Garbage In, Money Out

In my Forbes column last week, I discuss the incredible similarity between the computer models that are used to justify the Obama stimulus and the climate models that form the basis for the proposition that manmade CO2 is causing most of the world’s warming.

The climate modeling approach is so similar to that used by the CEA to score the stimulus that there is even a climate equivalent to the multiplier found in macro-economic models. In climate models, small amounts of warming from man-made CO2 are multiplied many-fold to catastrophic levels by hypothetical positive feedbacks, in the same way that the first-order effects of government spending are multiplied in Keynesian economic models. In both cases, while these multipliers are the single most important drivers of the models’ results, they also tend to be the most controversial assumptions. In an odd parallel, you can find both stimulus and climate debates arguing whether their multiplier is above or below one.

How similar does this sound to climate science:

If macroeconometrics were a viable paradigm, we would have seen major efforts to try to bring this sort of model up to date from its 1975 time warp. However, for reasons I have documented, the profession has decided that this macroeconometric project was a blind alley. Nobody bothered to bring these models up to date, because that would be like trying to bring astrology up to date.

This, from Arnold Kling about macroeconomic models could have been written just as well to describe the process for running climate models

Thirty-five years ago, I was Blinder’s research assistant, doing these sorts of simulations on the Fed-MIT-Penn model for the Congressional Budget Office. I think they are still done the same way. See lecture 13. Here are some of the things that Blinder had to tell his new research assistant to do.1. Make sure that there were channels in the model for credit market conditions to affect consumption and investment.

2. Correct the model’s past forecast errors, so that it would track the actual behavior of the economy over the past two years exactly. With the appropriate “add factors” or correction factors, the model then produces a “baseline scenario” that matches history and then projects out to the future. For the future, a judgment call has to be made as to how rapidly the add factors should decay. That is mostly a matter of aesthetics.

3. Simulate the model without the fiscal stimulus. This will result in the model’s standard multiplier analysis.

4. Make up an alternative path for what you think would have happened in credit markets without TARP and other extraordinary measures. For example, you might assume that mortgage interest rates would have been one percentage point higher than they actually were.

5. Simulate the model with this alternative scenario for credit market conditions.

6. (4) and (5) together create a fictional scenario of how the economy would have performed had the government not taken steps to fight the crisis. According to the model, this fictional scenario would have been horrid, with unemployment around 15 percent.

In the case of climate, the equivalent fictional scenario would be the world without manmade CO2, but the process of tweaking input variables and assuming one’s conclusions is the same.

  • Hey, be fair. Climate models only time warp back to 1979, not 1975!

    The first review of global warming research was the Charney Report of 1979. It estimated the climate sensitivity, the average global warming for a doubling of CO2, at 1.5C to 4.5C.

    The latest IPCC Assessment report, the Fourth Assessment Report of 2007, gives a range of 2.0C to 4.5C, immediately followed by the statement that values less than 1.5C are highly unlikely.

    I go into more detail, with links, here.

  • Zilla

    So, this is one of MR. Watt’s (of WUWT fame) captions from today’s postings which accompanies a picture purportedly of two Danish sciences in some snowy region of the globe:

    “Danish Meteorological Institute scientists measure temperature. GISS scientists are seldom pictured performing such menial tasks.”

    I’m sure you all know Mr. Watts, so take a look.

    My question: how is this anything but maligning, malicious, immature, and propagandist in nature?

  • Russ R.

    @ Zilla

    “My question: how is this anything but maligning, malicious, immature, and propagandist in nature?”

    It’s called humour. I suggest you give it a try sometime.

    If your problem is with the validity of the caption, go find yourself a picture of GISS scientists doing field work, and prove him wrong.

    And if your issue is with Watts’ writing style, why not direct your ‘question’ to him via his blog? What does posting this here achieve (other than making you look like a complete ‘tard)?

    Would you have found it so “maligning, malicious, immature, and propagandist in nature” if instead of poking fun at GISS scientists, the caption targeted at prominent skeptics?

  • Zilla

    Russ asks some excellent questions.

    But I do have to disagree with your first assertion that Mr. Watts is using “humor” (and if it is humor it is extraordinarily lame). Mr. Watts is simply being snide, which is okay in most circumstances but the manner with which he and other denialists handle their so-called criticisms of climate scientists is distinctly mean-spirited. How would you, Russ, like to be taunted on an internet website in this manner? Would you be chuckling softly at Mr. Watts’ “humor”? (By the way, humor is always the excuse denialists use when they are being particularly nasty).

    There is plenty of evidence that GISS scientists do work – why would one need a picture? Again, Mr. Watts is simply using petty

    The reason I am posting here is because I asked Mr. Watts on his own blog, in all honesty, if he reported all the information in his possession when he posts or does he cherry-pick information to reach a foregone conclusion. This made him very angry despite his overall tone of aggressive challenges toward people he disagrees with – Mr. Watts can dish it out, in other words, but he can’t take it. He will no longer post my comments, so I post my responses here and elsewhere.

    Very mature to use the word “‘tard,” by the way, brainy of you.

    And yes, I would find “poking fun” at Mr. Watts or Mr. Meyer in this manner equally distasteful. Tell me, Russ, are you a tribal person who thinks in terms of “us-against-them” to ask such a question? (Or perhaps I am just using “humor”)

  • hunter

    I don’t know if you read comments to your posts, but there is a very striking and disturbing similarity between the economic models and climate models.
    The risk management models that failed so badly were written by people who won the Nobel prize.
    The promoters got extremely wealthy.
    The IPCC of course won their prize and the wealth gained by its central promoters is well documented.

  • hunter

    Please stop the bs.

  • Zilla
    The image of “hands on” for the Danish data is used to emphasize that DMI uses measurements for temp data above 80 deg N Latitude, while GISS does 1200 mile interpolation.

    Of course, the concept that an average global temperature, for a day, a week or a month has any meaning is questionable, it certainly has no place in science. Trumping a -0.2 degree anomaly in South America with a +0.4 degree anomaly in Greenland, to get a positive average makes no sense and certainly can’t be called “scientific” data.

    Look at

    to put things in perspective.
    WUWT is a great PR site, that uses interesting facts to slam the BS of Romm, Tamino ad Schmidt, Hansen’s bulldogs.

  • ADiff


    By “maligning, malicious, immature, and propagandist” you mean ‘honest’, even when the truth is brutal?

    Methinks thou dost object too much.

  • Zilla

    hjbange, I hate to start a flame war but I might suggest you are also being somewhat picky in the data you choose to post. I see your point (that cherry picking data from disparate places such as S.America and Greenland is bad science) but then you should not propagate such “science” either.

    For instance, I look at your address and it’s a wordpress blog site.

    Why not go to the best equipped source for information?

    I do not think what I’ve posted is “bs,” but rather an unfortunately reality of the blog wars.

  • Wally

    Great post Mr. Meyer.

    As someone who does mathematical modeling in more traditional, experiment based sciences, I’ve often likened economic models to climate models. All modeling suffers from the problem of garbage in, garbage out. And its very difficult upon designing the model in the first place to know if you’re just making junk or not, as you make repeated assumptions about parameters, simplifications that eliminate whole sets of equations, etc. But in bio/phys/chem/engineering, you eventually test the model experimentally, or you validate it. So if you made a crappy model, that experiment will tell you so, and you have to redesign the model based on your new data. However, in econ and climate science, you can’t experiment. You can get data, but it is not in the controlled environment required of a true experiment. So you never know if your model is complete garbage or not. All you have is your best guess. So when people say stuff like “98% of climate scientists support AGW,” that is nothing but a best guess from 98% of the field. It simply does not carry the same weight of say 98% of scientists supporting a vaccine treatment, or Newton’s laws. Simply put, it is not a scientific theory, it is still just a hypothesis. Creating a model and running it, is not testing a hypothesis, its still just hypothesis generation. Testing your hypothesis is the validation or experiment. And if your hypothesis passes repeated experiments, then it gets to become a theory.

    Climate models and econ models have NEVER been validated. Its impossible. So we’re spending trillions of tax payer dollars on a few people’s best guesses regarding stimulus spending, TARP and the endless tax incentives in support of green tech, as well granting for studying the effect of global warming on X, Y or Z. And not surprisingly it much the same people that want to spend our money based on these climate models that want to spend it based on these econ models. And unfortunately much of the American population does not understand these kind of differences I describe above because our public schools are so absolutely awful.

  • JP

    All I can say is, “Mission Accomplished”. About 7/9ths the posts on this thread are either yours or people resonding to your posts. Of course, your complaints had nothing to do with the subject at hand, and only served to waste bandwidth on completely unrelated complaints. Again, congrats.

  • hunter

    “hypothetical positive feedbacks”

    Nope. Not a single “hypothetical” feedback has ever been put into a climate model. But you don’t give a shit about the truth, do you?

  • KuhnKat


    “Nope. Not a single “hypothetical” feedback has ever been put into a climate model. But you don’t give a shit about the truth, do you?”

    Mind listing the papers showing the solid research PROVING those feedbacks to an implementation level??

    It must suck to be you. Even the Modelers have to admit their feedbacks are little better than their cloud modeling which is virtually nil in reality as opposed to hypotheticals!! In fact, without much better handling of clouds the rest is meaningless.

  • Zilla

    Actually JP, at first I was getting to Mr. Meyer’s post – but the I could see no point in commenting on it. It seems to be a comparison between two unlike things motivated by an Obama-bashing sentiment. I’m simply here because Mr. Watts bravely banned me from his website after I asked him a difficult question he did not want to answer.

    “Methinks thou dost object too much.”

    Not sure I followed the Hamlet reference here, ADiff – I was objecting to the manner in which commentators like Mr. Watts handle their material, a manner which simply instigates juvenile echo-chambers against scientist.

    Methinks the ADiff dost ignore/rationalize too much.

  • Cthulhu

    “No one yet has been clever enough to structure a controlled experiment to isolate the effect of rising CO2 levels from other changing variables in the complex global climate.”

    It’s not a matter of being “clever”. Such a thing will *never* be possible. Many processes that occur on the Earth cannot occur in miniature and we will never make a “controlled experiment” the size of the actual Earth.

    Controlled experiments are used to observe and understand small scale behavior – like the mechanisms of radiation transfer and mechanisms of convection under different conditions. They give us data and equations. Climate models are built upon such data and equations to see what the large scale emergent behavior looks like.

    The computer aided calculations based on the experimental data show that a doubling of co2 leads to significant large scale warming. They show positive feedback in the climate system. Neither of these things are *assumptions* – they are results. What went into the models was not assumptions but experiment derived data and equations. The results are simply the result of that.

  • Wally

    “The computer aided calculations based on the experimental data show that a doubling of co2 leads to significant large scale warming. They show positive feedback in the climate system. Neither of these things are *assumptions* – they are results. What went into the models was not assumptions but experiment derived data and equations. The results are simply the result of that.”

    Here’s the flaw. You’re modeling only what you know to be true in these small scale experiments and applying it to a system that many orders of magnitude greater in complexity than any of the experiments, and is controlled by god knows how many more factors. So, for example, your model takes into account CO2 concentration, solar output, black body radiation and maybe a few other things. But you’ve ignored, and again, god knows how many factors. With only A, B and C to guide it positive feedback may occur, but you didn’t included D through Z. And you don’t have anyway to test the importance of D-Z. Or even what fraction of the changes occur thanks to A, B and C. So, you don’t get around the impossibility of experiments at planetary level climate. You have a couple of rough guides from smaller experiments. Like say the amount of radiation CO2 can absorb at given concentrations, but that’s only ONE parameter in your model. You did that experiment to find ONE parameter. You get another couple from H20, or CH4 or a few others, then maybe in a different equation you have the solar input (which itself is an assumption that isn’t based in experimentation), and few more well know things like radiation or convection. But the models needs to account for cloud formation, ocean turn over, albedo, CO2 uptake from plants, farts of cows, on and on and on. These are things that will largely never have experiments to test the amount of contribution to the Earths climate.

    Which is all a long winded way of saying your small scale experiments still don’t test the validity of the model. The model is guess based on some small fraction of knowledge from experiments and the vast majority assumptions on what the guy typing it all out on Matlab or something similar thinks might be true.

  • Cthulhu

    I think the major factors that affect climate have already been identified and the uncertainties in them are understood so that the climate sensitivity range from models is pointing at the actual range. Unknown unknowns might exist but at this point I think they are probably going to be little details that end up nudging the range in either direction by small amounts.

  • My mate and I were just discussing this specific article, she actually is normally attempting to prove me wrong! I am about to show her this particular post not to mention rub it in a little!

  • Ben

    “I think the major factors that affect climate have already been identified and the uncertainties in them are understood so that the climate sensitivity range from models is pointing at the actual range. Unknown unknowns might exist but at this point I think they are probably going to be little details that end up nudging the range in either direction by small amounts”

    “I think” is not appropiate when doing modeling. You either know for sure, or you are guessing. This is what is wrong with modeling the climate as it is being done now. Those little details have been wrong for the last 20+ years since they first started making the models – GCM’s for the initiated…(look at Hansen’s models from the 1990’s). The claim that we know more now and have better computers says nothing when none of the premises checked out to even being close to reality.

    Hansen’s graphs of actual temperatures are always off, his guesses on sensitivity ignore the fact that he has never been even in the realm of his proclaimed error. People point to other models where we have “scenario B: we reduce our greenhouse gas emmisions by 30+%”..and say well the actual temperature is a little lower then that, but he was close.

    Reality check says scenario B is not even applicable since it did not occur. If the models were correct, scenario A, business as usual would apply and would be “close” to the actual temperatures with the only error being the actual climate sensitivity. This is not the case. Until reality checks are part of this modeling along with results that are actually close, these models are worthless and are a waste of time along with all the money that goes into them.

  • Waldilla Kramb

    Great God Cthulhu, don’t waste your time. The denialists are obsessed with modeling. Never mind that scientists use multiple sources for data, or that the models have been accurate about past climate – the denialists will simply give generalized statements about why models are useless, even though they are a tiny part of the overall whole. The denialists will also argue that “it’s not testable” and “the hockey stick has never been replicated” – even though both arguments are essentially false.

    By the way, Breann, this may not be the best site to convince your mate with – most of what Mr. Meyer publishes is bunko, he is unqualified as a commentator, and his motives are mostly political.


  • JP

    You must be kidding Waldillia. You people still cannot get over the absurd Hockey-Stick! Why beat a dead horse, when even Dr. Mann refuses to answer his critics? Even Mann has moved on. And what use is a model if it cannot predict future event? Any decent modeler can model past events to prove whatever theory he wishes. It doesn’t matter if it is in econometrics or climate.

    And no, models are THE tool for Alarmists. Almost ever study they publish can be tied to some model. How about reading the IPCC some time, and look at the references to the GCMs.

  • Waldillo

    Not kidding. It is not me who “cannot get over the absurd Hockey-Stick,” my friend. Look back through any of these threads for multiple references to the “absurd Hockey-Stick.” Models, hockey stick, reproduction of experiments – these inspire most of the disinformation denialists circle around.

    What IPCC documents are you referring to specifically? It seems to me that there are a great number of IPCC documents filled with a good deal of data that is not model oriented. God only knows how many times I liked to their free online data (no one here actually reads the science, although a few try to fake that they do). And again, you are making essentially generalized statements. Ever read Real Climate on the subject of modeling? They have several posting which are very in-depth (if a little difficult to read) which answer a number of these sorts of charges.

  • Ben

    Denialists can be applied to both sides of this debate. People modeling this are in denial that their models are wrong. So can I call anyone who cites Real Climate as a legitamite source a denialist?

    And I deny nothing. Earth is warming since the LIA, man may have a little to do with this. But we have no idea how much because scientists are wasting their time with models that reinforce the computer science 101 tenant of: garbage in, garbage out.

    Last time I went to real climate I cited the IPCC to show they were wrong in a post and was banned ever since that. They do not want to discuss science or the truth at all. Real Climate created me as a skeptic just like so many others by their hostile attitude and their inability to take criticism in the fact that their own studies tend to contradict themselves, and are not scientifically sound.

    Next time, do not post a link to a web site unless its relavent to the discussion. Ad-hom attacks and all that nonsense…if you really want to discuss what is being said, do so. Don’t just say go to this web site which is more about politics then this one will ever strive to be…and say this site knows all and will educate you. I read real climate back when I was trying to figure this entire mess out…and look where I am now.

    You must force feed the kool-aid to people first, and then direct them to real climate. Otherwise, you are just wasting your time.

  • Zilla

    Well Ben, I posted a pretty straight forward question to Anthony Watts over at WUWT (“Do you post all relevant information when you write your blog or do you cherry pick your information?”) and was promptly banned. Seems to me that the answer is fairly apparent in the reaction of the blog host.

    And once again, Ben, you are obsessed with the modeling – something I’m betting you do not really understand well enough to critique.

    And the idea that RC is political, particularly compared to this one, is ridiculous. After all, Mr. Meyer is the fella who compared the “Obama stimulus” to GCMs at the top of this page – I could not have made up better proof of the political nature of this blogsite or the entire denialist camp. You might want to reevaluate where you are now.

  • Wally


    This blog is political. If it deals with climate science at all it pretty much has to be political, because of the gross politicalization of the science in the first place.

    And Re Modelling:

    1) You probably shouldn’t blindly call into question knowledge of people on this site. Its generally frequented by engineers or those in more tradiational sciences that know a great deal more about modeling than climate scientists.

    2) Those on the AGW side only have models to prove their case. Its the models that make up nearly 100% of the scientific “evidence” for dangerous or catastrophic AGW. So, quite naturally the debate centers around the (in)validity of those models. To case around these phrases like “you are obsessed with modeling” is to be quite ignorant of the science and debate of the science.

    But, now that I think of it, I should probably just let you spew your idiocy so to make it more apperent how far a drift the CAGW supporters actually are. So, carry on sir.

  • Zilla

    Wally says: “This blog is political.”

    I’m glad at least someone admits it. What I do not see is this same level of politicizing on the other end of the spectrum. I see it places such as this one and WUWT.

    1) The “knowledge” of the people on this site is not necessarily in question – although reading the responses here one has to wonder at the level of sophistication of a great many of the commentators. Nor is it at all clear that engineers do actually know more about anything other than, perhaps, engineering. And as I’ve said before, the models are only a small part of the whole. If you were as smart as you give yourself credit for you would realize it.

    2) More than just models, Wally. There’s land, sea and satellite temp measurements, physics, radiosondes, borehole measurements, permafrost and glacial melt observations, Yamal tree reconstructions, plus there is the fact (fact, mind you) that CO2 is a proven greenhouse gas and the fact (again fact) that temperatures have made a precipitous rise in the last 100 years. You may not be as smart as you give yourself credit for. You might actually be the one “ignorant of the science and debate of the science.” Responses like this make me blindly call into question the knowledge of the people on this site.

    And I will carry on, sir. Thank you.

  • Wally


    “What I do not see is this same level of politicizing on the other end of the spectrum.”

    Err, well than you haven’t been looking carefully enough or your biases are preventing you from seeing it, because its everywhere. Much of the ARRA is funding “alternative fuels/energies” for example. This is nothing more than AGW winning favoritism in the current political environment.

    “The “knowledge” of the people on this site is not necessarily in question”

    Eh, you questioned it, quite blindly even…pretty childish thing to do.

    “Nor is it at all clear that engineers do actually know more about anything other than, perhaps, engineering.”

    If you want to learn how to make mathematical models, you learn it from engineers, maybe physicists, plain and simple.

    “And as I’ve said before, the models are only a small part of the whole. If you were as smart as you give yourself credit for you would realize it.”

    The models, and what they are comprised of, is the absolute epicenter of the scientific debate surrounding CAGW.

    “There’s land, sea and satellite temp measurements, physics, radiosondes, borehole measurements, permafrost and glacial melt observations, Yamal tree reconstructions, plus there is the fact (fact, mind you) that CO2 is a proven greenhouse gas and the fact (again fact) that temperatures have made a precipitous rise in the last 100 years.”

    All of which in one way or another need to be incorporated into a mathematical model to predict the future climate. Whether its the raw data that’s been used to establish some feedback of CO2, or thermodynamics, it all ends up in the model. Its all they have Zilla. We could debate the validity of the Yamal tree ring data, true, but the reason we debate it is because of how it is used to create and support the models.

  • ADiff

    AGW is scientific issue (albeit a rather complex one considering the difficulty of resolving inputs from human activity when these are merely a fractional part of many other sources not entirely understood, much less well quantified).

    CAGW is almost entirely a political issue. It speculates possible events, based on aspects of some interpretations of AGW, and argues for a political program.

    CAGW advocates aren’t arguing science but are engaging in politics. They politicize AGW intensively, inherently corrupting the objectivity of participants to the extent they pursue science in support of CAGW assumptions and political programs. When scientists desire a particular outcome, and especially when such outcomes are identified a politically correct and even moral issues, scientific objectivity becomes not just imperiled, but impossible.

    And regrettably that’s where much of Climate ‘Science’ is at.

    Macro models can be useful tools in developing better understandings of systems, but historically haven’t generally been useful predictive tools for making policy decisions. Climate appears no exception. CAGW leans heavily on interpretations of a few such models, but has to do so in the face of most of the implied impacts to climate not being observed. Where’s the predicted increase in sea level change? It’s nowhere in evidence. Where’s the generalized increase in storms, hurricanes, droughts, floods and so forth? They have entirely failed to materialize. Where’s the rapid disappearance of the ice caps? That certainly doesn’t appear to be happening. Where we’re seeing change it’s very gradual and easily managed by adaptation (such as in changes in temperature variation patterns), so we’re back where we started with CAGW, back to Lawson’s criticsm: advocates of extreme measures to address the impacts of climate change not only exaggerate those impacts, they even more fundamentally fail to consider the inherent adaptive capacity of human beings.

    So we’re left here:

    Is the Earth warming? It has been for the past couple hundred years. Future changes in this trend are problematic.

    Is human produced CO2 contributing? Yes, it certainly appears so, but to an extent that’s uncertain.

    Is this changing the environment? Yes, it does appear so, but in ways that are far less extreme than some speculate and quite gradual. Many areas of speculated impacts do not appear being impacted as speculated.

    Is this dangerous? No, generally not. Most of the changes are not clearly negative and easily adapted to over time, especially as they are so gradual. Others may actually be positive. Exceptions occur in some specialized cases, particularly having to do with wildlife populations of a highly limited and specialized character who’s adaptive capacity is very restricted, either naturally or by virtue of changes imposed by other aspects of human activity.

    So in spite of a tendency to herd mentality (largely, but not entirely, resulting from the affect of CAGW politicization) AGW remains are area of uncertainty and scientific dispute. CAGW appears more and more mere hysteria and its dire predictions quite unlikely. However it’s virtually certain (as has been the case in all previous examples of this kind of ‘craze’) it’s social and political incentives will ensure it’s perpetuation for quite some time its obvious factual refutation. Political agendas involve incentives entirely different than those stated, and usually outlive there initially purported rationals. No doubt that’s also true in this case.

  • Waldomania

    I don’t think the science is in dispute, at least not where it counts – only in places like this is it in dispute. And I don’t think the science is based on models but on observable facts. Plus, the models are accurate:

    Sure, sure, someone is going to make some generalized statements like the ones above about why and/or how models cannot be trusted without specific examples; and/or someone will claim the models have been tampered post-production, again without offering obvious truth; and/or someone will claim the now cleared CRU proves something or the other, again without specific proof.

    Is human produced CO2 contributing to earth’s warming? Yes, it appears so. What we don’t know exactly, because we are in uncharted territory, is to what extent this warming will continue and to what extent it will damage the planet’s climate systems and ecosystems, if at all. What the smart people who know stuff, also known as scientists, can do is make predictions based on their own expert knowledge and by using an admittedly inexact method called computer modeling.

    So quit pretending you know any better.

    What the denialists do is repeat ad nauseum that the GCMs are inaccurate (which scientists admit), that scientists are trying to run our lives by suggesting a course of action to ward off worst-case scenarios.

    You know, I saw today on the Discovery channel that Edward Hubble made some initial mistakes on his calculations regarding the age of the universe. He didn’t get it right the first time so people doubted him. Of course, over time when techniques for measuring background radiation were refined, his theories were proven sound and his critics eventually silenced. Wonder what will happen to James Hansen?

  • Waldoopps

    Sorry, typing in a hurry – should have been Edwin Hubble.

  • Russ R.

    “Wonder what will happen to James Hansen?”

    His 1988 forecast has, over the last 22 years, been thoroughly invalidated by reality.

    He proposed 3 climate scenarios based on global CO2 emissions, and estimated global average temperature increases for each scenario.

    In the real world, CO2 emissions rose faster (1.8% per year) than his worst case “Business as Usual” scenario (1.5% per year), but temperatures have risen less than his best case “Drastic Emissions Cuts” scenario.

    Now, I don’t blame him for getting the emissions part wrong. He understandably didn’t anticipate the rapid industrialization of China, but if CO2 emissions rose even more than he predicted why haven’t temperatures risen the way his models predicted? The science is settled, right? We know exactly how much warming CO2 causes, right?

    It’s really simple. He overestimated the CO2 sensitivity in his models (4.2 C for a doubling), most likely because of a poor understanding of feedback effects. And rather than acknowledging this error, he’s continued to point at rising CO2 levels claiming “it’s worse than we thought” and acting like the world is ending, despite growing evidence that his forecast was too aggressive and his modeling approach is invalid.

    Any scientist with a shred of professional integrity would be dedicated to investigating and understanding any unexplained deviation between his models and reality.

    Unfortunately, Hansen stopped being a scientist and became a political hack instead. I expect that historians will not be kind to him.

  • PaulD

    This article has a good discussion of the shortcomings of the computer models: Global Warming Advocacy Science: A Cross Examination, Jason Scott Johnston
    University of Virginia – School of Law The relevant section is, “Crucial Shrouded Assumptions and Limitations of Climate Model Projections”
    For those who think we should rely on the models, read the above critique and then come back to discuss it.

  • WaldoDR

    Russ, I think you miss the point of the Hansen/Hubble analog. Perhaps Hansen’s theories will prove unsound – but the science community has accepted them. The blogosphere, not so much.

    Paul, why would you take the word of a law professor over that of a climate scientist? Shills has asked the same question: if IPCC science is so shaky, where’s the peer review proving them wrong? Why do denialists use a law professor to critique climate science? If I’m charged with a crime, I sure as heckfire don’t want a climate scientist as my defense – why would I listen to a lawyer on climate science?

  • Shills

    Geez ADiff. Much of what you write could just be copied and pasted from your prev. dribble. That would save you some time don’t you think???

    Anyone who reads ADiff’s post: For are more nuanced assessment of the observed effects of AGW, I suggest you read the relevant parts of the IPCC’s latest work group II publication.

  • Waldwheeeee

    ****”His 1988 forecast has, over the last 22 years, been thoroughly invalidated by reality.”


    Of course, someone is going to come on this very politically motivated blog and make some comment about how politically motivated Real Climate is. Or one could read the original Hansen paper (linked on RC). Or one could ask a lawyer about climate science.

  • Russ R.


    I’m familiar with both the links you provided, and they are both outdated. See here for observations up to 2010:

    And I did read the original Hansen paper. It’s right here:

    And I took the time to read the details of each of his 3 scenarios:

    “Specifically, in scenario A CO2 increases as observed by Keeling for the interval 1958-1981 [keeling et al, 1982] and subsequently with a 1.5%/yr growth of the annual increment.”

    “In scenario B the growth of the annual increment of CO2 is reduced from 1.5%/yr today to 1%/yr in 1990, 0.5%/yr in 2000 and 0 in 2010; thus after 2010 is constant, 1.9 ppmv/yr.”

    “In scenario C the CO2 growth is the same as scenarios A and B through 1985; between 1985 and 2000 the annual increment is fixed at 1.5 ppmv/yr; after 2000, CO2 ceases to increase, its abundance remaining fixed at 368 ppmv.”

    As it turned out, CO2 emissions have increased by more than Hansen forecast in his Scenario A (1.8% per year according to CDIAC data), yet global average surface temperatures have increased by less than he forecast in Scenario C according to all major sources (GISS, CRU & UAH) even though CO2 has increased to 390 ppmv vs. the 368 ppmv in his assumptions (a difference equivalent to 11 years worth of emissions).

    Because its predictions have not matched reality, I’m comfortable calling his model invalid.

  • Waldelicious

    Soooooo, even though Hansen’s scenario “B” is squarely within actual, observable temperature increases, and because he was “predicting” (which in and of itself means an educated, researched guess) a temperature increase which has clearly happened, you are unconvinced and not satisfied.

    You are unconvinced and not satisfied even though Hansen’s predictions, and IPCC model predictions, have been essentially accurate. Your reasons for being unconvinced are details and no the whole.

    No one said these predictions were going to get global mean temperatures exactly – they were predictions about temperature trends. Which have been proven correct.

    You are also unconvinced even though this is a brand new scientific discipline with admittedly much to learn – so when scientists predict a temperature rise in global climate, and then this rise in global temperatures occurs, you remain unconvinced and unsatisfied because it was not exactly what happened, despite being a “prediction.”

    Hansen was right. You are wrong. It has been proven.

    The obstinacy of the deniosphere is amazing.

  • Russ R.


    You’re misrepresenting something important here, namely… quantities.

    1. Hansen’s scenarios were based on specific, quantified input assumptions (GHG emissions), and predicted specific, quantified outcomes (temperature increases). Those input conditions were more than met, but the outcomes did not materialize.

    2. Specifically, Scenarios A, B and C predicted temperature increases of 1.05, 0.90 and .55 degrees Celsius respectively over the period of 1984 to 2010. Yet, despite GHG emissions that exceeded those assumed in Scenario A, the actual temperature increase amounted to only 0.40 degrees Celsius (All values from here).

    How can you possibly call his prediction “right” let alone “proven”?

    I’m being objective here… and I’m unconvinced.

  • Wally

    Russ, you might as well stop trying to convince waldo of anything, particularly that you’re attempting to be as unbias and objective as possible while searchering for the truth, he’ll just keep calling you a “denier” and brush of any and all inconsistancies with the hypothesis of CAGW.

    And really is there any more clear way of revealing who’s personal biases are getting in the way than regressing to name calling?

  • Waldollipop

    Russ, so again, Hansen was not absolutely exact, even though the trend he predicted has clearly taken place, even through he admittedly made a best case estimation at a time when the science was relatively new, and even though countless other scientists have signed on to original scenarios, you are not convinced. So Hansen overestimated – he, like the rest of us, is learning as he goes. He admits as much. But then, with new, more advanced knowledge and techniques, those experts working in the field become increasingly convinced of the rightness of Hansen’s basic scenarios. Even on the graph you posted he is squarely within the observed trends – not exact, mind you, but on track.

    Are you really being “objective,” my friend?

    But okay, we may agree to disagree.

    May I also assume that you doubt Mt. Saint Helens is a live volcano because the vulcanologists cannot precisely date when she will erupt again? Or perhaps, since there is no such thing as a triceratops anymore, only baby torosauri, you no longer believe in dinosaurs?

    By the way 1, where does that graph come from – it has a “photobucket” address.

    By the way 2, I am Waldo, Wally is someone completely different. I use variations of the “Waldo” moniker simply because it is more fun to come up with variations.

    Happy days.

  • Waldangit

    By the way 3, what are you doing, Russ, dealing with science that is over 20 years old? Of course it’s not as accurate as we would like – science is a progressive discipline (even I know that). That’s why we have scientists, to keep the science moving forward. Is it that surprising that Hansen’s science in 1988 is not as specific as you would like? Of course the quantities are not exactly what he predicted! This is the beginning of the climate science movement. Why not deal with Hansen et al’s science today?

    Let me ask again: are you really being “objective”?

    Happy nights too.

  • Russ R.


    Quick responses first:

    1. The graph is from David Middleton, Dec 22, 2009. Full story here.

    2. Apologies for mixing up your handles. Though it would be easier for everyone if you picked one an stuck with it (ideally not one that someone else is already using).

    3. I’m dealing with Hansen’s past predictions because they can be tested with recent observations, whereas it’s impossible to test his more recent predictions without seeing into the future.

    Am I really being objective? I’m just observing this centuries old process called the “scientific method”. It involves developing a hypothesis to explain a particular phenomenon. Proposing an experiment with observable, measurable outcomes, while predicting what the results would be if the hypothesis holds true. Conducting the experiment and comparing the actual results against the predicted outcome. Finally, dismissing the hypothesis if the results do not agree with the prediction, and refining the hypothesis to explain the new observations.

    In this case, Hansen’s hypothesis was that increases in CO2 and other trace gases would cause a certain amount of warming. He didn’t predict a “trend” (as that trend was already well underway). He said that for a given level of CO2 emissions, the planet would warm by a given amount (4.2 deg C for a doubling of CO2). 22 years later, CO2 emissions increased by even more than his highest extent of his range, yet temperatures increased by less than even the lowest extent of his range. Conclusion… reject the hypothesis. A better hypothesis would be the planet will warm by 1.2 degrees C for a doubling of CO2, which is in line what the historical observations have shown.

    “Even on the graph you posted he is squarely within the observed trends – not exact, mind you, but on track.” I think you’ve misinterpreted the graph. The shaded bar is irrelevant. What matters are the 3 scenarios forecasts from 1984 to present, and the observed temperature over the same time period. The observed temperature has never matched his Scenario A (even though GHG emissions have), and has been below his Scenarios B and C for almost every year since 1990 (even though GHG emissions have greatly exceeded the assumptions in both those scenarios). I really don’t see what’s “squarely within the observed trends”.

    “So Hansen overestimated – he, like the rest of us, is learning as he goes. He admits as much.” Please show me where he has admitted to overestimating. I would respect him much more if I could see that.

  • PeterB in Indianapolis

    “There’s land, sea and satellite temp measurements, physics, radiosondes, borehole measurements, permafrost and glacial melt observations, Yamal tree reconstructions…”

    Zilla, you had me going that you might be reasonalbe until you threw that bit in at the end about “Yamal tree reconstructions”.

    The land temperature measurements have been endlessly messed with. There is AMPLE evidence of this. The sea and satellite temps show no statistically significant warming in the last 15 years, even according to Phil Jones. Physics states that doubling CO2 concentration in the ABSENCE of any feedbacks will raise the temperature by around 1 to 1.2 degrees C per doubling.

    Radiosondes, borehole measurements, and permafrost all seem to indicate that feedbacks are very likely to be negative and not positive. Glacial melt observations are great. So are observations of all of the glaciers which are currently GROWING, which are conveniently ignored by the alarmists. Overall global ice cover has risen since 2007, which is not a long enough time to be significant, but then again, global ice cover records only go back to 1979 at best, which is not a long enough time period to be statistically significant either when it comes to global ice cover.

    Then, finally, we get to “Yamal tree reconstructions” which is what Mann used to create his “hockey stick” and what was also the main point of the infamous “hide the decline” exchanges. If you do not realize that the Yamal tree reconstructions have been thoroughly, completely, and totally discredited, I suggest you do further study on that subject.

  • PeterB in Indianapolis

    Waldangit, or whichever Wal you wish to be next…

    Hansen’s predictions in 1988 were WAY off. His predictions in 1993 were WAY off. His predictions in 2000 were WAY off. Now, you wish us to suddenly believe his current predictions are good because of “improvements in the science”??

  • WaldoB

    Of course, Peter B, you are wrong. The Yamal Tree Reconstructions were scientifically sound and accurate – you need to read something other than a blog site now and then. Hantemirov and Shiyatov used hundreds of Yamal trees and their results verified by Briffa, another of those annoying scientists who actually works in the field. McIntyre, on the other hand, used records of 12 trees he located somewhere on the internet and made accusations without any real evidence.

    And I do not know how you justify a “WAY off” prediction – even the graph posted by Russ B shows a pretty good match.

    You are simply one of the hysterical, exaggerating, arm-chair scientist denialists out there.

  • Waldo R

    Russ, you seem like a nice enough bloke, but once again and as always I have to ask how truly “objective” you are.

    You link to a blog (why can’t the denialists produce more than a two or three bonafide climate scientists at a time – why must they always rely on blogsites?) run by a guy who admits, up front, the he’s out to debunk “environmental extremists like Al Gore” and he has a background as a “geoscientist in the evil oil industry for almost 30 years. I have a BS in Earth Science (Geology concentration).”

    Is this an “objective,” much less credentialed source for your material?

    Please don’t bother trotting out the ‘I think for myself’ cliche (no one here does, everyone here tows the party line and parrots blog science) or the ‘new kind of science’ rational – either someone is a qualified scientist or not.

  • Wally

    Ok, after this little jem: “And I do not know how you justify a “WAY off” prediction – even the graph posted by Russ B shows a pretty good match.”

    While looking at this:

    Can we all just agree to ignore Waldo? How is it a “pretty good match” when CO2 levels are higher than scenario A and temps are lower than scenario C? Unless maybe “pretty good” has some scientific meaning that resembles “god awful” that I’m not aware of…

  • Russ R.

    “You link to a blog (why can’t the denialists produce more than a two or three bonafide climate scientists at a time – why must they always rely on blogsites?)… Is this an “objective,” much less credentialed source for your material?”

    Okay Waldo, let’s go to a source with unquestionable credentials and objectivity…. James Hansen himself.

    Here’s Hansen’s own data (GISTEMP land/ocean global mean) from 1984 to present, showing almost exactly 0.4 deg C of warming:

    And here’s Hansen’s original paper (see page 7 of the PDF), predicting warming of ~1.1 deg C from 1984 to 2010 for Scenario A (business as usual) to as little as ~0.6 deg C for Scenario C (drastic emissions cuts).

    Recapping, for those not paying attention… Hansen said temperatures would rise ~1.1 deg C if the world went about ‘business as usual’, but if the world heeded his warning and took ‘drastic emissions cuts’, then temperatures would only rise ~0.6 deg C. And what happened? The world didn’t take any action, global CO2 emissions exceeded his ‘business as usual’ assumptions, but global temperatures only rose 0.4 deg C (by Hansen’s own measurements).

    Objectively, 26 years is ample evidence. Hansen’s hypothesis has been tested, and it has failed.

    And you still haven’t shown me where he admitted to overestimating. Seriously… if he has, that’s pretty important for his credibility going forward. If not, he deserves to be ignored.

    Also, fair warning here… Name calling doesn’t add anything to the discussion. If you continue to use the term “denier”, “denialist”, or any derivative thereof, you’re going on my ignore list.

  • Walduss

    Well Russ, while the threat of your “ignore list” is certainly foreboding, I think the term “denialist” is apt. Please don’t take it personally.

    I might concede to arguments against using such terms if the people who raised the most ruckus also called out those who use the terms such as “alarmist” or “true-believers” or the like. I am only stooping to the level of discourse already well established on this site and ones like it.

    As to credentials: Hansen is a PhD climate scientist who has spent the last two decades working in consort with the world scientific community. Like it or not, he is the prominent voice among those who know and do the most. The blogosphere? Not so much.

    Reputation: Unsullied except for the blog-oriented deniosphere. He is dramatic at times, I’ll give you that (and he’d probably be much better off if he wasn’t), but he and his work is accepted by the critics who really know the biz. I’d say that puts him over your blog-source.

    Once again, I would be willing to be swayed if your criticisms worked both ways – that is, if you were as critical of your blog sources as you are of your scientific sources, you yourself would have a good deal more credibility. May I politely suggest, Russ, that you are not at all “objective.”

    And once again, I have to point out that you are judging Hansen by 22 year old science. He was making a prediction based on best available evidence at the time. What was the state of cancer research 22 years ago? The opinion of water on Mars? The giant squid? Computers? The scientific community is increasingly behind him, and has been over these 22 years, and these are the people who should know. It is only in the last couple of years, since Al Gore made a movie, that a certain segment of the population (and a certain segment of industry) became really incensed – which might lead one to believe the drive against AGW is political (a back lash against the green movement on some level).

    In any event, I shall be leaving for a bit, so you may have your echo chamber all to yourselves.

    Sunny days.

  • Russ R.

    Well Waldo,

    As expected, you ignore the data I provided (from Hansen himself), fail to substantiate your claim that Hansen admits he over-estimated (after being asked twice), continue to question MY objectivity, and persist with the name-calling.

    So… buh-bye.