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How good have climate models been at truly predicting the future?

A new paper from Hausfather and colleagues (incl. me) has just been published with the most comprehensive assessment of climate model projections since the 1970s. Bottom line? Once you correct for small errors in the projected forcings, they did remarkably well.

Climate models are a core part of our understanding of our future climate. They also have been frequently attacked by those dismissive of climate change, who argue that since climate models are inevitably approximations they have no predictive power, or indeed, that they aren’t even scientific.

In an upcoming paper in Geophysical Research Letters, Zeke Hausfather, Henri Drake, Tristan Abbott and I took a look at how well climate models have actually been able to accurately project warming in the years after they were published. This is an extension of the comparisons we have been making on RealClimate for many years, but with a broader scope and a deeper analysis. We gathered all the climate models published between 1970 and the mid-2000s that gave projections of both future warming and future concentrations of CO2 and other climate forcings – from Manabe (1970) and Mitchell (1970) through to CMIP3 in IPCC 2007.

We found that climate models – even those published back in the 1970s – did remarkably well, with 14 out of the 17 projections statistically indistinguishable from what actually occurred.

We evaluated these models both on how well modeled warming compared with observed warming after models were published, and how well the relationship between warming and CO2 (and other climate forcings) in models compares to observations (the implied transient climate response) (see Figure). The second approach is important because even if an old model had gotten all the physics right, the future projected warming would be off if they assumed we would have 450 ppm CO2 in 2020 (which some did!). Future emissions depend on human societal behavior, not physical systems, and we can usefully distinguish evaluation of climate models physics from paths of future concentrations.

Figure 2 from Hausfather et al (2019) showing the comparisons between model predictions and observations for a) the temperature trends (above) and b) the implied Transient Climate Response (TCR) which is the trend divided by the forcing and scaled to an equivalent 2xCO2 forcing.

However, it is not totally obvious how one should correct for the forcing assumptions because of subtle issues related to the different efficacy of different forcings and, of course, the remaining uncertainty in the real value of the actual forcings (driven predominantly by the aerosol component). For forcing projections that were close to linear, this didn’t make that much difference, but for scenarios that weren’t (notably scenario C in Hansen et al (1988)), the correction does not work well.

There are a few other results that stand out, notably the (infamous?) low sensitivity result in Rasool and Schneider (1971), which was mainly due to a lack of stratospheric adjustment and water vapor short wave absorption in their formulation. This was noted by Schneider (1975) and the calculation redone by Schneider and Thompson (1981) which turned out to be far more accurate. On the other hand, only Mitchell (1970) appears to have substantially overestimated the TCR – even while he predicted the temperature rise quite accurately (due to a compensation between a too large sensitivity and an underestimate of the forcings). [Amusing aside, both Manabe’s and Mitchell’s 1970 projections appeared in a special volume on the Global Effects of Environmental Pollution, reporting on an 1968 AAAS workshop and edited by (the now-notorious) S. Fred Singer before he went off the deep end].

It’s worth noting that this comparison includes two kinds of climate model – those published prior to 1988 which are energy balance models of varying complexity, and those published afterwards which are true GCMs and include atmospheric (and eventually, ocean) dynamics. Of the early models, the work of Sawyer (1972) stands out as being the most accurate in terms of both temperature trends and forcings, though this must be considered somewhat fortuitous.

The fact that both classes of climate model did so well in projecting future warming should increase our confidence that current climate models are getting things right for mostly the right reasons. While there are still real uncertainties in future warming associated with climate sensitivity, we can confidently state that the rate of surface warming we are experiencing today is pretty much what past climate models projected it would be.

Gosh, maybe we know something about climate after all!

Note: all the data and code for this study are available here.

References

  1. Z. Hausfather, H.F. Drake, T. Abbott, and G.A. Schmidt, "Evaluating the performance of past climate model projections", Geophysical Research Letters, 2019. http://dx.doi.org/10.1029/2019GL085378
  2. S.I. Rasool, and S.H. Schneider, "Atmospheric Carbon Dioxide and Aerosols: Effects of Large Increases on Global Climate", Science, vol. 173, pp. 138-141, 1971. http://dx.doi.org/10.1126/science.173.3992.138
  3. S.H. Schneider, "On the Carbon Dioxide–Climate Confusion", Journal of the Atmospheric Sciences, vol. 32, pp. 2060-2066, 1975. http://dx.doi.org/10.1175/1520-0469(1975)032<2060:OTCDC>2.0.CO;2
  4. S.H. Schneider, and S.L. Thompson, "Atmospheric CO2and climate: Importance of the transient response", Journal of Geophysical Research, vol. 86, pp. 3135, 1981. http://dx.doi.org/10.1029/JC086iC04p03135
  5. "Global Effects of Environmental Pollution", 1970. http://dx.doi.org/10.1007/978-94-010-3290-2
  6. J.S. SAWYER, "Man-made Carbon Dioxide and the “Greenhouse” Effect", Nature, vol. 239, pp. 23-26, 1972. http://dx.doi.org/10.1038/239023a0

197 Responses to “How good have climate models been at truly predicting the future?”

  1. 101
    Russell says:

    BPL:
    ” I couldn’t care less what either you or Carl Sagan had to say in Foreign Affairs. I care what TTAPS, and Schneider and Thompson, and Robock et al., etc. had to say in peer-reviewed science journals. Do you understand the distinction I’m drawing here? For you, this thing is inextricably bound up in politics. For me, it’s a science issue.”

    Holy climateball. Barton, if ” it’s a science issue ” why are you ignoring both the results reported above in the Journal of Geophysical Research, and what I had to say in Nature ?

    The hallmarks of science by press conference include self-publication and putting P-R before peer review. As the Science Editor of that not very learned journal Parade, Sagan published his conclusions there, and, notoriously, hired Porter-Novelli to spearhead the nuclear winter advertising campaign before TTAPS was accepted for publication by Science .

  2. 102
    Al Bundy says:

    David Young: Now on the science, it is indeed possible to make incremental progress.

    AB: Seems to me that science is way boring lots-of-nothing punctuated with Eureka!s. For the vast majority of humans Eureka! levels of creativity are unachievable even though orders of magnitude more of them find it fascinating. Sucks to not be born a super-model. Sucks to not be born rich-as-sin. Sucks to not have the sort of sentience required to play in the field. And it is just plain rude to insist that those who are playing productively to for-the-millionth-time fail to enlighten a (relative to them) moron. (And yes, I did just call you a rude sub-genius)
    ________________________

    Paul Pukite: It would be nice if you would actually show some real work instead of just yapping about your experiences with testing airplane wings.

    AB: Dude, he’s winging it!
    ________

    They usually get right those outputs used in tuning like TOA radiation balance. Things like regional climate they get wrong.

    AB: The way these things work is that science drills down while you scream bloody murder in an attempt to ensure that further drilling is minimized because infinite drilling hasn’t been achieved yet.

    Science has drilled down far enough to conclude, “We’re effed”. As to which subset of us is effed in what specific way, please stop trying your bestest to prevent the answer.
    ___________________

    J Doug Swallow: This is your chance, Jim Eager, to show me your work.

    AB: LOLOLOL. You think you’re important??? Sure, you are in your self and in any loved-ones you may or may not have, but in the scheme of things why on earth would Jim Eager waste his time trying the impossible, to educate you?

    Dude, you’ve been tagged “cohort replacement”. By YOURSELF. You want to grow a brain? Grow a brain.

  3. 103

    #83

    Your attempts to move the goalposts are noted, as is your false insinuation that only quantitative predictions are useful. If the predictions list in #73 were so obvious, then contrarians like Richard Lindzen, Roy Spencer, John Christy, etc. would not have messed up on them so many times. Hence them screwing up on the sign of water vapor feedback, tropospheric temperature trends, cloud feedback, and so on. Moreover, the predictions are useful for causal attribution, as in the case of vertical temperature patterns (ex: differential trends at surface + troposphere + stratosphere + mesosphere + thermosphere) pointing towards a greenhouse-gas-induced warming pattern, instead of warming from increases in solar output.

    I strongly suggest you read up on some of the published literature on causal attribution of warming, and the long history of false predictions made by contrarians, in contrast to the accurate predictions made by climate models. The Pierrehumbert video cited in comment #73 should get you started. It’s ironic that you claim this is “selection bias” and ‘not looking at the bigger’, when you’re the one cherry-picking the smaller domain of examples in contrast to the more numerous predictions cited to you, And you’re the one ignoring the relevant context from causal attribution, false predictions from contrarians vs. accurate model predictions, etc.

    Oh, and @33, frankclimate: do have to courage to actually respond when people rebut your points, instead of cross-referencing on Judith Curry’s blog to avoid criticism:

    https://judithcurry.com/2019/12/16/comment-by-cowtan-jacobs-on-lewis-curry-2018-and-reply-part-1/#comment-905105

  4. 104
    Mal Adapted says:

    David Young:

    #73: A comment with less scientific value is hard to imagine. Most of your points are just yes/no answers, i.e., qualitative. What we really need to know and what models are supposed to tell us are the magnitude of the changes, i.e., quantitative information.

    Snort! A comment with less value to the public policy debate is hard to imagine. I once said I didn’t wish to prosecute Mr. Young on RC. Sadly, enlightened self-interest informs us we can’t afford to indulge denialistic prevarication any longer, and he’s a repeat offender! Lots’o’links below.

    Science is about not fooling ourselves, first and foremost. How does one “David Young” get to decide what climate models are supposed to tell us? He thinks they aren’t useful unless they provide precise predictions of future climate. I think he’s ignoring the overriding reason we talk so much about climate change in the first place: it’s because so much is at stake, for everyone on Earth now living or yet to live! I’m convinced Mr. Young, like his fellow lukewarmers, simply rejects responsibility for the marginal climate-change cost of his carbon-intensive lifestyle, short of legalistic standards of proof.

    Is my claim ad hominem? Not, IMHO, against a self-imagined “skeptic” who has previously exposed his cognitive biases here. Mr. Young’s self-deceiving mindset is further exposed by his scornful dismissal of @AtomsksSanakan’s long list of verified facts, “qualitative” though they may be. Sure, we’d all love to narrow the confidence limits around TCR and ECS further. Nonetheless, we are past acknowledging that the current pace of climate change is 1) unprecedented in human history, 2) anthropogenic, i.e. driven by economics, and 3) already taking a toll on the biosphere and global human society, that is certain to mount with GMST!

    What motives might Mr. Young’s have for fooling himself? He has consistently implied, on RC and elsewhere, that the aggregate cost of AGW is trivial, and only “liberals” care about it. But that cost, in money and tragedy, is already shown to be non-trivial to date, and anyone who’s serious knows it’s open-ended as long as the global economy is powered by transferring gigatons of carbon annually to the atmosphere. Serious people agree, too, that we shouldn’t wait for ever-more-precise predictions of the eventual cumulative cost: “already greater than zero” justifies collective action now, as with a revenue-neutral carbon fee and dividend, to decarbonize our society as quickly as feasible. I’m on a fixed income, and would prefer not to pay for what I’ve been socializing out my private tailpipe all my life either: yet knowing I must start, I’d prefer to start now, at the margins of my household budget, before my household is either* burned up in a record wildfire or washed away by a record flood. Does Mr. Young recognize that AGW raises the risks those will happen to him? Do the precise probabilities matter? Uncertainty is not our friend!

    Mr. Young, during his prolific career in the blogosphere, has also dismissed as a “liberal” preoccupation the documented campaign of investment in public denialism by fossil-fuel capitalists. It’s worth belaboring, in a subsequent comment, obstinate “conservative” efforts to ignore or explain it away. My last for now: here’s Jerry Taylor, a former Libertarian and Vice-President of the Cato Institute, explaining why he changed his mind about global warming. Then he reveals how that made him change his mind about Libertarianism itself: “ideology = motivated cognition”! Let David Young’s cognition be judged by the RC jury.

    * If not (;^D) both simultaneously: “Time to call your insurance agent!”

  5. 105
    David Young says:

    #103. Did you read the Palmer and Stevens paper? If you did you would realize that climate models are not fit for purpose. In my previous comments I outlined why this is very well known based on 60 years of fluid dynamics research. This is your MO. You cite outdated or incorrect papers and ignore what you don’t like. That pattern indicates ignorance of fluid dynamics and numerical PDEs. BTW Frank is vastly more knowledgeable and is pleasant to interact with.

  6. 106
    nigelj says:

    J Doug Swallow @87 says: “Of the two, the sun or CO₂, which do you believe has the most influence on the earth’s climate? ” Its not about what anyone ‘believes’. Its about what the scientific evidence says, namely that CO2 is a huge factor in our climate.

    Plenty of small quantities and small changes in small quantities can have much larger effects than we would think, eg semiconductor theory. Do your agree or disagree? Give me a simple answer without arm waving.

  7. 107
    J Doug Swallow says:

    What I wonder about is why Barton Paul Levenson, #88, did not elucidate and explain his claim about Dr. Roy Spencer’s
    “famous failure with the satellite observations”? What would Dr. Roy Spencer’s interpretation of Genesis have to do with his work with satellite observations of the Earth’s temperatures? Please take the time to explain that as well as what follows:
    A remarkable, no holds barred attack was made on Spencer on the website The Daily Climate.  The Daily Climate article contained statements such as this:
    “Over the years, Spencer and Christy developed a reputation for making serial mistakes that other scientists have been forced to uncover.”
    This is not the sort of things that scientists say about each other, at least not in print.   Besides it was a complete lie, because Christy and Spencer are known to be very competent and careful scientists.  More interesting than what was said, is who said it.  Kevin Trenberth was the first author.  The two other authors were John Abraham and Peter Gleick.  All three of these scientists are aggressive defenders of global warming catastrophe theory.
    Let’s take Kevin Trenberth first.  By general acclaim, Trenberth is one of the smartest climate scientists alive.  Trenberth is a Distinguished Senior Scientist at the National Center for Atmospheric Research in Boulder, Colorado.  Ironically, Trenberth is a strong critic of climate models, for example here and here, yet he defends the alarmist predictions that are rooted in climate models.
    […]
    The lie the scientist believers in global warming are living is that the climate models reliably mimic the Earth’s climate and are suitable for predicting the future. Roy Spencer has developed a theory to compute climate sensitivity, using real data, data that does not invoke the monster climate models. His theories may or may not stand the test of time, but the climate establishment should stop acting like a science mafia protecting its turf. New ideas should be allowed to circulate freely, not be strangled at birth.

  8. 108
    J Doug Swallow says:

    #96 dhogaza says:
    16 Dec 2019 at 10:54 PM
    “Regarding the fact that CO2 is a tiny percentage of the atmosphere, go drop 300 micrograms of LSD – an extremely small percentage of your body weight – and report back regarding the inability of “trace amounts” of something not able to cause very noticeable effects …” This really makes one wonder why someone would not be able to understand the huge difference between the confines of the human body and the vastness of the Earth’s atmosphere and then try to make a comparison between the two. I wonder if dhogaza realizes that in addition to Carbon dioxide being such a minuscule part of the Earth’s atmosphere that it is also 1.6 times more dense than the rest of the Earth’s atmosphere Earth’s atmosphere . This that occurred in August 1986 at Lake Nyos proves that point that Carbon dioxide sinks when emitted into the Earth’s atmosphere.

    “On August 21, 1986, a small explosion occurred in Lake Nyos followed in the evening by an intermittent jet of water topped by a white plume. At 10 p.m. a major detonation occurred in the lake and carbon dioxide invaded the low lying valleys, killing more than 1500 people and 6000 head of cattle.”
    http://adsabs.harvard.edu/abs/1992JVGR…51..171L

  9. 109
    J Doug Swallow says:

    I hope that all of you who are trying to defame Roy W. Spencer, Ph. D. & Dr. John R. Christy realize that the two have better credentials to back up their views with than do a few alarmist who have little idea about what makes the Earth’s climate change and for the uninformed, it is always changing as the Younger Dryas demonstrated.
    Biography
    Dr. John R. Christy is the Distinguished Professor of Atmospheric Science and Director of the Earth System Science Center at The University of Alabama in Huntsville where he began studying global climate issues in 1987. Since November 2000 he has been Alabama’s State Climatologist. In 1989 Dr. Roy W. Spencer (then a NASA/Marshall scientist and now a Principle Research Scientist at UAH) and Christy developed a global temperature data set from microwave data observed from satellites beginning in 1979. For this achievement, the Spencer-Christy team was awarded NASA’s Medal for Exceptional Scientific Achievement in 1991. In 1996, they were selected to receive a Special Award by the American Meteorological Society “for developing a global, precise record of earth’s temperature from operational polar-orbiting satellites, fundamentally advancing our ability to monitor climate.” In January 2002 Christy was inducted as a Fellow of the American Meteorological Society.
    Education
    • Ph.D., Atmospheric Science, University of Illinois, 1987

    Roy W. Spencer received his Ph.D. in meteorology at the University of Wisconsin-Madison in 1981. Before becoming a Principal Research Scientist at the University of Alabama in Huntsville in 2001, he was a Senior Scientist for Climate Studies at NASA’s Marshall Space Flight Center, where he and Dr. John Christy received NASA’s Exceptional Scientific Achievement Medal for their global temperature monitoring work with satellites. Dr. Spencer’s work with NASA continues as the U.S. Science Team leader for the Advanced Microwave Scanning Radiometer flying on NASA’s Aqua satellite. He has provided congressional testimony several times on the subject of global warming.

    Dr. Spencer’s research has been entirely supported by U.S. government agencies: NASA, NOAA, and DOE. He has never been asked by any oil company to perform any kind of service. Not even Exxon-Mobil.

    “Along with the drastic temperature drop, one of the major features of the Younger Dryas is a massive die-off: 35 mammals (mastodons, giant beavers, saber-toothed cats, giant sloths, woolly rhinoceroses, etc) and 19 genus of birds became extinct in a very short time period. 
     
    Discovery sites of Clovis fluted points
    Hibben estimates that as many as 40,000,000 animals died in North America alone. In total, hundreds of millions of mammoths were killed. Remains were found all across Northern Russia from the Urals to the Bering Strait and even on the American continent (Alaska and Yukon). Only two small pockets of mammoths remained: St. Paul Island until 5,600 years ago and Wrangel Island until 4,000 years ago. 
     
    Human populations were already quite widespread at the time (Yurok, Hopies, Kato, Arawaks, Toltecs, Incas…), and at least one of them, the Clovis people who inhabited Northern America, was erased from the face of Earth during this period of turmoil. 
    The Clovis people were not a small localized tribe; their implantation sites cover most of Northern America, as indicated by the geographic range of their artifacts, particularly fluted points (see map on the right).” 
    https://www.sott.net/article/357709-Of-Flash-Frozen-Mammoths-and-Cosmic-Catastrophes

  10. 110
    J Doug Swallow says:

    “Earlier this week, University of Alabama in Huntsville (UAH) atmospheric scientist John Christy testified at a House Science Committee hearing on the Paris climate treaty. Christy’s testimony covers several important topics including the “low effectiveness” of surface temperature records for detecting anthropogenic global warming, the “curious” procedure NOAA scientist Tom Karl used in his “pause-busting” adjustment of sea-surface temperatures, the “tiny” impact the Paris Agreement is likely to have on global temperatures, and the insufficient empirical basis for claims that climate conditions are worsening.
    Today’s post focuses on Christy’s rebuttal of a Yale Climate Connections video designed to discredit satellite data as a reality check on the models used by the UN Intergovernmental Panel on Climate Change (IPCC) to forecast global warming and the associated climate impacts.”
    http://www.globalwarming.org/2016/02/05/satellites-and-global-warming-dr-christy-sets-the-record-straight/

    It will be interesting to see when the last time that Atomsk’s Sanakan, Al Bundy, Barton Paul Levenson or Kevin McKinney were requested to appear before Congress to give their views on any subject, let alone anything to do with the Earth and its climate.

  11. 111

    R 101: The hallmarks of science by press conference include self-publication and putting P-R before peer review. As the Science Editor of that not very learned journal Parade, Sagan published his conclusions there, and, notoriously, hired Porter-Novelli to spearhead the nuclear winter advertising campaign before TTAPS was accepted for publication by Science .

    BPL: But it passed peer review, didn’t it? This is what I mean by saying for you, the issue is inextricably bound up with politics. Sure, Sagan used the results to push his political views. That’s completely irrelevant to whether the results were valid or not. In fact, it’s an ad hominem argument, and you can’t seem to stay away from those. MY point is, nuclear winter studies use an adequate plume height algorithm, and something is wrong with the nuclear autumn studies because they inevitably find a plume height three times lower, which is similar to the unit error I found at EIA in 1982.

  12. 112
    J Doug Swallow says:

    # 88 Barton Paul Levenson says:
    16 Dec 2019 at 7:16 AM
    “JDS 77 lauds Roy Spencer to the skies, apparently unaware of his famous failure with the satellite observations. I wonder if he also agrees with Spencer’s creationism?”
    Why would his religious believes be of any interest to you?
    Fox News Channel apparently invited Mann to appear on the air and debate climate scientist Roy Spencer on the topic of global warming. Roy Spencer, a principal research scientist at the University of Alabama in Huntsville, is one of the most knowledgeable climate scientists in the world. He has been a Senior Scientist for Climate Studies at NASA’s Marshall Space Flight Center, receiving NASA’s Exceptional Scientific Achievement Medal for his global temperature monitoring work with satellites. Spencer currently holds the position of U.S. Science Team leader for the Advanced Microwave Scanning Radiometer flying on NASA’s Aqua satellite. He is frequently invited to testify before Congress and in state legislatures regarding climate science.
    Spencer’s scientific research leads him to be skeptical of the assertion that humans are causing a global warming crisis. He is also well-known among climate scientists for being an evangelical Christian.
    Mann declined Fox News Channel’s invitation to debate Spencer. Not content to be a gracious invitee, Mann took to his Twitter account to pour out venom at Fox News Channel, Roy Spencer, and Spencer’s religious beliefs. “No, @FoxNews, I’m not interested in ‘debating’ #climatechange and #evolution denier Roy Spencer on your ‘news’ network,” wrote Mann.

    When was the last time that you was invited to testify before Congress and in state legislatures regarding climate science, Barton Paul Levenson?

  13. 113
    tamino says:

    Re: #112 (J Doug Swallow)

    Apparently you are offended by Mike Mann’s characterization of Roy Spencer as a “climate change and evolution denier.” Clearly, you regard those as insults (you even refer to “venom”).

    Roy Spencer IS a climate change denier and evolution denier.

    Why is it that you regard the *truth* about Roy Spencer to be such an insult?

  14. 114
    Dan says:

    re: 112
    Go to the top of the page and do a search on “Roy Spencer” and you will see that he is a pure manipulator of data for his denier agenda. Hopefully you will learn something but that is doubtful since you are not a skeptic of someone who fits your agenda and it would require you to admit to being wrong.
    Here is one of just many examples:
    https://www.google.com/url?client=internal-element-cse&cx=009744842749537478185:hwbuiarvsbo&q=http://www.realclimate.org/index.php/archives/2008/05/how-to-cook-a-graph-in-three-easy-lessons/&sa=U&ved=2ahUKEwjbo8X9rMTmAhXGct8KHQxMBr4QFjAAegQIARAC&usg=AOvVaw1i419yfggaNXMM_nMd83KO

  15. 115
    David Young says:

    This thread is starting to degenerate into the wilderness of the political smear.

    Spencer is not a denier. He frequently defends the greenhouse effect on his blog. Tamino is just lying about this. Spencer thinks ECS is on the low end. He has some good arguments for this.

    Mal Adapted long screed is full llikewise of lies about me. It’s a classical rant by an angry immature supposed adult with vastly too much time on their hands.

    None of these comments address science in any way.

  16. 116

    JDS, multiple posts–

    I see the “1,000 year drought” meme has been dropped; even nicer would be acknowledgement that JDS had gotten the point (if that’s what actually happened.)

    Still a lot of irrelevant detail being thrown around–the Clovis people relate to anything we’ve been talking about how, exactly?–and the new obsession is Roy Spencer. Look, he’s moderately good at remote sensing–I say ‘moderately good’ because although UAH ‘works’, it’s very noticeably the outlier among climate data sets (suggesting it’s likely less accurate than its alternates), and because it is true that there is a history in the literature of UAH error–but so far he has yet to come up with anything that’s advanced the field appreciably. Dr. Mann, on the other hand, has had a major influence on the development of paleoclimatology. One could cite the credentials, but all that is easily searched by anyone.

    Anyone interested in learning, that is.

    JDS does offer up amusement, at least, when he sneers about the likelihood of his interlocuters being invited to testify to Congress. Dude, compare apples with apples! There are several folks interacting with you who do in fact have published papers to their credit–not me, in the spirit of full disclosure! So I’d guess they’d be well ahead of you in any hypothetical line to testify. At least they know what “1,000-year drought” means–“semantics” and all.

    (Though, on second thought, the denialati do have a pretty thin bench, and pretty low standards…)

  17. 117
    Mal Adapted says:

    tamino:

    Roy Spencer IS a climate change denier and evolution denier.

    Yep. I’d call Spencer’s own testimony unimpeachable: straight from the horse’s, uh, mouth, as it were. Regarding climate change:

    Well, first of all, I’m of the strong, professional opinion that most of the warming is due to nature rather than mankind. I don’t see how mankind can’t have some influence. I mean, after all, the presence of trees on the planet changes the climate compared to if the trees were not there. It would probably be hard for the climate and the earth to not know that 6 billion people live here.

    His strong, professional opinion, OK. Well, perhaps he can be taught. Now for his views on “evolutionism”:

    Twenty years ago, as a PhD scientist, I intensely studied the evolution versus intelligent design controversy for about two years. And finally, despite my previous acceptance of evolutionary theory as “fact,” I came to the realization that intelligent design, as a theory of origins, is no more religious, and no less scientific, than evolutionism.

    Having pursued my own childhood fascination with “natural history” to a doctoral program in Ecology and Evolution before finding an easier way to make a living, I can scarcely imagine a clearer repudiation of the first principle of science by a trained scientist than Spencer’s. The first principle is that you must not fool yourself—and you are the easiest person to fool. Science’s long-term success rests on intersubjective verification, i.e. “peer review” in the broad scope, precisely because it’s a way of trying really hard not to fool yourself. For it to work, you have to be trying! Sadly, Spencer’s petulant insistence that he’s right and the overwhelming consensus of specialists is wrong about both AGW and Evolution, Occam’s Razor be damned, makes it plain he prefers fooling himself.

  18. 118
    nigelj says:

    J Doug Swallow @109, the following list is just some of the climate misinformation and errors propagated by Roy Spencer, with supporting evidence. You will probbaly deny it and you are probably paid to have your head in the sand, but others may be interested.

    https://skepticalscience.com/skeptic_Roy_Spencer.htm

    Oh and vast volumes of CO2 are detected high up in the atmosphere, so why could that possibly be? Try using your brain, or cracking open a textbook or something.

  19. 119
    Ray Ladbury says:

    J. Doug Swallow,
    There is no need to denigrate the expertise or integrity of Spencer, Christy or any other scientist. Likewise, there is little to be gained from citing all the awards they’ve received (gummint agencies dispense awards like candy precisely because they can’t pay at rates competitive with the private sector–I can show you a drawerful). The quality of the work they have done speaks for itself.

    Unfortunately, of late, the UAH product seems to have been having some significant issues. It is a clear outlier when it comes to representing lower tropospheric temperatures. They disagree not just with the terrestrial temperature models, but also with the RSS product and perhaps more damning, with the balloon direct measurements of temperature. That doesn’t mean that the scientists involved are idiots or that they are purposely sandbagging the data to avoid showing the warming. The task of inferring lower atmospheric temperatures from satellite-based microwave measurements is a difficult one. However, one would think they would be more motivated to fix the clear biases in the product they provide.

    Ultimately, the criteria by which one judges a scientist have more to do with the clarity they bring to their subject matter. By these criteria, Spencer, Christy and the other scientists still in denial have shed little light and generated much heat. Worse, the statements made to nonscientists distort the science.

    Earth’s climate is indeed complex. There are many things we do not know and many other things we glimpse only dimly. There are aspects of the subject, however, that we know with near certainty, and the role of greenhouse gasses are in this last category. Climate science–and the conclusion that increasing greenhouse gasses poses a significant threat to future wellbeing of civilization–is on quite firm ground.

  20. 120
    zebra says:

    I am constantly amazed at how easily very smart people are manipulated by very stupid people like JDS.

    Folks, you are responding as if this person gives a crap about whether his statements meet any standard of logic or fact.

    He doesn’t.

    But you can’t resist providing him with the validation he seeks, instead of using the opportunity to educate anyone reading here about how science and reason actually work.

    It’s warrants, all the way up… but you have to be willing to enforce that.

  21. 121

    JDS 107: it was a complete lie

    BPL: No, it was not. Spencer and Christy repeatedly made mistakes that had to be uncovered by others in peer-reviewed articles, and then took up to a year to acknowledge that they’d made mistakes. That’s the fact, Jack. Deal with it.

  22. 122

    JDS 108: Carbon dioxide sinks when emitted into the Earth’s atmosphere.

    BPL: Briefly. Then it gets mixed with the atmosphere by turbulence, which is why it’s considered a “well-mixed gas.” Otherwise we’d all suffocate, all the time. Do the math.

  23. 123

    JDS 110: It will be interesting to see when the last time that Atomsk’s Sanakan, Al Bundy, Barton Paul Levenson or Kevin McKinney were requested to appear before Congress to give their views on any subject, let alone anything to do with the Earth and its climate.

    BPL: It will be interesting to see when you learn the difference between politics and science. But I don’t expect that to happen any time soon.

  24. 124

    JDS 112: Why would his religious believes be of any interest to you?

    BPL: You really don’t see the connection?

    Then I’ll spell it out for you. Roy Spencer is a man who can’t untangle his ideology from his science. He lets the former determine the latter, and therefore his science is unreliable.

  25. 125
    jb says:

    Douggie Swallow at 108:

    “I wonder if dhogaza realizes that in addition to Carbon dioxide being such a minuscule part of the Earth’s atmosphere that it is also 1.6 times more dense than the rest of the Earth’s atmosphere Earth’s atmosphere . This that occurred in August 1986 at Lake Nyos proves that point that Carbon dioxide sinks when emitted into the Earth’s atmosphere.”

    Hmmm. This is very interesting, especially in light of the fact that the measured CO2 profile shows that CO2 concentration does not vary much with altitude.

    https://www.atmos-chem-phys.net/11/2455/2011/acp-11-2455-2011.pdf

    I mean, wow, if CO2 is constantly sinking, that means that upper altitudes should be CO2 depleted in relation to lower altitudes – yet measurements contradict this. How can this be? I see many research opportunities for you, Douggie. Might I suggest a few avenues you might choose for your research:

    1. Perhaps there is some source of CO2 way up in the atmosphere that creates new CO2 to replace the sunken stuff. Of course, there would have to be some mechanism at the bottom that takes the sunken stuff out of the atmosphere, otherwise we would all suffocate (as BPL so wisely points out.) These things should be fun to search for.

    2. Maybe there is a “CO2 elevator” that takes the sunken CO2 and raises it to a high elevation where it can commence to sink once again. Not only would this be an exciting thing to search for, it would give you the the opportunity for world travel – Holy Grail style.

    3. Since you don’t seem to be averse to creationist style explanations, maybe the sunken CO2 is willed back into the upper atmosphere by some unseen power (we’ll call that a “Skyhook” mechanism.) It’s been pointed out that these types of things are hard to find, but that’s what makes it a worthwhile effort. And since you seem to have plenty of time on your hands …

    Now, why don’t you get to work with your research and stop polluting this blogspace.

  26. 126
    Al Bundy says:

    Mal Adapted: Let David Young’s cognition be judged by the RC jury.

    AB: GUILTY! But only because of Mal’s legalistic skills. Thus, I blame Mal for the verdict.
    _______

    J Doug Swallow: “Of the two, the sun or CO₂, which do you believe has the most influence on the earth’s climate?

    AB: The sun. Hands down. Now ask a relevant question: Of the two, the changes in the sun or changes in CO2, which do you believe has to most influence on the Earth’s climate?

    Obviously, since the sun is amazingly stable and CO2 is seriously unstable, especially in the Anthropocene. DUH changes in CO2 are orders of magnitude more important than changes in the sun.
    ______

    Kevin McKinney: JDS, multiple posts–

    I see the “1,000 year drought” meme has been dropped; even nicer would be acknowledgement that JDS had gotten the point (if that’s what actually happened.)

    AB: Geez, dude. Stop asking folks to betray their core. JDS is “PROUD TO BE STUPID” (hat tip to tamino since he showed up) and you expect him to admit learning something??

    Kevin M: (Though, on second thought, the denialati do have a pretty thin bench, and pretty low standards…)

    AB: Bull. They have NO standards. When is the last time you’ve heard ANY of the denialati say that ANYTHING anti-AGW isn’t Gospel regardless of how brain-dead?

    There you go, JDS, give us an example of where you have rejected a totally brain-dead denialist trope.

    Eh, I’m just feeding the machine. JDS is of sub-normal IQ and gets off on rattling smart folks cuz smart folks have many or all of the same flaws as dumba**es like JDS, which makes JDS feel better about flunking third grade, sixth grade, and tenth grade. How do we fix this, guys?

  27. 127

    DY 115: Spencer is not a denier. He frequently defends the greenhouse effect on his blog.

    BPL: You don’t understand the difference between the greenhouse effect and global warming, do you?

    DY: Tamino is just lying about this.

    BPL: I have never known Tamino to lie in his blog posts. He is considerably more honest than you are.

  28. 128
    Ray Ladbury says:

    David Young, actually, if you bothered to read the couple of sentences Tamino wrote, he said Roy is a climate-change denier, not a greenhouse effect denier. The only way he could have been more specific is if he had specified anthropogenic climate change. He has zero evidence to support his position that most of the change is naturally driven. Zero. And he must deny a great deal of evidence to maintain the position that it is naturally driven. So, I think the climate-change denier shoe fits as if it were made by a cobbler.

    And his position suggesting that “intelligent design” is just as scientific as evolution betrays a profound misunderstanding of what science is and how it works.

    So, I think you owe Tamino an apology.

  29. 129
    David Young says:

    #128, You are furthering the lie. Spencer is not a climate-change denier either. He knows the world has gotten about 1 degree C warmer and says so. You cite nothing to back up your smear. He and Judith Curry just think that internal variability is an under appreciated component of the climate system. There is nothing wrong with that except in your fever swamp of false political smears.

    BTW, the Skeptical [sic] Science piece on Spencer is the worst kind of partisan quote mining. The snippets are not specific enough to anyone anything.

  30. 130
    Mal Adapted says:

    David Young:

    Mal Adapted long screed is full llikewise of lies about me. It’s a classical rant by an angry immature supposed adult with vastly too much time on their hands.

    What lies, David? Please set us straight on the details of your explicit warrant in this thread!

    I’ve got at least as much time on my hands as you do, David. Lash out as defensively as you please, in front of all of us. I certainly can’t stop you, that’s up to the moderators. But do you not expect to be challenged? Do you think we’d allow your motivated nonsense to pass without contradiction? Science, shmience: your implied warrant here is to cast doubt on the peer consensus by manufacturing controversy where none exists. Sorry, but that’s socially unacceptable among the reality-based. And all you have to do to keep me quiet is to stop doing it.

  31. 131
    Ray Ladbury says:

    Measurements show that CO2 is well mixed in the atmosphere. Yet, JDS implies that because CO2 is 1.6x as dense as the predominant constituent, it must sink. From this, can we infer that Mr. Swallows resides in the “sunken place?” I think we can. Somebody startle him quick,and maybe we can get through.

  32. 132
    Mal Adapted says:

    Ray Ladbury:

    David Young, actually, if you bothered to read the couple of sentences Tamino wrote, he said Roy is a climate-change denier, not a greenhouse effect denier. The only way he could have been more specific is if he had specified anthropogenic climate change. He has zero evidence to support his position that most of the change is naturally driven. Zero.

    Spencer has literally signed his name to that position and cdesign proponentsism both:

    WHAT WE BELIEVE

    We believe Earth and its ecosystems—created by God’s intelligent design and infinite power and sustained by His faithful providence —are robust, resilient, self-regulating, and self-correcting, admirably suited for human flourishing, and displaying His glory. Earth’s climate system is no exception. Recent global warming is one of many natural cycles of warming and cooling in geologic history.

    WHAT WE DENY

    We deny that Earth and its ecosystems are the fragile and unstable products of chance, and particularly that Earth’s climate system is vulnerable to dangerous alteration because of minuscule changes in atmospheric chemistry. Recent warming was neither abnormally large nor abnormally rapid. There is no convincing scientific evidence that human contribution to greenhouse gases is causing dangerous global warming.

    Here, we have naked science denial in so many words. Isn’t science fundamentally a struggle against magical thinking? If so, then these people have laid down their weapons and surrendered! Our friend Russell has drolly dubbed them The “Cornball” Alliance 8^D.

  33. 133
    nigelj says:

    Al Bundy @126

    “Eh, I’m just feeding the machine. JDS is of sub-normal IQ and gets off on rattling smart folks cuz smart folks have many or all of the same flaws as dumba**es like JDS, which makes JDS feel better about flunking third grade, sixth grade, and tenth grade. How do we fix this, guys?”

    Good point and not easy to fix, but oddly enough its probably not the main priority. It’s the reasonably smart and deliberately stupid people that dominate the hard core climate denialism. Polling shows this. Roy Spencer would be a good example.

    But how do we fix the deliberate stupidity? Probably no easy answers because its driven by so many different things from vested business interests, religion, dunning kruger, politics and god knows what else.

    I think all we can do is beat them over the head with the facts until they eventually crumble, show them the economic benefits of an energy conversion programme, shame them, ridicule them, try to educate them, do a Zebra on them, it all helps and might convert a couple of the hard core denialist zealots, and more of the climate fence sitters. There is no magic bullet guys.

  34. 134
    J Doug Swallow says:

    This is the Green Party Of Canada’s link that was omitted in the preceding post
    http://www.greenparty.ca/blogs/169/2009-01-03/ppm-co2-altitude-and-mass-co2-atmosphere-8520-metres-beyond-which-there-practic

  35. 135

    DY on Roy Spencer, #115–

    What Barton and especially Ray said. No, Spencer doesn’t deny the greenhouse effect, and in fact does defend it on his blog. But he does deny the urgent need to reform our energy economy in order to mitigate carbon emissions. And he does so in defiance of a *whole* lot of evidence.

  36. 136
    Dan H. says:

    Many posters appear to be dismissing certain scientists, by equating them to some anti-science stand. It matters not if someone is an anti-vaxer, anti-GMOer, or anti-evolutionist. Their scientific work regarding climate change should stand on its own. Similarly, ones religious views are irrelevant also (would you dismiss Einstein’s theories because of his religious views?). It seems these posters are critical of these scientists just because they do not like their results. That is less science, and more politics or religion or what not.

  37. 137

    Dan H 136: Their scientific work regarding climate change should stand on its own.

    BPL: Fine. Roy Spencer’s scientific work had serious flaws that were exposed by subsequent work by others. Ergo…

  38. 138
    Dan says:

    re: 136. “It seems these posters are critical of these scientists just because they do not like their results.” That is a truly made up statement. No one “does not like their results”. That is irrelevant. It is that those scientists fail the scientific method (the cornerstone of science for centuries). Either through peer review or objective data analysis. This has been pointed out time and time again here by the moderators and by commenters. So repeating a debunked meme does not make it any more truthful. Read and learn. Their work on climate change does not pass the essential requirements of basic science. Some do not even pass the basic laws of thermodynamics.

  39. 139
    Ray Ladbury says:

    While I agree that a scientist can believe damn, near anything about religion and still produce decent science, there are myriad examples of a scientist’s religious or philosophical beliefs preventing his or her accepting reality even in the face of overwhelming evidence–viz. evolution.

    Religious belief in an omnipotent or even a very-powerful being can be a particular issue, since one never knows when said being will jam its almighty fingers into the celestial clockwork. So-called Intelligent Design is an example of such a cluster coitus–it ain’t science, but rather a Just-So story.

  40. 140
    David Young says:

    I give Kevin #135 credit for fairly summarizing Spencer’s position. Thank you. Mal Adapted (whose handle skillfully describes his connection to reality), Ladbury, and Barton’s comments add nothing of scientific value and are wrong factually. I’m a little surprised that Real Climate allows purely ad hominem attacks these days.

  41. 141

    #105

    You gave exactly the sort of substance-free response you usually do, along with tone trolling. The Palmer + Stevens paper does nothing to rebut the accurate, model-based predictions I cited to you in #73. For instance, it does nothing to change the fact that models correctly predicted that tropospheric warming would occur (contra John Christy and Roy Spencer), that cloud feedback was positive (contra Richard Lindzen), that there would be a multi-decadal positive water vapor feedback (contra Lindzen, Christy, and Spencer), that there would be a negative lapse rate feedback in the tropics as per tropical tropospheric warming being amplified relative to surface warming (contra Spencer and Christy), etc. You’re simply abusing the Palmer + Stevens paper to wish away decades of accurate predictions from climate models.

    You’ve done this sort of thing before, where your familiarity with climate science boils down to reading blog articles from Nic Lewis + Judith Curry, and only being familiar with a handful of papers they point you towards. That is not how one gets informed on climate science, let alone any other branch of science. Learn how to do a literature review. And no, you don’t get to claim the papers I discuss are “outdated or incorrect papers”, since it’s clear you don’t even read them; you’re willfully uninformed on the published literature, and use vague, evidence-free speeches to obscure that fact. So it’s actually you who “ignore[s] what you don’t like.” It’s not everyone else’s fault that they read the published literature and you don’t.

    For whenever you finally decide to read something Lewis + Curry didn’t feed to you, here’s your assigned reading list on some of the confirmed model-based predictions listed in #73:

    “Industrial-era global ocean heat uptake doubles in recent decades”
    “Observed and simulated full-depth ocean heat-content changes for 1970–2005”
    “Ocean warming: From the surface to the deep in observations and models”
    “How fast are the oceans warming?” [DOI: 10.1126/science.aav7619]
    “The ‘pause’ in global warming in historical context: (II). Comparing models to observations”
    “Assessment of the first consensus prediction on climate change”
    “Assessing temperature pattern projections made in 1989”
    “Evidence for climate change in the satellite cloud record”
    “Cloud feedback mechanisms and their representation in global climate models”

    I know full-well, given your track-record, that you’re not going to read or address any of that research. You’re not trying to actually learn about the models and their track-record; you’re trying to reach your pre-determined, biased conclusion to dismiss them.

  42. 142
    David Young says:

    BTW, Advocating against strong mitigation measures is a position that while unpopular with alarmists, does not imply “denial” of any science. Policy is a matter of values and priorities, not science as Bertrand Russell convincingly argued. So, can we just dispense with the political smears? It’s childish and deeply unjust, especially when it comes from anonymous nonscientists who have little knowledge of either science or policy.

    The other problem with it is that it makes rational policy impossible since that policy generally requires bipartisan support. One would note that Obama was able to accomplish virtually nothing on mitigation. The fracking industry gets credit for most of what little was accomplished. That process has continued under Trump. Natural gas is a logical first mitigation step albeit one that does nothing to feed the virtue signaling activist groups deep ideological delusions.

  43. 143
    zebra says:

    #140 David Young,

    Given Mal Adapted #132, your claim of “ad hominem” is clearly refuted.

    Ad hominem exists when there is no connection between the negative behavior cited and the proposition being examined:

    “Einstein is mean to his wife, so relativity must be wrong.”

    It would be absurd to claim that the opinion of someone who doesn’t accept the (philosophical) rules of science and established foundational theories and observations should carry much weight at all.

    The burden is on that person to provide exceptional justification for their exceptional claims. Where is Spencer’s data on God?

  44. 144
    David Young says:

    #141 strikes a new low even for Real Climate. What the cartoon character “gave” me is qualitative and is acknowledged by Steven and Palmer in their paper to be correctly simulated my simple models. It does not rely in any on GCMs. What the cartoon character is too biased to admit is that climate models are not skillful in either predicting the magnitude of future warming or patterns of changes as Palmer and Stevens say. The obfuscation of the important points with a recitation of largely unimportant qualitative statements is just pseudo-science and polemics of the worst kind. Typical of anonymous cartoon characters.

    “Fig. 1, which is taken from the Fifth Assessment Report of the Intergovernmental Panel on Climate Change (13), illustrates this situation well. It shows that all of the climate models can adequately reproduce the observed change in temperature—part of what we call the blurry outline of climate change. This is something that the Assessment Report draws attention to in its summary for policy makers. What is not discussed in the summary is what is shown by the thin horizontal lines on the edge of Fig. 1. Even after being tuned to match observed irradiance at the top of the atmosphere,† models differ among themselves in their estimates of surface temperature by an amount that is 2 to 3 times as large as the observed warming and larger yet than the estimated 0.5 °C uncertainty in the observations. The deemphasis of this type of information, while helpful for focusing the reader on the settled science, contributes to the impression that, while climate models can never be perfect, they are largely fit for purpose. However, for many key applications that require regional climate model output or for assessing large-scale changes from small-scale processes, we believe that the current generation of models is not fit for purpose.”

    from Palmer and Stevens gives a prefect summary of why the cartoon character’s reasoning is specious and has no scientific validity.

  45. 145
    David Young says:

    Spencer’s scientific positions on his blog do not reflect in toto any quite nonspecific and vague statements he may have signed a long time ago. Just to repeat for the political hacks out there.

    Spencer does not deny any aspect of modern science. He disagrees with activists on policy. He is an evangelical Christian which to many here is apparently enough to make him a fit subject to be pilloried. It’s really a futile exercise. No minds will be changed and nothing will or has changed due to public attempts to smear scientists in obscure comment sections on a blog that attracts quite few comments in general. Some anonymous (and in my view cowardly) non-scientists simply have too much time on their hands. I’m still surprised Real Climate allows it.

  46. 146
    William Jackson says:

    It seems to me people are whistling in the dark with their denialism…while the world goes to hell…figuratively or maybe not so figuratively speaking. As I will soon be seventy I am unlikely to see things really get much worse. I do wish I had some reason to hope!

  47. 147
    nigelj says:

    David Young @142, whats really sickening about your behaviour is the way you complain about peoples ad hominens and political “smears”, while you so frequently indulge in the same things yourself, eg by referring to some “cartoon character” and “virtue signaling activist groups deep ideological delusions.. ”

    The predictions listed at Atomsk’s Sanakans comments include plenty that make numerical predictions contrary to your rants.

    The sum total of your long winded rant is different climate models give different temperature predictions. People know that anyway, and my understanding is its because the impacts of feedbacks are not fully understood.

    Instead of stating the obvious and complaining about it, thus spreading doubt about the whole climate science issue, why not apply your scientific abilities to actually solving the problem? Because otherwise you are arm waving and doing more harm than good.

  48. 148
    nigelj says:

    David Palmer my comment was in reference to yours at both 142 & 144.

  49. 149
    JCH says:

    From this certainty stems the conviction that additional warming is best avoided by reducing or reversing emissions of long-lived greenhouse gases. – Palmer and Stevens 2019.

    The above is, I believe, called doing mitigation. “Or reversing” is doing substantial mitigation. Palmer and Stevens appear to be embracing those actions now.

  50. 150
    JCH says:

    …While we are certainly not claiming that model inadequacies cast doubt on these well-settled issues, we are claiming that, by deemphasizing what our models fail to do, we inadvertently contribute to complacency with the state of modeling. This leaves the scientific consensus on climate change vulnerable to specious arguments that prey on obvious model deficiencies; gives rise to the impression that defending the fidelity of our most comprehensive models is akin to defending the fidelity of the science; and most importantly, fails to communicate the need and importance of doing better. …

    What else can the first bold mean other than they embrace the consensus regardless of what they are saying about climate models in this paper?

    Isn’t the second bold a direct shot at the obvious person?

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