We in the USA have been doing the good stewardship role. More forests now then at the beginning of the 20th century. Less soot, less SO4.
        Reducing plant food (CO2). Not so good an idea. Telling a lie, to get your desired result, is never the same as telling the truth to get a so-so result.

        Rioy weiler

      • Roy,
        But, to mangle the metaphor a bit more, we are still pagan heathens, not *believing*, but *denying* the great truth about CO2.
        Just because we do a few honorable things, we are still not of the proper faith.
        The nobleness of the cause justifies the lies by the believers.

    • My favorite is “Of course a 6mm drop in sea level will eventually lead to 1000mm rise by 2100 …promise!”

  26. Back in 2007 at RealClimate, Gavin wrote a set of his own goalposts.

    http://www.realclimate.org/index.php/archives/2007/12/a-barrier-to-understanding/

    In the discussion thread Daniel Klein asks at #57:

    OK, simply to clarify what I’ve heard from you.

    (1) If 1998 is not exceeded in all global temperature indices by 2013, you’ll be worried about state of understanding

    (2) In general, any year’s global temperature that is “on trend” should be exceeded within 5 years (when size of trend exceeds “weather noise”)

    (3) Any ten-year period or more with no increasing trend in global average temperature is reason for worry about state of understandings

    I am curious as to whether there are other simple variables that can be looked at unambiguously in terms of their behaviour over coming years that might allow for such explicit quantitative tests of understanding?

    [Response: 1) yes, 2) probably, I'd need to do some checking, 3) No. There is no iron rule of climate that says that any ten year period must have a positive trend. The expectation of any particular time period depends on the forcings that are going on. If there is a big volcanic event, then the expectation is that there will be a cooling, if GHGs are increasing, then we expect a warming etc. The point of any comparison is to compare the modelled expectation with reality - right now, the modelled expectation is for trends in the range of 0.2 to 0.3 deg/decade and so that's the target. In any other period it depends on what the forcings are. - gavin]

  27. Bets on the duration of the current minimal warming?

    In 2005 solar physicists Galina Mashnich and Vladimir Bashkirtsev bet $10,000 with James Annan that global temperatures would be cooler during 2012-2017 than 1998-2003.

    http://www.guardian.co.uk/environment/2005/aug/19/climatechange.climatechangeenvironment

  28. Norm Kalmanovitch

    Time is up!
    “Key Points
    ■Models run with human forcing can produce 10-year periods with little warming”
    Global warming ended after 1998 and the Earth has been cooling since 2002. That is already a dozen years of “little Warming” from human forcing so the models have gone over the time limit. Do these models also predict the current nine years of cooling or when the 2ppmv annual increase in CO2 concentrarion will once again cause catastropic global warming as predicted by the models in the IPCC 2001TAR which predicted the non existant warming from human sourced CO2 emissions over the past ten years that never happened?

  29. It would be difficult to overstate the importance of timescales in attribution studies. For two or more different climate variables to compete as causes of an observed change in temperature, they must operate on similar timescales. Orbital forcing changes associated with 5 deg C or greater variation but operating over 22,000 to 100,000 years, or diurnal variations of 5 to 10 C between mid-afternoon and pre-dawn temperatures are largely irrelevant to century long trends, such as the 0.8 C temperature rise during the past 100 years. The latter, of course, is characterized by many short term peaks, dips, and flat intervals, with recent years unexceptional in this regard, but the critical issue is the extent to which multidecadal influences are competing to explain the rise during this time period.

    Although CO2 and other GHGs probably played a role in the warming throughout the entire century, solar forcing and perhaps changes in volcanism may have dominated the early years. Much attention , however, has been focused on the second half, as epitomized by the IPCC conclusion that anthropogenic GHGs very likely contributed most of the forcing between 1950 and 2007.

    This interval was not chosen arbitrarily. Probably because of both mid-century “global dimming” from aerosols, and subsequent “global brightening” from reduced aerosol pollution, a different interval – e.g., 1976 to the present – would have required a very different dividing up of attributions. For the 1950-2007 interval, however, I find the evidence for the IPCC conclusion to be very substantial. It was suggested that the conclusion was based on CMIP3 models, but these models are probably unnecessary to reach the same conclusion based on other evidence.

    The latter can be considered in terms of forcings and natural unforced variations.The major positive forcings were those from GHGs, black carbon aerosols, and solar irradiance (including its spectral components). Between GHGs and black carbon, an estimated 3 W/m^2 has been attributed to the former and 0.9 W/m^2 to the latter at the top of the atmosphere, as reviewed by Ramanathan. At the surface, the GHG forcing is 1.6 and the black carbon forcing is negative at -1.7. These represent changes since pre-industrial times, but the post-1950 values are probably similar. The contribution of solar forcing since the Maunder Minimum has been estimated at about 0.24 W/m^2 – see review by Gray et al 2010. Although approximations are necessary to relate these values to the 1950-2007 interval, it is unlikely that the ratios have changed greatly, and so a dominant forcing role for GHGs at about 72% can be inferred.

    The natural variations consist mainly of short term fluctuations (less than a decade) due to ENSO and other chaotic elements, plus longer term climate “oscillations” – mainly the AMO and PDO, with total “cycle” lengths in the neighborhood of about 60 years. It has been suggested that the AMO is a Statistical Artifact, and that the PDO is in part anthropogenically forced. However, here it would be prudent to consider them as independent variables acting upon global temperatures. When this is done, the 1950-2007 interval choice is important, because both the AMO and PDO tend to average out over that interval, whereas they would not have if different intervals had been evaluated, including even longer ones. In that sense, the paper by Santer et al may be too general, because it is not merely interval length but also start and end dates that bear upon significant net effects from oscillations that exhibit both peaks and valleys.

    If “very likely” is interpreted as about 90% likelihood, the evidence supports the IPCC attribution, although this is somewhat subjective and therefore amenable to reasonable disagreements. Clearly, 100 percent confidence would have been unjustified for two reasons. The first is uncertainty about the assigned magnitudes – for example, if solar influence must be scaled up to account for forcing not apparent in the total irradiance data, the solar role would increase. The second is the possibility of unidentified and undetected factors competing with the GHGs to warm the planet. By their nature, they can’t be assigned a precise magnitude.

    Whether the IPCC attribution is accurate or not, the more central point is that one can’t merely compete anthropogenic and non-anthropogenic influences purely as a function of time. It is also critical to ask how each was varying during a particular interval of interest.

    I don’t plan to bet on the next 17 years, but I expect that the warming trend of the past will continue, and that it will not be necessary to wait 17 years to observe this.

    • For the correct URL re PDO and anthropogenic forcing, see anthropogenically forced.

    • My long comment was not meant to suggest that models were irrelevant in quantifying attributions and estimating forcings, but rather that there is independent evidence pointing in the same direction.

      • Alexander Harvey

        Fred,

        If the IPCC didn’t document how it arrived at this finding that is a pity.

        From what I recall of the error intervals on the total vs natural forcing only figures, reliance on the models would have led to a much stronger statement. The other sources of information could be seen as affirming the statement but weakening of the strength of the assertion down from the model only level.

        The statement seems to have been made not so much on the basis of the models as over the dead bodies of the models. My memory may be playing tricks with me but I think I recall irritation in the weakness of the statement from some quarter.

        Bizarrely this was one of the IPCC better calls. Worded as it is and spanning the period that it does, it is prety bulletproof.

        You noted this here and we noted it when commenting on two papers which were said to refute it but failed due on the ~50 year period point.

        One was an empirical decompostion and the other was cyclic patterns.

        If this paper becomes freely available I will look at it. If not, not. It is not clear to me whether it represents a tightening or a loosening compared to other published positions (did anyone ever conclude in print that shorter invervals would be significant?). To that extent it seems a bit pointless or somehow political. There seem to be any number of papers that get published that would fail a test of significance. Hopefully I am wrong.

        Alex

      • The paper starts:

        1 Introduction

        Since the late 1970s, it has been recognized that the identification of human effects on climate is inherently a signal-to-noise (S/N) problem [Hasselmann, 1979; Madden and Ramanathan, 1980; Wigley and Jones, 1981; Wigley and Raper, 1990; Allen et al., 1994; Santer et al., 1994, 1995]. The warming signal arising from slow, human-caused changes in atmospheric concentrations of greenhouse gases is embedded in the background ‘noise’ of natural climate variability.

        Thus it’s clear from beginning that the issue is considered well known from distant past. Their aim is to make the argument more quantitative.

        To me the task appears to be practically impossible to resolve based on data for periods of over 10 years. The conclusions must become very sensitive on the assumptions made for such periods. They are analyzing mostly the period 1978-2010, i.e. only 32 years for the real data.

        Concerning the model dynamics, I’m very much concerned by the fact that the models are not stochastic. Leaving the explicit influence of stochasticity out, may lead to models that are too stable in other ways, when the aim has been to make the models to have an internal variability comparable with the real climate. This may make the models almost irrelevant in estimating the low frequency “noise” important for the longer period S/N ratio. This problem is common to all models and therefore undetectable in model-to-model comparisons.

      • Alexander Harvey

        Pekka,

        Thanks, if and until it is clear to me how they have come to their conclusions I have little of much interest to say except that I hope they have been careful. It is not clear to me if their “required” refers to necessity or sufficiency.

        There are times when one is forced to pick cherries and that needs different statistics. In this case, given the record post 1997/8 how many additional years are “required”?

        Also, if it can be argued that such a paper is a product of its times how does that effect its chances of becoming a hostage to fortune at the earliest available opportunity?

        I think I probably agree with you on the need to allow for greater long period noise. It would be interesting if the model outputs and the TLTs were related back to a stochastic emulation with specifed model parameters given estimated values and ranges. Perhaps it should be made clear that this is not a test for the presence of a real signal in a real world but of the ability of a model to predict the relative amplitudes of the “signal” and the “noise”.

        We may come to face two difficult questions: how one detects the presence of a GW signal in a record that is essentially flat, and why we didn’t define that method before we had sight of the data?

        Alex

    • Fred,
      Blaming the PDO on nasty humans is obviously attractive to the AGW community. As things continue to fall apart for the AGW movement, the reach of anthropomorphic forcings will have to be expanded in scope and time. But realize it is also the best thing possible for skeptics. Making great ocean oscillations that are well understood to be long term events into human caused events or even better, an aquatic version of the MWP, will only point out how contrived AGW is.

    • I notice that in my comment, I had stated that the IPCC attributed most of the 1950-2007 “forcing” to GHGs. Of course, they attributed most of the “warming” to the GHGs, and that was what i attempted to evaluate.

    • Thanks for the link Fred.
      See David Stockwell’s interesting statistical analysis of temperature.trends in evaluating such climate shifts.
      Stockwell’s recent accumulation supersensitivity solar modeling shows natural forcing could explain almost all the climate variations.

      Now to find which match the data better, and better predict future changes.
      May the best model win.

      Re: “expect that the warming trend of the past will continue”
      Which “warming trend of the past”?
      From ~1975?
      From the LIA ~1800?
      From the end of the last glacial period?
      See below

  30. JC Re “what are your bets for the duration of the current period of “minimal warming” ?
    My “bet” is that there will be a “cooler period” of ~ 30 years or ~ 1/2 the 60 year PDO cycle. See D’Aleo & Easterbrook, Loehle & Scafetta 2011, Syun-Ichi Akasofu 2010; Nils-Axel Mörner 2011 etc. Since that is on top of the long term rise from the Little Ice Age, the cooler gradient period may be shorter, say ~ 27 years? or about till 2030 to 2035? However Ed Fix is predicting two short 8 year solar cycles – which could well give several shorter smaller intermediate cooler and luke warmer periods. Shorten that for China’s growth rate. Then add a pinch of salt for each volcanic winter. Mix in some uncertainty, and voila – a cooler trend somewhere between 20 and 35 years from now.

    I.e., it gets down to how do you quantifiably define ““minimal warming”?

    e.g., Fred Haynie’s Future of Global Climate Change finds almost all CO2 variations can be modeled by natural forcings. So if we want to quantitatively distinguish anthropogenic forcing from the null hypothesis of natural forcing, then we need to add a bit of red noise and compare noisy data with models +/- sigma . If “warming” is > 90% anthropogenic, and “minimal warming” is < 50% anthropogenic, then voila – (As Charlie A notes above): "100+ years, if the definition of “minimal warming” is less than 0.2 C/ decade. :)".

    Now if we want to quantify that "minimal warming" period well that would get into a battle of wits.

  31. Question: Shall prospects of global cooling be considered a disaster too?

    Answer: Note: Nikola Scafetta believes that, “The partial forecast indicates that climate may stabilize or cool until 2030-2040.” Scafetta’s forecast is based upon, `physical mechanisms’ and `the phenomenon of collective synchronization of coupled oscillators,’ such as for examples, ENSO effects and solar activity. Qing-Bin Lu believes that, “a long-term global cooling starting around 2002 is expected to continue for next five to seven decades.” Humanity will adapt and global cooling need not necessarily be considered a disaster for everyone. Even so there will be many challenges, as for example, Canadian wheat production. And, there always is the possibility of disaster. Walter Starck noted that if only humans really were able to heat the globe, “and it helps to prevent another ice age, this would be the most fortunate thing that has happened to our species since we barely escaped extinction from an especially cold period during the last ice age some 75,000 years ago.”

  32. Gee, why didn’t they just name it “Our Excuse in AR5 for Why We Were Really Expecting, Honest, this Long a Period of No Warming”.

  33. So now it’s 18-39 years to determine if there is an AGW signature in global temperatures trends? What happens if there is still a level or negative trend for the next 8 years? A new paper, perhaps? It might be interesting to apply the same analysis to ocean heat content which is Dr. Pielke Sr’s preferred measure or to sea level rise.

    • Chuck L,
      In 8 years it will be discovered that a minimum time frame of 25 years is needed. The paper is probably already written and ‘reviewed’, to be held in memory someplace until needed.

  34. The large author team is interesting. Lots of heavy hitters, all-stars even, but not known for noise research, to my knowledge. Team!

    • Ah yes. My PhD supervisor had a rule of thumb: “more authors than text, not worth reading”. I’ll let that one go through to the keeper as I haven’t read the paper and wouldn’t be qualified to comment anyway.

  35. Meanwhile in the weather’s not climate until it is department, this from Joe Bastardi on his Weatherbell blog. It concerns the forecast for the fast approaching record breaking cold in parts of the country:

    “I have been looking over records and maps in the plains. I have had some fun pointing out how Al Gore gets slapped by mother nature. But in all seriousness, I hope people understand and appreciate the implication of this forecast by the modeling. I am looking at it in disbelief, for its almost too cold to be true. That nothing like this in on the records may mean that is true.

    I would hope that mets and news outlets in the affected areas start understanding what could happen here. Its not like this is mid October after all. And perhaps someone in the mainstream media can point out that while Al Gore touts his agenda driven ideas, mother nature has other ideas about what is really true and what isnt.

    If this turns out right, its as historic an extreme in meteorological magnitude as any of the other events we have seen.. maybe not in sensible weather, but breaking all time earliest cold by what this implies is mind boggling.”

  36. There is peer reviewed science that suggests – as a result of Pacific variability especially – that the world is not warming over the next 10 years (Mochizuki et al 2010, Swanson et al 2009, Tsonis et al 2007, Keenlyside et al 2008) – albeit with immense uncertainties surrounding the origins and limits of decadal variability.

    Most recent warming (1976-1998) occurred in ENSO ‘dragon-kings’ in 1976/77 and 1997/98. Dragon-kings are defined ( (Sornette 2009) as extreme events that occur at times of chaotic bifurcation. There are large fluctuations in between La Niña and La Niña at these times followed by decadal changes in the frequency and intensity of ENSO events.

    The multivariate ENSO index of Claus Wolter can be seen here – http://www.esrl.noaa.gov/psd/enso/mei/ – it shows a La Niña bias (blue) to 1976, El Niño (red) to 1998, and La Niña since. The warm Pacific decadal mode adds to surface warming and vice versa. The mechanisms involve convection changes with a cloud response and energy transfer between ocean and atmosphere. This is the origin of most of the ‘noise’ in the temperature record.

    These modes last for 20 to 40 years – so we are looking at another 10 to 30 years of no warming and there is nothing to suggest that this is the limit of ENSO variability. The 11,000 year ENSO proxy shows a variability not seen in the recent record. A shift for instance between La Niña dominant to El Niño dominant about 5000 years ago that resulted in the drying of the Sahel. El Nino dominant in the medieval optimum and La Niña in the little ice age.

    http://i1114.photobucket.com/albums/k538/Chief_Hydrologist/ENSO11000.gif

    An 800 year Australian isotope proxy – http://i1114.photobucket.com/albums/k538/Chief_Hydrologist/800yearENSOproxy.gif
    (http://eprints.jcu.edu.au/2482/) – shows La Niña peaking around 1700AD and becoming more El Niño biased since.

    Assuming that I am right in thinking that ENSO is driven by transient impulses from the southern polar front – driving more or less cold Southern Ocean water into the Humboldt Current and the south Pacific gyre. The gyre is nicely shown in this Wikipedia image –
    http://en.wikipedia.org/wiki/File:South_Pacific_Gyre.png

    The polar front changes largely in response to sea level pressure difference between the pole and the sub-Antarctic – as measured by the Southern Annular Mode (SAM) index. SAM is influenced by ozone and solar UV interactions in the stratosphere.

    As solar UV declines from a 1000 year high – I am expecting a more negative SAM and an uptick in La Niña frequency and intensity in the longer term.

    I would give odds on for 10 to 30 years of no warming, even money for a longer term cooling and a dead set certainty for eventually triggering OHC and ice sheet feedbacks and plunging into a glacial in a decade.

    Robert I Ellison
    Chief Hydrologist

    • Chief, this guy would probably agree with you.

      http://wattsupwiththat.com/2011/09/13/climate-disaster-declining-rainfall-rising-sea-levels/#comment-742318

      Your Aussie as well, you should know his wines.

      His explanation for reduced rainfall in WA seems reasonable, plausible, and ties in with your post. I wondered what you would make of it. The only thing I am not sure of is how it relates to the disparity between sea levels on the west coast versus the east.

    • There is peer reviewed science that suggests …

      Peer reviewed science impresses you? Boo!

      From some Wiki garbage (‘nonliear’ my own. Ignore it or consider it hearsay … This is my choice for Climate Forcing

      It is characterized by variations in the temperature of the surface of the tropical eastern Pacific Ocean—warming or cooling known as El Niño and La Niña respectively

      Your choice for Climate Forcing?

      Assuming that I am right in thinking that ENSO is driven by transient impulses from the southern polar front

      That’s a rather safe bet for a collector of Mad science.

      Personally I’m not much interested in mad science. It suffers from the same problem as much of peer review science … mediocrity

      Global warming or cooling is entirely about energy in and energy out. If energy in is greater than energy out in a period the planet warms – and vice versa.

      You could have been right (see nonlinear highlight) but you are wrong. You went and ruined it with the follow on comment. Global temperature is partly set by the net planetary heat flux over the increasing long to very long time scale. At shorter time scales it’s all about where the heat ‘sits’.

      The lesson that you should draw from that is you should not expect Global warming or cooling to vary over years because of a change in solar flux.

      If global mean temperature does vary on a time scale less than years, it is interesting and points to the significance of the mechanism involved in doing such.

      When I read variations in the temperature of the surface of the tropical eastern Pacific Ocean … and with cyclical behavior in the order of years …

      More from that Wiki(garbage)

      El Niño, accompanies high air surface pressure in the western Pacific, while the cold phase, La Niña, accompanies low air surface pressure in the western Pacific.[2][3] Mechanisms that cause the oscillation remain under study.

      Mediocre science?
      Yes that above would be obvious …

      However …

      ocean surface temperature + storms + currents + multiyear cycling + ocean surface temperature = involvement of biology

      It’s probably unavoidable.

  37. http://ocean.dmi.dk/arctic/meant80n.uk.php

    Air temps in arctic are almost precisely the
    same as the average for the past 50 years–
    So it is unlikely air temps have created ice loss–
    BUT CONVERSELY–
    the increased open arctic water SHOULD be
    affecting the arctic air temp-
    but is not(large expanses of 1 degree C arctic water make it
    difficult for air temps to
    drop to minus ten C –but since that is what is happening, then in fact
    there must be
    much more cold air around to create “normal” arctic
    temps for this time of the year)

  38. Judith

    You ask

    So, what are your bets for the duration of the current period of “minimal warming” ?

    My grand-pappy told me never to bet on the weather, but here goes anyway:

    Now that we know it will only become statistically significant if it exceeds 17 years, I’d bet on at least 20 years.

    [I'd also bet that when it reached 16.5 years a new study will come out challenging Santer et al. and moving the goalpost to 25+ years.]

    Max

  39. Edit note: “and I made this point point in…” How many points for that? ;)
    _____
    As JC implies, any significant change over a 60-yr+ period is likely to be predicted at chance level, at best, as the natural forces operating on those timescales are (systematically?) omitted from the modelling.

    If there is any sort of 60ish-yr. cycling, then a 30-yr base is the very worst possible; the best you can to is predict the opposite of whatever is happening now. If it’s warming, it will cool, and vice versa.
    LOL

  40. Note re above: the trick and problem in a 30-yr. projection of “the opposite”, of course, is to know “the opposite of what?” Predeciding the axis rather begs the question.

  41. The models need to be capable of being initialised with known values (say from 1995) and allowed to run for the 17 years. Initialise them multiple times with varying values within the error ranges of those known quantities.

    Then see how many of those runs can reproduce the observed (lack of)warming. If its no different from their previous “10%” then something’s amiss and my take would be that in the models, climate behaves no differently to unpredictible weather over the 17 year period.

    Something within me is uncomfortable with this concept though. I’m just not sure my pet butterfly wont screw the whole thing up…

  42. The 17 is a very nice number if you wish to cover up you poor fits; large volcanic activity tends to occur in the 13-17 year frequency. One big volcano and the molders can all shout; ‘we are going to have to start from now.!’

  43. ON GLOBAL MEAN TEMPERATURE TREND CALCULATIONS

    I fail to understand why highly educated people of the world attempt to calculate climate (long-term) trends along the profile (short-term) of a wave instead of the trend for all the waves peaks.

    The curve that passes through all the global mean temperature (GMT) peaks is the upper GMT boundary line shown below.

    http://bit.ly/ocY95R

    It is reasonable to assume a shift in climate is indicated if the upper GMT boundary line had been a curve with an increasing positive slope with increasing years, or the upper and lower GMT boundary lines had been diverging with increasing years.

    Fortunately, as shown in the graph above, the upper GMT boundary line is a straight line having the same global warming rate of 0.06 deg C per decade as the global warming trend line for the whole data. Also, the upper and lower GMT boundary lines are parallel, showing no change in the magnitude of the GMT swing with increasing years. As a result, the vertical cooling or warming swing of 0.5 deg C between the two GMT boundary lines is cyclic and is therefore natural.


  44. The multi-model average TLT trend is always larger than the average observed TLT trend

    At last!

    Thank you.

    I don’t need to point out this anymore for my thousand times.

  45. JC

    So, what are your bets for the duration of the current period of “minimal warming” ?

    My bet is for global cooling from the current global mean temperature anomaly of about 0.45 deg C to about 0.15 deg C by 2030.

    http://bit.ly/ocY95R

    I am prepared to place a $1000 USD bet on it.

  46. Perhaps this has been covered here, but I don’t see anything with a quick search. What about Roger Pielke Sr’s objection that ocean heat has flatlined since 2003? What do the models say about ocean heat content? Shouldn’t it go up every year to account for the extra heat absorbed by CO2?

  47. When oceans are warm, it snows more and Albedo increases.
    When oceans are cold, it snows less and Albedo decreases.
    This is the powerful negative feedback to temperature that has make the climate temperature extremely stable in a narrow range for ten thousand years.
    This is the only place in this thread, so far, that the word Albedo is found.
    You are all on the wrong track without Albedo.

    • Herman, where I live, when oceans are warm we get El Nino droughts, which lower the albedo, since there are no clouds to reflect the suns rays. When oceans are cold, we get La Nina & flooding rains over most of Australia.

  48. Seems to me none of the prominent climate scientists currently ruling the roost have ever done any original research. Their work results from running computer programs that they almost certainly did not design themselves, & the data they feed into those programs was not generated by their own efforts either. Therefore, there is no way they can claim their results are accurate. Why would anyone trust major policy decisions affecting the entire world to the opinons of such people?

    • Ray,

      The real issue and this deadend thread indicates it again is why the public has it’s politics questioned when the core scientists get a complete pass on their politics?

      http://www.carseyinstitute.unh.edu/publications/IB-Hamilton-Climate-Change-2011.pdf

      They wouldn’t reply honestly at this point but that there is little effort from authority or consensus allies tells you what you need to know. It’s taboo on this thread as well, why?

      • If the scientists are right, evidence of climate change will become more visible and dramatic in the decades ahead. Arctic sea ice, for example, provides one closely-watched harbinger of planetary change. In its 2007 report the IPCC projected that late-summer Arctic sea ice could disappear before the end of the 21st century. Since that report was written, steeper-than-expected declines have led to suggestions
        that summer sea ice might be largely gone by 2030, and some think much sooner. We will find out in time—either the ice will melt, or it won’t. The Arctic Ocean, along with other aspects of the ocean-atmosphere system, presents an undeniable physical reality that could become more central to the public debate.

        http://bit.ly/r2kAnw

        Excellent point.

        Regarding the arctic ice, do we have the data for the 1940s? What we must compare is the Arctic sea ice now with that for the 1940s, not look at what happened to the sea ice in the global warming phase since the 1970s.

      • Girma

        Data pre-1940?

        While not of the same quality or type as we have today, a glance here http://www.athropolis.com/map9.htm will show a little hint of the sort of navigation maps made by ships and surveys for settlements over the centuries.

        The quality of the data isn’t great, but with a concerted effort, perhaps inferential reconstruction of some accuracy may be possible.

        For instance, in http://www.arctic.gov/publications/arctic_and_climate_change.pdf on page 9, we see:

        “The 100-year historical record from ships and settlements
        going back to 1900 shows a decline in ice extent starting about 1950 and falling below pre-1950 minima after about 1975.”

      • Thanks Chief.

        http://bit.ly/qBGAn6

        I have never seen the ice-extent data before the 1970s. As I expected, it was at its minimum in the 1940s and maximum in the 1970s.

        It is extremely sad that they only show us the data since 1970s.

      • Thanks chief

        Our analysis suggests that the ratio of the Arctic to
        global temperature change varies on multi-decadal time
        scale. The commonly held assumption of a factor of 2–3
        for the Arctic amplification has been valid only for the
        current warming period 1970–2008. The Arctic region did
        warm considerably faster during the 1910–1940 warming
        compared to the current 1970–2008 warming rate (Table 1).
        During the cooling from 1940–1970 the Arctic amplification
        was extremely high, between 9 and 13. The Atlantic
        Ocean thermohaline circulation multi-decadal variability is
        suggested as a major cause of Arctic temperature variation.
        Further analyses of long coupled model runs will be critical
        to resolve the influence of the ocean thermohaline circulation
        and other natural climate variations on Arctic climate
        and to determine whether natural climate variability will
        make the Arctic more or less vulnerable to anthropogenic
        global warming.

        http://1.usa.gov/nBuI9B

        Why do they talk about loss of sea ice starting from only the 1970s?

      • Girma and Bart R

        Before the satellite era there were records of Arctic temperature trends and sea ice extent. These show a cyclical trend (around 60-year cycles). Here is a list of some of the papers:

        Bengtsson et al. The early century warming in the Arctic
        http://www.mpimet.mpg.de/fileadmin/publikationen/Reports/max_scirep_345.pdf

        “The Arctic 1920-1940 warming is one of the most puzzling climate anomalies of the 20th century. Over a period of some fifteen years the Arctic warmed by 1.7 °C and remained warm for more than a decade. This is a warming in the region comparable in magnitude what is to be expected as a consequence of anthropogenic climate change in the next several decades. A gradual cooling commenced in the late 1940s bringing the temperature back to much lower values although not as cold as before the warming started. Here, we have shown that this warming was associated and presumably initiated by a major increase in the westerly to south-westerly wind north of Norway leading to enhanced atmospheric and ocean heat transport from the comparatively warm North Atlantic Current through the passage between northern Norway and Spitsbergen into the Barents Sea.”

        Chylek (2006) study on Greenland warming
        http://meteo.lcd.lu/globalwarming/Chylek/greenland_warming.html
        http://www.agu.org/pubs/crossref/2006/2006GL026510.shtml

        We provide an analysis of Greenland temperature records to compare the current (1995–2005) warming period with the previous (1920–1930) Greenland warming. We find that the current Greenland warming is not unprecedented in recent Greenland history. Temperature increases in the two warming periods are of a similar magnitude, however, the rate of warming in 1920–1930 was about 50% higher than that in 1995–2005.

        Polyakov et al. Arctic air temperature and pressure dataset
        http://people.iarc.uaf.edu/~igor/research/amplif/index.php
        http://farm4.static.flickr.com/3175/2851297269_77757a7cd4_b.jpg

        Polyakov et al. Variability and Trends of Air Temperature and Pressure in the Maritime Arctic, 1875–2000
        http://journals.ametsoc.org/doi/full/10.1175/1520-0442%282003%29016%3C2067%3AVATOAT%3E2.0.CO%3B2

        The Arctic SAT record shows two maxima: in the 1930s–40s and in recent decades, with two colder periods in between. In contrast to the global and hemispheric temperature, the maritime Arctic temperature was higher in the late 1930s through the early 1940s than in the 1990s.

        Polyakov & Johnson, Arctic decadal and interdecadal variability
        http://www.agu.org/pubs/crossref/2000/2000GL011909.shtml

        Atmospheric and oceanic variability in the Arctic shows the existence of several oscillatory modes. The decadal-scale mode associated with the Arctic Oscillation (AO) and a low-frequency oscillation (LFO) with an approximate time scale of 60-80 years, dominate.
        Both modes were positive in the 1990s, signifying a prolonged phase of anomalously low atmospheric sea level pressure and above normal surface air temperature in the central Arctic.
        Consistent with an enhanced cyclonic component, the arctic anticyclone was weakened and vorticity of winds became positive. The rapid reduction of arctic ice thickness in the 1990s may be one manifestation of the intense atmosphere and ice cyclonic circulation regime due to the synchronous actions of the AO and LFO. Our results suggest that the decadal AO and multidecadal LFO drive large amplitude natural variability in the Arctic making detection of possible long-term trends induced by greenhouse gas warming most difficult.

        The temperature record for Ilulissat, Greenland (near the mouth of the Jakobshavn Glacier) goes back into the 19th century.
        http://www.cru.uea.ac.uk/cru/data/greenland/illulissat.dat
        http://farm3.static.flickr.com/2620/3797223161_16c1ac5e39_b.jpg

        This record shows the same cyclical trend and that the warming at Ilulissat was greater in the first half of the 20th century than in the second half.

        So there are data out there suggesting that the current warming/melting cycle since 1979 is not unprecedented, but just part of a longer-term cyclical trend.

        Max

      • Girma and Bart R

        I just noticed that the Chief has already cited you some links to pre-satellite Arctuc temperature and sea ice data. Some of this overlaps with what I just posted.

        Max

    • .–>Why would anyone trust major policy decisions affecting the entire world to the opinons of such people?

      When you say people do you mean dumazz schoolteachers?

  49. Where’s the video?

  50. If you want to look at shorter trends, we have been having some success with data exploration on the global fluctuations thread. Peter317 had a good idea of looking at differential CO2 (d[CO2]) against temperature. This is essentially CO2 perturbation data and the results are very interesting; the following graph summarizes the findings:
    http://img402.imageshack.us/img402/7351/co2pdpmodels.gif
    Rapid differential changes in CO2 levels track with global temperatures, with a variance reduction of 30% if d[CO2] derivatives are included in the model.
    This increase in temperature is likely due to a reduced capacity for the biosphere to take-up the excess CO2 initially. Or that’s one theory if CO2 is the causal agent. Another idea is that temperature causally bumps up the CO2 due to an Arrhenius relation, but the effect of this would seem minimal.

    Overall this kind of data modeling is very easy if you have any experience with engineering controls development. The model is of the type called Proportional-Derivative, and it essentially models a first-order equation
    \Delta T = k[CO_2] + B \frac{d[CO_2]}{dt}
    Others might have different terminology for this but that the jargon I am familiar with.

    • I want to do some more analysis on this – unfortunately I’m now into one of my super-busy periods at work, so I’ll only be able to do bits and pieces over the next few weeks (too tired to do much thinking when I eventually get home)

      • (too tired to do much thinking when I eventually get home)

        I feel your pain. Just imagine if we got paid for doing this?

      • The Laplace transfer function for this data is (k+B*s) for CO2 to Temperature, or its reciprocal 1/(k+B*s) for Temperature to CO2.
        The first is variant of a differentiator & derivative, and the second is an integrator. So the question is one of pinning down the actual causality chain.

      • As I’m not yet up to speed on RStudio, I did a bit of playing around with a spreadsheet.
        As there appears to be a very good correlation between SST and differential CO2, I thought I’d see how it worked the other way round.
        So I integrated the SST data over time to get the cumulative data and plotted it against the average atmospheric CO2 concentration from Mauna Loa. The two graphs appear to be very close to being proportional.
        This all strongly suggests (to me at any rate) that the rate of increase of atmospheric CO2 is proportional (or very close) to the SST.

        This further suggests that either:

        1) the SST is dependent on the rate of CO2 increase, or

        2) the ocean ‘outgasses’ CO2 at a rate (close to) proportional to the SST

        It seems to me that a plausible mechanism lends itself more readily to the latter rather than the former.

      • That is what I found out as well. What you may want to try is an exponential smoother on the Temperature with a time constant of 180 months. Try that instead of the integration. That is the result of the best fit I got with the first-order Proportional-Derivative model. It is also more like a rate-law associated with an outgassing effect, where the CO2 concentration should be the convolution of the Temperature with an outgassing CO2 impulse response. The exponential smoother acts as the convolution operation. The integration is OK but it assumes an infinite impulse response for CO2.

        Yes, I can see #2 happening to some degree because that is the conventional chemistry view, but it has to be consistent with the causality of the fluctuating man-made carbon emissions. What happens if we find a nicely lagged cross-correlation of fluctuating CO2 emissions with fluctuating global fossil-fuel-based carbon emissions? Then we would have two causality links, FF –> CO2 –> Temperature, instead of the one for Temperature –> CO2.

        In any case, interesting stuff.

      • It seems to me that a plausible mechanism lends itself more readily to the latter rather than the former.

        There is one problem with this interpretation: The latter has not happened, i.e. there’s no reduction in the carbon in the ocean mixed layer. On the contrary the carbon in that layer has increased. The lower layers of the ocean have not warmed significantly. Thus they cannot either support this explanation.

        The outgassing from ocean cannot be the reason, when there’s no outgassing.

      • That’s a good observation. The knee-jerk thinking is that people think in terms of their carbonated soda on a hot day. They see the bubbles fizzing more rapidly so they assume that the same thing is happening in the climate, i.e. more CO2 is escaping. But then when you say that the CO2 in the soda is actually increasing they have to rethink the situation.

        In other words, it doesn’t match their intuitive world-view — the carbon in the ocean is increasing so how can more be outgassing (scratching their heads). Of course, this is just a steady-state flow problem, if their is more CO2 in the atmosphere as well.

        That brings up an interesting idea I have. There has been talk that freshwater lakes may have a bigger effect on climate than previously imagined. What exactly happens to dissolved gases like CO2 when lakes start to freeze up in the winter? Think about what happens when your soda can accidentally freezes … it goes flat. Is there something about that decrease in temperature that can release lots of CO2? I can’t remember what the phase diagram does at low dissolved gas concentrations.

        BTW I did do the correlation of CO2 with fossil fuel emissions.
        The cross-correlation of the yearly changes, d[CO2] and d[FF], show a zero-lag peak with a significant correlation. The odds of this happening if the two time-series were randomized is about 1 out of 50.
        http://img30.imageshack.us/img30/6048/co2ccemissions.gif

        Left chart from is from the “Detection of global economic fluctuations in the atmospheric co2 record” that Jon did a few days ago.
        http://judithcurry.com/2011/09/06/detection-of-global-economic-fluctuations-in-the-atmospheric-co2-record/

        This is not as good a cross-correlation as the d[CO2] and dTemperature data — look at year 1998 in particular, but the zero-lag correlation is clearly visible in the chart..

  51. This is interesting- i certainly like that they’ve shortened the timescale from 30 to 17 years for a model pass/fail test (if i’m reading this right), but i’m still quite confused on how the models are being treated.

    Am i right in my ‘reading’ that they haven’t examined non-anthropogenic models in any detail? Which would seem to act as a predetermination straight from the off (though i understand that little work has gone into these models).

    There does seem to be an in-built assumption in this work from the off- though i must say i’m very interested to read the whole paper.

  52. “Minimal warming over a single decade does not disprove the existence of a slowly-evolving anthropogenic warming signal.”

    It doesn’t disprove the existence of greenshirt aliens with misanthropic tendencies either.

    It does howvever prove that natural variation can offset the effect of a 40% increase in co2. And it did it without help from any major volcanos.

    So the question is, which natural variations were responsible? Hmm??

  53. I think Santer and team have used the misleading ‘volcano trick’.
    Yes there have been periods of 10 years in the recent past when there was no warming. But these were due to the influence of the volcanic eruptions of El Chichon (1982) and Pinatubo (1991). That’s clear in Fig 5 and Fig 7 of their paper. But there is no equivalent volcanic eruption to explain the current lack of warming.

    • PaulM, the “volcano trick” and the aerosol trick are tightly linked. Prior to 2007 roughly, the explanation for the 1910 to 1940 temperature rise was increased solar forcing and decrease volcanic activity. That was despite the knowledge that the solar reconstructions of the time indicated more solar variation than likely. That lead to, “since circa 1950, the anthropogenic warming has surpassed solar variation.” This last 10 to 12 years has put the high climate sensitivity predictions between a rock and a hard spot.

      If it weren’t for the political implications and magnitude of egos, I would expect a statement from the climate science community that the models and observations tend to indicate that the sensitivity to CO2 appears to be 2 C +/- 1C with the impact of internal variability greater than originally estimated. Because of the position the climate community is in, >17 years allow some breathing room for the more egotistical. That greater than 17 years should be more on the order of 30 years since internal variability is easily on the order of 40% to 50% of the increased CO2 forcing. Why? Because if the models properly modeled internal variability they could show thirty years of neutral/cooling temperatures.

      This is really pretty humorous. The higher sensitivity estimate is mainly due to Hansen. When Hansen and Manabe’s estimates were combined, they gave the target range that scientists had to shoot for. Most scientists are not into ground breaking papers unless they are totally convinced they are right. The uncertainty monster pressures scientists into not rocking the boat too much so they tend to believe results that are less dramatic, more in line with accepted wisdom. There are probably quite a few unsubmitted papers who’s results were unbelievable for the researchers at the time.

  54. Cui bono from this paper? Certainly it seems like an effort to neutralize Douglass et al.

    • I think Douglass was the excuse. I think the evaluation by Knight et al on what would falisify the climate models was the actual target. 15 years is getting uncomfortably close.

  55. “This will feed the “weird weather” theme.”

    No doubt David. But it is damn funny that these global warming events so often seem to be held in the middle of some record breaking cold. It has to bug them…

  56. To paraphrase Trenberth from climategate emails, you can’t just call it noise, you have to actually describe the natural process causing the pause, otherwise it is just guesswork. Clearly though the pause is caused by natural variation, the possibility of which had previously been completely ruled out by Hadley in their infamous IPCC lie when they asserted that since models could separate out human from natural variation then it was sure that the declining natural variations could not explain recent warming. Well that argument is now utterly discredited but it was the entire basis for the IPCC alarmism in the first place.

    Hadleys model based prediction in 2005 (the earlier effort to deal with the pause paradox) was that the current flat period would end in 2009 whence the the temperature would immediately shoot up rapidly. This 17 year prediction will also be proven wrong and the period will be continuously extended until grant funding agencies eventually wise up. The plain fact is that they didn’t expect this pause in warming and all explanations for it are just retrospective, meaningless waffle.

    • To paraphrase Trenberth from climategate emails, you can’t just call it noise, you have to actually describe the natural process causing the pause, otherwise it is just guesswork.

      I very much agree with this. Noise can propagate from other sources and it is worthwhile to track those through any laws of physics you can apply. So even if you don’t know the source, you can do this; that is why uncertainty propagation techniques are taught to all freshman physics students.

      So if we look at the noise in global temperature, can this noise propagate up from noisy variations in CO2 levels? Take a look at this set of charts:
      http://1.bp.blogspot.com/-S5PeFWheTHg/Tm70q–ifhI/AAAAAAAAAgU/YOy_x1SMqFU/s1600/CO2_PD_P_Models.gif

      Is it CO2 driving the Temperature variations, or is it the other way around? Causality drives the direction of the propagation of noise.

    • To have an idea of what was thought before, the IPCC TAR from 2001 is an appropriate source. What was expected based on models can be seen from the Figure 9.3.

      Looking at the 10 first years from the point of origin, we see that the spread between different model runs is much larger than the average expectation for the warming trend. One or two of the runs return to the original temperature even after 20 years.

      On the other hand I do agree that the issue is not really about signal and noise as the noise is most commonly understood, but of oscillatory variability in the models, as it is almost certainly in the real Earth system as well. The weakness of the paper is in the fact that statistical properties of variability can be studied for the higher frequency effects corresponding periods of a few years at most, but beyond that there isn’t appropriate data. Thus the analysis doesn’t tell at all, whether the longer term variability is presented correctly by the models. The conclusion that the S/N is improved with longer periods is proven only for the models studied, not for the real Earth system as far as I can see.

      The variability of the temperature trend is not in strong contradiction with the models, but that doesn’t prove that the models are valid for that kind of analysis. Better understanding of the real processes that have contributed to the recent climate is really needed for more convincing interpretation of the resent past.

  57. On Moving the Goal Post

    IPCC:

    For the next two decades, a warming of about 0.2°C per decade is projected for a range of SRES emission scenarios. Even if the concentrations of all greenhouse gases and aerosols had been kept constant at year 2000 levels, a further warming of about 0.1°C per decade would be expected.

    Santer et al, 2011:
    Minimal warming over a single decade does not disprove the existence of a slowly-evolving anthropogenic warming signal.

    Our results show that temperature records of at least 17 years in length are required for identifying human effects on global-mean tropospheric temperature.

    What is the magnitude of this phantom human caused warming according to Santer et al?

    As 17 years are required to identify human caused warming, could we stop calling CO2 a pollutant until then? Could we also defer any CO2 tax until then?

    • Instead of the warmenista hand-waving attempts to explain pauses in GHG warming, lets consider that CO2 should have warmed 2001-2001 by .2C and it actually fell .05C (HADCRUT3).

      (I’m ignoring all other factors as per IPCC wishes).

      That means after 1998 there was a natural cooling of .25C that was offset by the .2C of CO2 warming.

      If that true, it would appear that the only thing keeping a little ice age from happening is burning of fossil fuels.

      Question …

      Why are there no warmenista papers suggesting what I have just suggested.

      I mean if there are sooooo convinced of CO2’s warming potential, why not make the obvious case?

      Could it be they know its a scam and it didn’t even cross their minds they were right?

  58. Max

    Thanks for the link.

    If arctic sea ice was at its minimum in the 1940s as it is now, and it was at its maximum in the 1970s, why are they scaring us with “Arctic Sea Ice: Death Spiral Continues” in the following blog?

    http://bit.ly/pr5v4k

  59. “As 17 years are required to identify human caused warming, could we stop calling CO2 a pollutant until then? Could we also defer any CO2 tax until then?”

    Can one of you scientifically hip types explain in simple language ( talk to me like the idiot that I am) the implications of this 17 year thing? At first glance it looks like since we’ve had no statistically significant warming since 1998 (perhaps cooling since 2002) we’re actually only a few years away from a 17 year period with no warming. But I know that can’t have the implications it seems to have as they’d never have left themselves open in that way…

    Rereading the statement above I’m guessing that while 17 years is necessary to identify warming, the absence of such a trend during that span is not sufficient to rule warming out.

    • pokerguy, I am an anachronism who sees what is in front of me. You are pokerguy… If you had been forced to attend a poker game by your ‘friend’ who then requires that you play with a deck that has things such as… 2035 Glaciers, Polar Bears,… as wild cards that The House (IPCC) alone gets to value. The game is High Table Steakholders, are you a steakholder too? Your ‘friend’ writes porn to himself for gods sake. Haven’t you seen enough to know it’s a rigged game? You still want to be a good guy for your ‘friend’. Seventeen years is a very long time. Forget about playing poker with them is my advice. If they cheat, it’s a crooked house; we all know that don’t we?

  60. As mentioned in an earlier comment, the global surface temperature anomaly data show that the century-long 0.8 C rise in temperatures has been punctuated by numerous peaks, dips, and flat intervals, with recent years unexceptional in that regard.

    The Santer et al paper addresses TLT data, which has a shorter history. Here, too, however, UAH MSU TLT data show similar short term ups and downs indicating that short term variability is imposed on longer trends. Under these circumstances, deciding what interval to examine to compute a short term trend is often very arbitrary. Because of the 1998 “super El Nino” peak, some individuals have chosen that year as a start point for a flat temperature trend, but from a strictly scientific perspective, there is no clear justification for that. An equally arbitrary choice of 1999-2009 would demonstrate a positive slope, deviating upward, for example, from the flat or slightly declining interval from 1986-1996, also arbitrarily selected. Taken over the entire interval since 1978 (slightly more than 32 years), the decadal warming trend is positive at about 0.14 C. I’m not sure that any selection of interval subsets within that range can be interpreted as meaningful for interpreting longer trends.

    The short term variability observed with temperature is also seen with related measures, including ocean heat content and sea level rise, although the technology adequate for assessing short term variability in these measures has been lacking until relatively recently.

  61. pokerguy,

    well, I’m no expert, but here’s my interpretation.

    I believe the 17 years is based on a 95% (2 sigma) probability. ie at any given time it is 95% likely that the preceding 17 years will give a positive trend.

    This also means, of course, that in a long temperature record, say 100 years, we can *expect* to see a negative trend over a 17 year period five times. Indeed it’s a 50:50 bet that such a trend has been in the data once in the last 20 years.

    It self evidently therefore does *not* follow that a 17 year negative trend disproves AGW.

    A 32 year trend, OTOH can only be expected as a 4 sigma event (3.9 from the paper), which from memory is a once in 16,000 year event. I’d take that as falsifying(!)

    And, of course, the 17 years refers to the overall trend, *not* a negative peak to trough variation. That would be much more likely, which is the test you’re applying by picking 1998 as a one off, rather than looking at the overall trend since 1998.

    So clearly, the surface temperature record is consistent with AGW hypothesis. The IPCC characterise the attribution as “very likely” which seems about in line with this paper, perhaps a little conservative.

    That’s my interpreation, but I’m a rank amateur. Corrections, builds from those better informed?

    • Think about sea level. If sea level is rising 2mm a year for decades and then starts rising by 3mm * per year for a few years and then starts falling by 6mm a year in 2010, would you consider a prediction of 1000mm to 1900mm in 100 years realistic considering that is 10mm to 19mm per year? Not once has sea level risen above 40% the average needed to make those predictions come true.

      Every decade that drops in temperature by .05C ** makes the chance of temperature making it to 2C unlikelier and unlikelier.

      * Biased satellite record
      ** Biased HADCRUT3

      • Bruce,

        I think sea level is really OT here, but I’d say two things immediately occur:

        1) The prediction 100 years ahead depends on the physics rather than the history.

        2) I wouldn’t take note of one year’s data either way

      • 1) My response to that is … when do you claim AGW started?

        If the answer is 1980, you have 31 years of data.
        If the answer is 1970, then have 41 years of data.
        etc

        2) Every years data is 60% or more below where it needs to be to make the prediction of 1m to 1.9m of sea level rise.

  62. Steven – The excerpt you quoted was unrepresentative of the entire article you linked to, which readers might want to visit for the full context. It also reported surface data, not TLT data, and the interval cited did not include 1998, where subtracting ENSO might have moved the starting temperature lower I don’t think that was particularly relevant to my main point, however, which was that arbitrarily selecting a short interval can allow you to find almost any trend you want.

    • “It also reported surface data, not TLT data,”

      They stick a thermometer in the dirt or did they measure the temperature of the lower troposphere?

      I know it didn’t include 1998. If you want to include 1998 that’s fine. If you don’t that’s fine too. But don’t say ignore ENSO one time and take it into account the other. Either way you have no warming since either 1998 or 1999.

      You should be more specific about exactly what I misrepresented because I don’t see it.

      • They did not measure the lower troposphere, but rather surface air temperature, which is different. TLT data comes from satellite recordings of oxygen microwave emissions processed through complex algorithms.

        Whether surface air temperature trending since 1998 (ENSO excluded) would be the same as trending since 1999 is uncertain, but my point was that neither is a good guide to longer trends. At this point, if we are interested in TLT data – the subject of the Santer et al paper- we should probably start at the beginning of the TLT record – 1978.

        As to what the article concluded that I believe you omitted, it would probably be best for readers to visit it themselves. I think it makes some of the same points made by Santer et al.

      • To clarify, land temperature anomalies are recorded as surface air temperature, but ocean temperature records are a more complex function that I believe also incorporates data from the water surface itself.

      • Now I understand Fred, you can make applications from the lower troposphere to the surface but not from the surface to the lower troposphere because the correlation is unidirectional. It is all so clear now.

        One small point Fred. I consider it confrontational to accuse me of misrepresenting something. If you want to accuse me of being wrong I could care less, I have been wrong before and I will again. Now what exactly was I misrepresenting?

      • Now I understand Fred, you can make applications from the lower troposphere to the surface but not from the surface to the lower troposphere because the correlation is unidirectional.

        That’s partly correct, Steven, even if you meant it as sarcasm. The air surface temperature measured in HadCrut, GISS, etc. is very strongly coupled to the surface itself, mainly by conduction, and is therefore a good average representation of the surface. Lower tropospheric temperature measured by satellites is heavily weighted by signals at higher altitudes, and is best reflected by temperatures at a few kilometers up. The surface is represented, but only to a minor extent. The two are correlated partially, but not completely, particularly over short timescales. The TLT should therefore not be considered a measure of surface air temperature.

        As to your representation or misrepresentation of the article you linked to, why don’t you repost the link, repost the original except you quoted from it, and then let others judge whether that excerpt accurately conveyed the points the article attempted to make?

      • If you can’t tell what the the troposphere is doing from the surface temperatures over short periods of time it stands to reason the reverse is true. Yes, I happen to think correlations indicate that there is, well, a correlation.

        No, I don’t need to post anything. You said I was misrepresenting something yet you seem unable to identify what it was . Identify what it was or state you were mistaken least I start to think you are purposely misrepresenting me.

      • If you can’t tell what the the troposphere is doing from the surface temperatures over short periods of time it stands to reason the reverse is true.

        That’s correct, but I’m not sure what point you’re trying to make. TLT and surface air temperature tend to correlate partially, but only partially, although the correlation improves with interval length. The two phenomena are not the same, and even more relevantly, their variability is not the same. The variability Santer et al analyzed as a function of timescale was from the TLT data. .

      • I’m not sure what your point was Fred, other then perhaps saying TLT doesn’t need to be adjusted for ENSO and claiming I was a liar. I don’t see where you are backing up either of your points.

      • Well Fred, I guess I am not the only one confused. Perhaps you should write the authors of the paper and tell them not to include surface temperatures in their paper:

        “Because of the large effect of year-to-year variability on decadal trends, roughly 10% of the 10-year TLT trends in the 20CEN/A1B runs are less than zero (Figure 4A). This result shows that anthropogenically forced models can replicate the recent muted warming of the surface [Easterling et al., 2009; Knight et al., 2009] and the lower troposphere.”

        I think since you said I misrepresented something you should be able to point out exactly what I misrepresented. I really didn’t say much and it is not my responsibility that you read things that aren’t there so you may man up and make your apology any time now.

      • Steven – I think you may in fact be confused. The paper was about TLT trends and the variability in those trends. It accurately implies that surface temperature data would yield similar conclusions, but it does not analyze the variability of surface temperature (as far as I can tell from this post – I haven’t yet been able to read the full paper)..

        As to your excerpts from the article you linked to – again, readers can review the article to determine whether you adequately conveyed its points. I don’t think you did, but others can judge for themselves.

        My overall point may be getting lost in all of this. Short term ups and downs in TLT (and also in surface temperatures) have been common historically during the past century’s warming trend, and current temperature behavior has been similar in this regard. One can arbitrarily select short term (e.g., decadal) intervals to show trends in various directions, but based on the history of the past century, they have little value in evaluating the longer term trends.

      • One more small point, Steven, about your “make your apology” comment. Consider a reader coming to this thread with an interest in understanding the subject and viewing assessments from participants he or she finds reasonable. I think your comment, which is adversarial rather than substantive, is likely to make you look foolish in the eyes of those readers. At least, that’s how I would respond as a reader encountering this thread.

  63. Word on the street: “Mother Nature has switched gears and is diving into the fall season. Temperatures are dropping into the 30s at night and word on the street is that snow guns are already firing at some of our favorite [ski] resorts. The countdown has officially begun!”

    Question: Will we again see the UK’s elderly burning books this winter to stay warm? Will the Heteratoi of the AGW phalanx toast in the Cancun sun this winter while drinking margaritas and sharing climate porn stories?

    • ‘Solar activity during the current sunspot minimum has fallen to levels unknown since the start of the 20th century. The Maunder minimum (about 1650–1700) was a prolonged episode of low solar activity which coincided with more severe winters in the United Kingdom and continental Europe. Motivated by recent relatively cold winters in the UK, we investigate the possible connection with solar activity. We identify regionally anomalous cold winters by detrending the Central England temperature (CET) record using reconstructions of the northern hemisphere mean temperature. We show that cold winter excursions from the hemispheric trend occur more
      commonly in the UK during low solar activity, consistent with the solar influence on the occurrence of persistent blocking events in the eastern Atlantic. We stress that this is a regional and seasonal effect relating to European winters and not a global effect. Average solar activity has declined rapidly since 1985 and cosmogenic isotopes suggest an 8% chance of a return to Maunder minimum conditions within the next 50 years (Lockwood 2010 Proc. R. Soc. A 466303–29): the results presented here indicate that, despite hemispheric warming, the UK and Europe could experience more cold winters than during recent decades.’ http://iopscience.iop.org/1748-9326/5/2/024001/pdf/1748-9326_5_2_024001.pdf

      UV/ozone influenced blocking events happen in the SH as well – so it is a global thing.

      Cheers

  64. “We’ve got to ride this global warming issue.
    Even if the theory of global warming is wrong,
    we will be doing the right thing in terms of
    economic and environmental policy.”
    – Timothy Wirth,
    President of the UN Foundation

    http://green-agenda.com/index.html

    Hey, Chief!! Who do you think is missing the point on this board?

    • …e.g., Government should never fail to take advantage of a government-created hoax to fabricate the next hoax.

      • Dear Wagathon,
        You may be right in your previous analysis that AGW may be a fraud. Please remember that the AGW believers cannot be all wrong, and some of them must be right, at least some of the time.

  65. “A 32 year trend, OTOH can only be expected as a 4 sigma event (3.9 from the paper), which from memory is a once in 16,000 year event. I’d take that as falsifying(!)”

    Thanks for this. I’d take it as falsifying too of course, as most sane people would. Of course, all this temperature trend hoohah begs the vitally important question concerning the role of natural drivers. Roy Spencer makes a pretty damning point for those who buy the IPCC’s virtual certainty. That is, there is no paper anywhere that comes close to ruling out natural climate factors. The question over much of the last few hundred years is not whether the globe’s been warming, but why.

    Well how about the simplest, most basic answer available, that we’re simply recovering from the extreme lows of the Little Ice Age. From a “philosophy of science ” standpoint, isn’t the simplest explanation the most preferred broadly speaking?

    • The consensus of the scientific community seems to be that it is “very likely” anthropogenic, not certain.

      As to whether your suggestion is the simplest, most basic answer – I guess that’s a matter of opinion.

      Perhaps you could suggest some predictions that such a hypothesis would make, and what could falsify them?

      For AGW, the thesis isn’t of course just about the historical temperature data, but a convergence of many, independent, lines of evidence.

      • While recovering from the LIA is indeed the simplest hypothesis, it is not a mechanistic hypothesis like AGW, so no predictions can yet be made. First we have to figure out what causes the LIA and the other natural oscillations. Thus this is not a simple case of alternative mechanisms. It is a case of a known (AGW) versus a known unknown (LIA). This is precisely why the issue cannot be settled at this time, unless AGW is independently falsified (which I happen to believe has happened).

    • pokerguy

      Your “recovering from” implies a natural regular median or attractor the ergodic system will always seek.

      Far from being a simple or basic answer, it depends on a farfetchedly difficult baseline assumption such as to render the entire ‘hypothesis’ meaningless aphoristic nonsense.

      Also, in any large and complicated enough dataset, some sigma-4 event ought be observable in over half of all observations. Record high or low, long span of this or that type, high frequency or short span between like events.

      Which is why no one uses sigma level to falsify tests in this way on this type of data.

      It’s like saying, “See! Not only did it land heads, but it also points exactly 32 degrees off magnetic north! The coin must be two-headed!”

  66. A natural climate explanation calls for no special hypothesis. It’s the AGW crowd that has something to prove. Such an explanation by its nature simply keeps the attention where it belongs, that is on the long range forecasters who rely on natural drivers and who season after season, year after year have been beating the climate models with their built-in warm bias.

    The forecasters only get better as they learn more, while the modelers look ever more foolish. UKMET at one point stopped issuing long range forecasts altogether. WHy? Because they’ve become such a joke in in the UK.

    • What is this “natural explanation” concept, such that it does not require a specific mechanism? Explaining how nature works is what science does. Technically speaking emerging from the LIA is not a scientific explanation at all, just a claim.

      • David, I’m simply asserting that I believe the warming we’ve seen since coming out of the Little Ice Age has nothing to do with humans contributing C02 to the atmosphere…until proven otherwise.

        You made what seems to be the same statement I did with respect to predictions: “While recovering from the LIA is indeed the simplest hypothesis, it is not a mechanistic hypothesis like AGW, so no predictions can yet be made.”

      • I personally have not seen yet a single paper that is correct enough to link global warming to Milankovitch cycles or other natural variations. If you find the same, then humans must be the cause of global warming, there is no other.

      • Perhaps you mean until you find the same, otherwise I do not understand your comment. The problem is we know that natural variation is large enough to explain the observed warming, but we do not know enough to know if it actually does or not. That is what makes it a known unknown. The issue is in limbo until this is resolved.

      • But you have no scientific basis for your assertion. It is merely a conjecture, not even a hypothesis. That is my point.

      • Yes I do: Waters of Lake superior, Arabian Gulf, and the Mediterranean are warming considerably above the average. They have two things in common: 1) They receive considerable amount of anthropogenic waste heat, and 2) These water bodies can not “cleanse ” themselves of anthropogenic waste heat dumped into them. If the heat accumulated in these water bodies is natural, their temperature would be about the same as their surroundings, but they are not.

      • Mechanism…? Mechanisms! But then that is a statistical problem requiring the best and brightest who are sitting their posterior distribution bragging about their fat tails.

      • We certainly should have a sufficient appreciation by now for the holistic processes involved in global warming to know that GCMs cannot effectively model climate change except perhaps in the most abstract way possible—such as by way of using the mathematics of chaos. When you consider what we would have to deal with you realize that there is not enough computing power on earth to do the job and that is if we knew what we were doing.

        Shifting crusts and volcanic eruptions, oscillations of solar activity on multi-Decadel to Centennial and Millennial time scales with variations in cosmic radiation as our solar system skitters through the spiraling arms of the Milky Way at the edge of the galaxy, the role of the big planets—Saturn and Jupiter—and their interaction with and effect on the Earth: the Earth’s rotation; a changing North Pole; and, variations in the magnetosphere… Unlike thinking of climate as the result of CO2 as a single unit, we cannot even begin to grasp the complexity of the processes involved in climate change unless we at least begin to think of a ‘single unit’ in no less simple terms than the ‘Earth’s rotation/sea temperature,’ as a whole.

        Mazarella tells us that if we look at climate change as a part of a holistic process, we see that included in this single unit are changes in ‘atmospheric circulation’ and ‘like a torque,’ variations in atmospheric circulation can in and of themselves cause ‘the Earth’s rotation to decelerate which in turn causes a decrease in sea temperature.’ It may soon be possible to model this effect mathematically. A study conducted by UCSB researchers (Physical Review Letters) involved filling cylinders with water and then heating the water from below and cooling the water from above. This was done to better understand the dynamics of atmospheric circulation and hopefully enable researchers to mathematically model a phenomena observed in nature known as swirling vorticies.

      • Agree. The climate science and issue is in limbo until it is addressed completely. But we cannot say that it is caused naturally for there is absolutely not a single paper that is correct enough to link global warming to natural variations. If you have a paper, please give a chance to read it and respond.

      • Nabil, there are many papers that link GW to natural variations, just not conclusively. The same is true for linking GW to AGW.

  67. Just to add, of course the word “natural” does not mean “simple.” I have a respect bordering on awe for the complex systems that drive our ever evolving climate. By the way, that’s something that seems conspicuously absent among the more rabid alarmists who claim to have got it just about all figured out.

    • No-one is saying they have it “all figured out”.
      On the other hand, just because everything isn’t “figured out” it doesn’t mean that nothing is known.

    • “By the way, that’s something that seems conspicuously absent among the more rabid alarmists who claim to have got it just about all figured out.”

      You mean like this one:
      “Obviously, the cause of global warming both before and after 1940 is the same: solar activity during that period was inordinately high. It’s the sun, stupid.”

      You don’t see any alarmism there, but cries and wails about an alarming solar induced little ice age are sure to follow.

  68. “Because of the large effect of year-to-year variability on decadal trends, roughly 10% of the 10-year TLT trends in the 20CEN/A1B runs are less than zero (Figure 4A).”

    So, if I read this correctly, a ten year flat trend has a 10% chance of being meaningless and a 90% chance of being meaningful.

    “Minimal warming over a single decade does not disprove the existence of a slowly-evolving anthropogenic warming signal.”

    Okay, but why use 10 years since we are way past that point now. We will soon be at 14 years, and, if we get the La Nina that is brewing below the surface of the Pacific, we will certainly have 15 years of no warming. Seems like Santer’s paper is already out of date.

    Easterling and Wehner produced a similar paper not too long ago where they demonstrated that 10 year flat or negative trends could happen. I addressed it here.

    http://judithcurry.com/2011/09/12/santer-on-timescales-of-temperature-trends/#more-4810

    The primary problem with such assertions is that flat trends of the past could be attributed to some element of natural variation that correlated with their occurrence. The current flat trend cannot. For example, the current flat trend looks almost the same if you use ENSO corrected data. And there has been no unusual amount of volcanic activity. It is likely that the modeled 10 year flat trend also corresponded to modeled natural variation that yielded those trends.

    Also, with flat trends of the past, we know what their durations were. The duration of the current trend is unknown. 15 years looks very likely, and so 17 years is not much of a stretch. Hopefully Santer will be there to answer for his paper in 3 years and four months.

    • “The current flat trend cannot. For example, the current flat trend looks almost the same if you use ENSO corrected data”

      Well this guy adjusts the temperature records, including HadCRUT, for ENSO and solar cycle and finds the warming continues:
      http://tamino.wordpress.com/2011/01/20/how-fast-is-earth-warming/

      This one too:
      http://zzzbbb.blogspot.com/2011/08/june-2011-update.html

      I mean look at what’s happened since 1998 (or even 2002, the other cherrypick) – less El Ninos, more frequent and stronger La Ninas, a declining solar cycle into a historically kinda-low and long minimum, and PDO switch.

      What would we expect from that? Cooling.

      What do we have instead? Temperatures gone flat.

      Perhaps the wakeup call here should be the *lack* of cooling in the last 10 years given all the things above, rather than the “lack” of warming.

      Would hate to see what happens when the solar cycle and ENSO rises out it’s current near-slump and then find that AGW was continuing all along as well.

      • “Well this guy adjusts the temperature records, including HadCRUT, for ENSO and solar cycle and finds the warming continues:”

        Tamino is telling you what happened since 1975. The no warming claim starts in 1998. And the no warming claim since 1998 applies even if you ENSO correct the data. Same goes for your other guy.

        ENSO is not a reason for the flat trend. There have been 6 El Ninos and 5 La Ninas since 1998. Don’t know where you get the idea that ENSO is in a slump. We had a heavily El Nino dominated period from 77 to 98. But since 98, ENSO has been fairly neutral.

        The warmers keep telling us that the change in TSI refected by the solar cycles is tiny compared with CO2 forcing. And next year, solar cycle 24 will max out. So we are well past the minimum. The solar cycles that we had in the 20th century, before 24, were larger than average, so there is no reason to expect a return to them.

      • “Tamino is telling you what happened since 1975. The no warming claim starts in 1998. And the no warming claim since 1998 applies even if you ENSO correct the data. Same goes for your other guy.”

        Doesn’t look like it to me:
        http://tamino.files.wordpress.com/2011/01/adj1yr.jpg

        There doesn’t even seem to be a let up of warming there.

        The other guy even is even reproducing hadcrut under an assumption of accelerating warming.

        “ENSO is not a reason for the flat trend. There have been 6 El Ninos and 5 La Ninas since 1998. Don’t know where you get the idea that ENSO is in a slump.”

        It’s more the distribution I am think about. Eg the period begins with a super El NIno and ends with a strong La Nina. The trend is negative, in terms of a slump, how much lower can it get. Eventually we get to the point where we need 3 La Ninas back to back just to continue the decline.

      • lolwot:
        Tamino must have made that up, because it has no correlation with reality. This is what it looks like since 98.
        http://reallyrealclimate.blogspot.com/2011/07/rss-and-uah-divergence-charts.html

        “Eg the period begins with a super El NIno”
        That super El Nino was immediately followed by two years of La Nina. The effect of the two on the trend was to neutralize each other out.

        “Eventually we get to the point where we need 3 La Ninas back to back just to continue the decline.”

        Again, I have no clue as to what you are talking about. I gave you the ENSO chart and it cleary shows that there was a balance of ENSO events. Also, the ENSO corrected data shows the same trend as the uncorrected data. I don’t have an updated copy, but this one shows you that the 98 starting point made no difference.

        http://reallyrealclimate.blogspot.com/2008/07/gavin-schmidt-enso-adjustment-for.html

      • The graph of Taminos I posted is adjusted for solar cycle and ENSO.

        It shows no slowdown, let alone flattening.

        1998 is not actually the point where temperature flattens (use a 5 year mean and you see warming continues to 2002)

        ENSO has declined significantly since 2002 (eg: http://tamino.files.wordpress.com/2011/01/mei1.jpg) and so has the solar cycle.

        That’s why when Tamino adjusts for both those factors he finds the warming has continued even past 2002.

  69. I would suggest the important point to accept, for most commenators on this blog, of the Santer paper is not so much the figure of 17 years, which I would agree is probably debatable, but that the concentration on annual figures which we see in “it hasn’t warmed since 1998″ type arguments is just a nonsense.

    I do have a habit of harping on about graphs. Graphs are good. Graphs are scientific. You can see features in graphs that aren’t obvious in tables of results.

    http://farm4.static.flickr.com/3594/3391620722_2692a33e49.jpg

    You can see from this graph, even with a relatively short 5 year averaging, that its looks quite likely there is a causal link between periods of rapid warming and the sunspot cycle. So on that basis alone you’d need to average out the results over at least 13 year period.

    On the other hand, if you want to spin some sort of political argument that AGW isn’t quite the problem conventional science says it is, maybe you wouldn’t!

    • The solar minimum is the elephant in the room. If the longterm warming trend is currently about 0.2C/decade all you need is the downturn in TSI since 2002 to cause about 0.2C cooling and that just explains the “flatness” in temperature.

      Climate science might have a problem with the recent TSI downturn causing 0.2C cooling, but you’d think the idea would be right at home for certain skeptics who decry climate science and bang on about obvious “big ol’ yeller” in the sky all the time and how it influences climate so.

      Yet if the downturn of the solar cycle had caused the flatness, it means the flatness is temporary and that the longterm warming hasn’t stopped. And they’d rather not entertain that idea. Which is why I call it the elephant in the room.

      So you get this ridiculous situation where skeptics who big up the Sun won’t attribute any cooling impact to the recent solar minimum, or they’ll try to minimize it’s impact. If you ask where the cooling is, they’ll appeal to lags and how complicated the matter is. The cooling will happen soon they assure us, just wait. They don’t entertain the idea that the cooling has happened, and it was canceled out by the ongoing warming.

      Then they’ll go and complain that AGW should be falsified by 10 years of flat temperature data and that things like this Santer paper are just making excuses. With not a sense of irony.

      • “Yet if the downturn of the solar cycle had caused the flatness, it means the flatness is temporary and that the longterm warming hasn’t stopped. ”

        Well, if you want to suggest that the solar effect is strong enough to balance out CO2, then you also have to attibute a fairly large share of 20th Century warming to it.

        http://reallyrealclimate.blogspot.com/2008/07/20th-century-sunspot-trend.html

        You can’t have it both ways either.

      • Two points:
        Firstly, your link isn’t a proper scientific reference.
        Secondly, the graph shows only sunspot frequency not TSI data.

        The point is that TSI is slightly sinusoidal according to the state of the solar cycle. If there is a general warming trend due to other factors this sinusoid will, together with random variations, be superimposed on that linear rise.

        Consequently there will be periods of 7-8 years when temperatures do look flattish, and other periods of similar length when they will jump.

        We’ve just passed a very deep solar minimum. So, if past experience is a good guide, we should see another jump in the next few years.

      • “If there is a general warming trend due to other factors this sinusoid will, together with random variations, be superimposed on that linear rise.”

        So you are saying that the variation due to TSI is as strong as that due to CO2?

        “Firstly, your link isn’t a proper scientific reference.”

        Yeah, gotta have a Phd in climate science to run a trend line through a data set. LOL.

        I need one of those proper scientific references, like the Mann publications where neither Mann or his peer reviewers can tell when data is being used upside down.

        “Consequently there will be periods of 7-8 years when temperatures do look flattish,”

        The cycles are only about 11 years long. That doesn’t give you 7-8 years of minimum. Also, the current flat trend is now more than 13 years long.

      • In terms of the adjusted records, over the most important period it doesn’t look like it provides much warming at all in this one:
        http://tamino.files.wordpress.com/2011/01/spots.jpg

        As tempterrain points out this kind of cyclic impact is significant over the short term, over say 7 years, but over the longterm not necessarily.

      • lolwot: “As tempterrain points out this kind of cyclic impact is significant over the short term, over say 7 years, but over the longterm not necessarily.”

        That doesn’t help you explain a 13+ year flat trend. And solar minimums, in the cyclinc sense, don’t last 7 years. More like 3.

      • “That doesn’t help you explain a 13+ year flat trend.”

        Well it does because Tamino’s solar and ENSO adjusted graph – and that other guy’s – clearly show no flattening when those two are taken into account. That’s the entire point. You’ll have to explain what they’ve done wrong in their analysis.

      • What would the response be if we mention that all of the last 8 years are in the top 10 in a 130-year record of global surface temperature? Does that look like cooling, or what?

      • Yes, of course, for AGW rejectionists, any argument will do. No doubt some of them will be tempted to write in claiming they’d said it was the sun -all along!

        I’d say there is a slight problem, however, with the solar cycle argument, in that the cooling of the early 90’s was largely attributed to the volcanic eruption from Mt Pinatubo. It could be that the falling TSI , at the time, had a larger effect than was generally realised and the eruption a correspondingly smaller effect.

      • For AGW believers, as we see in numerous silly news articles and public statements about hurricane middle names, any leaf that blows, any could that sails by overhead, is a reason to blame CO2.

      • lolwot: “In terms of the adjusted records, over the most important period it doesn’t look like it provides much warming at all in this one:”

        It hadn’t reached equilibrium from the previous rise. Even the period that you show is considerably higher than what we had at the beginning of the 19th century. Then around 1977 we switched to a strongly El Nino dominated period.

  70. Mikel Mariñelarena

    Fred, further up in the thread you bring about once again the aerosols topic as an explanation for the flattening/declining of the temperature record during parts of the 20th century. You may recall that some time ago we discussed the lack of direct evidence of surface cooling due to aerosols over the regions most affected by them (China/India). As it happens, I think that right now we are witnessing another excellent example of how powerful aerosols actually are at cooling the surface.

    Last June 4th there was a huge volcanic eruption at Puyehue-Caulle, southern Chile. The enormous amounts of ash reached the stratosphere, went round the world driven by the permanent westerlies of those latitudes and forced airports to be shut down as far away as Australia. The most affected towns were Angostura and Bariloche, just west of the volcano. They’ve received layer upon layer of ash on the ground and, to this day, Bariloche Airport remains closed. Experts say that the ongoing emissions of the volcano are mainly composed of sulfates.

    A disaster for the locals. But fortunately for climate analysis, the GHCN station at Bariloche Airport has remained in operation. Its current data is available here: http://data.giss.nasa.gov/work/gistemp/STATIONS//tmp.301877650003.1.1/station.txt Needless to say, one would expect a strong cooling effect of the aerosols over that station. None of that is observed. Last June the average temperature was actually just *above* the mean of the preceding decade, at 3.1C, and last July it hit the average, at 2.3C.

    I may be missing something but, looking at these data, I once again find myself unable to believe that the much more scattered industrial aerosols may have had as strong an effect on the global temperatures as the IPCC claims. I’d very much welcome any explanation for this paradox.

    • Hi Mikel – I don’t recall the previous discussion, but in case it wasn’t mentioned then, much of the evidence for anthropogenic aerosol cooling has been addressed in various papers by Martin Wild. Volcanic aerosols will cool depending on the quantity and duration of their contribution to stratospheric aerosols, with Pinatubo (1991) associated with two to three years of cooling. Smaller eruptions will have smaller and briefer effects.

      • Mikel Mariñelarena

        Fred, thanks for the reply but I read the Wild paper and didn’t really find any quantitative *surface temps record* evidence in it. Just some anecdotal mentions in passing to seasonal records in China. On the other hand, I’m not talking about smaller eruptions’ effects on the global temperature. I’m talking about an example of a massive, ongoing aerosol forcing over a small area not having any measurable effect on its temperature (at least during the current SH winter). I realize that this is in stark opposition to the mainstream thinking you like to cite on the aerosol-cooling link but that’s why I’m asking myself.

      • I think other readers who visit the Martin Wild review (and also read some of the referenced papers) will disagree that it is “anecdotal”. TData on volcanic eruptions are also robust, with little doubt about their cooling effects. In my view, the latter is not a very controversial area, given the quantity of data.

        I don’t know anything about the eruption you mentioned, although I infer it was not of the Pinatubo magnitude. The distribution of volcanic aerosol cooling will depend on atmospheric circulation – particularly in the stratosphere – and also on the availability of sunlight, because the cooling effect involves scattered solar radiation.

      • Mikel Mariñelarena

        I may have to re-read the Wild paper and again look exactly for what I failed to find the first time: local temperature observations on the surface matching the expected effects of the aerosol radiative forcings the paper does talk a lot about. But what I’m talking about here is quite straight-forward: skies covered by sulfates during several months and temperatures remaining at average values.

        As for the large tropical eruptions and *global* cooling relationship, uncontroversial in the literature it might be. But I’ve also wondered sometimes why the Krakatoa 1883 eruption (one of the largest in modern history) doesn’t show in the HadCRUT record: http://www.metoffice.gov.uk/hadobs/hadcrut3/diagnostics/global/nh+sh/annual_s21

      • The following is a news item, so I’m not sure if it reliably reflects the evidence, but it suggests that the eruption didn’t spew enough sulfur dioxide into the atmosphere for significant climate effects –
        Chile Volcano. Large particle volcanic ash settles out very rapidly, and it is the very small particles seeded by sulfuric acid (from SO2) that are more important in causing durable and widespread cooling. This does not appear to be a constant percentage in volcanic eruptions, but was presumably large in the case of Pinatubo.

      • Regarding the Krakatoa eruption, the data you linked to does suggest a subsequent cooling for 5-10 years relative to 1883, although not all of that interval cooling may have been due to Krakatoa.

      • The real issue with volcanic cooling is how high the explosion tosses the sulfate aerosols. For example, the Mt. St. Helen’s explosion was sideways, leveling the surrounding forests, so very little of the ejecta went in to the upper troposphere/lower stratosphere and there was no real effect on global temperature. In the case of Pinatubo there was a lot of sulfate pushed upwards.

      • The real issue with volcanics is that there is no uniqueness theorem.

        The issue is the time of the year, latitude and type.The Krakatoa problem is well known eg Stenchikov 2006 ie that the models over estimate the global forcing.Hansen suggested that the observations were incorrect,however the Giss model gets the AO sign incorrect and arctic central temps incorrect in scale and time so.This is due to the incorrect heteregenous chemistry at high latitudes eg chapter3 WMO 2003 ,Ozone assessment 2011.

        There are a number of interesting suggestions that ocean damping ie transport is the reason eg Gleckler 2006 Stenchikov 2009 however they are not convincing .

        Another approach is the injection of water vapour into the stratosphere ie a negative feedback to volcanic forcing eg Joshi and Jones 2009 which would of course be problematic to both reconstructions and the present understanding .

      • Mikel,
        Carl Sagan, in the aftermath of the first Gulf War but while the Kuwaiti oil fields were still burning, famously predicted significant cooling effects from the aerosols of the fires.
        He was wrong as well. The impact of aerosols was not well understood then, and apparently is not now.
        Some skeptics point out that the aerosol factor is in no small way a fudge factor used by AGW believers to put a name on cooling they cannot easily identify.

    • Mikel,

      You say ” Needless to say, one would expect a strong cooling effect of the aerosols over that station. “.

      Aerosols from volcanic eruptions do have a cooling effect once they reach the stratosphere but the effect of high wind speed in the upper atmosphere would rapidly disperse these, and any local effects would be very slight.

      • Mikel Mariñelarena

        I can understand that. But the problem here is that the aerosols in the particular spot that I mentioned have been on the *troposphere* above (indeed they have even reached the ground) during several months. This is similar to what happens with industrial aerosols: they never reach the stratosphere and are washed away in 1-2 weeks (Ramanathan). However, we are told that they have a strong and global cooling effect. How can tropospheric aerosols have a global but not local effect?

        Fred: my understanding from reading, for example, Michael Mann and the very news article you link is that only very large *tropical* eruptions have a global cooling effect, as the aerosols from these volcanoes have the potential to spread to the whole stratosphere. This is not the case with extratropical volcanoes, such as the Chilean one, due to different circulation patterns in the stratosphere at those latitudes. But this doesn’t say much about the local effects of extratropical volcanoes. I’m still struggling to see why a permament cloud of aerosols from a nearby volcano is unable to measurably cool the surface but much less powerful chimney stacks are able to cool sorrounding regions to the extent that this cancels GHG warming.globally.

      • It’s the constancy of industrial aerosol emissions that determines the persistent widespread effects. Aerosols emitted for only a short time would have minimal effects that subside very quickly.The industrial aerosols are rich in SO2, while apparently, the Chilean volcanic eruption did not (according the news item) spew enough SO2 into the atmosphere for discernible climate effects. I’m not sure, therefore, what is the basis for your description of a “permanent cloud of aerosols”, particularly as it relates to sulfur emissions.

      • Anthropogenic aerosols are emitted into the troposphere and fall out with in hours to days – so they are effective only in that range. Which could be thousands of kilometres.

        There is a suggestion that the effects depend on the mixing ration with black carbon – higher ratios favouring more warming rather than cooling.

        http://ramanathan.ucsd.edu/files/pr176.pdf

        Volcanic effects depends on the type of volcano, the height of the plume and the size of the particle.

        http://www.earth.ox.ac.uk/~tamsinm/VEA.pdf

        The effect of big volcanoes is about 0.22C over a short time.

        Anthropogenic sulphates are not known well – but the net anthropogenic forcing is positive over the whole of the century with IPCC forcings.

      • In addition to the Ramanathan paper cited above by Chief Hydrologist, the review article by Ramanathan and Carmichael is informative in quantifying both the positive and negative forcing effects of aerosols as a function of their components. Overall forcing at the TOA is negative averaged over all aerosols, but significant atmospheric heating and a net positive TOA forcing is possible for aerosols with a strong black carbon component, and some of this will eventually be transmitted to the surface despite the reduction in surface insolation from the light scattering and absorptive properties of the aerosols. Most of the relevant aerosols are anthropogenic in origin, although natural events such as forest fires can also contribute, particularly to the black carbon fraction – a role that was not mentioned in the article unless I overlooked it.

        These forcings considerably outweigh contributions from volcanic eruptions, mainly because the latter are sporadic, and their aerosol contributions are transient.

      • The net warming is a result of mixing of black carbon and sulphide – is observed in Chinese plumes as a result of fossil fuel burning.

        BC is a factor that seems relatively important.

      • Mikel,

        I’m not an expert on this sort of thing but this paper:

        http://ruby.fgcu.edu/courses/twimberley/EnviroPhilo/Aerosols.pdf

        suggests that aerosols can have either a cooling or warming effect depending on their altitude.

  71. Phil Jones of CRUgate admitted that there has been no significant global warming since 1995.

    And, that is after all of the shenanigans, involving data corruption and data gone missing.

    The global warming house of cards collapsed in the UK.

    We then learned that the raw data for New Zealand had been manipulated; and, NASA’s data is the next CRUgate: satellite data shows that all of the land-based data is corrupted by the Urban Heat Island effect.

    Manipulation of the data is so bad that the recent discovery concerning a weather station in the Antarctic where the temperature readings were actually changed from minus signs to a plus signs to show global warming almost comes as no surprise.

    And then, there was a study showing the ‘tarmac effect’ of land-based data in France where only thermometers at airports–in the winter–showed any warming over the last 50 years. Since then, the problem of data corruption due to continual snow removal during the winter at airports where thermometers are located–while all of the surrounding countryside is blanketed in snow–has been shown to extend far beyond the example in France (e.g., Russia, Alaska).

    In reality, there essentially has been no significant global warming in the US since the 1940s. The only warming that can be ferreted out of the temperature records is in the coldest and most inhospitable regions on Earth, such as in the dry air of the Arctic or Siberia where going from a -50 °C to a -40 °C at one small spot on the globe is extrapolated across tens of thousands of miles and then branded as global warming.

    Warming before 1940 accounts for 70% of the warming that took place after the Little Ice Age ended in 1850. However, only 15% greenhouse gases that global warming alarmists ascribe to human emissions came before 1940. Obviously, the cause of global warming both before and after 1940 is the same: solar activity during that period was inordinately high. It’s the sun, stupid. Now we are in a period where the sun is anomalously quiet; and, now we are in a period of global cooling and have been for almost a decade.

    And what about the measurement of atmospheric CO2? We learned that the CO2 readings are based on measurements taken on the site of an active volcano (Mauna Loa) and have been completely fabricated out of whole cloth by a father and son team who have turned data manipulation into a cottage industry for years. (e.g., “Time to Revisit Falsified Science of CO2.” by Dr. Timothy Ball)

  72. Perhaps I didn’t devote enough time to reading the abstract of the paper given above, but isn’t this still an issue of believing model results while ignoring actual measurements? Browsing quickly though the comments, there is the always-present issue of whether the error bands are correctly calculated..

    But even if the statistics were handled in a way that Steve McKintyre would approve of, we still are asking that models with known issues with clouds, among other things, be believed when actual measurements differ. Yes, it is possible that natural variability could cause actual temperatures to fall outside the range of model predictions without invalidating the models, but I’m not yet ready to accept model outputs under these conditions.

  73. The IPCC FAR seemed content to use about 15 years to feel a sense of “strengthening confidence” in earlier projections:

    “Since IPCC’s first report in 1990, assessed projections have suggested global averaged temperature increases between about 0.15 and 0.3°C [0.27 and 0.54°F] per decade for 1990 to 2005. This can now be compared with observed values of about 0.2°C [0.36°F] per decade, strengthening confidence in near-term projections.”

    http://www.ucar.edu/news/features/climatechange/faqs-wg1-spm.jsp

    Utilizing a similar, more recent period, the trends are closer to 0.1°C /decade.

    http://www.woodfortrees.org/plot/hadcrut3vgl/from:1996/trend/plot/hadcrut3vgl/from:1996

    If the fact that the first 15 year period fell within the range projected by the first IPCC report gives us “strengthening confidence”, what should the fact that the more recent 15 year period is well outside the projected range do to our confidence?

  74. Global warming or cooling is entirely about energy in and energy out. If energy in is greater than energy out in a period the planet warms – and vice versa.

    Here is this centuries values for energy in – the most accurate to date – from the SORCE project. The peak of cycle 24 is due next year with the lowest sunspot number since 1928. Peak to trough seems to be about 0.1oC difference.

    So what about the longer term? The cosmogenic isotope record suggests that the 20th saw a 1000 year high in solar activity.

    Sunspot records suggest a lower activity in the early part of the record. The error bands are significant earlier in the record – but there is little to suggest major variability in visible and near IR solar radiation.

    Energy out is measured by the CERES record in the 21st Century thus far. We can see little change in IR and a net decrease in reflected SW – giving a net warming that outweighed the fall in incoming energy in the middle of the last decade. This will have changed again with the more recent major La Niña.

    So this should lead to an increase in ocean heat content – as was shown by von Schuckmann et al 2010.

    Putting most of it together in a multiple linear regression method – <a href="http://www.agci.org/docs/lean.pdf&quot; shows effects of volcanoes, ENSO, net anthropogenic influences and solar irradiance.

    She neglects changes in TOA as a result of cloud changes that are clearly shown in the ocean/TOA flux correlation available only in the satellite era. Cloud is fundamental to the behaviour of Earth systems – and I think that there is more evidence – and more reason to suspect – change in cloud than otherwise. Most especially in the central Pacific – an area of great importance in global energy dynamics.

    The role of sulphide is complex. For volcanic emissions it depends on the type of volcanic emission, the height of the plume and the size of the particles. For anthropogenic emissions it depends critically on the mixing ratio with black carbon. Sulphide mixed with black carbon can increase the warming potential rather than cool – but persists for hours to days in the atmosphere.
    It seems minor – about 0.1W/m2 relative warming over the past decade in recent work.

    There are 3 areas where AGW has got it horribly wrong.

    * Clouds – since when is it likely that clouds don’t change when hydrology for one thing changes all the time. Leaping into different states for 10’s, 100’s and even thousands of years.
    * Top-down solar UV interactions with stratospheric ozone and resultant modulation of the location of the jet streams.
    * Dynamical complexity – abrupt and non-linear change.

    They are all somewhat linked.

    Arguing against these is to reject whole swathes of science – but it seems many people will – quite often on the basis of noodles-for- brains plots – and for reasons I am convinced have more to do with the AGW version of a spaceship cult.

    We are in a cool Pacific decadal mode – http://www.osdpd.noaa.gov/data/sst/anomaly/2011/anomnight.9.12.2011.gif – the evidence can be seen in the broad, cold V over much of the central Pacific. This is nutrient rich water upwelling from the deep ocean in the Eastern Pacific. As well, we are in La Niña again. The cold tongue can be seen evolving in the equatorial Pacific. It will continue to grow in the months to come as upwelling intensifies in the cold tongue. La Niña are much more frequent and larger in cool Pacific modes. To call such coherent, powerful and obvious systems ‘noise’ is nonsense beyond belief.

    The cool modes last 20 to 40 years and this one started after 1998. The only question in my mind is the depth of the cooling over the next decade or three.

    Cheers
    Robert I Ellison
    Chief Hydrologist

  75. John M

    Good point

    The Fifth Assessment Report should say the following:


    Since IPCC’s first report in 1990, assessed projections have suggested global averaged temperature increases between about 0.15 and 0.3°C [0.27 and 0.54°F] per decade for 1990 to 2005. This can now be compared with observed values of about 0.03°C [0.05°F] per decade, DASHING confidence in near-term projections.”

    http://bit.ly/cxeFBg

  76. Girma and JohnM,

    I’m not sure how 0.2 deg C firstly gets halved to 0.1 deg C which then gets cut again by 70% to 0.03 deg C.

    But why stop there? Why not 0.00000003 deg C per decade? I’m sure if you go back far enough you’ll be able to get this figure somehow. If not just make up the numbers to suit.

    Better still, why not claim that it’s cooling by 0.2 deg C per decade and it’s our all our patriotic duties to burn as much fossil fuel as we possibly can?

    • Speaking for my own number of 0.1 deg C/dec, it’s called an “ordinary least squares linear trend”, the same sort of mysterious device the IPCC used.

      You may be more familiar with the simpler term “rise over run”.

  77. Tempterrain

    For EIGHT long years the trend has been cooling as shown below.

    http://bit.ly/pA0sIe

    The Gt of human emission does not seem to have any effect on the global mean temperature trend.

    Tempterrain, do you recall the statement:

    “Be awkward if we went through a early 1940s type swing!”

  78. Girma

    “For EIGHT long years…”

    The whole point of the paper is that for a 95% confidence you need 17 years of data to see a net poitive trend.

    Which means that you can *expect* to see a cooling trend over the previous *17* years 5% of the time. (say 2 or three times in the previous 50 years to today)

    A cooling trend of EIGHT YEARS, even if it were real, and however capitalised by your good self, is entirely consistent with, and indeed, predicted by, the AGW hypothesis in general and this paper in particular.

    • VeryTallGuy

      A cooling trend of EIGHT YEARS, even if it were real, and however capitalised by your good self, is entirely consistent with, and indeed, predicted by, the AGW hypothesis in general and this paper in particular.

      VeryTallGuy, please give me a big break.

      Why?

      IPCC AR4:

      For the next two decades, a warming of about 0.2°C per decade is projected for a range of SRES emission scenarios. Even if the concentrations of all greenhouse gases and aerosols had been kept constant at year 2000 levels, a further warming of about 0.1°C per decade would be expected.

      VeryTallGuy, if you have not seen that statement by the noble prize winning IPCC, please find it here: http://bit.ly/9pwVyH

      What is the observed decadal trend?

      Only 0.03 deg C per decade: http://bit.ly/cxeFBg

      This is less than 1/6th of the 0.2 deg C per decade warming predicted by the IPCC. Why does the IPCC exaggerate by 566% (= 0.2-0.03)x100/0.03)?

  79. “But you have no scientific basis for your assertion. It is merely a conjecture, not even a hypothesis. That is my point.”

    When I say recovery from the Little Ice Age in some sense “explains” global warming, I mean to say that the current warming trend began when the LIA ended and has been proceeding more or less apace ever since. I do not understand why Co2 has to be brought into the discussion. During the MWP, Co2 levels were much lower than today with temps as high or even higher. I do not mean that there is some “golden climate mean” toward which global temps are somehow irresistably drawn to correct.

    • Pokerguy,

      CO2 gets brought into the discussion because our understanding of the radiative properties of CO2 and the effect of its presence in the atmosphere means there is an a priori expectation that an increase in the CO2 levels of the kind we have seen should lead to warming. It has to come into the equation regardless of whether there is a plausible “natural” cause which could explain recent warming or not.
      The problem I have with the “coming out of the Little Ice Age” argument (apart from the lack of any actual mechanism) is that it is now much warmer than before the LIA started. As for the MWP, we don’t know that global temps were “as high or higher” than today, but even if they were the fact that it would have been due to some “natural” factor(s) rather than CO2 doesn’t alter our expectation that increased CO2 levels should have caused warming in recent decades and should do in the future.

      • a priori expectations increase superstition and fear and ultimately cognitive dissonance that can only be dealt with by AGW True Believers by ignoring reality. If you are going to look to natural factors you realize that global warming fearmongers are “spitting in the wind,” as in, “You can go outside and spit and have the same effect as doubling carbon dioxide,” and, “If the atmosphere was a 100-story building, our anthropogenic CO2 contribution today would be equivalent to the linoleum on the first floor,” as follows:

        “A major new scientific study concludes the impact of carbon dioxide emissions on worldwide temperatures is largely irrelevant, prompting one veteran meteorologist to quip, ‘You can go outside and spit and have the same effect as doubling carbon dioxide.’

        “That comment comes from Reid Bryson, founding chairman of the Department of Meteorology at the University of Wisconsin, who said the temperature of the earth is increasing, but that it’s got nothing to do with what man is doing.

        “‘Of course it’s going up. It has gone up since the early 1800s, before the Industrial Revolution, because we’re coming out of the Little Ice Age, not because we’re putting more carbon dioxide into the air.’”

      • Reid Bryson, founding chairman of the Department of Meteorology at the University of Wisconsin, obviously says some very silly things.

      • aa,
        Silly, maybe. Right, probably.
        aa, have you noticed that no studies are supporting the apocalyptic clap trap and that all you believers are doing is playing defense? All the studies are showing modest impacts of CO2, and the studies that claim otherwise fall apart under scrutiny.
        In Australia, and the UK, the pushback on AGW policy demands is giong to be an important cause in government change. In the US, AGW policies are now avoided to be even spoken of.
        Your defense now consists not in pointing out the facts but in trashing the skeptics, hiding data in more and more blatant manners, and shouting louder and louder?
        Do you really think impugning the likes of Reid Bryson is a good strategy? Do you still refuse to notice that cliamte science is so brittle that any move from the orthodox crisis claims is met with a hail of childish behavior by the AGW community?
        Do you really still not get it?

      • Many AGW True Believers have become keptics over the years. As for example, Meteorologist Dr. Reid Bryson, one of the “Fathers of Meteorology.” Bryson became a leading global warming skeptic in the last few years before passing away in 2008.

      • hunter,

        have you noticed that no studies are supporting the apocalyptic clap trap and that all you believers are doing is playing defense? All the studies are showing modest impacts of CO2, and the studies that claim otherwise fall apart under scrutiny.

        What I notice is that there are plenty of studies indicating the likely adverse consequences of AGW but you just dismiss them out of hand without any evidence that you have actually subjected them to any scrutiny or indeed would be qualified to judge their findings if you did so.

        In Australia, and the UK, the pushback on AGW policy demands is giong to be an important cause in government change. In the US, AGW policies are now avoided to be even spoken of.

        Given the current political situation in the US and the attitude of your political right towards climate change it is not surprising that there is no immediate prospect of legislation on climate change. That says more about US politics than the reality of the threat from AGW. There is actually little pushback in the UK against the govts climate change policies, apart from the usual shrieking of the right wing press. All main parties are on board. I can’t comment on Australia.

        Your defense now consists not in pointing out the facts but in trashing the skeptics, hiding data in more and more blatant manners, and shouting louder and louder?

        You’ll notice that I actually pointed out some facts in my original comment in reply to Porkerguy, in contrast to your content free response. I see a lot of assrtions in your commernts generally but few actual facts. The skeptics get “trashed” because often their behaviour deserves it.

        Do you really think impugning the likes of Reid Bryson is a good strategy? Do you still refuse to notice that cliamte science is so brittle that any move from the orthodox crisis claims is met with a hail of childish behavior by the AGW community?

        I didn’t “trash” Reid Bryson, I pointed out that a couple of statements of his which were quoted were rather silly. The fact that you can’t even see that they were silly is your problem. Does he get a free pass for saying ridiculous things in public? The childish behaviour is almost entirely on your side.

        Do you really still not get it?

        Yeah, I get it. The fake skeptics think they can do or say whatever they like without any consequences and we are just supposed to just take it, and even take the blame for your behaviour. Sorry, no deal.

      • You’ll notice that I actually pointed out some facts in my original comment in reply to Porkerguy

        Apologies to pokerguy – I wasn’t trying to insinuate he was overweight or anything.

  80. “As for the MWP, we don’t know that global temps were “as high or higher” than today,…”

    That said, it seems to me most fair minded people would have to agree that MM’s attempt to erase the MWP altogether speaks volumes about how “inconvenient” that balmy period is…The warmists have to be able to use the word “unprecedented” in order to buttress their shaky case, and the MWP is a major Achilles heel.

  81. Wagathon

    “If the atmosphere was a 100-story building, our anthropogenic CO2 contribution today would be equivalent to the linoleum on the first floor”

    This, whilst a flippant and obviously deliberately misleading quote does beg a genuinel interesting question on how to judge the impact of anthropogenic CO2, and communicate that.

    Judging the significance of an impact is generally best done with dimensionless numbers, as an absolute quantity without comparison can be very misleading; for example quoting anthropogenic CO2 as the number of molecules emitted per second gives an astronomically huge number with no relevance.

    For CO2 we could choose (Mass Co2/Mass atmosphere), which gives the lino on the floor answer.

    Or we could use the (Anthropogenic Co2/Natural Co2), currently around 35% (increasing the 280 natural to 390ppm current rough total)

    Or we could use the CO2 forcing fraction, (Co2 forcing/TSI) say.

    Or we could use impact, perhaps (Impact of CO2 forcing/Impact of Milankovich cycles), which would be roughly unity.

    Which of these do you think gives the best overall summary of the impact of anthropogenic CO2 and why?

    • Common Sense & Perspective vs. Pseudo Science & the Politics of Fear:

      “There is no dispute at all about the fact that even if punctiliously observed, (the Kyoto Protocol) would have an imperceptible effect on future temperatures — one-twentieth of a degree by 2050.” ~Dr. S. Fred Singer

      Man’s contribution to all greenhouse gases: 0.28%

      Water Vapor accounts for 95% of all greenhouse gases.

      CO2 accounts for just 3.5% of all greenhouse gases, most of which is Natural

      99.72% of all greenhouse gases are … Natural

      _________

      Based on concentrations
      (ppb) adjusted for heat
      retention characteristics……..% of All……% Natural….% Man-made

      Water vapor………………………95.000%……94.999%…..0.001%
      Carbon Dioxide (CO2)…………..3.618%……..3.502%…..0.117%
      Methane (CH4)……………………0.360%………0.294%…..0.066%
      Nitrous Oxide (N2O)……………..0.950%………0.903%…..0.047%
      Misc. gases (CFC’s, etc.)………0.072%……..0.025%……0.047%

      Total………………………………..100.00%……..99.72%…….0.28%

      _________

      • Wagathon,

        cite for figures please.

        Also specifically how you justify a CO2 man-made proportion of 0.117 vs total of 3.618 when the observed increase is 100ppm of 380ppm.

      • Ok–Dr. S. Fred Singer, atmospheric physicist, Professor Emeritus of Environmental Sciences at the University of Virginia, and former director of the US Weather Satellite Service, in a Sept. 10, 2001 Letter to Editor, Wall Street Journal

      • I think there may be a bit of a credibility gap when you quote figures from Fred Singer, in the employ of the Heartland Institute, and at the same time say
        “It is obvious that the IPCC deals only in politics and that, from the beginning, has never been anything more than an ideologically motivated purveyor of “lies, damn lies, and statistics.””

        The figures are interesting but only from the psychological point of view as to why you post these numbers which have obviously been deliberately constructed to deceive?

        A naive audience might take them at face value, but those on a site such as this will be well aware of the provenance. I wonder what your motivation is?

      • “…deliberately constructed to deceive?”

        So, are we are talking about Mann’s ‘hockey stick’ again then, or are we talking about those who purposefully defend a lie to support a hoax and bash anyone who tells the truth? Obviously, any real scientist like Lindzen who holds an abiding respect for truth will be in the crosshairs of the AGW True Believers and will be the victim of their attempts at character assasination and politics of personal destruction.

      • Wagathon “So, are we are talking about Mann’s ‘hockey stick’ again”

        No – we’re talking about your deliberate use of obviously misleading figures right here

      • Translation: you will continue to ignore the ‘hide the decline’ pseudo-science of the AGW True Believers–i.e., you choose religion over science.

    • CO2 makes up 390 ppm (0.039%) of the atmosphere

      Some Examples of Important Small Amounts:
      – He wasn’t driving drunk, he just had a trace of blood alcohol; 800 ppm (0.08%) is the limit in all 50 US states, and limits are lower in most other countries).
      – Don’t worry about your iron deficiency, iron is only 4.4 ppm of your body’s atoms (Sterner and Eiser, 2002).
      – Ireland isn’t important; it’s only 660 ppm (0.066%) of the world population.
      – That ibuprofen pill can’t do you any good; it’s only 3 ppm of your body weight (200 mg in 60 kg person).
      – The Earth is insignificant, it’s only 3 ppm of the mass of the solar system.
      – Your children can drink that water, it only contains a trace of arsenic (0.01 ppm is the WHO and US EPA limit).

      from http://www.skepticalscience.com/CO2_is_a_trace_gas.html

  82. Brain Fodder:

     What do the Vostok ice cores show about the past 650,000 years? For example, the current levels of atmospheric CO2 is at about the lowest level in the geological history of the Earth. Will Happer’s testimony in the Senate established that, “the planet is currently starved of CO2, and has been so starved for several million years.”

     What do the Minoan, Roman, and medieval warm periods have in common? Current global temperatures are 5°F cooler than these previous warm periods.

     The WMP (the Medieval Warm Period) existed in the IPCC’s its 1990 report. In its 2001 report, however, the IPCC wiped the WMP. Instead, they printed Mann’s ‘hockey stick’ graph, knowing that it was erroneous. Moreover, the IPCC showcased Mann’s graph and reproduced it over and over, even after Mann’s graph had been debunked. It is obvious that the IPCC deals only in politics and that, from the beginning, has never been anything more than an ideologically motivated purveyor of “lies, damn lies, and statistics.”

    • Wagathon,
      You obviously have not read the climategate mails very closely. The mails reveal the story behind that graphic in the 1990 IPCC report. The story behind it is quite interesting and not what you think. The graph was known to be in error at the time it was put into the report as it had been superceded by better research. That graph was created by Lamb, “founder” of CRU. Folland had included the graph and Jones and others discussed in the mails whether or not they should tell the whole history behind the graph and how it mistakeningly made its way into the report. As Jones explained they had corrected Lamb’s graph but buried the correction in a little know journal to preserve Lamb’s honor. Folland was unaware of the correction and put in the lousy hand drawn graph you refer to.

      Learn your history.

      • Science & Reality vs Science Fiction & ‘Media Reality’:

        With the first challenges to the IPCC’s use of the now discredited Mann ‘hockey stick’ graph, a raft of papers supporting Mann were floated by authors of other papers were co-authored by Mann. This was shown by Dr. Legman: nothing but a circle-jerk of shallow rebuttals by Mann’s pseudo-science sycophants supported by circular references and prejudices. Rather than recognizing the essential work of objective realists and seeking the truth, the IPCC hid behind its pseudo-science house of cards and continued to maintain the fiction that the MWP (Medieval Warming Period) never happened. The real truth is that the attempted abortion of the MWP was a purposeful attempt by the IPCC to eliminate an appreciably warmer period in the temperature record that confutes allegations of human CO2 as the cause of global warming. We see far more than the IPCC failure to admit a mistake: the IPCC continued to lie to cover up a planned and knowing perpetration of a scientific hoax.

      • Steven

        I could use some clarity on this issue. My mind is open. Are you talking about Mann’s Hockey Stick? As far as I can tell those guys continue to vigorously defend its accuracy. The best analysis of “Mike’s trick” and the “hide the decline” hoohah I’ve seen…along with their implication for the accuracy of the graph as a whole…is that provided by R. Muller here:

      • This is probably not going to work, but just in case, it is supposed to be a temperature reconstruction of the Colorado Plateau by Salzer et. al. 2005

        [IMG]http://i122.photobucket.com/albums/o252/captdallas2/salzertemp.png[/IMG]

        It is kinda neat looking at individual, non-Mannian, reconstructions to see what is there. Salzer’s shows a modern warming, hints of the LIA and if you look closely, remarkably stable temperatures during the MWP. Not too frightening though. I have no clue how well Salzer did as a paleo guy, but it is interesting if you live in the western states. He also has a precipitation reconstruction.

    • what’s worse is that Wagathon’s 3 points are wrong.

      Medieval warm period 5F warmer than present? Pull the other one. Not backed up by current science *at all*.

      The claims that the world is CO2 starved – irrelevant given the issue is the logarithmic rate of CO2 change not the absolute value. In fact the world being “CO2 starved” actually means any absolute change is going to have a larger impact. If we started at 2000ppm for example then 600ppm more wouldn’t be close to a doubling. But as we start at 280ppm, 600ppm is a tripling. So ironically, as is far too common, these junk simplistic wagathon style arguments actually backfire. But you know noone ever notices, you rarely see anyone pointing out the signficance of starting so low with CO2 in terms of the potential forcing

      • Imagine the effect of starting at 0ppm then

      • And perhaps “noone ever notices” that no one really cares that you do not understand that the CO2 ppm at Mauna Loa can change by as much as 600ppm in a single day or that CO2 in a commercial office building may exceed outdoor ambient levels by 700 ppm or more.

  83. Pray good sire how it is that you know anything about the Medieval warming Period. You endlessly cast doubts on recent scientific observations yet proclaim the MWP is cast iron fact. How is that?

  84. Santer mostly says what most have been thinking already, which is that ten years is not enough for natural variability to be averaged out while thirty is. When looking at longer cycles of variability, you have to be careful not to include solar variation and aerosol forcing that are not part of natural variability, and that seem to account for a lot of the long-term effects in the temperature record. I am skeptical that once these slow forcing changes are included there is anything left for long natural changes, which is already only 0.2 C in amplitude anyway.

    • I’ll see your 30 and raise you 30 because that’s the only way you are going to be averaging in the ocean oscillations.

      • The ocean oscillations (so-called) are highly correlated with solar and aerosol forcings, so I am skeptical of those being any separate phenomenon, however poorly explained they are.

      • What causes them is only important in this context if you have reason to believe they have stopped.

  85. I suggested here in 2007 a slowing down of surface temperature increase.

    http://www.americanthinker.com/2007/11/enso_variation_and_global_warm.html

    ‘A negative tendency of the predicted PDO phase in the coming decade will enhance the rising trend in surface air-temperature (SAT) over east Asia and over the KOE region, and suppress it along the west coasts of North and South America and over the equatorial Pacific. This suppression will contribute to a slowing down of the global-mean SAT rise.’
    http://www.pnas.org/content/107/5/1833.full

    You exclude solar variation from natural variation???

  86. My question woiuld be: What happens when human related forcing such as aerosols, sulfur emission, etc. act in opposition to other human related forcing such as greenhouse gas emissions? In other words, the notion of a 17-year minimum time frame to see the anthropogenic signal assumes that the forcing would all be in the same direction, yes?

  87. ohgodwhatidoingherequestionmark

    • Pratt,

      Quite a string of firecrackers you’ve set off here! Might we be hittin’ the fire-water a bit freely this evening? Possibly a bid to knock Robert off his “top commenter” perch? Both?

      Mostly good stuff IMHO, incidentally.

  88. I don’t see any mention of the ENSO oscillations in their work despite the fact that they dominate satellite estimates of temperature of the lower troposphere. These oscillations constitute the signal but apparently the authors subsume it into their imaginary “noise” which they then attempt to duplicate by modeling. The entire concept is worthless because it is divorced from reality.

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