Analysis of James Hansen’s 1988 Prediction of Global Temperatures for the Last 30 Years

Guest analysis by Clyde Spencer

Introduction

There have been articles on WUWT recently, here and here, commemorating the 30 years since James Hansen gave Senate committee testimony about his view of the human influence on climate. Some apologists for Hansen have, without more than subjectively comparing graphs, claimed that his prediction was extremely accurate. The following is his official 1988 prediction for three different scenarios of future trace-gases implicated in anthropogenic global warming:

I have highlighted the observed 1958-1988 annual average temperatures in red to make the line more legible.

The apologist’s claims for extreme accuracy are based on the subjective impression that the temperatures over the last 30 years have tracked his prediction of temperatures from forcing of intermediate ‘greenhouse gas,’ other trace- gasses, and aerosol assumptions (Scenario B). He assumed two significant volcanic eruptions during that 30-year period. However, there was only one, Mt. Pinatubo (1991, VEI 6). Therefore, had he assumed that there would only be one eruption, his estimates would have been higher and would have tracked B even more poorly than they have. Were it not for two exceptionally strong El Niño events in the last 20 years, it is unlikely that current temperatures would be anywhere near as high as they are currently. However, he did not consider the role of El Niño’s in his computer model. Therefore, it is just luck that his predictions came as close to reality as they did. The greatest intellectual ‘sin’ for a scientist is to be right for the wrong reasons!

Hansen dramatically emphasized that “The most recent two seasons (Dec.-Jan.-Feb and Mar.-Apr.-May, 1988) are the warmest in the entire record.” This is really a non sequitur. It would be notable if the last point(s) in a long upward-trending series were not the warmest in the series. And, indeed, the 27 seasons preceding the two 1988 record temperatures were all lower than the 1981 seasonal high! (See the next graph, below) Basically, Hansen got lucky again that he had a couple of warm seasons that allowed him to make such a statement to impress the uncritical Senators. Otherwise, he would have had to truncate his graph at 1981 to make a similar claim. He also added an extra season of data to his ‘30-year’ time-series, probably to accentuate the claim. Two seasons sounds more impressive than one season.

Hansen claimed “The warming is almost 0.4 degrees Centigrade [sic] by 1987 relative to … the 30 year mean, 1950 to 1980 … The probability of a chance warming of that magnitude is about 1 percent.” The first graph, above, with the red line, shows that 0.3 °C would be a more accurate estimate. One should be suspicious of such a claim when his own data demonstrated that the temperature had already exceeded that for one season in 1981! Are we to believe that at least two events with a 1% probability occur within 7 years of each other? He then claimed that the recent temperatures were about three times the standard deviation (0.13) of the baseline annual temperature average. Actually, the standard deviation of the annual averages for the 1958 to 1988 period is more like 0.15. Thus, the 1988 quarterly temperatures were about two ‘standard deviations’ above the previous 30 years of temperatures, not three! He was playing loose with the facts!

The values at the beginning and end of a noise-free, increasing, linear time-series will have the largest differences from the mean; meaning, that it is expected that they will likely have the largest standard deviations from the mean. The standard deviation of a time-series varies directly with the slope of a smooth trend-line and, the number of samples. To analyze time-series data properly, it should be de-trended, the mean set to zero, and the residuals used to get an accurate estimate of the probability of a random deviation from the mean. Hansen should know that! He is describing behavior (the first two data points of 1988) that is a function of the slope, not the internal variance of the data. Again, Hansen is trying to snow the Senators. No one is arguing that temperatures aren’t increasing. It is evident from the graphs. Nevertheless, he is offering sophistry to convince the Senate committee that what we are seeing is extremely rare.

However, most of his apologists are engaging in qualitative hand waving and not using any mathematical or statistical analysis to quantify the quality of his prediction, even when based on false assumptions. The question is, “How skillful was Hansen in quantitatively predicting the climate for the next 30 years, based on a computer program that assumes CO2 is the ‘control knob’ on global temperatures?”

Graphical Analysis

If one were to fit a linear, least-squares regression to Hansen’s 30-year data, and extrapolate it 30 years into the present, how would it compare with Hansen’s prediction? I’ll call this a naive prediction, a simple extrapolation of past trends, without making any assumptions about the cause of the warming, or the presence of extenuating influences such as volcanic aerosols. Implicit in this naive prediction is that it represents “Business as Usual,” the trace-gas assumption made by Hansen for his Scenario A.

The following graph is derived from Hansen’s Figure 2 in his Senate testimony, with higher temporal resolution than the prediction graph above. According to Hansen, the baseline for the calculation of the ΔT (anomaly) is the average temperature for the period of 1950 through 1980, although, he does not provide that average temperature.

The R2 value for the red trend-line is lower than I would like to see, with time only accounting for about 19% of the variance in temperature. Smoothing with annual averages and removing the seasonality would increase the R2 value. Nevertheless, substituting 60 years for x in the regression equation, gives a predicted anomaly of 0.467 °C for 2018. That is lower than Hansen’s Scenario C – that is, reduction (“draconian emission cuts!”) of the things driving warming – was supposed to be. Note that the slope of the regression line predicts a change of less than 1 °C per century, about the amount commonly claimed for the last century. Therefore, it may be a reasonable long-term approximation of future warming.

However, the period of 1958 to 1988 probably is not the best interval to use for prediction. The R2 value is low also because there are two distinct trends – one negative and a longer one that is positive. It appears that the 30-year interval he used was a pragmatic choice to provide the most current measurements for the Senate testimony. The two trends change over between about 1964 and 1970. Calculating the slope of the trend-line for the period of 1964 through 1988 would probably be the best choice. Doing so, provides better than a two-fold increase in the R2 value and increases the slope of the trend-line (green) to 0.0181 °C per year, for a predicted anomaly of about 0.803 for 2018.

Let’s compare the above, seasonal temperature graph with the most recent (2018/06/18) annual temperature series produced by Hansen. [ http://www.columbia.edu/~mhs119/Temperature/ ]

Note that the slope of the trend-line (green) for the period from 1970 through 2018 is almost the same as that obtained above ― 0.017 versus 0.018 °C per year. In hindsight, it appears that the selection of the period from 1964 through 1988 was a better choice for future prediction than the entire 30-year set. This graph shows an estimated anomaly of about 0.80 °C for 2018. Unfortunately, he does not provide an R2 value for his “Best Linear Fit,” nor are error bars provided for the temperatures, which is typical for his work.

It appears that the average global-temperature trend has been reasonably well behaved since at least 1970, and probably since about 1964. That is, it has not shown the longer-term non-linearity characteristic of Hansen’s 1988 predictions.

Let’s return now to the graph first shown, which was Hansen’s 1988 prediction with Scenarios A, B, and C. I have plotted the naive extrapolation, in green, on top of the original graph.

In the early years, the three scenarios are all close to each other, and probably close to the uncertainty of the temperature measurements. Therefore, I’ll focus on the 21st Century behavior. Note that the trend-line (green) best tracks Scenario C, the “draconian emission cuts!” I suspect that Hansen scheduled one of his two hypothetical volcanic eruptions for about 2014, driving Scenarios B and C temperatures down temporarily. The trend-line prediction is clearly lower than Scenario B (intermediate trace-gas), and much lower than Scenario A, the supposed “Business As Usual.” How much lower you ask? For 2019, the trend-line predicts an anomaly of about 0.80, while Hansen’s Scenario A is about 1.55; that is almost 94% higher than the trend-line prediction. Looked at another way, Scenario A has a slope (post 1988) of about 0.033 while the observed temperatures have a slope of about 0.017. That is, Scenario A has a slope twice the slope of the naive prediction, which matches the observed data recorded since 1988.

Conclusion

Using only Hansen’s own data, the above demonstrates that Hansen was not “extremely accurate” in his 1988 predictions because a simple, commonly unreliable, linear extrapolation performed better than his model in predicting the last 30 years of temperatures. One of the consequences of demonstrating the ‘Business As Usual’ linear extrapolation of past temperatures as being superior to the model used by Hansen, is that it isn’t necessary to appeal to anthropogenic influences to account for a phenomenon that started 12 millennia ago, with the end of the last major glaciation. Occam’s Razor suggests that the best explanation for something is the simplest explanation. That is, there is no compelling need to complicate the explanation with human interference. Climate changes. That is what it does. That is why climatologists use a 30-year average of weather to define a climate regime or episode. While I’m sure that humans are having an impact on climate, it isn’t just their CO2 emissions, and it certainly isn’t fossil fuel combustion that is the primary control of temperature. Notwithstanding how poor Hansen’s predictions actually were, I think we should still keep before us his assessment of computer modeling:

“There are major [my emphasis added] uncertainties in the model, which arise especially from assumptions about (1) global climate sensitivity and (2) heat uptake and transport by the ocean, …”

He should have mentioned also the need for parameterization of clouds in the models. In any event, we should take computer model ‘projections’ with a grain of sea salt – and anything that Hansen says with a block of salt.

Steven Mosher graciously provided the original graphs and quotes from Hansen through a link to a copy of the Senate Committee testimony, which he uploaded to WUWT comments:

[ https://climatechange.procon.org/sourcefiles/1988_Hansen_Senate_Testimony.pdf ]

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126 thoughts on “Analysis of James Hansen’s 1988 Prediction of Global Temperatures for the Last 30 Years

      • At this point we’re all Doomsday survivors – multiple times over.

        But sarcasm aside, and a little off-topic (although the issue is probably a general one), and not to hijack another thread, but I’d actually like to take this opportunity to generally apologize to the board for my comment concerning David Appell last week – it was really not intended as much more than a muttered ‘to the moon, Alice!’ – Appell hadn’t even appeared on the board when I made that comment, and as far as I understood from the post, he had been banned – so it wasn’t like I was expecting to be talking directly to the guy.

        On the other hand, I have to remember the acrimony that dominates this issue – it has attracted alarmists, extremists – basically the hyper-paranoid – and I should have realized how my comments would be taken – perhaps deliberately, in some cases, but It was foolish and unnecessary of me to present the opportunity.

        Basically, I went home the other night feeling a bit ashamed of myself, so I’m belatedly pulling a Rodney King, and saying, ‘can’t we all just get along.’

        I suppose I should also remember that I’m a little bit more rough-trade that most people who post here, who probably come from ‘gentler’ society – so I should respect that, and I promise to behave better in the future.

        And as much as it pains my pride, I suppose I should apologize to Mr. Appell as well.

        • Thanks, Joel. That’s the right tone to take and you deserve respect for making this post.

        • I think it’s admirable that you apologize. That takes guts and a conscience. I know I’ve said things here I later regret.

          I would be very nice if we could “all just get along.” It’s pretty difficult given the level of acrimony that the topic of climate change elicits. Some of the comments are astonishing in their vitriol, and it’s hard for me to understand.

          No one will win this argument unless the climate changes enough that it is having an undeniable negative impact; otherwise skeptics won’t believe it. It’s hard to know what that would take, since there are so many justifications for disbelief. For now it seems to me best to seek a compromise rather than waste time and energy fighting. But when the best answer makes no one happy, in the current political climate that threatens re-election in both parties, so no one wants to touch it.

          Anyway, that was a nice apology.

          • Kristi, with respect to no one will win this argument. There really are two arguments… The much bigger one and the most important one is the political argument that we MUST put a massive CO2 tax on all Western societies (especially America), right now, in order to save the planet and human civilization. (Actually according to the catastrophists it was already too late a couple of decades ago but they keep moving the goalposts). If Trump makes it long enough to be re-elected, we will have won that argument because with each passing month, fewer and fewer people believe in CAGW and no countries will stay committed for very long if the US is out. If that happens, then the second and lesser argument about what effect CO2 is having on the climate will become a “who cares”, and by 2050 it will be forgotten. Canada is already about to exit. When Europeans find they CANT compete with the US and Canada if they have to rely on expensive and unreliable energy… well how long do you thing they are going to stay with this Progressive NWO agenda? There are much better sources for large scale deployment of energy than wind and solar and it is MUCH more effective and easier to adapt to any negative impacts if energy is extremely cheap and plentiful.

        • Joel Snider

          We have all dropped a bollock or two online.

          It’s the first time I have encountered David Appell, or rather, him presenting himself with his given name.

          I tried to remain impartial, I didn’t even watch the video, before I read his comments.

          And I discovered the guy is a boorish oaf who provokes people. He has the benefit of an education, with which to educate others, yet his chosen path is to bully people with that education to think as he does, not to think, as education would have us, in a constructive manner.

          When I did watch the video, I discovered he was an inarticulate boorish oaf. Barely able to string a sentence together, far less an argument, and utterly unable to support an argument with rational analysis, instead, persistently referring to the work of others.

          The man is a walking encyclopaedia, with as much imagination as the paper one is written on.

          Education is worthless unless devoted to new concepts, new ideas, new horizons. David Appell’s education is, in my humble opinion, wasted. I can learn nothing from him. Far worse, he would consider it demeaning to teach me anything.

        • Joel and HotScot,
          Appell is a ‘creative science writer’ and he earns his living writing creative articles for customers that pay for stories supporting the CAGW meme. By his own admission, he couldn’t hack the other enterprises he attempted, before becoming a creative science writer. Creatively, he is the master of half truths, communicated with subtle guile. He also uses his ‘creative’ writing skills to troll, insult, antagonize, and bully anyone who disagrees with him. The man’s communications indicate he has no shame, no conscience to appeal to, liberating him to pursue his ‘creative’ art without any sense of guilt. This site is populated with so very many who have advanced science degrees, have published in journals appropriate to their specialized skills and experiences, yet Appell disparages all as unworthy of his ‘smartitude’. This is just one of the petty slurs, the smug insults he employs to trigger anger in his opponents to get them off the facts and science he just can’t refute when his guile fails him.

          Don’t let him get to you. Don’t play his game. I say that, knowing I have the same ‘call bullshit’ reflex when I’ve had enough. I’ve worked some rough jobs and lived in some very rough neighborhoods, where insults and slurs had to be met directly… or you would rapidly become a target, a victim, or a crime statistic. I also have to tamp that reflex down, in so called ‘civil society’. God help us all….

      • Commuting is off the table for the dead, I’m afraid.

        You see, according to the anti-human climate alarmists, my fellow citizens and I drowned long ago.

        Do not shed a tear for us, though. They also claim we rightfully deserved it. Something about “Malthusian scientific predictions/projections” or some such…

  1. Hansen made his 1988 prediction..based on what was the temperature history in 1988
    …since 1988, the temperature history prior to 1988…has been significantly cooled
    That would have been the only data Hansen could have used to make his prediction.

    If you take his same prediction….based on the new adjusted, homogenized, fiddled with data…the old data was wrong…the new data is right

    …all of his scenarios are off the chart warmer

      • And someone will say, “But Hansen 1999 is not a global chart it is a U.S. chart.

        Well, look at GISS 1980. It’s a global chart whose profile looks a whole lot like Hansen 1999 (the 1930’s being hotter than subsequent years).

        https://s3-us-west-1.amazonaws.com/www.moyhu.org/2017/07/gissbastach.png

        Hansen 1999 is a better global proxy than any Hockey Stick chart. Temperature charts from around the world have the same profile as the Hansen 1999 chart with the 1930’/40’s being as hot or hotter than subsequent years.

        None of the unmodified temperature charts from around the world resemble the Hockey Stick charts (which show the 1930’s and 1998 as much cooler than either Hansen 1999 or the UAH satellite chart show.

    • Latitude:
      Hansen said warmer, and it got warmer.
      He could have said “colder” !

      If I ever get to make a public prediction,
      like Hansen did, I want to be in charge
      of the actuals, and then I will make sure
      my prediction turns out to be “right” !

      Wait, a minute …
      Hansen WAS in charge of the actuals —
      in charge of the global temperature compilation
      that he predicted,
      and other government bureaucrats
      were in charge of other average temperature
      compilations, and I assume all of them
      had been predicting lots of global warming!

      So, the bureaucrats (predictors)
      were also in charge of
      the wild guess infilling
      for a majority of the surface grids,
      and they also got to make “adjustments”
      to raw data, whenever they felt like it
      … meaning they had the power
      to make sure their climate predictions
      looked good !

      A huge conflict of interest !

      My climate change blog:
      http://www.elOnionBloggle.Blogspot.com

  2. Good point on the el nino – Climate has alway had cyclical swings, on annual, decadal and century scales.

    If Hansens prediction was the gold standard, his prediction should be slicing through the middle of the sine wave,
    Instead, real temps are only touching his prediction on the crest of the sine wave.

    • Joe,
      Hansen’s ‘predictions’ are classic linear thinking in a cyclical world.
      “Use linear extrapolation and expand the display scale to visually steepen the trend, to scare the hell out of them sheep! The shearing time is here again!”
      SOP for rent/grant seeking CAGW proponents.

  3. And the Hansen presentation was rather bogus from the start, as US (the best land records) showed a cooling trend from 1945 to 1975. Following Tony Heller, the 1930’s were warmer in the US than any time since, and international records are too sparse to draw much of a conclusion for a less than one degree change.

  4. In a 1988 New York Times article Jim Hansen said that the 1951 to 1980 world average temperature was 59 deg F. Later on he said it is 57.2 deg F. Can somebody enlighten me as to what changed it. Perhaps one temperature average includes ocean temps? Otherwise the hottest year of 2016 at 58.8 deg F would be below average using the 1988 number of 59 deg. It is hard to find absolute temperature data rather than anomalies which does not give much idea of the average temperature used to base the graph on. It makes it much easier to change data. Very convenient.

    • By 2040, the 1940s will be an Ice Age. Pray for our grandparents.

      Yeah, the lack of absolute temps almost makes model predictions nonfalsifiable, the way people fiddle with baselines these days. Really needs to be a requirement if they’re going to claim policy relevance. The real world has absolute temps!

  5. Therefore, had he assumed that there would only be one eruption, his estimates would have been higher and would have tracked B even more poorly than they have.

    In my view, a good demonstration of this premise is confirmed by Nick Stokes v. RicDre in this comment thread:

    https://wattsupwiththat.com/2018/06/22/thirty-years-on-how-well-do-global-warming-predictions-stand-up/#comment-2385167

    Therefore, it is just luck that his predictions came as close to reality as they did. The greatest intellectual ‘sin’ for a scientist is to be right for the wrong reasons!

    AMEN…and there ought to be some mention of a moral ‘sin’ when they don’t admit it!

  6. Hansen’s temp prediction was basically a continuation of the temperature trend which began circa 1850,

    I am going to predict crop yeilds will continue to increase
    Life expectancy will continue to increase
    computers will get smaller and faster.
    etc.
    Likewise , temps will likely to continue the upward trend
    SL will continue to rise at the rate of 3.0mm ish per year

    95% of the population would have gotten the temp trend correct based on past performance

    Look at what he got wrong

    No artic ice (or was that al Gore
    permanent flooding of NYC, etc

    • “Hansen’s temp prediction was basically a continuation of the temperature trend which began circa 1850,”
      Hensen’s Scen B had trend of 0.284°C/decade over the 30 years. Scen C showed 0.123; most global surface indices show about 0.18°C/decade.

      The trend since 1850 of HADCRUT 4 is 0.051°C/decade. That would have been a very poor predictor (but better than zero trend).

      • Which would be great, except 1) Scenario A was the policy that actually happened, and 2) the model appears to assume the low-emissions policy began decades before 1988, as it diverges before 1988, so it’s even further off than one would expect given the reality was Scenario A.

        If Hansen had stood up there and said “Scenario C is the most likely outcome of business as usual” it would have been a nonproblem, and they would have cut his funding and reduced his importance.

  7. Hansen’s projection was also with a much lower CO2 output. He didn’t anticipate China’s massive growth and CO2 production. CO2 actual generation has been something like double what Hansen thought would be produced in the worst case scenario.

    • “He didn’t anticipate China’s massive growth and CO2 production.”

      Hansen’s scenarios were worked out in terms of expected CO2 concentrations. We have the numbers he used, and they proved very accurate. Here is Gavin’s recent plot:

      https://s3-us-west-1.amazonaws.com/www.moyhu.org/2018/06/gavco2.png

      Note that the observed (black) falls almost exactly on top of scenario B. This in turn is very close to scenario A. Scen A was based on exponential increase with 1.5% annual growth; B continued with linear increase in growth after 2000. IOW, the red is tangent to the blue, and so they are very close over the period.

      So that is what actually happened. China’s growth formed part of the increase, and part compensated for reductions in emissions in Europe and (recently) US.

      • So that is what actually happened. China’s growth formed part of the increase, and part compensated for reductions in emissions in Europe and (recently) US.

        In Hansen’s documentation, did he predict specifically that China’s CO2 production increase and European/US CO2 reductions were how his predicted CO2 concentration level would be attained, or did he merely make a general prediction without specifying how the concentration would come about?

        If the latter, why should we believe in the worth of the model/prediction? Isn’t that a bit like me building a model that predicts that in wet weather, car accidents are going to increase?

        • “or did he merely make a general prediction without specifying how the concentration would come about?”
          He made no prediction at all about CO2. He calculated temperature based on scenarios. He did not know how much fuel people would burn in the future, and made no claim to know. That is why there are three scenarios, to cover the range. If he was predicting, there would be only one.

          The scenarios were constructed based on existing trends, with provision for possible changes in the future (beginning 2000).

          Scenario A for CO2 is just a simple geometric progression:
          CO2 ppm= 235 + 117.1552*1.015^n
          where n is the number of years after 1988.

          That is all. There is nothing about China. I have shown the plot above, and what happened is indeed remarkably close. That is all that matters for checking the prediction. In fact, it is even closer to Scen B, which follows the tangent to Scen A after 2000. There is little difference between A and B for CO2 in these years.

          • That is all. There is nothing about China. I have shown the plot above, and what happened is indeed remarkably close. That is all that matters for checking the prediction.

            Why isn’t it more important to know why the “prediction” was able to predict what it “predicted”, rather than just that it did?

            If you don’t know why your “prediction” was accurate, then do you even have a “prediction” in the first place?

            Maybe what you really are is nothing but a broken watch being evaluated at the right time of day.

          • I do not consider that it matters why CO2 has increased, when one is testing the underlying claim that temperature will rise if CO2 increases.

            The only relevant point being has CO2 increased, or not, and if so by how much, and thence to consider whether temperature has increased in accordance to the prediction that temperatures will rise with CO2 increases.

          • The only relevant point being has CO2 increased, or not, and if so by how much, and thence to consider whether temperature has increased in accordance to the prediction that temperatures will rise with CO2 increases.

            Then in such a case the most you’ve done is presuppose that CO2 is the driving factor in the temperature increase, a (Beg the Question) fallacy in reasoning. It could just as easily have been the case that CO2 concentrations overall would have fallen while temperatures rose during the time period in question.

            As it stands now, Hansen proved nothing other than the two coincide by happenstance on the slope of a graph, but not what, if anything at all, that means to earth’s climate.

          • richerad — “I do not consider that it matters why CO2 has increased”

            It matters quite a lot when emission policy is at once the independent variable in your model, the only variable that can be directly affected by Congress, and the entire reason for your testimony.

          • No, that’s not true Nick — he was modelling the effect of emissions policies. If the actual emissions turned out to be significantly worse than his assumptions in Scenario A, but the actual concentrations are more like B, then he was way off in his assumptions.

            Remember, emissions are the only variable 1988 Congress can affect. They can legislate neither concentrations nor temperatures.

            Suppose we told Hansen in 1988 what emissions would actually be like through 2018, but did not tell him how concentrations would respond or what temperatures would occur. Using otherwise the same assumptions, we know he would have predicted higher concentrations, and even more warming than shown in A.

          • “Remember, emissions are the only variable 1988 Congress can affect”
            In fact, Congress in 1988 had no reliable data on tonnage emissions, and neither did Hansen. That came later with UNFCC asking governments to collect it. The only data both had to work with were gas concentrations. Just like the current situation with methane.

      • Nick,
        You seem to be overlooking the obvious. If he was very accurate in his predictions of CO2 concentrations, but got the temperatures wrong by at least a two-fold factor, then obviously CO2 doesn’t have the expected influence!

      • Hansen’s predictions were not based on CO2 levels, but on GHG emissions. From the graph formed Fig 3 of Hansen’s testimony to Congress. The caption reads :-

        Scenario A assumes continued growth rates of trace gas emissions typical of the past 20 years, i.e., about 1.5% yr-1 emission growth; scenario B has emission rates approximately fixed at current rates; scenario C drastically reduces traces gas emissions between 1990 and 2000.

        There is a good reason for concentrating on GHG emissions. The purpose was to advocate policy to reduce GHG emissions. Scenario A was business as usual. Scenario B was included to show that merely maintaining GHG at current (mid-1980s) levels would make very little difference. It is drastic emissions cuts that are required to stop global warming.

        There have not been policies proposed to cut aggregate global emissions. Try looking up graphic ES.1 on the UNEP emissions gap report 2017. The only issue is whether BAU comes out as Hansen forecast. I used data from IPCC AR5 Report WG3 Summary for Policy Makers graphic SPM.1 to compare the actual emission trends from 1990 to 2010, with the scenarios.

        https://manicbeancounter.files.wordpress.com/2018/06/hansen-1988-scenarios-v-act-trends.png

        The actual emissions trend is closest to Scenario A. But crucially the rate of rise in emissions was much lower than Scenario A in the 1990s and higher than trend in the 2000s. Global average temperatures responded to the increased emissions post 2000 by slowing down or stopping. Seems that Hansen’s forecasts are contradicted by the data.

      • Nick, this is exactly the kind of infuriating three-card monte that gives climate science such a bad name. The scenarios are based on emissions policy — it says so right in the PDF. Congress can no more set CO2 concentrations than they can set the force of gravity. But they can pass emissions policy, and that was the point of Hansen’s testimony.

        So Hansen was right about concentrations, but only because he was wrong about both emissions and sinks (yes, I am aware these were assumptions in his model, not something he worked out — assumptions matter). Getting two things wrong that cancel out does not an accurate model make.

        • As I said, the greatest intellectual sin is to be right for the wrong reason. Although, on reflection, I guess it could be worse to be wrong for the wrong reason and try to pass it off as being right. 🙂

        • “The scenarios are based on emissions policy”
          But they do not predict emissions policy. As I keep saying, this is elementary. If you are making a prediction you give one number. Not three numbers that are explicitly said to be designed to cover a range.

          I gave the aircraft design analogy elsewhere. A designer might give performance figures for loads of 500 and 1000 kg. He isn’t saying anything about the policies that might have created those loads. He isn’t saying which is likely. He is just giving figures that will help you if you do, say, want to fly with 883 kg. He covers the range of possibilities, with enough points to interpolate. As best he can.

          Hansen doesn’t actually know what level of emissions will lead to what concentrations. At the time, there weren’t reliable measures of emissions (in tons) at all, and he doesn’t cite any. What he can say is that gas concentrations are going up, and if they keep doing that, this is what will happen. And he did.

  8. From the article this had meaning to me.
    ” Therefore, had he assumed that there would only be one eruption, his estimates would have been higher and would have tracked B even more poorly than they have. Were it not for two exceptionally strong El Niño events in the last 20 years, it is unlikely that current temperatures would be anywhere near as high as they are currently. However, he did not consider the role of El Niño’s in his computer model.”

    If a computer model is incapable of predicting an El Nino what good is it? I think that is fundamental. These events seem to be very important.

    If natural events like an El Nino are excluded what utility do such models have? If they can’t be predicted then they are worthless and unreliable.

    The influence of natural cycles should be mandatory or the model should be rejected out of hand.

    It would simply appear to me that if that is the case there is a lot more work to do before you have a valid climate model.

    • Charles,
      I agree. A valid climate model, calibrated and certified for demonstrated predictive value, is far beyond our current understanding of terrestrial climate science. As you point out, predicting el ninos is beyond current climate model capabilities. We can’t even program the ever-present and ubiquitous convection driven clouds into the models because we just don’t understand them well enough. Pretending the current models have any predictive value is irrational, at best, and self inflicted CAGW masochism at worst.

      • Thanks

        I do not comprehend shat standards of performance they could be using. I worked in the Naval Nuclear program for 35 years. Thank goodness we did not use this kind of garbage to come up with reactor designs.

        How could this kind of crap be used for policy decisions?

        Do we have any standards at all?

        • I’m with ya, Brother! I’m a metallurgical engineer (BS/MS) that worked on all kinds of aerospace and astrospace ‘things’ that had to reliably work the first time and every time! If we developed something new and novel, it didn’t get on a production flight vehicle until it had been demonstrated reliable and predictable to accepted flight readiness standards and the customer and applicable regulatory agencies fully accepted it to their standards as well.

          If we built flight vehicles to climate model ‘standards’, no one would buy our commercial airplanes, military fighters, missiles, or space related products! Too f’d up, dangerous, and unreliable! Yet we are supposed to ‘buy’ the climate models unreliable ‘predictions’ as substantiation for world-wide abandonment of inexpensive, reliable, predictable, and 24/7/365 dispatchable electrical generation utilities that use oil, coal, and natural gas feed stocks.

          It’s worth repeating: Pretending the current climate models have any predictive value is irrational, at best, and self inflicted potentially lethal CAGW masochism at worst.

          • J Mac

            With your last comment you did manage to put a big grin on my face.
            I had not intended to do this here, but my guess is that you and maybe a few others will even bother to go to the figures on my OneDrive links.
            During those 35 years I spent time reviewing the results of FFT analysis of signals from our equipment. My experience goes back to the time before desktop FFT analyzers.
            Again, I apologize for the links, but this is the only way I have been able to do it.
            I will furnish my analysis results of the latest H4 global data and Nino 3.4.
            H4
            These are the results with the latest data that I acquired this week.

            https://1drv.ms/u/s!AkPliAI0REKhgZh5uQ3r6hAEhmtPeg

            The cyclical fit has 98 sinusoids. Everybody talks about a 60-year cycle. Well there it is. Notice how it explains what happened from 1910 to 1945 and from 1950 to 2010. The next prominent one is the 208-year cycle referred to as the de Vries. I combined it with the 67-year cycle. When I fit the entire record just assuming CO2 alone was acting I came up with an ECS of 1.96. However, when I combined the 98 cycles with CO2 look at what happened to the ECS. It is only 0.222.

            Here is a look at more recent events.

            https://1drv.ms/u/s!AkPliAI0REKhgZh6j3pqDIBnMdx0gw

            Now for the fun part. This is what I am indicating is in the future:

            https://1drv.ms/u/s!AkPliAI0REKhgZh7hGO7SwzYt36vGQ

            There is a green line there. It is under the blue line.

            The solution for this has been holding quite well. I have been showing roughly the same thing for over a year.

            Nino 3.4

            The data I use in this analysis is a combination. It is monthly until 1990 where it becomes weekly data. From 2014 onward it is daily data.

            https://1drv.ms/u/s!AkPliAI0REKhgZh8daVvzHszMuG79w

            https://1drv.ms/u/s!AkPliAI0REKhgZh9HFbNDBK7FWViUw

            Now for projections.

            https://1drv.ms/u/s!AkPliAI0REKhgZh-T3ILoK189xrxzA

            I have been showing an El Nino in 2019 for some time. I expect new data early next week. I may be biased but I think my projections are better than what I see on the NOAA site.

            Enjoy.

          • J Mac

            I decided to go all out. I do look at a lot of things and one of them is UAH. The length of the UAH record does not enable projections. They tend to be a little wild owing to the shortness of the record, but it does provide useful information.

            For the UAH analysis I use the data from Mauna Loa for CO2. I do have a very precise fit. It is a quadratic fit with a sine wave on top.

            https://1drv.ms/f/s!AkPliAI0REKhgZh4Jee-1Gw8oXbzdA

            I am expecting an update on UAH from Dr. Spencer any day now so this is with last month’s data.

            https://1drv.ms/u/s!AkPliAI0REKhgZkASsIZ4gfFm9e4AA

            Note that the figure does include a pause line. I added that feature because as the temperature drops, if it does, I anticipated a return of the pause line. BTW, its starting point is not cherry picked. I actually calculate where the slope would be minimal.

            That figure is interesting but here is what I am after. We have all seen Dr. Spencer’s figure which shows how the models perform with respect to the balloon data. I changed that figure slightly.

            Instead of the balloon data I used a five-year moving average of the UAH data and its solution in red from the above figure. Instead of the model data I substituted the ECS values of the best estimate based on a value of 3.0.

            https://1drv.ms/u/s!AkPliAI0REKhgZkBPGtRgiAEFBAaEw

            Pay attention to one more thing. Not long ago Nic Lewis and Dr. Curry estimated that the ECS value of 3 is off by about a factor of 2. I believer their estimated value was 1.61. That is shown on the chart. It would seem with that value we are finally correlating with measurements. How in the world could the value be 3.0?

            I don’t know what the answer is but how serious is CO2 if the ECS value is 1.66. Is it really worth the expense we are going through?

            It gets even better. Dr. Spencer reviewed what Nic Lewis and Dr. Curry did.

            http://www.drroyspencer.com/2018/04/new-lewis-curry-study-concludes-climate-sensitivity-is-low/

            Here is a very important statement by Dr. Spencer.

            “If indeed some of the warming since the late 1800s was natural, the ECS would be even lower.”

            Bingo!

            With my cyclical fit I do think the ECS is lower because I assume the cyclic fit is natural sources.

            Dr. Spencer used this figure.

            https://1drv.ms/u/s!AkPliAI0REKhgZkClctphXouBBnNLg

            I have a much lower value of ECS that seems to work quite well with this figure.

            It is one thing to ask how important CO2 is if the ECS is 1.66. It is something else if it is lower than 0.5.

    • “If a computer model is incapable of predicting an El Nino what good is it?”
      It is a climate model. ENSO variations are weather, even though about the longest duration of weather events. They come and go, but the effect of changing the atmosphere persists.

      We had two big El Ninos in the period, but at least big La Ninas (1999, 2008 and 2011-12). ENSO is an oscillation, and tends to cancel out.

        • “We haven’t canceled out the 2014-2016 El Nino so it should be excluded. “
          You can say that Nino was cancelling the 2011/12 La Nina.
          But arguing for the exclusion of data to suit just gets silly.

          • The only silly nonsense is including a super El Nino at the end of a linear trend. Sorry, but I thought you were somewhat intelligent at one time. I was clearly mistaken. The El Nino was clearly 100% noise since the warming has now disappeared completely. The only reasonable way of handling it is to ignore it.

            The 2011-12 La Nina was in response to the 2010 El Nino. There were 3 years between that and the 2014-2016 El Nino. I can only chuckle at your obvious desperation. You want to throw simple logic out the window to maintain your “beliefs”.

            What’s really amazing is we have been having warm Pacific Equatorial conditions since mid February and still no warming showing up in the data. That means other parts of the planet are cooling.

            http://www.cpc.ncep.noaa.gov/products/analysis_monitoring/enso_update/heat-last-year.gif

          • “The 2011-12 La Nina was in response to the 2010 El Nino.”
            So what was the 2008 La Nina a response to? And why does it matter? The fact is that ENSO ups and downs come along, and are just part of our weather cycle. You can’ t just prune the ups.

          • Richard,
            The alternative is to rely on strong low-pass filtering to suppress the outliers from the general trend. One should use all the data available, but use it appropriately.

      • Nick,

        You said, “ENSO variations are weather,…” And basically, volcanic eruptions affect the weather and Hansen attempted to address them. As usual, you are engaging in sophistry.

        I wish I had your confidence and insight that ENSO cancels out when temperatures are increasing.

        • Clyde,
          What we know about ENSO is that it has been going on for a long time, and the temperature has remained fairly stable. And it doesn’t have a source of heat, that we know of; it is an intermittent heat transfer. So it is an unlikely source of either warming or cooling trend.

          • I disagree in that the oceans are a huge reservoir of heat, which has been built up over lengthy periods of time, and if in any lengthy period there are more El Ninos than La Ninas, then it is almost certainly going to lead to a corresponding warming episode since more of the heat stored is released into the atmosphere.

            The big problem is the time scale. We do not know over what period we should look at, and that is one reason why I consider the favoured view that climate is the average of weather over a 30 year period, is misconceived, and it is using too short a reference period.

          • Nick,
            You said, “…and the temperature has remained fairly stable.” “Fairly” is a weasel word. It is lacking precision and context. But, that is what I have come to expect from you, despite demonstrating that you are capable of quantitative analysis.

            Volcanoes have also “been going on for a long time…”

  9. Clyde,
    “Using only Hansen’s own data, the above demonstrates that Hansen was not “extremely accurate” in his 1988 predictions because a simple, commonly unreliable, linear extrapolation performed better than his model in predicting the last 30 years of temperatures.”

    There is a lot of hindsight in your choices in linear fitting. Hansen was making a genuine prediction.

    But it is hardly surprising (now) that a linear extrapolation of trend will work. We have a variable that is increasing due to a cause that is rising fairly regularly. You expect that the response will, except for superimposed natural variations, likewise rise smoothly. Given that, you can either compute the variation from underlying cause, or estimate the derivative and project. The key phrase here is, “given that”. Most would say that you shouldn’t extrapolate linearly without reason, because if an observed rise is just natural variation, it won’t be sustained. It could just as easily head down as continue up.

    It is, of course, better to calculate (like Hansen) from the basic cause if you can, because estimating the derivative from a short period is very error-prone. But it is still possible that an estimate will turn out right.

    “I suspect that Hansen scheduled one of his two hypothetical volcanic eruptions for about 2014”
    He said 2015. But the dilatoriness of this late volcano would have had little effect on the forecast over the whole period.

    • “It is, of course, better to calculate (like Hansen) from the basic cause if you can”

      I agree with this statement. The question is, do we understand the basic causes well enough to do the calculations?

        • Well Hansen did it and got somewhat close to what actually happened more through luck than any skill possessed by his model.

        • I can’t believe that you are persisting in claiming that “it worked out pretty well” when his ‘business as usual’ was twice the actual slope of the temperature!

          • You persist in thinking scenarios are some sort of prediction. Scenario A is not what happened. Methane and CFCs increased at a far slower rate, as per scenario C or below. Aware this might happen, Hansen also calculated scenarios B and C. And what actually unfolded was between B and C. On that basis, his prediction “worked out pretty well”. He was not, repeat, not, predicting that scenario A would happen.

          • I never said that Scenario A was a prediction per se, and I hope I never inadvertently implied it. Hansen defined it as the trace-gas concentrations that could be expected if no changes were made, i.e. Business as Usual. However, Hansen predicted what Scenario A (which you say above was actually highly accurate with respect to CO2) would produce in the way of temperatures. The anomaly temperatures for Hansen’s Business as Usual are 2X reality! The actual temperatures were tracking the Draconian Reductions most closely of the three scenarios, up until the time of the hypothetical volcanic eruption that didn’t take place. Note that, in 2015, Scenario C was almost on top of the green trend-line, while Scenario B was about 0.4 deg C above it! It is only wishful thinking on your part that Scenario B was being tracked.

    • Nick,

      I should point out that your qualitative claim (6/22/18) that “…the prediction was remarkably accurate.” is what motivated me to spend the time to demonstrate that you did not have a quantitative basis to your claim.

      There was no hindsight in my choices. The premise was that a simple extrapolation might be adequate to explain temperature behavior, within the bounds of normal variation. The obvious choice was the whole 30-year period of data available to Hansen. However, the facts that the R2 value was low and it was obvious that there was a transition in the trend about 1964 suggested that a better choice was the post-1964 data for calculating a regression line.

      What was truly interesting is that when I started looking for data to validate Hansen’s and my predictions, I was confronted with the problem of avoiding comparing apples and oranges, what with people using different anomaly baselines, sometimes conflating ocean temperatures with land air temperatures, and applying different corrections. Then I stumbled on Hansen’s most recent graph of actual temperature data and discovered that the slope of the trend line was almost exactly the same as my naive extrapolation. I made no assumptions about was was driving the trend from 1964 to 1988, yet it turned out to be right. Whereas, Hansen assumed CO2 was driving his Scenario A, and it turned out to be wrong!

      The reason I chose a linear extrapolation was a 2nd degree produced a fit that was a bowl because of the transition of trends about 1964. That left me with a linear trend as being risky, but clearly appropriate for 1964 through 1988. The question was, would it be poorer than Hansen’s work for post-1988 predictions? I agree, and acknowledged above, that a linear extrapolation is fraught with risk. Yet, the important point is that such a poor predictor was far superior to Hansen’s non-linear predictions!

      OK, I overlooked Hansen’s remark about the volcano erupting in 2015, and estimated that it was about 2014, assuming some time delay to observe the effect with annual averaging. However, Scenario C deviates strongly (about 0.2 deg C) from the green trend line right after the hypothetical eruption. It then takes a while for the temperature to climb out of that ‘valley,’ which keeps Scenario C below my prediction for more than a couple of years.

      In summary, you claimed that Hansen’s predictions were “remarkably accurate” when Scenarios A & B were significantly above the actual anomaly temperatures, whereas, the naive prediction would have tracked Scenario C very well had there not been a hypothetical volcanic eruption in 2015 driving down the temperatures. You and I may disagree on the exact meaning of “remarkably accurate,” but rest assured I will never ask you for help with my tax preparation!

      • “There was no hindsight in my choices.

        The obvious choice was the whole 30-year period of data available to Hansen. However, the facts that the R2 value was low and it was obvious that there was a transition in the trend about 1964 suggested that a better choice was the post-1964 data for calculating a regression line.”

        You can say that now with hindsight. Yes, what happened in those 30 years was that temp went down, then up again. You now say that is the formation of a new trend from 1966. But at the time, you might well have said it was a rise to a temporary peak, and a longer data stretch should be used. In fact, your linear predictor is very dependent on the choice of 1966 as a start. As your plot shows, had you chosen 1958 you would have got half the trend, and choosing in between gives a trend in between.

        “I agree, and acknowledged above, that a linear extrapolation is fraught with risk. “

        It can also work, especially if there is reason to expect a trend to continue. And Hansen gave reason for that expectation, and calculated the trend from basics. You have figured the trend based on analysis of a period. It depends a lot on what period. But you can get lucky, and may even do better than Hansen’s calculated trend. But that doesn’t take away from the substance of Hansen’s analysis, which is that there are physical reasons why an uptrend of about this magnitude should continue. And it did.

        • Nick,

          You said, ” But that doesn’t take away from the substance of Hansen’s analysis, which is that there are physical reasons why an uptrend of about this MAGNITUDE should continue. And it did.” The “magnitude” is the crux of the problem. It isn’t off by just 10%! The magnitude of his forecast slope was TWICE that of reality. His prediction gave an anomaly that was 94% greater than reality. That is, attributing warming primarily to CO2 gives the WRONG magnitude! “There are none so blind as those who will not see.”

          His forecast was WRONG! That means that the hypothesis is wrong and at least needs to be modified. To keep doing the same thing and expecting a different result is a commonly accepted definition of insanity.

          Actually, all extrapolations are risky, not just linear extrapolations. But a model that only gives the correct sign to the trend is next to worthless. And, a model that can’t give you an answer to withing a few percent is obviously so flawed that one should not have confidence that it won’t fail in the future for the same reasons that a simple extrapolation might fail — there are things we don’t understand that might change suddenly and change or even reverse the slope of the trend.

          • Clyde,
            “The magnitude of his forecast slope was TWICE that of reality.”
            I think you are still basing this on just one of his scenarios, A, which is not what happened. Here is a plot of the actual forcings that transpired:

            http://www.realclimate.org/images/anthro_h88_eff.png

            Between B and C, reflecting the reduced growth of CFCs and methane, which were below even C. And here is the plot of scenario trends and various observed surface trends:

            https://s3-us-west-1.amazonaws.com/www.moyhu.org/2018/07/hanstrends.png

            As you see, midway between B and C, exactly corresponding to the forcings.

          • Nick,

            Your link above is comparing the predicted temps with CMIP5, not reality.

            You have lost sight that the point of contention is whether Hansen’s ORIGINAL predictions for temperature were “remarkably accurate” or not. I demonstrated that his predictions were considerably higher for both scenarios A and B, and were only reasonably accurate for scenario c, which contained a flawed assumption for the last 4 years.

          • “Your link above is comparing the predicted temps with CMIP5, not reality.”
            No, CMIP5 is used to combine the observed gas changes into a single forcing number. It is basically a weighted sum. That number can then be compared with the forcings corresponding to the scenarios (also CMIP5 weighting). That combined figure does lie about halfway between scenarios B and C. Temperature is not in that plot.

  10. I don’t get the point of this article. It seems like nit-picking. since Hansen’s original predictions (updated many times since), he seems basically been validated by measurements. what am I missing?

    • He has been invalidated to the max.

      Global T has followed most closely his scenario in which CO2 emissions quit growing in 2000. In the real world, CO2 emissions have tracked his high CO2 scenario. T is nowhere near his forecast for that scenario.

      Hence, his prediction has been shown false.

      • “In the real world, CO2 emissions have tracked his high CO2 scenario.”
        They even more closely followed his mid-range scenario B. But there is more to scenarios than just CO2. And the other gases were much below Scenario B.

        “Hence, his prediction has been shown false.”

        Actually, I see two lines of deprecation here.
        1. The prediction was way off
        2. He just got lucky. A linear extrapolation does as well.
        This article seems to be of the latter.

        • Nick,
          Upstream you said that Hansen was not predicting CO2 emissions. To bring that up is a red herring. What Hansen attempted to predict was temperatures and failed so badly that in any application, be it the performance of an aircraft, or the return on an investment, a two-fold error would be unacceptable. Can you imagine contracting for a new fighter plane and telling the government that it would do Mach 2, and then when tested only achieve Mach 1?

          Actually, I am claiming both 1 and 2.

          • If you are predicting the performance of an aircraft, you will have a scenario, such as the load it is carrying (including fuel). You will have provisos like ice, headwinds etc. The designer is not expected to predict these things. And if he gives a prediction for carrying 500 kg, and you test it carrying a ton, you can’t then say it was a bad prediction. You have to look up what the designer predicted in these circumstances.

            Hansen’s situation is exactly the same, and I really don’t see why that is so hard to understand.

          • NS… I get the impression that it’s hard because you make it more difficult by conflating ‘scenario’ and ‘prediction’.
            In your example above ‘500 kg’ and ‘a ton’ are a couple of potential scenarios, not predictions.
            Potential outcomes– (for example: not getting off the ground because there is insufficient lift to carry a ton, or plummeting into the ocean because of insufficient fuel to reach destination when carrying a ton) — would be good to know (predicted) when designing the wings, selecting engines, or sizing the fuel tank.
            Besides, if the manual states the aircraft’s design capacity is 500 kg and ‘you test it carrying a ton’… whoever the conceptual ‘you’ is… assuming you survive I hope you will have learned to distinguish between a ‘bad prediction’ made by the designer and a really bad decision made by you.

          • Yes, indeed those things are good to know, and designers should predict what would happen in those circumstances. The point is that the prediction and circumstances are coupled, and in this situation no-one would think of saying otherwise – that a designer should give predictions independent of the weight carried. Or predict the weight that will be carried. But somehow that simple proposition gets lost when looking at the similar proposition with predicting temperature. Hansen says if you burn this much (scen A) it will warm this much. If you burn less (scen C) it will warm this much. Yet people insist that he fails if temperature doesn’t follow the Scen A prediction, without checking whether scen A is actually what happened.

          • OK, my ‘hypothetical’ implied that the design specifications for testing were part of the contracting document. Your suggesting that the testing parameters were different is again your sophistry at play.

            It is perhaps hard for me to understand because I’m not coming up with a lot of ‘what ifs’ to apologize for Hansen’s lack of skill in prediction based principally on CO2 as the ‘Control Knob.’ When he says “Business as Usual,” versus “Draconian Reductions,” I take him at his word. Clearly, we did not have “Draconian Reductions” in the last 30 years, and while you claim that what has transpired in the way of trace-gas concentration is actually close to Scenario B, that is against a backdrop of recent alarm about Arctic methane and CO2, and methane leaks from ‘fracking.’

            OK, you are subjectively impressed with how well Scenario B tracks reality. In 2015, when the hypothetical non-volcano impacted Scenario C significantly, Scanario B was about 0.4 deg above Hansen’s trend-line (~0.75). That is, it was about 50% above reality, whereas Scenario C was about 3% low. The latter is in the range of what I would call usable predictions for policy predictions, and the former is ‘half-credit,’ at best.

          • Clyde,
            “When he says “Business as Usual,” etc”
            If you were testing a plane, you wouldn’t be doing any of this. You wouldn’t be asking what the designer thought about whether you might be carrying one ton loads, or whether there was demand to carry loads of carrots or whatever. You would simply look at what load you were actually carrying, and what the designer predicted for that load. And that is how you should approach Hansen’s predictions.

          • It is perhaps hard for me to understand because I’m not coming up with a lot of ‘what ifs’ to apologize for Hansen’s lack of skill in prediction based principally on CO2 as the ‘Control Knob.’

            His prediction wasn’t based principally on CO2, e.g. look his at Fig. !.

            When he says “Business as Usual,” versus “Draconian Reductions,” I take him at his word. Clearly, we did not have “Draconian Reductions” in the last 30 years,

            Actually we did for all but CO2 (which followed B fairly closely)..

            and while you claim that what has transpired in the way of trace-gas concentration is actually close to Scenario B, that is against a backdrop of recent alarm about Arctic methane and CO2, and methane leaks from ‘fracking.’

            Methane followed below Scenario C up until ~2009 but has since resumed something more like Scenario B. Methane plateaued about 1800 ppb after 2000 (Scenario C ~1920ppb) after 2008 it resumed climbing and is now ~1880 ppb

    • chris,
      How do you arrive at the conclusion that he has “been validated by measurements?” I demonstrated that his ‘business as usual’ scenario has a trend twice that of reality. The point of the article is that you and Nick Stokes seem perfectly happy to accept Hansen’s predictions, despite a demonstration that they are of poor skill, and a simple ‘business as usual’ extrapolation of temperatures available to him in 1988 give an almost perfect match to reality, and reality comes closest to his prediction for “draconian emission cuts.” His predictions may be good enough for government work, but they are well outside the boundaries of “nit picking.”

      Hansen may have updated his predictions as it became evident that were wrong. However, the point is, he attempted to influence the 1988 senate committee and the general public by claiming that he could reasonably predict future temperatures (when he couldn’t), and used invalid arguments to try to impress the senators with his expertise. Interestingly, no one has challenged me on the other criticisms that I made about his testimony. Everyone seems to be sticking with the indefensible claim that Hansen was “remarkably accurate,” when he obviously was not. It is not unlike, “I don’t care what you say, I know that he can walk on water!”

  11. On Hansen prediction, unfortunately everybody tries in their own way to compare with observed with scenario A, B & C but nobody talks on the observed data validity. The observed data: does this accounts all climate systems [IPCC defined this] appropriately. Also, IPCC stated that global warming starting year is 1951 and this is around half the trend. In such a scenario what does these analysis claim???

    In the last figure of the article, more data points are below the green line.

    Dr. S. Jeevananda Reddy

  12. If Hansen’s forecast was conducted using unjiggered temperatures, especially the Karlization^тм perpetrated in 2015 to get rid of the Dreaded Pause that lasted as long as the T rise ending in the 1990s that had underpinned AGW, and had he not persobally pushed down the 1930s-40s temperatures so that 1998 ‘could’ break a record in the instrument series, then proponents could argue, that, hey, it was a forecast that went in the right direction – maybe aerosols confounded it moderately and all we have to do is wait until the full force of the added CO2 can work its magic.

    Were I a supporter (impossible to be with the known manipulations that routinely go on with the data) I would say, well, considering sceptics position, it could also have declined in temperature but it didnt. Your analysis will be seen by the faithful as nit picking.

    • “If Hansen’s forecast was conducted using unjiggered temperatures, especially the Karlization^тм perpetrated in 2015”

      In fact, Hansen’s forecast was based on land temperatures as measured by land stations. At the time there weren’t really SST indices; he had recently developed a met stations only index (1987) which continued as GISS Ts, which is what he used for comparison in the original graph. And this is unaffected by anything that happened to SST.

      • Nick,
        That is why I stayed with Hansen’s original data and compared it to his most recent data — to avoid the issue of data sets that conflate SSTs with land temps. He was, after all, predicting the surface land temperatures. I don’t have a lot of faith in Hansen’s temperatures either way because of documented adjustments. I was basically hoisting him on his own petard by using ONLY his data and demonstrating that even under the most favorable conditions his predictions failed to be of utility. His predictions have the same sign as the recent general trend, but a betting person would have said that was an even bet that it would be maintained barring anything to significantly disturb the system.

  13. Instead of saying Hansen was right or wrong, I submit that the worst thing Hansen did was to narrow the focus of attention to CO2.

    Here’s a not quite recent paper which didn’t get much attention, except for the researcher being called the D-word.

    https://uwaterloo.ca/news/news/global-warming-caused-cfcs-not-carbon-dioxide-study-says

    “By proving the link between CFCs, ozone depletion and temperature changes in the Antarctic, Professor Lu was able to draw almost perfect correlation between rising global surface temperatures and CFCs in the atmosphere.”

    https://uwaterloo.ca/news/sites/ca.news/files/styles/body-500px-wide/public/uploads/images/20130528%20-%20CFCs%20Climate%20Change1.png

    • Instead of saying Hansen was right or wrong, I submit that the worst thing Hansen did was to narrow the focus of attention to CO2.

      Remarkably he achieved that by emphasizing that half of the effect was due to other trace gases.

  14. James Hansen was one of the first computer climate modellers that in 1988 predicted warming scenarios. Because he actually published 2 papers in 1981 on CO2 forcing and went to Congress twice to testify in 1987 and again in 1988 in favour of global warning you may accurately say that he James Hansen is the father of computer climate modelling . However he is the father of a scientific discipline that started with a scam as Willis has pointed out and has had to tell one lie after another just to keep the scam going. Billions have been wasted on this scam and billions more will be wasted before the scam ends.

    The only consolation we skeptics have is that each one of us is contributing the hastening of that end. I ask everyone I meet “Have you seen global warming yet? I have been looking for it for 30 years and cant seem to find it. Do you know where it is? If they mention something like the Arctic or Greenland I give them statistics that I have learned in 6 months of studying this for 8 hours a day.
    TELL EVERYONE YOU MEET THAT IT IS A SCAM AND WHY.

    1 WUWT contributer said, this scam in comparison makes Bernie Madoff look like a petty thief. Bernie Madoff in the end caused losses 0f ~$7 billion to his investors. As least they had a choice to invest or not. The world’s poor DO NOT have a choice. They are paying for James Hansen and others’ scam every day so that the end result might be $7 trillion down the drain before it is all over.

    Now for some comments about James Hansen

    It boggles the mind how truly deranged this man is. He is completely unstuck mentally and a bonafide nut case, devoid of any common sense or rational thought. To think he was the director of the Goddard Institute of Space Studies(GISS) a division of NASA for a large % of time of the 32 years that he worked there. Before he retired in 2013, he turned that agency into an agency of global warming. He was arrested 5 times for protesting illegally for green causes.

    Some of his predictions and some statements in his own words, and hallmarks of his life are as follows:

    1) In 1988 he predicted that the Hudson River would overflow because of rising sea level caused by CO2 and New York would be underwater by 2008.
    2) In 1986 he predicted that the earth would be 1.1C higher within 20 years and then by
    3) 1999 he said that the earth had cooled and that the US hadn’t warmed in 50 years
    4 He had also said that the Arctic would lose all of its ice by 2000.
    5) In december 2005, Hansen argued that the earth will become “a different planet” without U.S. leadership in cutting global greenhouse gas emissions.
    6) He then reversed course again and said in march 2016 that the seas could rise several metres in 50 to 150 years and swamp coastal cities .
    7) He also said that global warming of 2C above preindustrial times (~ 1850) would be dangerous and that mankind would be unable to adapt.
    8) In 2008 he coauthored a paper that said that unless mankind limited the CO2 to 350ppm that we would have not have the same planet that we grew up with. Well 10 years later we are at 410ppm and the planet looks the same to me.
    9) in 2009 Hansen called coal companies criminal enterprises and said that Obama had 4 years left to save the planet.
    10) In 2012 Hansen accused skeptics of crimes against humanity and nature.
    11) Hansen is involved with a 2015 lawsuit involving 21 kids that argues that their constitutional rights were interfered with by CO2
    12) in 2017 he has admitted that CAGW does not happen with burning fossil fuels.
    “One flaw in my book Storms of My Grandchildren is my inference you can get runaway climate change on a relatively short timescale. ”
    “Do you think that’s possible on a many-millions-of-years timescale?
    It can’t be done with fossil-fuel burning.”
    13) Then he said “But if you’re really talking about four or five degrees, that means the tropics and the subtropics are going to be practically uninhabitable.”

    He doesnt seem to know that their average temperature is 28C.
    14) But then he said that climate change was running a $535 trillion debt
    15) He has been quoted many times that equates climate change to all sorts of extreme weather events. No database in the world shows any more than there ever were.
    16) Hansen has published way over 100 fraudulent climate studies with almost all of them using results from computer climate models that are woefully inadequate and that have never been validated except by the human modeler.

    Obviously the man just doesnt know when to shut up.

  15. Hansen vs reality…

    GISTEMP almost exactly matches Hansen’s 1988 observed temperatures. GISTEMP barely touched Scenario B during the 2016-2017 El Niño. It’s currently headed back down to Scenario C, the undiscovery of fire.

    https://debunkhouse.files.wordpress.com/2018/06/hansen_1yr_epic_fail.png

    The 5-yr average, closer to climatology than 1-yr, fails even more epically.

    https://debunkhouse.files.wordpress.com/2018/06/hansen_5.png

    Satellite temperatures are even funnier…

    https://debunkhouse.files.wordpress.com/2018/06/hansen_uah.png

    • There’s the comparison I wanted to see! Thanks, David.

      We need to be including UAH for all these comparisons going forward since the Hockey Stick charts are garbage to begin with.

      UAH shows 1998 as the second warmest year in the satellite record, with 2016 being the warmest by 0.1C (statistical tie).

      The Hockey Stick charts have cooled 1998 into an also-ran showing several years beyond 1998 as being hotter than 1998.

      Thus, the Climate Change Charlatans could make the claim of “Hotter and Hotter” for the last few years. They couldn’t make that claim if they used the UAH chart.

      That’s why they don’t use the UAH chart. But we should be using it because it is the most accurate of any temperature chart and hasn’t been bastardized right before our eyes like the Hockey Stick charts have been.

      And keep in mind that Hansen 1999 shows 1934 as being 0.5C warmer than 1998 which makes it 0.4C warmer than 2016. In other words, we have been in a temperature downtrend since 1934 and it is continuing.

      • “That’s why they don’t use the UAH chart.”
        A very obvious reason is that Hansen was predicting temperatures for the surface, not lower troposphere.

        I wonder why UAH a,d not RSS? RSS was all the rage just a few years ago, with UAH rarely cited.

      • The UAH data are the only data I trust. Everything else is contaminated. I still evaluate the H4 record simply because its length offers advantages.

        Dr. Spencer just issued a monthly update. I have already analyzed it. Not much of a change.

        Please take the time to look at my earlier comment that included an evaluation of the UAH data. It will be worth your time even though it is a little painful due to the links.

        In that earlier comment note how well the Lewis/Curry value of ECS=1.66 matches the data. The IPCC value of 3.0 sure doesn’t.

        I did one more thing today. I analyzed the 5-year moving average of the UAH data assuming CO2 alone was responsible. The ECS value came out at 1.69. That sure seems to support the Lewis/Curry number. BTW, the correlation coefficient came out at 0.896.

    • David,
      You said, “GISTEMP barely touched Scenario B during the 2016-2017 El Niño.” And, that only happened because of the non-volcanic event that coincided with the El Niño.

      Hansen probably would have been better off spreading out the effects of his two postulated volcanic eruptions over the 30-year period rather than arbitrarily picking two dates for them.

      • I never noticed that… How fracking funny! The only time Hansen’s model was right was when it was the most wrong… LOL!

  16. “Unfortunately, he does not provide an R2 value for his “Best Linear Fit,” nor are error bars provided for the temperatures, which is typical for his work.”

    I had to laugh at this. It would be very odd indeed to show error bars on data that must represent single observations for a simple linear regression to be appropriate. The data are not shown, only the running means, for visual purposes. If the best linear fit is based on yearly means it would not be appropriate to provide an R-squared value; the tool is for visual purposes, and not to account for a percent of variability.

    Only one volcano? What about El Chi Chon?

    • Silber,

      Certainly you are not suggesting that a mean value does not have an associated standard deviation! That is absurd! While one can argue about the meaning of such calculations with non-parametric data, the calculations can still be useful.

      If you look at the BEST temperature data, you will see error bars (called uncertainties) associated with the annual temperatures.

      It would further seem that you are suggesting that there is no way available to assess the prediction of variance in anything but singular raw data points. Inasmuch as temperature data consist of daily averages, further averaged on monthly and annual periods, it would seem that the claims of climatologists are not subject to verification or prediction. How convenient for those in the business of raising the alarm about future temperatures.

      El Chichon last erupted in 1982, well before the 1988 predictions. Are you trying to be funny?

      If I didn’t recognize your name, I’d suspect that you were a new poster here, who didn’t know what he was talking about.

      • El Chichon last erupted in 1982, well before the 1988 predictions. Are you trying to be funny?
        I think she’s trying to point out that the El Chichon eruption in 1982 was included in all of Hansen’s scenarios (as was Agung).

        • However, the concern is over the post-1988 predictions, not past history. I was speaking to the two assumed eruptions post-1988, only one of which happened, and Silber asked about a pre-1988 eruption. Hello?

  17. Biased selection of a staring point , in addition to retrospective manipulation of past data points , yields the predictive power of the prescient “Carnac the Magnificent” – The Anti- Huffington Post

  18. A simple way to remove the effects of ENSO is to calculate global temperature trends separately for El Nino years, La Nina years, and neutral years, as John Nielsen-Gammon did in 2012. Those three nearly identical trends reveal the long term global warming independent of ENSO. Dana Nuccitelli calculated those same trends but using a different index of ENSO to decide which were El Nino, neutral, and La Nina years, and got nearly identical results to John Nielsen-Gammon. The key plot with an explanation, and updated through 2015, is available elsewhere, and that plot updated through 2016 is available as a YouTube video.

    A more sophisticated approach to remove the ENSO influence is to use multivariate regression, as Gavin Schmidt did up through 2017 (reposted at Open Mind). In that same Open Mind post, Tamino showed the trend after removing the influences of not only ENSO, but also volcanoes and solar variations; later, Tamino plotted the rates of those trends for easier comprehension.

    • TallDave,

      We all seem to be beating a dead horse, but there are those like Nick who de-Nye that the horse is dead. It would serve everyone better if we could agree that Hansen’s forecast failed and we could move on to discuss just why it failed and how to make improvements. Nick, and those in his camp, are an impediment to moving forward. Clearly, to me, the assumptions about the climate sensitivity to trace-gas concentrations is too high by about a factor of at least two. It seems that modern climate models may actually be worse, overestimating by about a factor of three! It would seem that the Russian model(s) have the most skill. However, my attempt to locate a paper at Harvard came up empty handed. I think that what the Russians have done could be instructive, but they don’t seem to be getting much traction in the grant-funded community.

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