Update On My Climate Model (Spoiler: It's Doing a Lot Better than the Pros)

In this post, I want to discuss my just-for-fun model of global temperatures I developed 6 years ago.  But more importantly, I am going to come back to some lessons about natural climate drivers and historic temperature trends that should have great relevance to the upcoming IPCC report.

In 2007, for my first climate video, I created an admittedly simplistic model of global temperatures.  I did not try to model any details within the climate system.  Instead, I attempted to tease out a very few (it ended up being three) trends from the historic temperature data and simply projected them forward.  Each of these trends has a logic grounded in physical processes, but the values I used were pure regression rather than any bottom up calculation from physics.  Here they are:

  • A long term trend of 0.4C warming per century.  This can be thought of as a sort of base natural rate for the post-little ice age era.
  • An additional linear trend beginning in 1945 of an additional 0.35C per century.  This represents combined effects of CO2 (whose effects should largely appear after mid-century) and higher solar activity in the second half of the 20th century  (Note that this is way, way below the mainstream estimates in the IPCC of the historic contribution of CO2, as it implies the maximum historic contribution is less than 0.2C)
  • A cyclic trend that looks like a sine wave centered on zero (such that over time it adds nothing to the long term trend) with a period of about 63 years.  Think of this as representing the net effect of cyclical climate processes such as the PDO and AMO.

Put in graphical form, here are these three drivers (the left axis in both is degrees C, re-centered to match the centering of Hadley CRUT4 temperature anomalies).  The two linear trends (click on any image in this post to enlarge it)


And the cyclic trend:

These two charts are simply added and then can be compared to actual temperatures.  This is the way the comparison looked in 2007 when I first created this "model"

The historic match is no great feat.  The model was admittedly tuned to match history (yes, unlike the pros who all tune their models, I admit it).  The linear trends as well as the sine wave period and amplitude were adjusted to make the fit work.

However, it is instructive to note that a simple model of a linear trend plus sine wave matches history so well, particularly since it assumes such a small contribution from CO2 (yet matches history well) and since in prior IPCC reports, the IPCC and most modelers simply refused to include cyclic functions like AMO and PDO in their models.  You will note that the Coyote Climate Model was projecting a flattening, even a decrease in temperatures when everyone else in the climate community was projecting that blue temperature line heading up and to the right.

So, how are we doing?  I never really meant the model to have predictive power.  I built it just to make some points about the potential role of cyclic functions in the historic temperature trend.  But based on updated Hadley CRUT4 data through July, 2013, this is how we are doing:


Not too shabby.  Anyway, I do not insist on the model, but I do want to come back to a few points about temperature modeling and cyclic climate processes in light of the new IPCC report coming soon.

The decisions of climate modelers do not always make sense or seem consistent.  The best framework I can find for explaining their choices is to hypothesize that every choice is driven by trying to make the forecast future temperature increase as large as possible.  In past IPCC reports, modelers refused to acknowledge any natural or cyclic effects on global temperatures, and actually made statements that a) variations in the sun's output were too small to change temperatures in any measurable way and b) it was not necessary to include cyclic processes like the PDO and AMO in their climate models.

I do not know why these decisions were made, but they had the effect of maximizing the amount of past warming that could be attributed to CO2, thus maximizing potential climate sensitivity numbers and future warming forecasts.  The reason for this was that the IPCC based nearly the totality of their conclusions about past warming rates and CO2 from the period 1978-1998.  They may talk about "since 1950", but you can see from the chart above that all of the warming since 1950 actually happened in that narrow 20 year window.  During that 20-year window, though, solar activity, the PDO and the AMO were also all peaking or in their warm phases.  So if the IPCC were to acknowledge that any of those natural effects had any influence on temperatures, they would have to reduce the amount of warming scored to CO2 between 1978 and 1998 and thus their large future warming forecasts would have become even harder to justify.

Now, fast forward to today.  Global temperatures have been flat since about 1998, or for about 15 years or so.  This is difficult to explain for the IPCC, since about none of the 60+ models in their ensembles predicted this kind of pause in warming.  In fact, temperature trends over the last 15 years have fallen below the 95% confidence level of nearly every climate model used by the IPCC.  So scientists must either change their models (eek!) or else they must explain why they still are correct but missed the last 15 years of flat temperatures.

The IPCC is likely to take the latter course.  Rumor has it that they will attribute the warming pause to... ocean cycles and the sun (those things the IPCC said last time were irrelevant).  As you can see from my model above, this is entirely plausible.  My model has an underlying 0.75C per century trend after 1945, but even with this trend actual temperatures hit a 30-year flat spot after the year 2000.   So it is entirely possible for an underlying trend to be temporarily masked by cyclical factors.

BUT.  And this is a big but.  You can also see from my model that you can't assume that these factors caused the current "pause" in warming without also acknowledging that they contributed to the warming from 1978-1998, something the IPCC seems loath to do.  I do not know how the ICC is going to deal with this.  I hate to think the worst of people, but I do not think it is beyond them to say that these factors offset greenhouse warming for the last 15 years but did not increase warming the 20 years before that.

We shall see.  To be continued....

Update:  Seriously, on a relative basis, I am kicking ass


  1. Joshua Vanderberg:

    If temperatures fall until 2030, and I think that there is a good likelihood they will - the damage this will do to the scientific community will be massive. The loss of credibility will spill over outside of climate science.

  2. marque2:

    Unfortunately all the sciences are getting corrupted by government funding. All these universities get subsidized funding from the government - bit get it in the form of grants for study proposals.

    If Columbia university researches apply for a.grant to study that say canned foods are just fine it is much less likely that they will get a grant. Who wants to pay for the status quo. Study that canned foods will cause cancer and you will get the funding. And because you want funding for the next project the outcome better be positive so you can get grants for follow up studies. There is no money if you can't find a scare.

    Part of the answer is to greatly reduce government funding for non military research because it creates a built in bias for the "bad." At least with military research - it is for making products the government can use so it has less bias - if a missile won't work it won't work - fudging those studies gets your company in trouble in the future. ( note I am not trying to advocate bigger military - just pointing out the research has less bias because it involves useful products that have a need and purpose)

  3. HenryBowman419:

    I think you should consider posting this to Watts Up with That. If nothing else, you'll get a huge number of comments,

  4. LarryGross:

    Would any armchair climate scientists type here be willing to attempt to explain how come scientific hurricane models are so flawed - yet still relied on - or what people believed the Ozone Hole Scientists even though they never provided 100% certainty of their position or how about lung cancer and cigarettes? Did you every see absolute proof of the connection or a guarantee that if you do smoke you will always get lung cancer? So do you not believe cigarettes can cause lung cancer? how do you know? who do you believe?

    This is just the modern day equivalent of Luddites - internet style.


  5. MingoV:

    In 2003 I was one of the non-climatologist scientists who reviewed the final draft of the IPCC's 2004 report. I won't go into details of how bad the report was, but I will discuss the climate models. All 25 submitted models failed to meet the IPCC's rather lax criteria. The IPCC then created its own model that barely met the criteria but deliberately predicted higher temperatures (4-6 degrees C) at the poles to generate "the ice is melting, the coasts will flood" panic. I looked at the 20 years of data used to "train" the models, assumed that temperatures for the next ten years would be the same as the mean of the previous 20 years, and got results that were nearly perfect. The "no-change" model worked better than all others.

  6. MingoV:

    Hurricanes cannot be predicted by climatologists because real climate changes take hundreds of years. Hurricanes are hard to predict by expert meteorologists who have access to a zillion bits of weather data and modern computer models.

    The ozone hole nonsense was based on: 1. Failure to understand the cyclical pattern of ozone distribution, 2. Bad atmospheric sampling data from the 1960s and 1970s, 3. The confusion of correlation with causation (eg: wrongly blaming freon just because it was found in the ozone layer), and 4. The continual desire to blame chemicals for every bad environmental event.

    Cigarette smoking by itself cannot cause lung cancer. The smoke contains procarcinogens, not carcinogens. Procarcinogens make it easier for carcinogens to cause cancers. If no carcinogen comes along, the smoker doesn't get lung cancer. This information has been known for decades, but anti-smoking activists keep beating the "smoking causes cancer" drum. The correct statement is "smoking increases the risk of cancer."

  7. obloodyhell:

    }}} I never really meant the model to have predictive power.

    Would that morons who call themselves "climate scientists" could say the same thing about their own ridiculously egregious models.

    Instead of being honest, they lie and twist the data to contort appearances into the notion that theirs does better than yours.

  8. obloodyhell:

    This is one of the primary goals of Postmodern Leftism, to destroy all faith in our heritage of Western Thought, including its basis in Greek Rhetoric and Philosophy.

    Why do you think they've switched to BS "deconstruction" as a primary tool? It allows EVERYTHING to be "reductio ad absurdum", ergo, everything is absurd.

    Postmodern liberalism is a societal cancer, nothing less.

  9. LarryGross:

    Climate is more complicated than hurricanes. The point is that scientists build models that predict hurricanes - multiple models and all of them are not 100 % accurate and often not "correct" - but we STILL RELY ON THEM because they STILL give us info that is useful that we'd not have otherwise - and the science of modelling will ALWAYS be evolving and get better.

    You say Ozone nonsense, The majority of people and govt do not think it is nonsense - took it seriously - AND TOOK ACTION because they BELIEVED even if the models were not perfect that they did indicate a serious threat. Back in those days consensus did not mean global conspiracy.

    How do you know ANYTHING about lung cancer and cigarettes other than what you read?
    Do you consider yourself more knowledgeable than the scientists who study it? Do you actually doubt that if you smoked 3 packs a day for 40 years that you'd NOT be very likely to get lung cancer? this is the kind of Luddite thinking that is infesting "armchair" scientists these days.

    It's anti-science - coming from people - who themselves have no training or education in science - just what they read on the internet and "believe".

  10. obloodyhell:

    }}} Unfortunately all the sciences are getting corrupted by government funding.

    Not the hard ones. Only the ones that have "wishful thinking" built into their Null Hypothesis models... like climate science.

    Math, Physics, even Chemistry and most forms of Engineering -- still doing just fine. No money grubbing quacks and charlatans there...

  11. LarryGross:

    that's just plain ignorant guy. all science, around the world? WTF whether it's studying tsunamis or astroids flying at earth or mapping the genome?

  12. Sam L.:

    My guess? The IPCC will lie about it.

  13. Harry:

    Coyote, what does one mean by global temperature? How is that measured? What is the foundation for the data, on a global scale, in particular for tenths of a degree?

    I am sure there are plenty of observations from Europe and North America, at least where there is reliable information, like in Oxford, or Cambridge, Massachusetts, for the last century. Then there are a million times more observations from airports and other places like harbors, ships at sea, and others that are precise to a degree, plus or minus a degree or more, depending on the method of the observer. For example, a six-footer reading a thermometer on the wall in Wichita Airport might read that thermometer differently, and may not have cared about precision since the exercise may not have been that crucial to inform pilots of the weather.

    But then, what about the Southern Hemisphere? If one goes back 100 years,what do we know about South America Africa, or the Atlantic in between? We have had stations in Antarctica measuring how cold it is since the '50's, but barely nothing before that, and even today there is disagreement on whether the Ross Ice Shelf is expanding.

    Does one not have to use the least significant integer when drawing a scientific conclusion from data, which means that you have to round off that precise data from your digital thermometer at MIT?

    I am not arguing that the world has not warmed since 1850, but there has to be some scientific humility here. The boys at the IPCC have none of that, which was part of your general point. They think mostly in tens of billions, plus or minus five billion.

  14. Harry:

    I meant to say, what about at the Wichita Airport in 1932? Or, the Johannesburg Airport, if there was an airport, and somebody to bother to record the temperature at noon and midnight. How about the weather in Diego Garcia, or the top of Mount Everest? Were there clouds that day in any and all places where observations were made, including Boston, and how did one adjust for that?

    I know this might be picky. Computers have given us immense power, especially PC's that freed mortals from punch cards and the Masters who ran the air-conditioned rooms with tape drives. But GIGO still applies in this empirical world.

  15. mesocyclone:

    Nice work.

    BTW, in an email conversation with a climate modeler, one of the first things he said was that the xxO's are not periodic.

    The other is that chaos does not defeat climate models. I think he's right about that (which doesn't mean the models are right, but weakens one criticism).

    I haven't gotten to asking about PDO and AMO and ENSO, etc and how they are now being handled.

  16. Gil:

    As opposed to many a denier thinktanks that get funded by big business.

  17. Gil:

    Strange how nowhere else it is said that global warming stopped in 1998. Real measurement show a consistent over a century. It also shows the global cooling of 1940 to 1970 was no near as cool as the 18th century.

  18. LarryGross:

    There's literally a world of science on the planet from genetics, to cancer research to tsunami, earthquakes, volcanoes, mapping the genome, detecting asteroids headed for earth, ozone holes, etc, etc, etc and the only two times I can recall a general attack on science RECENTLY was NOT the Ozone holes but instead the link between lung cancer and cigarettes - which was then found out to be a deliberate campaign by the tobacco companies to discredit the science - and then climate science - and again campaigns to discredit the science and the irony is - the climate "deniers" seem to not have the distrust and global conspiracy theories for other science - just climate science. No global conspiracies to get funding to map the genome or study how to eradicate smallpox or malaria other diseases, or develop less flawed, better prediction models for tsunamis and hurricanes... nope - just this one particular field of science that about 95% of scientists have arrived at consensus at - and even though all other science also is never 100% certain - a strong consensus is NOT viewed as a global conspiracy like climate science is.

    Nope - there is not a single website for Tsunami or hurricane deniers... no accusations of global conspiracies to get more funding.... etc... no "doctoring" the data... no armchair scientists accusing the Tsunami researchers of deception and lying... hell - no one even looking over their shoulders at the data to accuse them of taking "incorrect" observations or using bad data from the past, etc...

  19. marque2:

    It is amazing that alarmists point this out but ignore the fact that large corporate interests also fund alarmist research centers including gasp - Big Oil! Big Oil funds alarmists at least as much as denies if not more.

    But keep up the dream

  20. marque2:

    East Anglia CRU and Hadley reasearch have jointly determined that

    "In Hereford, Hereford, and Hampshire hurricanes hardly happen."

  21. nehemiah:

    There is more money in play over climate control (oxymoron) than any other scientific pursuit. The entire economies of industrialized nations are under attack because "warming" is bad.

    Al Gore just hopes he can get his carbon credit market exchange up and running before he dies of frost bite.

    Geez Larry in the face of actual scientific evidence that indicates the alarmists may have overstated their case you insist that we are deniers. Wow, talk about self-delusion.

  22. marque2:

    Gil if you have not heard of the pause - which is talked about everywhere - including some of the IPCC releases from the last two weeks you just haven't been paying attention or being disingenuous. I am sure you have heard the latest alarmist claim that the Oceans are sucking away all the heat and that is why temps are still down.

  23. marque2:

    When I went to grad school I knew two people who were post doc working for a chem professor - both of them independently told me the experiments weren't working out so they were asked to falsify data. One refused and was asked to leave the other quit in about six months. I know this is one instant e but I suspect there is a lot more of this going on then we care to admit because of the funding draw.

    As the scientists experiment closer to the practical side vs theoretical - there is less impulse to fake it because when you actually build the device it won't work - and you get the blame.

    But even in Particle physics there are more and more people wondering if the scientists are seeing what the want to see rather than discovering new subparticles. And if that boat were rocked? Billions in lost funding for I these physicists and loss of income of course.

  24. LarryGross:

    yep - the global conspiracy knows no bounds... evil scientists, corrupt governments (all of them) and big corporations - all are now "in" on the conspiracy.

    Good God.

  25. marque2:

    Larry you are the one with the tin foil hat. I am just pointing out every group gets funded by corporations. And it is lame to point out that one side is getting money from oil therefore they are bad - but when my side gets the same money from oil it is OK. Or when GE or George Sorros donate money to Warming causes that can be ignored - but OMG the Koch brothers gave money to the other side ...

    No conspiracy here - just facts.

  26. LarryGross:

    yes.. this kind of thing happens in govt, industry and academia.

    does it mean an entire field is corrupt?

    do you think the folks that do Hurricane modelling are falsifying data to get more funding?

    NOAA satellites? falsifying data to get more money?

    cancer research? mapping the genome? tsunami, volcanoes, etc?

    it's just loony Marque2... this kind of thing DOES happen IN ALL FIELDS - but does it happen all the time in one field?

    this is sound bite logic guy.

  27. LarryGross:

    no Margue2 - in order for your narrative to hold together - there has to be a global conspiracy because you claim that all of them are "in on it".

    I don't doubt for a minute that some scientists are getting money on less than honorable intentions - on both sides but for you to say that ALL of them are - around the world - in every case - then you are into tin foil hat territory.

  28. marque2:

    Yes, I believe there is much more corruption than most people thing. Some outfit did a survey of published studies and found about 1/3 were falsified. There is a lot of pressure to get the right results, from funding agencies, to just personal pride. Science has ceased to be done just for the joy of science.

    As for the Hurricane folks. Well there are so few hurricanes for them to study, I understand how they do not have a complete data set yet.

    And NOAA satellites, the data has been falsified more money - you are correct. Cancer research - the study stuff where they do statistical surveys is almost all fraudulent and designed to get headlines for some evangelist group, or at least poorly done.

    Got to tell you if you really look into it, only those who are doing applied sciences - those that would get in trouble if the job isn't done right, are actually doing credible work any more.

  29. marque2:

    What global conspiracy. I hear often from left wing types that some study they don't like was funded by evil corporations. Lots of studies with left wing and right wing potential are funded with corporate money, and I would guess it goes more to the left.

    So for Gil to post - that the funding is from corporations is silly. And for you to defend him, because I know are a smart guy and know corporations fund everyone, is downright asinine.

  30. LarryGross:

    1/3 of all studies are falsified? In whose world? That's just plain ignorant.
    hurricanes, tsunamis, storms, there are none in the world to study ? what kind of foolishness is that?

    NOAA is falsifying data to get more satellites? good god man.

    how about the GPS satellites? they're falsifying also?

    and the guys studying asteroids and volcanoes also?

    good god.

    this is totally lame, anti-science - on a global conspiracy basis.. totally loony.

    Scientists are human as are engineers and applied science. there are screw-ups in every science... and bad actors - but to accuse science in general - on a global conspiracy basis is just loony as hell.

  31. LarryGross:

    the global conspiracy that you say exists in climate science. don't you think that most scientists around the world doing climate research are involved in a conspiracy to lie to people about the climate and that's why there is "consensus"?

    don't let me put words in your mouth - you tell me - but at least be honest enough to admit what you do think.

  32. Gil:

    Or should that read "yes the deniers must be well-funded (it's not as thought they can be expected to work for free) so they can easily defeat the evil conspirators from destroying modern society"? Or "both sides are funded but one clearly evil so the fact deniers get funded is okay"? Or. best of all, "climate scientists are funded by taxes (i.e. extortion) whereas deniers are funded by private interests (i.e. voluntary payments) so they're clearly moral in their income"?


  33. Gil:

    Actually, no Libertarians do believe in conspiracies in pretty much all parts of government. E.g.: public schools are there to create drones, hospitals and medical research centres are there to create disease and disorders then create medicines to "cure" what they created, government create wars to secure more funding, government find more "poor" people to get more funding for welfare, etc.

  34. Gil:

    BTW: you definitely would have to cite such talk without linking to some ho-hum denier site. Deniers complain about future computer model gone wrong yet ignore the past data is factual and is graphed and continues to ongoing warming (esp. since 1998) and at the end of the 20th century temperatures are far warmer than the 19th century.

  35. OrphanIsland:

    You should ask for a grant or something M8! , how big will the polar caps get ? 110% 120% ?

  36. skhpcola:

    Trying to have a rational discussion with retards that would like to appear competent and unbiased, while they sling denigrations such as "deniers," is pointless. These people worship the idea of global warming and gobble up the dogma of the cult.

  37. skhpcola:

    "just this one particular field of science that about 95% of scientists have arrived at consensus at"

    Bullshit, like 95% of everything you write and think that you know. Do some research (if you are capable of such) on the claim of consensus, look at who those grifters are and what their qualifications are, and--if you are at all rational and honest--you will understand that your stance is entirely built on bullshit...just like it always is.

  38. LarryGross:

    people who "explain" things in terms of global conspiracies have their own issues though....

  39. marque2:

    I was just talking about funding sources, you are changing the subject, and the topic, to avoid the issues.

  40. LarryGross:

    you don't really know much about funding sources guy. You're assuming much of it, but when you say that one side or the other - is seeking funding sources on a global basis for bad purposes - you are talking about a conspiracy - and the funding premise is secondary - even if you actually had a list of particulars - which you do not have.

    it's what you suspect - in terms of funding sources and "conspiracy" and it's with respect to one specific area of science. For instance, you do not accuse the folks who model hurricanes and tsunamis of such global conspiratorial behavior or seeking funding for bad reasons, etc...

    why don't you admit this? it's one particular science that you suspect of a global conspiracy on getting funding from govts to further a lie... isn't that what you think?

  41. skhpcola:

    Good point. I assume that you are referring to the "global conspiracy" that thousands of "scientists" (most of which were not credentialed in a discipline that was even tangentially related to climate issues and some of them weren't even scientists) from all over the globe conspired to create a false "consensus" that AGW was real. Is that what you were referring to? Because that is bullshit, too.

  42. LarryGross:

    how come this only happens with Climate Science and not Tsunami or Hurricane science?

  43. skhpcola:

    I'm not in on the conspiracy, so I can't say with any degree of certainty, but I would wager money that I don't have that it is due to the billions of dollars grifted and spent by advocates of the AGW bullshit. Hurricanes and tsunamis are localized events, but the specter of Gaia-murdering AGW effects every living thing, according to Al Gore and the rest of the oxygen thieves that hawk the lies.

  44. LarryGross:

    but if you believe that the reason that 95% of the world scientists agree about GW and know they are wrong but are colluding on a worldwide basis - isn't that a global conspiracy?

    Hurricanes and tsunamis occur on a world wide basis. People who study them do so around the world - AND they get govt funding to do so - around the world.

    Look at this chart of Hurricane Sandy:


    and notice how wrong the models were - and how many models there were - all wrong and each model the product of a likely govt-funded scientist or team of scientists.

    Does this prove that they are corrupt and incompetent and trying to get more money for more modelling? Don't you think the hurricane modeler are also colluding and engaging in scientific quackery?

  45. skhpcola:

    "95% of the world scientists agree about GW"

    The fact that you continue to cite this thoroughly fictitious datum in support of your bullshit opinion demonstrates why 95% of people on the intarwebs consider you a clueless buffoon. Your uninformed and characteristically bullshit opinion on climate change is based on lies and propaganda manufactured to appeal to low-info dumbasses who will gleefully intone it as a mantra to fend off the truth.

  46. marque2:

    Yeah the article about 97% of research published papers turned out to be 0.3% on closer inspection, Turns out the guys just threw out 8000 papers and where a paper said might, or some similar word, they substituted will, or other stronger words to make the number work.

    Everyone has to say "might" or "possibly could", or else they won't get more funding from the PC government apparatchiki.

  47. LarryGross:

    no matter the percentage - you guys say that scientists are colluding on a global basis to foster a fraud on people - right?

    so you are saying there is a global conspiracy no matter the percent, right?

  48. skhpcola:

    Are you saying that there isn't a global conspiracy, in the face of a wealth of corroborating evidence that their nightmare "consensus" has been shown--repeatedly--to be complete bullshit? That their models were one-off bullshit constructs designed to bolster fantastical claims that--again--have been shown to be bullshit?

    And I see that you haven't done your due diligence in verifying the basis of your full-retard position that "95% of sciencey-type ideologues and liars are in consensus on anthropogenic climate change." Seriously, Larry, it is nearly impossible to remain civil with you when you persist in being an absolute assclown and glory in being willfully ignorant of easily found facts. I suspect that's mostly due to selection bias in your choice of reading material, because you do seem to get a charge from nonsense that is obvious to sentient humans, yet becomes a core tenet of your fucktarded religion of leftist doofusness.

  49. marque2:

    Yes, and that has been shown in 2 climategates now, which 1000's of emails proving the point.

    That is why they are making false studies with an appeal to popularity, like this one and the last major one where 97% of scientists believed that global warming was real, until they threw out some 3000+ surveys and of the 78 they chose, the question was do you think the world has warmed in the last 400 years, rather than do you think the world has warmed in the last 400 years due to AGW.

    If the truth is on your side, why all the fake surveys? Why all the hiding and losing of base data? Why all the hiding from FOIA (and the British equ) requests? Why are universities not releasing the data / methodology behind the studies? Why are the computer simulations all secret code?

    It is interesting that the truth is so important that it has to be hidden, manipulated, distorted, etc.

    And I am not talking about the parasites that get grants based on "global warming" to project what will happen to clams should such a thing exist - they are just trying to get money so they have to mention it in their articles.