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Green and Armstrong’s scientific forecast

Filed under: — gavin @ 20 July 2007

There is a new critique of IPCC climate projections doing the rounds of the blogosphere from two ‘scientific forecasters’, Kesten Green and Scott Armstrong, who claim that since the IPCC projections are not ‘scientific forecasts’ they must perforce be wrong and that a naive model of no change in future is likely to be more accurate that any IPCC conclusion. This ignores the fact that IPCC projections have already proved themselves better than such a naive model, but their critique is novel enough to be worth a mention.

The authors of this paper actually have a much larger agenda, and that is to improve the quality of forecasting used in public policy and business everywhere – by the use of ‘scientific forecasting principles’ (of which they have enumerated 140). Most of these principles seem commonsensicial (don’t overfit a statistical model, test models on out of sample data etc.) and are listed on one of their many websites. Basically, you just assign a subjective numerical score for reflecting how well you match a particular principle and at the end you get a ‘scientific’ number that says how well you are doing.

Armstrong helped set up a journal dedicated to this goal, as well as running yearly meetings for scientific forecasters. However, in a recent review of progress he notes: “the diffusion of useful forecasting methods has been disappointing”, and that “forecasting meets resistance from academics and practitioners”. This seems surprising – why wouldn’t people want better forecasts?

G+A’s recent foray into climate science might therefore be a good case study for why their principles have not won wide acceptance. In the spirit of their technique, we’ll use a scientific methodology – let’s call it ‘the principles of cross-disciplinary acceptance’ (TM pending). For each principle, we assign a numerical score between -2 and 2, and the average will be our ‘scientific’ conclusion…

Principle 1: When moving into a new field, don’t assume you know everything about it because you read a review and none of the primary literature.

Score: -2
G+A appear to have only read one chapter of the IPCC report (Chap 8), and an un-peer reviewed hatchet job on the Stern report. Not a very good start…

Principle 2: Talk to people who are doing what you are concerned about.

Score: -2
Of the roughly 20 climate modelling groups in the world, and hundreds of associated researchers, G+A appear to have talked to none of them. Strike 2.

Principle 3: Be humble. If something initially doesn’t make sense, it is more likely that you’ve mis-understood than the entire field is wrong.

Score: -2
For instance, G+A appear to think that climate models are not tested on ‘out of sample’ data (they gave that a ‘-2’). On the contrary, the models are used for many situations that they were not tuned for, paleo-climate changes (mid Holocene, last glacial maximum, 8.2 kyr event) being a good example. Similarly, model projections for the future have been matched with actual data – for instance, forecasting the effects of Pinatubo ahead of time, or Hansen’s early projections. The amount of ‘out of sample’ testing is actually huge, but the confusion stems from G+A not being aware of what the ‘sample’ data actually consists of (mainly present day climatology). Another example is that G+A appear to think that GCMs use the history of temperature changes to make their projections since they suggest leaving some of it out as a validation. But this is just not so, as we discussed more thoroughly in a recent thread.

Principle 4: Do not ally yourself with rejectionist rumps with clear political agendas if you want to be taken seriously by the rest of the field.

Score: -2
The principle climatologist that G+A appear to have talked to is Bob ‘global warming stopped in 1998’ Carter, who doesn’t appear to think that the current CO2 rise is even anthropogenic. Not terribly representative…

Principle 5: Submit your paper to a reputable journal whose editors and peer reviewers will help improve your text and point out some of these subtle misconceptions.

Score: -2
Energy and Environment. Need we say more?

Principle 6: You can ignore all the above principles if you are only interested in gaining publicity for a book.

Score: +2
Ah-ha!

In summary, G+A get a rather disappointing (but scientific!) score of -1.66. This probably means that the prospects for a greater acceptance of forecasting principles within the climate community are not good. Kevin Trenberth feels the same way. Which raises the question of whether they are really serious or simply looking for a little public controversy. It may well be that there is something worth learning from the academic discipline of scientific forecasting (though they don’t seem to have come across the concept of physically-based modelling), but this kind of amateur blundering does their cause nothing but harm.

In association with their critique, G+A have also launched a very poorly thought out ‘climate challenge‘ that is essentially a bet on year to year weather noise. No one is likely to take them up on that, and they don’t seem to be interested in the rather better thought through bets on offer from James Annan and Brian Schmidt. Thus again, the conclusion must be that they are not serious about their stated goals. That’s a shame.

Shorter Armstrong and Green: If our publications are not cited, climate sensitivity is zero.

‘Shorter’ concept by Daniel Davies and Elton Beard

149 Responses to “Green and Armstrong’s scientific forecast”

  1. 101
    Vernon says:

    Well, I fail to see the difference between weather forecasting modeling and climate forecasting modeling. Both use physics and high mathematics take current information and project future events. Now Gavin said

    Weather forecasts take today’s situation and calculate how it will evolve over the next few days. They are initial value problems. Climate models do not assimilate current data but instead produce changes in climate as a function of changing boundary conditions, and thus are a boundary value problem – that is not the same as a forecast (which would require an estimate of the ‘weather’ component as well as the climate component).

    However, the climate model takes the current conditions and the physics and adjusted the non-physics based assumptions on a best fit for past records. If there were no assumptions, then I would agree that this is just a model of the physical and there is no questions… put in x, get out y. The problem with your argument is that there are underlining assumptions in the GCM models which are based on the best guess of the underlying reality. Since there is less than complete understanding of all aspects of climate change, then the models have to guess how some of the aspects work, according to the IPCC. This means that the GCM models are doing forecasts. A&G specialize in forecasting, so their taking the IPCC to task for using GCMs for forecasting and not following the forecasting guidelines seems more than reasonable to me.

    [Response: Wrong. The parameterisations that you allude to have nothing to do with improving the fit for past records. For instance, new physics is being added in to convection schemes to allow for lofting of ice particles by convective updrafts. The observations to evaluate this are drawn from field campaigns and satellite observations. The impact of the new physics on how well the models match up to the 20th Century trend is at the point unknown and the decision to incorporate the new physics has nothing to do with that. This is a fundamental difference between statistical modelling and physical modelling which neither you, nor A+G yet appear to grasp. – gavin]

  2. 102
    Michael T says:

    I am curious about a critique of a document pertaining to physics and CO2. Abstract:

    The atmospheric greenhouse effect, an idea that authors trace back to the traditional works of Fourier 1824, Tyndall 1861 and Arrhenius 1896 and is still supported in global climatology essentially describes a fictitious mechanism in which a planetary atmosphere acts as a heat pump driven by an environment that is radiatively interacting with but radiatively equilibrated to the atmospheric system. According to the second law of thermodynamics such a planetary machine can never exist. Nevertheless, in almost all texts of global climatology and in a widespread secondary literature it is taken for granted that such mechanism is real and stands on a firm scientific foundation. In this paper the popular conjecture is analyzed and the underlying physical principles are clarified. By showing that (a) there are no common physical laws between the warming phenomenon in glass houses and the fictitious atmospheric greenhouse effects, (b) there are no calculations to determine an average surface temperature of a planet, (c) the frequently mentioned difference of 33 C is a meaningless number calculated wrongly, (d) the formulas of cavity radiation are used inappropriately, (e) the assumption of a radiative balance is unphysical, (f) thermal conductivity and friction must not be set to zero, the atmospheric greenhouse conjecture is falsified.

    Link: http://icecap.us/images/uploads/Falsification_of_CO2.pdf

    Thank you

  3. 103
    SecularAnimist says:

    Rod B wrote: “There is considerable evidence for intelligent design of the Universe, or at least some omnipotent entity having some say and engineering of the process.”

    It is self-evident that “intelligence” exists in the universe, instantiated in the form of intelligent entities, the paradigmatic example being human beings, along with non-human animals whose intelligence is similar enough to our own that we are able to recognize it as “intelligence”.

    I would argue that there is plenty of evidence that intelligence is pervasive in the universe. It is not at all clear what the role of intelligence in the evolution of the universe is. For example, the overall process of biological evolution might be regarded as an “intelligent” process, through which life adapts to changing conditions by “trying stuff out” (mutation), retaining the stuff that works and discarding what doesn’t work (natural selection). Of course all of this begs the question of exactly what we mean by “intelligence” anyway.

    [edit for off topic]

    [Response: ID is OT. Take it elsewhere. – gavin]

  4. 104
    Vernon says:

    Gavin, so your saying that the models have no assumptions built into them? That they exist and when compared to past records they were correct to begin with and that none of the assumptions have been changed?

    Also I want to understand you correctly..

    The impact of the new physics on how well the models match up to the 20th Century trend is at the point unknown and the decision to incorporate the new physics has nothing to do with that.

    So your going to change your model and whether it actually forecasts the past correctly or represents the current climate does not matter because it will give valid predictions of the future?

    If your model does not predict the past correctly, does not predict the 20th century correctly, then how do you know it predicts the future correctly? Basically, your model puts assumptions in for water (clouds), sulphates, black carbon, orgianic carbon, biomass burning, mineral dust, aviation, land use, solar all which per the IPCC are at the low to the very low level of scientific understanding. If your putting swag into your model, then it is not purely based on scientific understanding and is a forecasting tool.

    Both weather and climate models take what information we have and based on grid, make predictions of the future. If the understanding of all the aspects of climate were actually scientifically understood, then maybe we would not be having these discussions. Since your model is making a forecast the same way a weather model is, then A&G’s assessment of the IPCC making forecast is equally valid.

    [Response: ????? Of course the models have assumptions built in to them. They are precisely a quantitative exploration of what all our assumptions amount to. But – and this is the key point – we don’t alter the assumptions to improve the match to past behaviour. Instead, we alter them based on current observations of important physics and processess. It’s the difference between ‘in sample’ calibration and ‘out of sample’ testing. We will change the model to better reflect known physics, and from past experience, improving the detail of the physics also improves the match to climatology and past climate change. The latter is a consequence of the former, but the former is not driven by the latter. In any case, the models already do a pretty good job for past climates, mainly because they are driven to a large extent by the forcings (which are not part of the model). Those forcing functions are the best we can find and are largely independent of the model development process.

    Finally, climate model projections are only good for a portion of what might happen in the future – the portion that is driven by changes in the forcings. They cannot project the specific path the weather may take and do not take into account the current weather state. Thus they are not the same as weather models. – gavin]

  5. 105
    Richard Ordway says:

    Has anyone thought of using Baysian statistical forecasting methods as an adjunct for indenpendent analysis of future climate change (GW) probabailities of possible GW events and timings?

    I understand that this method was used reasonably successfully in finding a lost hydrogen bomb off Spain in 1966 and the lost Scorpion submarine as well as having other successes.

    There are so many GW data sets out there and long-term research, that I wonder if this method might be useful?

  6. 106
    catman306 says:

    Here’s some apparently new physics that may change some climate models:

    http://www.latimes.com/news/science/la-sci-ozone26jul26,1,7432125.story?ctrack=2&cset=true

    The original is at Nature but I have no subscription.

  7. 107
    Hank Roberts says:

    Richard, a few people have, and written about it. Here are some:
    http://www.google.com/search?q=Bayesian+climate+model

  8. 108
    Chuck Booth says:

    Re # 102 ICECAP website and its alleged refutation of the role of CO2 in global warming

    I haven’t read the article in question, but a quick scan of the site’s mission statement (http://icecap.us/index.php/go/about-us) and its FAQ page (http://icecap.us/index.php/go/faqs-and-myths#4 ), esp. its conclusions about how global warming will affect plants and animals, leads me to be very skeptical of any conclusions drawn. I’m not overly impressed with the credentials of ICECAP’s contributors, either. On the positive side, it isn’t denying the reality of global warming.

  9. 109
    Phillip Shaw says:

    Re #104:

    Vernon,

    Do you know of any weather forecasting models that factor in assumptions about sulphates, black carbon, organic carbon, biomass burning, mineral dust, aviation, land use, and insolation? I doubt it. Do you know of any weather forecasting models that can be used to predict the weather, say, ten years from now. I doubt that, too. As a number of the posts above have explained, weather and climate models are fundamentally different tools.

    It appears that you are being deliberately obtuse, a condition that just reduces your credibility. Nor will it win many converts to your position.

    Regards,
    Phillip

  10. 110
    Timothy Chase says:

    catman306 (#106) wrote:

    Here’s some apparently new physics that may change some climate models:

    http://www.latimes.com/news/science/la-sci-ozone26jul26,1,7432125.story?ctrack=2&cset=true

    Well, as far as I know, the models haven’t taken into account reduced co2 uptake in plants due to heat and drought stress as of yet. We know that it will occur, and recently a study came out which suggests that we may have been hitting it the past few years. But the conclusions were tentative. Then there is the twilight zone of clouds which we discovered I believe within the past year (which I believe will be easy to incorporate), the reduced co2 uptake of the Southern Ocean, the increase in poleward flow due to hurricanes, which becomes more important the more intense they become, etc. But all of this pales, I believe, in comparison with the nonlinear behavior of ice.

    Incidently, I don’t about the twighlight zone, but all of these additional unaccounted for effects are effects working against us – and as such the models are being conservative in their estimates of how bad things will get and overestimating the time that it will take to get there – assuming its steady-ahead.

    PS Reminds me of a time when I was in the Navy on board the USS Jason. Manuevers. We were given several warnings to adjust course by the USS Williamette – to no avail. We had fire in one of the enginerooms for five hours — and much of the crew was afraid that the front end of the ship would fall off before we made it back to port.

    We probably should have adjusted course.

  11. 111
    Hank Roberts says:

    One model has now incorporated the effects of ground level ozone, and that’s the news story

    here:
    http://www.nature.com/nature/journal/vaop/ncurrent/abs/nature06059.html
    This is just the first page, in their usual fashion, but it’s a good summary of what was modeled here.

    NOTE: Look at the sidebar for links to the supplemental online material — you can see that without a paid subscription. Often much of that is very helpful in understanding the article.

  12. 112

    [[The atmospheric greenhouse effect, an idea that authors trace back to the traditional works of Fourier 1824, Tyndall 1861 and Arrhenius 1896 and is still supported in global climatology essentially describes a fictitious mechanism in which a planetary atmosphere acts as a heat pump driven by an environment that is radiatively interacting with but radiatively equilibrated to the atmospheric system. According to the second law of thermodynamics such a planetary machine can never exist. Nevertheless, in almost all texts of global climatology and in a widespread secondary literature it is taken for granted that such mechanism is real and stands on a firm scientific foundation. In this paper the popular conjecture is analyzed and the underlying physical principles are clarified. By showing that (a) there are no common physical laws between the warming phenomenon in glass houses and the fictitious atmospheric greenhouse effects, (b) there are no calculations to determine an average surface temperature of a planet, (c) the frequently mentioned difference of 33 C is a meaningless number calculated wrongly, (d) the formulas of cavity radiation are used inappropriately, (e) the assumption of a radiative balance is unphysical, (f) thermal conductivity and friction must not be set to zero, the atmospheric greenhouse conjecture is falsified.]]

    Where to start? This guy is wrong in so many ways it’s difficult to know where to begin.

    First of all, every atmosphere physicist in the world is aware that most of the atmosphere is not in radiative equilibrium. You can approximate the stratosphere that way, but of course in the troposphere conduction, convection and evaporation of seawater are important thermal transfer mechanisms. The greenhouse effect is often illustrated in introductory textbooks with a radiative equilibrium model because it shows the essentials without going into incredible complexity…

    have to go, more later

  13. 113
    David B. Benson says:

    Re #102: Michael T — Down a bit on the sidebar is a link to the AIP dicovery of Global Warming pages. WHile it is all quite good, in this case I suggest you read the page entitled “The Carbon Dioxide Greenhouse Effect” to counter the rubbish in the abstract you quote.

  14. 114
    Hans Henrik Hansen says:

    Re # 108

    The website itself (and its possible ‘inclination’) appears irrelevant as long as the article is submitted by two German physicists, Gerhard Gerlich and Ralf D. Tscheuschner.
    At the end of their ‘acknowledgement’ they state (p. 94):
    “The authors express their hope that in the schools around the world the fundamentals of physics will be taught correctly and not by using award-winning “Al Gore” movies shocking every straight physicist by confusing absorption/emission with reflection, by confusing the tropopause with the ionosphere, and by confusing microwaves with shortwaves.”

    [Response: I agree, the website’s inclination is immaterial (though indicative), but the paper falls simply because it lousy physics. The planetary albedo is apparently a mystery to the authors, as is the ratio of Earth’s disc to it’s surface area, and they take exception to energy balance diagrams ‘because they do not fit in the Feynman diagrams in quantum field theory”. This is bunkum of a high order. – gavin]

  15. 115

    Okay, continuing with the nut case manifesto. I’ll requote the six points at the end and give them special attention.

    [[(a) there are no common physical laws between the warming phenomenon in glass houses and the fictitious atmospheric greenhouse effects,]]

    Duh. They’ve pretty much known it was a bad analogy for over a century. But because “the greenhouse effect” is a bad name for it in no way proves that the effect doesn’t exist.

    [[ (b) there are no calculations to determine an average surface temperature of a planet, ]]

    Wonder how they did it, then? The original poster doesn’t know much about elementary physics. A temperature can be defined for any material object, and the Earth is certainly a material object. I’d say if you take a large sample of the point temperatures all over that surface, correcting for any relative-area bias, you come as close to the average temperature as you need to come. The figures I’ve seen are 287 K for Hadley and 288 K for the US standard atmosphere.

    [[(c) the frequently mentioned difference of 33 C is a meaningless number calculated wrongly, ]]

    It’s the difference between the surface temperature (288 K) and the equilibrium emission temperature (255 K). The figure is derived by the mathematical technique called “subtraction.” And the figure is certainly meaningful; it’s a rough indication of the magnitude of the greenhouse effect on a given planet with minimal geothermal sources. 505 K for Venus, 33 K for Earth, 4 K for Mars. That pretty much gives the relative strengths of their respective greenhouse effects.

    [[(d) the formulas of cavity radiation are used inappropriately,]]

    You mean actual radiation by gases is in lines and isn’t gray? Does this guy honestly think climatologists don’t know that you can’t apply the blackbody Stefan-Boltzmann law to all objects? Again, you can apply it and be accurate enough in a demonstration of how the greenhouse effect works. Nobody is claiming that that’s the whole story. In short, this point is a straw man argument.

    [[(e) the assumption of a radiative balance is unphysical, ]]

    At the top of the atmosphere it damn well is physical, unless this guy knows some other source and sink of terrestrial energy which roughly match one another. N-rays, perhaps?

    [[(f) thermal conductivity and friction must not be set to zero,]]

    Nor are they in a serious model, but for a simple model to illustrate how the greenhouse effect works, you can ignore them. The average radiative flux received by Earth’s surface is about 170 watts per square meter from Solar energy and 324 watts per square meter from the atmosphere. Conduction and convection between them amount to about 24 watts per square meter. So you’ll get roughly the right answer even if you ignore conduction and convection.

    Does this guy really think “friction” is a serious term in Earth’s thermal energy budget? Does he think the atmosphere lags the surface in rotation time or something? Didn’t Galileo figure this one out?

    [[the atmospheric greenhouse conjecture is falsified.]]

    As long as you don’t actually learn about it.

  16. 116
    Svet says:

    Over at http://www.climateaudit.org/?p=1827, Steve McIntyre says “The only policy that I’ve advocated is one of full, true and complete disclosure of all aspects of climate calculations used in policy arguments. If properly constructed data sets support AGW, so be it“. He then asks “for an article or text that provides…the best articulation of the underlying physics by which increased CO2 leads to approx 2.5 deg C warming. … I don’t want an article that merely reports GCM output.” and says “My interest is in understanding the very best expositions of AGW theory on their own merits, rather than alternative explanations.”

    Gavin, can you point him to a resource that sets out the underlying physics by which increased CO2 leads to approx 2.5 deg C warming without recourse to a GCM? If you cannot then I don’t know who can. What have you got to loose?

    As an interested but non-technical observer, it has long frustrated me that intelligent, well intentioned professionals on either side of the AGW “debate” snipe at each other across the front lines on the assumption that the people on the other side MUST be unintelligent or not well intentioned. The result is typically more noise but no resolution.

  17. 117
    Vernon says:

    RE 109: Well, I am not an expert but per wikipedia:

    The global climate models used for climate projections are very similar in structure to (and often share computer code with) numerical models for weather prediction but are nonetheless logically distinct[.]

    The only real difference is the scale of the grids and the time period. Oh and many weather forecasting models do not model the oceans. The fact is that weather forecasting models and climate models are related. The principle difference is the grid size and the time period. Both have significant aspects that are not know and a ‘best guess’ is used and even though Gavin say not, to get the best guess, I would suspect that the both models were run against past or future data to see if the ‘guessed’ attributes are close.

    If you took the climate model and reduced the grid size and ran it for a week period, I would be surprised that you would not get a result for each grid that could not be used for a weather forecast.

  18. 118
    Rafael Gomez-Sjoberg says:

    Re#102, 112 (ICECAP writeup about refuting the greenhouse “conjecture”)

    I just took a quick look at this “refutation” for the fun of it. At least it looks like the authors know how to use LaTeX properly. The writeup reads like those wacky attempts by amateur pseudo-physicists to “prove” that Einstein’s theory of relativity is wrong by playing around with equations that they don’t fully understand. I actually heard in the radio some time ago about some random guy that, without any formal training in physics, quit his job (and asked his wife to support him) so that he can spend a year refining his anti-relativity “theory”. Suffice to say that the guy doesn’t even understand the basic concepts of momentum and energy. He says that the few physicists he has talked to (one or two very patient university professors), and who have tried to explain why he’s wrong, are just a bunch of snobs that hide behind lots of “unnecessarily complicated math.” And the rest of physicists that refuse to waste time looking at his “theory” are affraid of the truth. Sounds familiar?

    In their greenhouse refutation, the german guys go so far as to have a whole section on Magnetohydrodynamics as the main “physical foundation of climate science”, including citations to some books on astrophysics!!!! Maybe they are talking about the climate on the surface of the Sun.

    The german authors of this writeup should invite the relativity dude to spend his sabatical year with them. I’m sure the three compadres, their minds lubricated by copious amounts of Bavarian beer, will come up with some grand-unification theory. Beware physicists and climate scientists!!! You might end up without a job when these dudes are done with their scientific revolution.

  19. 119
    Timothy Chase says:

    Gavin (inset to #114) wrote:

    … and they take exception to energy balance diagrams “because they do not fit in the Feynman diagrams in quantum field theory”. This is bunkum of a high order.

    Huh.

    I may have to check it out: this sounds histerical…

  20. 120
    James says:

    [Does this guy really think “friction” is a serious term in Earth’s thermal energy budget? Does he think the atmosphere lags the surface…]

    No, no, no. Sheesh, don’t you guys understand basic planetary physics? Haven’t you ever seen a terrestrial globe, with the rod going through the poles for the planet to rotate on? The friction comes from the axle of the planet.

    (Apologies to Terry Pratchett, for the axle idea :-))

  21. 121
    Philippe Chantreau says:

    No matter how much explaining Gavin does, there is a VERY widespread (almost universal in laymen) belief in the denialist camp that GCMs are statistical models, built from and adjusted for the observed temperatures (hence the recent assault on surface stations!). Let them believe it, it shows the quality of their effort to comprehend the big picture. As for the other German dudes rethinking the all atmospheric physics idea, let us salute the restraint of the RC team whence the qualificative of “crackpot” does not fly as liberally as in, say, Lubos’ blog.

  22. 122
    Eric Swanson says:

    Rd: #102, etc and #116

    Take a look at the list of “experts” at icecap.us:

    http://icecap.us/index.php/go/experts

    The list includes almost all of the people that one would label “denialists”. There’s Singer, Michaels, Balinuas, the Idsos, Spencer, Balling, Carter, Sharp, Legates, Jaworowski, Hoyt, De Freitas, both Grays, etc. And, lots of TV weathermen too. That web site might be called the “Not Real Climate” site because of it’s inclusion of many people who have received funding from corporate sources that have an interest in continued burning of fossil fuels. Some have done good science in their day but no longer seem interested in actually doing science, only spreading their own special disinformation as it suites them.

    The article in question is just another in a long series of articles which can be shown to be seriously flawed. But, each one is picked up by the media as proof that there’s no Global Warming, thus, the average person is left with the impression that there is still some debate or, worse, that there’s no problem. In the court of science, they lose, but in the political world, they may win.

  23. 123
    J.C.H says:

    Gavin mention albedo, and since the Germans introduced the crackpot wacko, I’ve been curious about this for months and think of it every time I see albedo:

    What would be the potential impact of requiring worldwide that all new vehicles and new structure/replacement roofing and siding be white? That would roll up to fairly large surface area. Too small to be worthwhile?

  24. 124
    Eli Rabett says:

    JCH, it would significantly cool urban areas.

  25. 125
    Hank Roberts says:

    > albedo

    You can have any color you want, as long as it reflects infrared. The former head of California’s Air Resources Board was just fired for, among other things, having decided to call for:

    “‘cool paint’ for cars. By blending in special pigments, car paint of any color can be made to reflect much of the sun’s heat energy. That will keep the vehicle’s interior cooler and reduce the demand on the air conditioner — which in turn improves fuel efficiency…”
    http://republican.sen.ca.gov/opeds/99/oped3944.asp
    http://www.ceitoday.com/ceih.shtml

    It’d probably do the same thing for building temperatures. So you needn’t insist on “white” paint to accomplish this.

    “…Earth and the atmosphere as a whole maintain an albedo that hovers around 29 percent.

    “Ramanathan notes that if Earth’s albedo were to increase only three percent, the resulting climate change would throw the planet into an ice age. A three-percent decrease would create a severe heating effect comparable to that caused by a sixfold increase in atmospheric carbon dioxide, far greater than anything projected by today’s climate models.

    “Global warming and global dimming both have the potential to alter Earth’s prevailing albedo through complex climate feedbacks. Ramanathan suggests there is evidence that they already have. ….”
    http://scrippsnews.ucsd.edu/Releases/?releaseID=761

    If you don’t recognize the name Ramanathan, look him up:
    http://www.aip.org/servlet/SearchClimate?collection=CLIMATE&sourceQuery=vdkvgwkey+%3Ccontains%3E+%2Fweb2%2Faipcorp%2Fhistory%2Fexhibits%2Fclimate+and+%28Ramanathan%29&queryText=&SEARCH-97.x=30&SEARCH-97.y=26

  26. 126
    cce says:

    This presentation by energy conservation founding father Art Rosenfeld talks about California’s white roof efforts, and white roofs in general.

    http://webcast.ucsd.edu:8080/ramgen/UCSD_TV/11832.rm

  27. 127

    [[What would be the potential impact of requiring worldwide that all new vehicles and new structure/replacement roofing and siding be white? That would roll up to fairly large surface area. Too small to be worthwhile?]]

    Urban areas only cover about 2% of the Earth’s land surface, which in turn covers 29.2% of the world’s surface area. And albedo affects surface temperature in a relation dependent on the one-fourth power of the product. So while this would have noticeable effects locally, it would not alter the mean global temperature very much.

  28. 128
    Alex Nichols says:

    #120 The list includes almost all of the people that one would label “denialists”.

    I noticed that the Rt.Hon Christopher Lord Monckton makes an appearance on icecrapdotcom too. I heard him advertising his new board game on the radio this morning. He’s offering a £2 million prize for solving it, “from my threadbare aristocratic pocket” Perhaps threadbare, but evidently not empty.

    Is there any downtime on the Goddard Institute supercomputers?

  29. 129
    Rod B says:

    Only about 20% of the albedo is a reflection from the surface. And since all the cars and horizontal roofs make up one-zillionth of the surface, you’ll never see the improvement. Reflective autos have a picayune to zero effect on gas mileage; the California guy was probably fired [edit]

  30. 130
    Dano says:

    127 (BPL):

    There are impacts beyond global average temperature, namely the indirect climate effect of net decreases in energy consumption. Lower energy usage from light-colored roofs would mean less GHGs emitted.

    Interestingly (to me anyway), is that the recent article by Ausubel (that “forgot” to mention that the land available for solar power is readily available today – roofs) raises an interesting conundrum – light-colored roofs raise urban albedo but solar panels on all roofs would lower it; we’d have to plant more trees to raise ET to offset [as I’m a green infrastructure guy, that would mean job security ;o) ].

    Best,

    D

  31. 131
    Hank Roberts says:

    We need a roof/pavement material that’s selective — one that reflects (or re-emits, in one of the infrared windows) whatever sunshine it can’t turn into electricity.

    I guess plants do that, more or less.

  32. 132
    AlZ says:

    Aren’t we overdue for a Friday round-up? Just saying

  33. 133
    John Mashey says:

    re: #130, #131

    1) The US EPA says good things about cool roofs:
    http://www.epa.gov/heatisld/strategies/coolroofs.html
    In particular, it has maps of expected savings.

    So it’s not just California, although it is certainly quite relevant here, given that peak electricity usage is Summer afternoons for air conditioning, for which global temperatures are far less relevant than local temperatures. We all know that handling peak electricity usage ends up using the least efficient power plants.

    2) Of course, building houses sensibly in the first place helps a lot.

    3) About selective materials, I’d really wish for window material that could selectively (presumably under control of wireless sensor nets):
    a) be transparent
    b) be reflective (or even PV, although that might be too much to ask).

    We use reflective window shades on some big windows, which make it cooler in Summer, and warmer in Winter, but it would be nice if one could get the effect to be programmable and automatic.

    4) re: Robert Sawyer (head of California Air Resources Board) getting fired out here: I don’t think that had anything to do with paint… although the stories are confusing. His replacement, Mary Nichols, is *highly* respected in environmental circles, has done this job before (under Democratic administration), and is by all accounts very good. This is good, given the peculiar/unique role of the CARB in setting standards in the US.

  34. 134
    Dano says:

    RE 133 (J Mashey):

    Your 2) is being addressed with new LEED-ND standards (ND = Neighborhood Design) that are being tested via pilot projects now. My major project will use these standards, once I get the plan approved.

    Best,

    D

  35. 135
    John Mashey says:

    re: #134 Dano
    re: LEED-ND: yes, good.

    Our new town center is being built to (at least) LEED-Gold, and we (PV Climate Protection Task Force) have recommended mandatory adoption of LEED-H (for new homes), beyond the current strong recommendations/checklists, but this will be under debate for a while, as it is in other nearby towns, to sort out the most practical ways to implement such things, and also, how to work rules into retrofits. Relatively few new houses get built here, but there are several zero-carbon ones in progress right now.
    http://www.portolavalley.net/building/pdf/bpe_grnbldg_pv.pdf
    http://www.coolpv.com

    This has gotten pretty far away from Green&Armstrong forecasting, although the myriad of small actions required reminds one that there is no single silver bullet. One *can* confidently forecast that buildings last many decades, which makes that part of the infrastructure rather persistent. I.e., it’s yet another issue where one must start early and keep at it for decades.

  36. 136

    [[There are impacts beyond global average temperature, namely the indirect climate effect of net decreases in energy consumption. Lower energy usage from light-colored roofs would mean less GHGs emitted. ]]

    Good point. I hadn’t considered that.

  37. 137
    garhane says:

    This general reader continues endlessly grateful for the presence of Real Climate and the heavy load of worked up contributions, as by Gavin in the present case. Alas, it is also a case of casting pearls before swine, as seen in some responses that seem to have been provoked by the shallowest of emotional hooks. I guess it can’t be helped where the system, striving to turn everything into a commodity and pressing hard to reduce the cost of production, dumbs down the population over time and produces a generation of people who think like cartoons.
    Lie the Italian guy said in the 16th Century, “still, it does move.” And, you know, they are down to a pretty low class of offering now, that most of us can spot. We still need the sober analysis to be found in this blog, but we are definitely learning how to spot the clowns.

  38. 138
    Ben Kalafut says:

    Glad you guys took this one on!

  39. 139
    Hank Roberts says:

    Anyone seen a 2-layer roof that would allow pulling hot air out and venting it away (after heating the hot water supply) during hot weather but also allow switching to pulling it down into or around the living space in cold weather? Seems a shame to throw it away. I could just ask the roofer to put on two roofs with an air gap and some cleanout hatches, but sure wish it were already designed and approved.

    But back on topic, a bet’s been offered by Dr. Hansen:

    http://environment.newscientist.com/channel/earth/mg19526141.600-huge-sea-level-rises-are-coming–unless-we-act-now.html

    “As an example, let us say that ice sheet melting adds 1 centimetre to sea level for the decade 2005 to 2015, and that this doubles each decade until the West Antarctic ice sheet is largely depleted. This would yield a rise in sea level of more than 5 metres by 2095.

    “Of course, I cannot prove that my choice of a 10-year doubling time is accurate but I’d bet $1000 to a doughnut that it provides a far better estimate of the ice sheet’s contribution to sea level rise than a linear response.”

  40. 140
    Hank Roberts says:

    > Robert Sawyer, CARB

    KQED I believe has the program as a podcast online now.
    Info found here: http://shirlrelo2.blogspot.com/2007/07/rworknews-on-radio-this-am.html

  41. 141
    Stephen Berg says:

    I assume you’ve all seen this:

    “Frequency Of Atlantic Hurricanes Doubled Over Last Century, Climate Change Suspected

    Science Daily — About twice as many Atlantic hurricanes form each year on average than a century ago, according to a new statistical analysis of hurricanes and tropical storms in the north Atlantic. The study concludes that warmer sea surface temperatures (SSTs) and altered wind patterns associated with global climate change are fueling much of the increase.

    …(continued)”

    http://www.sciencedaily.com/releases/2007/07/070730092544.htm

    The paper is here:

    http://www.mmm.ucar.edu/people/holland/files/NaturalVariabilityOrClimateTrend.pdf

  42. 142
    mz says:

    About the bet.
    Is it similar as in me having a forecasting competition vs you for daily temperatures during the year like this:
    -my daily temperature model would be re-evaluated once every day. It would expect no change from the previous day (thus tracking real temp with one day lag).
    -your model should forecast the daily temperatures for the full year beforehand, no tracking allowed.

    If I win the contest, does that mean that the temperature doesn’t change during a year? Of course not. It only tells that there is some slowness in the changes of weather.

  43. 143
    laservisor says:

    Why should we care about every half-wit and his brother who decides to publish his uninformed and unscientific “critique” of the IPCC? I think you folks are wasting your time and unintentionally boosting their legitimacy by responding to everything that jumps.

  44. 144
    jacob l says:

    hello first time post been reading for about 4 months.

    after reading gavins article I checked out Armstrong’s “audit”.
    unfortunately they didn’t provide the reasons as to why they rated chapter 8 low. The biggest thing that I notice is that other chapters and working groups do meet the missing principle.
    The best example I would have is item 1.1″ describe decisions that might be affected by the forecast.” This is discussed in working groups 2 and 3.
    below is nine other items that I think should have been rated higher
    and why.

    1.4 Consider whether the events can be forecasted.
    Climate response to volcanic and orbital forcing shows that the climate does respond to forces in a predictable way.

    3.3 avoid biased sources of data.
    Global temperature estimates goto various lengths to avoid the urban heat island affects and other errors. There are other lines of evidence that the earth is warming like higher sea levels and earlier spring greening.
    The line spectra of co2,h20 and other gases are well tested.

    4.3 Ensure that information is valid
    The Supplementary material for chapter 3 covers temperatures.
    There is also discussion of the U.H.I effect in chapter 3.
    The radiative properties of green house gases are testable and have been for more than 50 years.

    7.3 be conservative in situations of high uncertainty of instability.
    The report “ar4″ didn’t include Greenland and antarctic ice flow
    in sea level rise because of the lack of consensus. This should be counted as a example of being conservative, maybe overly so, but if they take the heat they should get some credit.

    10.9 shrink the forecasts of change if there is high uncertainty for the predictions of the explanatory variable.
    Climate sensitivity doesn’t change because it is hard to predict how much co2 will be emitted.

    12.5 use trimmed means, medians, or modes.
    Both chapters 10 and 11 have charts that compare models and show the mean. Figure 10.5 is a fair example of this.

    12.6 use track records to very the weights on component forecasts.
    palaeoclimatic data as described in chapter 6 is used for this purpose.

    13.32 Conduct explicit cost-benefit analyzes.
    That is not the job of wg1 should have reviewed working groups 2 and 3

    most of my experience in climatology is reading this blog and most of working group1 of ar4, so there is much I don’t know but I am sure that is and most of the other points are unreasonably harsh.

    some points like 13.9 “Provide full disclosure of methods” wouldn’t even be mentionable if links to the source code for model E or GFDL’s models where provided

    there are two point’s I don’t get.
    13.29(Revised) Tests of statistical significance should not be used.
    13.30 Do not use root mean square errors(RMSE) to make comparisons among forecasting methods
    thank you for time

    [Response: Thanks – That’s exactly the feeling I had. The two points at the end are particularly obscure. I tried to follow the references to why they are there but the source papers for these claims are not particularly clear. Having said that, climate model skill scores (Taylor diagrams and the like) are not simple RMSE and they aren’t how errors in projections are assessed in any case. I’m pretty sure there are no p-values calculated anywhere for whether a model is ‘correct’. – gavin]

  45. 145
    Ray Ladbury says:

    Re 102. The linked document is just about the saddest excuse for a scientific paper that I have ever seen–well, maybe with the exception of his previous attempt to disprove the greenhouse effect:

    http://unglaublichkeiten.com/unglaublichkeiten/htmlphp/einlg1.html

    Both papers are a series of attacks on straw men–this guy has no understanding of anything to do with climate, atmospheric physics–and most important he does not know what he doesn’t understand. I particularly like the references to the fact that energy balance diagrams are not Feynmann diagrams and the emphasis on friction. [edit]

  46. 146
    John Mashey says:

    re: #145 Ray
    It’s August 1, not April 1, but this was a good for a laugh.

    My German is rusty, but I knew unglaublichkeiten means something like “unbelievable things”, and when I went to the overview “Uebersicht” link, and immediately noticed:
    -the words “Sieg heil”
    -above a sketch of a saluting entity with a winged helmet and feet,
    – with a prominent SS-lightning-bolt insignia next to it,
    – and a title that included “…bevorstehende Rückkehr unseres Messias” (imminent return of our Messiah),
    -and a list of topics ,of which the first was:
    [UFO-Geheimbasen des Dritten Reiches. i.e., UFO secrets (?) of the Third Reich]

    I decided that applying Google Translate would likely not yield productive information.

  47. 147
    Andree Henkel says:

    Re 130 Dano
    I thought on that recently “wouldn´t the low albedo of solar install. make UHI effects worse”
    it depends:
    incoming sunlight = reflected sunlight (albedo) + absorbed and used sunlight + absorbed but not used sunlight
    the absorbed and used sunlight causes no additional UHI as long as the Energy is consumed within the city anyway, resulting in waste heat, which causes (a low) part of UHI
    the absorbed but unused sunlight may cause additional UHI, so the albedo number alone is misleading here, the interesting number is albedo + efficiency of the installation, if it´s lower than that what the surface albedo would be otherwise then indeed there would be additional UHI effect, if it´s higher it actually decreases UHI,
    may be the difference 1-albedo-efficiency is something that designers of solar installs should try to reduce, so there arises no UHI related argument against solar installs within cities

    Andree

  48. 148
    Jordan says:

    To John Mashey,

    It is often said that that the web is not a reliable source of information.

    The link given in #105 is to “icecap”. The above link (“unglaublichkeiten”) looks like a pretty cranky affair (hence UFOs, third reich, etc). The nature of the site suggests that it would be illegal according to German law and it is a dot-com – so why should we believe it is even based in Germany?

    The chances are the website has simply latched onto Gerlich’s work for its own reasons. It summarises his work and presents the summary like a formal document of the university. But it is probably nothing of the kind – I don’t want to give credence to anything this website has to say.

    The university seems to be a respectable institution. My guess is that a German state funded institution would be unlikely to accmomodate Gerlich if he really were a campaigner for the neo Nazi fringe.

    The neo Nazi stuff looks like a distraction. It would be more interesting to see answers to Gerlich’s arguments.

  49. 149
    Hank Roberts says:

    http://environment.newscientist.com/article/dn12453-prepare-for-another-ten-scorching-years.html

    Journal reference: (Science, vol 317, p 796)

    —— EXCERPT BELOW —- SEE LINK FOR FULL ARTICLE —–

    Prepare for another ten scorching years

    * 19:28 09 August 2007
    * NewScientist.com news service
    * Jim Giles

    Temperature records will be repeatedly shattered over the next few years, say researchers behind the first rigorous look at how global climate will change during the next decade.

    The prediction comes from an innovative technique that combines the approaches used by weather forecasters, who typically look a few days ahead, and climate modellers, who produce projections that run up to the end of the century. The result is a model that can project as far as 2015, filling in a long-standing gap in climate predictions….

    “This is a very important paper,” says Rong Zhang, an oceanographer at the Geophysical Fluid Dynamics Laboratory in Princeton, New Jersey, who is using similar techniques to study the Atlantic Ocean. “This is just the beginning for this approach.”

    Buoys network

    The forecast is only possible because better figures are available on the state of the world’s oceans, says Doug Smith, a climate modeller who developed the predictions with colleagues at the Hadley Centre for Climate Prediction and Research in Exeter, UK.

    A network of automated ocean-going devices, now numbering around 3,000, has been deployed around the planet since 1999. The devices, known as Argo floats, provide updates on ocean temperature and salinity — factors that are critical in determining global climate patterns.

    Armed with the Argo results, Smith was able to create a climate model that started with an accurate representation of the world’s oceans. Without access to such data, traditional models had ignored the fine details of current climate. That meant the predictions they produced were only reliable for periods decades in the future, at which point the influence of variations in factors like ocean temperature will have been swamped by more powerful forces, such as greenhouse warming.
    Temperature plateau

    Smith’s approach seems to be working. Some of the figures published this week come from a trial of the model that was run in 2005. Comparisons with subsequent observations show that the model captured the recent plateau in global temperatures.

    Such lulls could be used by climate change sceptics to argue that the world is not warming as predicted and that plans to cut greenhouse gas emissions are unnecessary, says Smith, so it is useful to be able to spot a brief pause in what is expected to be a steady increase. “There would be pressure not to mitigate emissions if we couldn’t predict a flattening,” he says.

    —-END EXCERPT ——