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Simple Question, Simple Answer… Not

Filed under: — group @ 8 September 2008 - (Français) (Japanese) (Finnish) (Czech)

Guest commentary by Spencer R. Weart, American Institute of Physics

I often get emails from scientifically trained people who are looking for a straightforward calculation of the global warming that greenhouse gas emissions will bring. What are the physics equations and data on gases that predict just how far the temperature will rise? A natural question, when public expositions of the greenhouse effect usually present it as a matter of elementary physics. These people, typically senior engineers, get suspicious when experts seem to evade their question. Some try to work out the answer themselves (Lord Monckton for example) and complain that the experts dismiss their beautiful logic.

The engineers’ demand that the case for dangerous global warming be proved with a page or so of equations does sound reasonable, and it has a long history. The history reveals how the nature of the climate system inevitably betrays a lover of simple answers.

The simplest approach to calculating the Earth’s surface temperature would be to treat the atmosphere as a single uniform slab, like a pane of glass suspended above the surface (much as we see in elementary explanations of the “greenhouse” effect). But the equations do not yield a number for global warming that is even remotely plausible. You can’t work with an average, squashing together the way heat radiation goes through the dense, warm, humid lower atmosphere with the way it goes through the thin, cold, dry upper atmosphere. Already in the 19th century, physicists moved on to a “one-dimensional” model. That is, they pretended that the atmosphere was the same everywhere around the planet, and studied how radiation was transmitted or absorbed as it went up or down through a column of air stretching from ground level to the top of the atmosphere. This is the study of “radiative transfer,” an elegant and difficult branch of theory. You would figure how sunlight passed through each layer of the atmosphere to the surface, and how the heat energy that was radiated back up from the surface heated up each layer, and was shuttled back and forth among the layers, or escaped into space.

When students learn physics, they are taught about many simple systems that bow to the power of a few laws, yielding wonderfully precise answers: a page or so of equations and you’re done. Teachers rarely point out that these systems are plucked from a far larger set of systems that are mostly nowhere near so tractable. The one-dimensional atmospheric model can’t be solved with a page of mathematics. You have to divide the column of air into a set of levels, get out your pencil or computer, and calculate what happens at each level. Worse, carbon dioxide and water vapor (the two main greenhouse gases) absorb and scatter differently at different wavelengths. So you have to make the same long set of calculations repeatedly, once for each section of the radiation spectrum.

It was not until the 1950s that scientists had both good data on the absorption of infrared radiation, and digital computers that could speed through the multitudinous calculations. Gilbert N. Plass used the data and computers to demonstrate that adding carbon dioxide to a column of air would raise the surface temperature. But nobody believed the precise number he calculated (2.5ºC of warming if the level of CO2 doubled). Critics pointed out that he had ignored a number of crucial effects. First of all, if global temperature started to rise, the atmosphere would contain more water vapor. Its own greenhouse effect would make for more warming. On the other hand, with more water vapor wouldn’t there be more clouds? And wouldn’t those shade the planet and make for less warming? Neither Plass nor anyone before him had tried to calculate changes in cloudiness. (For details and references see this history site.)

Fritz Möller followed up with a pioneering computation that took into account the increase of absolute humidity with temperature. Oops… his results showed a monstrous feedback. As the humidity rose, the water vapor would add its greenhouse effect, and the temperature might soar. The model could give an almost arbitrarily high temperature! This weird result stimulated Syukuro Manabe to develop a more realistic one-dimensional model. He included in his column of air the way convective updrafts carry heat up from the surface, a basic process that nearly every earlier calculation had failed to take into account. It was no wonder Möller’s surface had heated up without limit: his model had not used the fact that hot air would rise. Manabe also worked up a rough calculation for the effects of clouds. By 1967, in collaboration with Richard Wetherald, he was ready to see what might result from raising the level of CO2. Their model predicted that if the amount of CO2 doubled, global temperature would rise roughly two degrees C. This was probably the first paper to convince many scientists that they needed to think seriously about greenhouse warming. The computation was, so to speak, a “proof of principle.”

But it would do little good to present a copy of the Manabe-Wetherald paper to a senior engineer who demands a proof that global warming is a problem. The paper gives only a sketch of complex and lengthy computations that take place, so to speak, offstage. And nobody at the time or since would trust the paper’s numbers as a precise prediction. There were still too many important factors that the model did not include. For example, it was only in the 1970s that scientists realized they had to take into account how smoke, dust and other aerosols from human activity interact with radiation, and how the aerosols affect cloudiness as well. And so on and so forth.

The greenhouse problem was not the first time climatologists hit this wall. Consider, for example, attempts to calculate the trade winds, a simple and important feature of the atmosphere. For generations, theorists wrote down the basic equations for fluid flow and heat transfer on the surface of a rotating sphere, aiming to produce a precise description of our planet’s structure of convective cells and winds in a few lines of equations… or a few pages… or a few dozen pages. They always failed. It was only with the advent of powerful digital computers in the 1960s that people were able to solve the problem through millions of numerical computations. If someone asks for an “explanation” of the trade winds, we can wave our hands and talk about tropical heating, the rotation of the earth and baroclinic instability. But if we are pressed for details with actual numbers, we can do no more than dump a truckload of printouts showing all the arithmetic computations.

I’m not saying we don’t understand the greenhouse effect. We understand the basic physics just fine, and can explain it in a minute to a curious non-scientist. (Like this: greenhouse gases let sunlight through to the Earth’s surface, which gets warm; the surface sends infrared radiation back up, which is absorbed by the gases at various levels and warms up the air; the air radiates some of this energy back to the surface, keeping it warmer than it would be without the gases.) For a scientist, you can give a technical explanation in a few paragraphs. But if you want to get reliable numbers – if you want to know whether raising the level of greenhouse gases will bring a trivial warming or a catastrophe – you have to figure in humidity, convection, aerosol pollution, and a pile of other features of the climate system, all fitted together in lengthy computer runs.

Physics is rich in phenomena that are simple in appearance but cannot be calculated in simple terms. Global warming is like that. People may yearn for a short, clear way to predict how much warming we are likely to face. Alas, no such simple calculation exists. The actual temperature rise is an emergent property resulting from interactions among hundreds of factors. People who refuse to acknowledge that complexity should not be surprised when their demands for an easy calculation go unanswered.


623 Responses to “Simple Question, Simple Answer… Not”

  1. 501
    Ray Ladbury says:

    Mugwump and Steve Reynolds:

    See:

    http://www.aip.org/statistics/trends/highlite/ed/figure14.htm

    http://www.aip.org/statistics/trends/highlite/ed/figure8.htm

    http://www.aip.org/statistics/trends/highlite/ed/figure9.htm

    Actually, patents is an excellent metric. It shows the level of applied R&D, and gives a good idea where future economic growth is headed.

  2. 502
    Steve Reynolds says:

    Ray, talking about European scientific innovation, this seems pretty inefficient:

    [Repair time] would go past the shutdown already scheduled for CERN’s facility to begin its winter break. It usually shuts in mid-November and resumes at the end of March or early April, to avoid its heavy use of electricity during the winter months when Europe has high demand for power.

  3. 503
    Ray Ladbury says:

    Steve, Actually, CERN lost more time than this due to failures of US magnets. They are opening up the biggest machine ever made–there are bound to be some glitches. And you will note that they have a supercollider, while ours is still a hole in the ground in TX, despite over a billion dollars of expenditures. Now THAT is inefficient.

    A quick look at how the respective currencies are doing (and have done since introduction of the Euro) provides another indication.

  4. 504
    Nick Gotts says:

    Further on innovation and patents, though not directly related to Ray’s point, an interesting item on a forthcoming report claiming current IP systems are stifling rather than promoting innovation (the lack of practical results from recent advances in genetics is used as an example).

    http://news.bbc.co.uk/2/hi/science/nature/7632318.stm

    Whatever you think of the particular claim, it reinforces Ray’s point that innovation doesn’t just happen – you have to get the supporting institutional systems right.

  5. 505
    dhogaza says:

    Ray, talking about European scientific innovation, this seems pretty inefficient…

    Saving money is suddenly inefficient? They have a choice as to when to run the thing – when electricity is cheap, or when electricity is expensive. Choosing to only run it when electricity is cheap says nothing about the efficiency of European science and engineering.

  6. 506
    Hank Roberts says:

    > inefficient

    Tasty bait, nicely jiggled

  7. 507
    Mark says:

    And further to #505.

    The laws of physics will not change because there’s a new year.

  8. 508
    Steve Reynolds says:

    Ray: “They are opening up the biggest machine ever made–there are bound to be some glitches.”

    I agree, and did not mean to criticize that. But I expect the capital cost of ‘the biggest machine ever made’ is pretty high, so the efficiency of only running it 1/2 the year because of electricity costs seems pretty questionable. Either it should have been built to be more energy efficient, or located in a place with less expensive energy.

  9. 509
    Hank Roberts says:

    You can look it up.
    http://www.spectrum.ieee.org/sep08/6690

    —–excerpt follows——-

    … CERN’s estimated annual electricity consumption could approach 1000 gigawatt-hours …. The massive LHC will account for about 60 percent; less than 15 percent of the total will go to mundane functions like keeping the lights on; and the other accelerators in the complex will account for the rest. A big part of the consumption is the hundreds of enormous superconducting magnets, … cryogenically cooled to temperatures between 1.8 and 4.5 kelvins (colder than outer space). If the temperature creeps even a fraction of a kelvin above that, the magnets stop working and lose control of the beam. An uncontrolled beam can melt 500 kilograms of copper in an instant, causing serious damage and halting the experiment for months. So it is crucial to keep power flowing into CERN at all times.

    But CERN does not generate any of its own power, so how does it ensure an unbroken supply of electricity?

    The LHC’s location enables a unique power procurement system: power comes in from both France and Switzerland. CERN has an agreement with French supplier Électricité de France (EDF) that guarantees a source of reliable, affordable electricity, with one caveat: for 22 days a year during the winter, power costs become prohibitive. (During that time, all the experiments at CERN are shut down.) The contract stipulates that the accelerators will operate mainly from spring to fall, when the public strain on the electrical grid is low. The agreement also means that CERN must reduce its electricity consumption on demand or pay a whopping fine.

    But what if EDF’s system fails? Because the results of a power outage would be so disastrous, CERN also has a number of backup plans….

  10. 510
    dhogaza says:

    Either it should have been built to be more energy efficient…

    Dude, if you can figure out how to generate the magnetic fields required more efficiently than by using superconducting magnets, I’m sure they want to hear from you, just before you hear from the Nobel Committee.

  11. 511
    Ray Ladbury says:

    Steve,
    Actually it’s a pretty efficient way of running things–you take data half the year and analyze it the other half at your home institution. Remember this is a global institution–the US, Japan et al. are paying to play. Even running half the year, they will have many, many terabytes of data to analyze. Dhogoza is right–the superconducting magnets are about the acme for a cyclotron, and you have to consider that energy is not the only consideration. Each experiment is like a small city, and you have to supply the folks there with the wherewithal to live and work.

  12. 512

    Please consider the following question………….

    CAN WE EXAMINE THE NEED TO SAVE EARTH’S ECOLOGY AS WELL AS THE MANMADE ECONOMY?

    In light of the increasing number of emergent and convergent, human-driven challenges that appear before the family of humanity on the far horizon, I believe it is vital for the blogging community to come together and, if only for a few moments, “get real” about what our species is doing, here and now, in these early years of Century XXI, to extirpate biodiversity, degrade the environment, dissipate Earth’s resources and threaten the very existence of life as we know it.

    Once the economy has been bailed out, I would like the self-proclaimed Masters of the Universe among us, the ones with hundred of millions of dollars in their priviate bank accounts, who are so adamant and urgent in their appeals to save the economy, to turn their attention, energy and vast wealth to the task of saving Earth and its environs from ruination.

    After all, what is the point of choosing to save the economy now if that choice means we could inadvertently ravage the Earth, upon which any manmade construction, even the colossal global economy, depends for its existence?

    What kind of economy can function without adequate resources and ecosystem services only the Earth provides?

    Steven Earl Salmony
    AWAREness Campaign on The Human Population, established 2001
    http://sustainabilitysoutheast.org/index.php

  13. 513
    Steve Reynolds says:

    Ray: “Actually it’s a pretty efficient way of running things–you take data half the year and analyze it the other half at your home institution. Remember this is a global institution–the US, Japan et al. are paying to play. Even running half the year, they will have many, many terabytes of data to analyze.”

    Yes, but if more than one group is doing experiments, one can run while the other analyzes.

    Ray: “Dhogoza is right–the superconducting magnets are about the acme for a cyclotron…”

    Sure, they use no energy directly to maintain the field, so I assume cooling requires most of the power. If they are spending $100 million a year on electricity, did they choose sufficiently efficient insulation and cooling systems?

    Mark: “The laws of physics will not change because there’s a new year.”

    That argument could be used to say CERN should wait until the AGW problem is solved before they use all that energy.

  14. 514
    Ray Ladbury says:

    Steve Reynolds suggests a new policy for LHC: “Yes, but if more than one group is doing experiments, one can run while the other analyzes.”

    And I’ll let you tell the group that gets to go second–OK? Actually that’s not practical for a whole bunch of reasons. The detectors are pretty much permanent–they’re the size of a large building and take about a decade to install. Only the builders of the detectors know how to use them, in general.

    As to efficiency, there are a whole lot of reasons why you don’t want to be inefficient. Should you lose cooling, you go from superconducting (zero resistance, very high current) to conducting (finite resistance, same current). This happened one time at Michigan State and deafened just about everyone in the building. Very impressive. Actually, they probably spend just about as much on Helium as on electricity. Believe it or not, Steve, they do think about things like this. It’s a pretty impressive undertaking–and you get a whole helluva lot more science out of it for the buck than you do with the space station (aka the orbiting pork barrel).

  15. 515
    Hank Roberts says:

    > If they are spending $100 million a year on electricity,
    > did they choose sufficiently efficient insulation and cooling systems?

    Smells tasty, yes. Twitches as dragged by. Almost lifelike. Tempting ….
    Nah.

  16. 516
  17. 517
    Philippe Chantreau says:

    Steve, considering where the LHC is located, I’d say their electricity likely comes from hydro and nuclear

  18. 518

    I have it on good information that when the LHC was fired up the other day, a mini black hole was formed and the Earth was destroyed.

  19. 519
    dhogaza says:

    Believe it or not, Steve, they do think about things like this.

    I’d even venture to suggest that they might even know more about the subject than Mr. Reynolds, [edit]

  20. 520
    m lordy says:

    The UK Met Office recently released a report responding to climate change scpetics who think that global warming stopped in 1998. They state “Global warming does not mean that each year will be warmer than the last.” But as I understand things, it DOES mean that.

    Due to rising concentrations of greenhouse gases, every year more heat will be retained than leaves. But in recent years excess heat has been stored in oceans, not the air. Am I right? Can anyone confirm or deny?

    If I am right I think organisations like the Met Office should be more explicit that the world as a whole IS heating up every year, but the world’s air temperature follows a more haphazard upward trend.

    [Response: The met office is correct. We do not expect the global temperature to increase every year, year after year. There is plenty of variability (including, but not limited to, ENSO, NAO and PDO etc.). We expect the overall heat imbalance to be a little more steady, but there too, we do not anticipate an increase every single year - at least at the moment. - gavin]

  21. 521
    Ray Ladbury says:

    Barton,
    As Hank says, you can look this stuff up:
    http://www.hasthelhcdestroyedtheearth.com/

    ;-)

  22. 522
    Francois Ouellette says:

    There is an interesting discussion on this thread about the relative merits of basic and applied research. I used to think that “basic” research was important too, and served as the basis for applied research. But I’ve changed my mind after a few years in the scientific community, followed by a few years as an entrepreneur, and through a lot of readings on history and sociology of science. The Vannevar Bush model may appear to have been hugely successful, but in fact it was only successful for those “basic” scientists who were flooded with funding to do things that had no relevance whatsoever to industry or the public good. This has reinforced a certain caste of scientists, who have come to believe that they deserved a privileged status. This lasted for the entire duration of the cold war, and afterwards things started to get ugly. I started my scientific carreer in the early 80′s at the time when big industrial labs, like Bell and IBM, started shrinking and shrinking. And so did research budgets. And so, too, did the status of scientists in our society.

    Now we are slowly reverting to the model that made the success of the Western world: a closer interaction between “basic” and “applied” science, a link that the Bush model had more or less severed, while pretending to strengthen it. This is the model of science as “useful knowledge”, in the words of Joel Mokyr.

    But one of the reaction of the scientific caste to this has been to retreat to their ivory tower, and try to re-establish their privileged status by claiming that their useless science is indispensible. My own pet theory (which I grant myself the permission to have) is that the climate change issue is an illustration of this phenomenon. Here we have scientists running a blog to tell us, poor peasants, what we ought to think, and what science is all about, and how asking for a simple explanation is not something we should do. Let us just trust them, and everything will be fine.

    When I left the shielded world of academia to become an entrepreneur, and try to make fructify the science that I had contributed to build, I was faced with a real world where all those nice principles did not apply. Though I knew it, being confronted with it, and having to deal with it because it’s your livelihood that is at stake, makes it suddenly very real. In industry, things HAVE to work, no matter how and why. And what is a beautiful lab setup is NOT a good production setup. In a lab, you can repeat your experiment 100 times to get a good result. In industry, a yield below 90% will kill you.

    This post (written by a physicist like me) did and did not surprise me. A lot of scientists think like that. Computer models make you feel smart. With the click of a mouse, you get as many results as you want. The bigger the program, the smarter you feel. But when you get to the point where you can’t explain the results and just say “the model says it”, then you’re on a very dangerous track.

    The renowned physicist and former colleague of mine John Love once told me that if you can’t get an answer with a “back of the envelope” calculation, then the problem is not worth attacking. It’s something one should remember.

    My first encounter with a scientific problem was like that. I was faced with a problem that was intractable analytically, so I had to resort to a computer calculation. It was a coupled set of nonlinear differential equations. Something quite simple if compared to climate models, I admit. I wanted to see what would happen to spectral measurements under conditions of high laser intensity, when you saturate the absorption. At some point, I “discovered” a very interesting effect: that the Doppler broadening of the line would disappear at high intensity. But it was tricky to program and prone to instabilities, so I could never really be sure of my results: was it real or a numerical artefact?

    So I went back to the equations. Most published solutions would take them to the third order of perturbation. Nobody thought that the fifth order would make any significant change. But I went ahead and looked at the fifth order. There were a plethora of terms, but I found out that most of them would not contribute, but with a very simple criterion I could select the few that did. And then I could relate this to a diagrammatic approach (à la Feynman) that made it even easier to see the important terms. Suddenly, what was an intractable problem that could only be solved numerically had a very simple graphical solution!

    But then came my first encounter with this great feature of the scientific institution: the publishing system. Since I was not from Bell labs or MIT, my paper was rejected in Physical Review, and I had to publish it in the Canadian Journal of Physics, needless to say a much less prestigious journal with much smaller readership. Nevertheless, five years later, while at the poster session of a conference, I noticed a poster with experimental results that demonstrated the effect that I had predicted. It was very satisfying for me, because I thought that nobody would ever pay attention to my results! But the real satisfaction was to see that the effect was for real!

    But in the end, the numerical calculation alone would not have been enough. I could have been wrong. At the very least, had I not simplified the problem I would not have understood the result. “Explanation” is important. “Simple explanation” even better.

    So to tell people that “explanation” is not important, and that we can trust complex computer models, is, in my opinion, not a very good advice. To claim that this is how “scientists” work is pure hubris. I would be tempted to say that this is how less talented scientists work, but then I don’t believe that they are less talented. They just have not faced the real world.

  23. 523
    Mark says:

    Francios, to say that “and that we can trust complex computer models, is, in my opinion, not a very good advice. To claim that this is how “scientists” work is pure hubris.” is bad advice and evidence of hubris.

    Some maths integrals cannot be solved symbolically and MUST be solved using discrete mathematics. Some systems cannot be predicted symbolically (Game Of Life, for example) and can only be explained AFTER simulation has shown what happens.

    To say that scientists don’t work that way indicates that YOU speak for all scientists and know how they ALL work.

    Now, rather than diss the current methods, will you come up with some CONSTRUCTIVE criticism?

  24. 524
    dhogaza says:

    The renowned physicist and former colleague of mine John Love once told me that if you can’t get an answer with a “back of the envelope” calculation, then the problem is not worth attacking. It’s something one should remember.

    The Four Color problem, and its solution, dismissed with the wave of a hand …

  25. 525
    Francois Ouellette says:

    Makr, I thought this WAS constructive criticism. The bloggers here often pretend themselves to speak for the “scientific community”. They don’t speak for me that’s for sure, but then maybe I’m not a member of the “community”, and maybe I don’t want to be. Maybe I’m just someone who practiced science for a number of years and tried to make some valuable contributions (useful knowledge…). I don’t think ANYONE should speak in the name of all scientists, or should give lessons on what is or what isn’t science.

    I sure know that some problems cannot be solved analytically. I certainly don’t think that climate models are useless. But there is great danger in blindly trusting complex computer models, and there is great value in “back of the envelope” calculations. In any case, a back of the envelope calculation will give you an answer that lies well within the range of estimates of complex models who do not seem to have improved over the past 15 years, so that fact alone should tell you something. I simply oppose the view that we cannot or should not even ask for a simple and clear estimate. Like in the example I gave, the model should rather help you find what is important and what isn’t. The model helps you simplify the problem. I don’t see how this would be such a bad approach.

  26. 526
    CL says:

    This reminded me of many of the posts that I read here…

    Economic and planetary collapse: Is it a therapeutic issue?

    http://www.energybulletin.net/node/37091

    ‘April fireboats’

  27. 527
    Mark says:

    #525

    Well maybe this:

    “and that we can trust complex computer models, is, in my opinion, not a very good advice. To claim that this is how “scientists” work is pure hubris.”

    wasn’t the right wording, else this:

    “I certainly don’t think that climate models are useless. But there is great danger in blindly trusting complex computer models,”

    is untrue.

    Who says anyway that the trust in complex computer models is blind?

  28. 528
    Lloyd Flack says:

    Francis,
    The back of an envelope calculations of greenhouse gas effects do have the same sign as what vou get from complicated models and come within half an order of magnitude in size. Since such calculations leave out the feebacks they underestimate the effects by enough for them to be a poor guide to action. What they can de is provide a check that the complicated models are doing something plausiable.

  29. 529
    Ray Ladbury says:

    Francois Ouellette, Well, since ALL of the advances currently driving economic growth were developed under the Vannevar Bush model, I would contend that support for your argument is pretty weak. You speak of a “closer interaction” between basic and applied science–Good Lord, man, have you ever heard of the Manhattan Project? The Apollo Program? Fermilab or now the LHC? My own discipline is very applied and very practical. You are taking your own (quite limited) experience of science and generalizing from that to some very broad and incorrect conclusions. You know nothing of how science is done even in the majority of subfields of physics. You know even less of climate science. Where, for instance, do you get the idea that we accept the output of climate models “blindly”? Where do you get the idea that climate models have not improved? Do you even know any climate scientists? Then, how, pray tell do you conclude that they’ve retreated to the “Ivory Tower?” When you are so woefully misinformed on climate science, why should we trust your opinions about other matters (e.g. scientific funding).
    For your criticism to make it to “constructive,” you have a lot of ignorance to rectify. You are at the right place. Start reading where it says “START HERE”.

  30. 530
    dagobert says:

    #520 – Gavin’s response: “We expect the overall heat imbalance to be a little more steady, but there too, we do not anticipate an increase every single year – at least at the moment.”

    Could you please elaborate on the “at least at the moment” bit? Why is that? Would the imbalance be more steady with further rising temperatures or don’t we know enough about it yet?

  31. 531

    Francois Oulette posts:

    John Love once told me that if you can’t get an answer with a “back of the envelope” calculation, then the problem is not worth attacking.

    I agree. We shouldn’t have gone to the moon, or developed aviation, or heart pacemakers. Too complicated! Just stick with what you can do on the back of an envelope!

  32. 532
    dhogaza says:

    In any case, a back of the envelope calculation will give you an answer that lies well within the range of estimates of complex models who do not seem to have improved over the past 15 years, so that fact alone should tell you something.

    Yes, outright falsehoods like this tell us that you don’t know what you’re talking about.

  33. 533
    Nick Gotts says:

    I think people were missing Steve Reynolds’ point: the LHC is locaterd in decadent social-ist Europe, so it’s by definition inefficient.

  34. 534
    Francois Ouellette says:

    Barton Paul Levenson,

    Why such an overreaction?! I’m pretty sure that you could estimate what was needed to go to the moon with a back of the envelope calculation: how much weight you have to extract from the earth’s attraction, how much fuel will be needed etc. It’s not such a complicated problem. The engineers working on it mostly used slide rules as their primary tool. They certainly knew how to simplify a problem and get a quick answer. I never said that you could solve all the details of a problem with such a calculation, only that you should be able to quickly estimate the solution. The same with aviation. As a matter of fact, the first airplanes were developed much more on a “trial and error” basis than on actual theory. It took a long time for theory to catch up with practice. I think your choice of examples is rather poor.

    Having mentioned John Love, I should have added that he nevertheless went on to write a 400 page classic book on optical waveguide theory! It’s not like he doesn’t like to get into the details! The design of optical waveguides does rely on complex software, as does most design today. But from what I know, the use of such software is more of an art than a science. Put in the hands of non experts, it’s likely to give results that don’t make sense. I had a friend who ran a succesful consulting business because he knew how to use complex finite difference thermo-mechanical design software, and that’s because he had been a pioneer in developing such software for over 25 years.

    [edit]

  35. 535
    Francois Ouellette says:

    Ray Ladbury,

    Again why such wrath? Why am I being told that I have a “limited” experience with science and that I “know nothing” of how science is done? Are you the Ray Ladbury who writes for Physics Today? Or the one who studies damages to electronics? In any case, I don’t see that you would have a much more extensive experience than I.

    Why would I have such limited experience of science? I’ve been on grant committees that covered the entire Information Technology field in Canada, I’ve reviewed hundreds of proposals. I’ve done due diligence for many technology-based startups, I’ve worked in biotechnology, and I’ve published a few dozen papers and reviewed many hundreds. I’ve spent the last two years studying the history and sociology of science, and have probably read many more books on the subject than you have. Have you read Joel Mokyr? John Ziman? David Hull? Margaret Jacob? John Zammito? Eliot Freidson? Diane Paul? And that’s apart from the “classics” of Thomas Kuhn or Karl Popper, and even Bruno Latour.

    Since I got interested in the issue of climate change, I have probably read more than 300 papers on the subject, and that’s in the primary literature.

    So please, before you accuse me of knowing nothing and having limited experience, try to get to know more. I won’t accuse you of anything, because I don’t know you.

    It does seem like it is IMPOSSIBLE to make any sort of criticism of climate science without suffering these personal attacks. Have you ever wondered why? Don’t you think that this phenomenon is quite revealing in itself?

    Now if you want to have an intelligent discussion of the effects of the Vannevar Bush doctrine and how it evolved in the post-cold war era, I’m very open. But if you just want to attack my credentials because that’s the only response you can think of, well let us end that debate right now.

  36. 536
    Ray Ladbury says:

    Franscois Ouellette, Why the hostility? Hmm. How about the fact that you come on here with accusations that the entire climate science is composed of effete snobs who have “retreated to the Ivory Tower”? How about your claiming the climate scientists accept the output of their theories and models uncritically because it makes them “feel smart”? How about your claim that any knowledge that cannot be applied to turning a profit RIGHT NOW is “useless”? To me, these sentiments represent not just red flags waved to provoke controversy, but provound ignorance of how science works and how it eventually leads to technology. By your reckoning, I suppose Benjamin Franklin should have put away his Leyden Jars and kites and stuck to printing presses and stoves. By your criterion, Rutherford was wasting his time firing alpha paticles at foils of gold. We need to invest broadly in basic research precisely because we cannot pick the winners for tomorrow’s technologies. And you sure as hell are not going to populate the science and engineering schools of tomorrow if you preclude avenues for bright young people to satisfy their curiosity. Why would they go into science and engineering when they can tack another zero onto their paycheck by getting an MBA and still enjoy that Friday Afternoon Club party?
    Are you aware of the story Richard Rhodes tells in his book “Dark Sun” about the chemistry problem that confronted the Soviet nuclear weapon designers? They knew they couldn’t purify enough U-235 in time, so they knew (from their spies) that they had to go the Plutonium route. They also knew from their spies that the trans-uranics had a chemistry similar to the Rare Earths. Problem: The Politburo had forbidden study of the rare earths in the Workers’ Paradise as an extravagant luxury. The only reason they succeeded was because a chemist had risked the Gulag to satisfy his curiosity by doing experiments late at night. The Plutonium was produced using this chemist’s hurriedly copied notebooks.
    Yes, I’ve read lots of history and philosophy of science. However, I also think there’s something to be said for learning how science is done by actually doing it, don’t you?
    I’m afraid a detailed discussing the relative merits of Vannevar Bush would take us too far afield from the topic of this board. This is a board where non-climate scientists (myself included) come to learn about climate science. If you want to learn about that subject, this is a good place to start. And certainly your comments betray an ignorance of how climate science is actually done. If you took offense at my tone, I apologize. I tend to respond to agressive and provocative statements in kind.

  37. 537
    Francois Ouellette says:

    Ray, i don’t see how I was agressive. Provocative, maybe. What’s the point of having 524 comments if it’s only to have cheerleaders? If the whole point of the blog is to learn about climate science, why have comments at all?

    What I’ve learned of climate science was through the primary literature, not blogs. Am I wrong to believe that it is a more reliable source? Now you accuse me of saying all sorts of things that I did not say. I never said, for example, that the entire climate science community was composed of “effete snobs”!!! That’s a little too provocative! I never said that knowledge that cannot be applied right now is useless!!! Where did you find that? Please quote what I said, not how you interpret it.

    For what it’s worth, two companies currently make a living off of one of my patented inventions, which was made in the context of academia, so I guess I should know something about technology transfer, and going from “basic” to “industrial”. I started off as a physicist in nonlinear laser spectroscopy, and ended up an entrepreneur running a business with 100 employees, sold to a major American corporation. Yet I have published many papers of “basic” research. So why should I not be entitled to have an opinion on the subject? Does the fact that I disagree with Spencer Weart’s opinion on simple explanations mean that I’m a dangerous skeptic payed by the oil industry? Would that not be simplistic?

    So what have you read apart from the plutonium story? Have you read David McKenzie’s study of the history of intercontinental missiles? Have you read Loren Graham’s fine history of Soviet science? Or Naomi Oreskes’ history of Continental Drift, or Peter Bowler’s history of Darwinism, T.R. Reid’s history of the microchip, Robert Friedel’s history of western technology, or Joseph Needham’s history of Chinese Science and technology? How long a list do I need to supply to satisfy you that I’m not an ignorant bigot? How about your list?

    Now if you want to pursue the discussion, that’s fine. Let’s go. I’ll stay away from Vannevar Bush. Have you read Myanna Lahsen’s fine sociological study of climate modelers? All this is not to say that everything they do or say is wrong! But scientific commnities have their own dynamics. We hear a lot about “science”, and there is a lot of confusion between the knowledge itself, and the social institution that produces it. Many scientists brandish “science” as a rhetorical weapon, so that if someone attacks the institution, they reply that they attack the knowledge. But the scientific institution has many flaws, just like it has many virtues. I compare it with democracy: it’s a pretty flawed system, yet there is no better one. The important thing is that there is a lively public debate to uncover those flaws, and at least appear to correct or avoid them. No scientist I know will claim that peer review, for example, is a perfect process. Actually I know of no one who doesn’t think that it’s utterly biased and unfair. But if someone from outside the institution says the same thing, suddenly it’s the best thing since sliced bread!

    I have argued that climate science is very much representative of today’s pure academic science. I don’t know of any climate scientist who doesn’t work in an academic or quasi-academic setting, ie. mostly publicly funded. Is that an ivory tower? Certainly, to a great extent. That means that they are not accountable for anything they do or say. I don’t see how a modeler would be fired if her predictions turned out to be wrong. The same can be said of particle physicists, or evolutionary biologists. But those two latter fields do not make predictions on which important public policies are likely to be based. In fact the last time evolutionary biologists did that, it was quite a fiasco! So one should be cautious to rely on an institution that does not have a track record of accountability, or where accountability is not part of the culture (as it is in industry, for example), if you have to make important public policies. Wall Street CEO’S also do not have a culture of accountability. Whatever they do, they always have their golden parachute. I have seen plenty of that from very close.

    So feel free to comment on this humble opinion. I would appreciate if you would refrain from personal attacks this time.

  38. 538
    Hank Roberts says:

    > Francois Ouellette Says:
    > 28 September 2008 at 9:31 AM
    > I’m pretty sure that you could estimate what was needed to go
    > to the moon with a back of the envelope calculation

    Jules Verne did the one-way calculation in about much:

    —————————-

    “… we shall have but 400,000 pounds of fulminating cotton; and since we can, without danger, compress 500 pounds of cotton into twenty-seven cubic feet, the whole quantity will not occupy a height of more than 180 feet within the bore of the Columbiad. In this way the shot will have more than 700 feet of bore to traverse under a force of 6,000,000,000 litres of gas before taking its flight toward the moon.”

    Barbicane and his bold colleagues, to whom nothing seemed impossible, had succeeding in solving the complex problems of projectile, cannon, and powder. Their plan was drawn up, and it only remained to put it into execution.

    “A mere matter of detail, a bagatelle,” said J. T. Maston.

    http://www.fourmilab.ch/etexts/www/etm/etm_chap9.html
    ————————————————-
    But you’ll notice nobody has tried his method.

    I recall Heinlein said it took him and his wife days of work — using up many pencils, on rolls of brown butcher paper — to get the elements right for “Destination Moon.”

    Show your work?

    People are still trying to get this kind of thing right, and writing software to help:
    http://www.physicsforums.com/showpost.php?p=249113&postcount=36

  39. 539
    Guenter Hess says:

    Dear Mr Ouellette #537,
    You certainly expressed the difficulties a lot of scientists and engineers, working as experimentalists in the industry, have with the assumptions, proofs and papers that get published about climate science in popular journals and in the internet.
    Many of us are humbled by nature, because even if we understand the underlying basic physics and chemistry of our production processes, nature might surprise us with unexpected root causes and results. The certainties in climate science certainly come as a surprise.
    However, one also has to accept that the climate science community came to a consensus how to evaluate the results of modeling. This evaluation in turn provides the evidence that leads to the conclusions of the IPCC. Moreover, one has to assume that the serious journals provide this insight.
    Unfortunately, the climate science community seems to be also very defensive, if someone asks questions to understand the reasoning.
    I experienced that it is immediately concluded that one does not understand the basic physics, which is usually not the case. You have to get used to it. However, this blog on realclimate is an excellent forum for very interesting discussions.

  40. 540
    Ray Ladbury says:

    Francois, First, congratulations on your record of achievement. I mean that. I respect those who can turn their discoveries into useful technology. Now, maybe you can explain how these accomplishments give you special insight into climate science. You seem to be saying that your record of accomplishment should confer on you some special expertise when you refuse to grant respect to climate scientists in their own metier. You do know that these guys get PhDs in this stuff, right? And that they then work for 20-30 years to really reach the top of their game? Now why should I believe that you have reached such a pinnacle of expertise based on perusal of 300 papers–and I don’t even know which papers? Lahsen’s paper did not impress me much. Like so much of the crap published in STS (not all, mind you), it strikes me as rather shallow. She seems to have listened to the modellers only with an eye to quote mining rather than gaining understanding. Of course modellers have to take the output of their models with a grain of salt. Do you think that is news to them?
    Again, you seem to have complete contempt for any science that has no immediate application. You also have a misimpression that somehow the reality of the threat of climate change is contingent on climate models for its validity. This is not correct. You also misunderstand Spencer’s essay as supporting your position. We know the planet is warming. We know from basic physics that if you add CO2 to the atmosphere, the planet must warm. We know from paleoclimate that the sensitivity is likely somewhere between 1.5 and 5.5-6 degrees per doubling. Climate models place tighter limits on that range, and in so doing actually do more to limit risk than raise alarm. The models are also critical for looking at the implications of climate change, but again, here, their effect is more to limit risk than raise alarm.Without the models, we are flying blind in the Andes in a snow storm.
    Francois, it’s great that you read about climate. That you have reached a conclusion that climate change is not a serious threat would suggest your sampling has not been representative.

  41. 541
    Mark says:

    Francois, #537.

    Provocative. Meaning: to provoke.

    Again you use sentences and then say you never meant them.

    I hope your research is more clearly thought out.

  42. 542
    Lloyd Flack says:

    Francis,
    We can create simplified models of the effect of the greenhouse gases themselves. These can be described on less than one sheet of paper. They will give us the sign of the change and an indication of the order of magnitude. But they do leave out some feedbacks and do not give us results that we can use for policy decisions. The results of these simplified models are indicative only. They provide us with a proof of principle and ,to a lesser extent, with a reality check for the more complex models.

    But the climate is a complex system and some of the feedbacks such as circulation patterns are emergent properties than cannot be easily predicted from the initial model assumptions and data. These feedbacks can only be dealt with through complicated models.

    The sort of simplified models you are talking about will, if well chosen, give us the gist of what is happening. But they give biased results, underestimating temperature changes as it happens, though in principle the biases could have been in the other direction. Critics will and have queried the simplifications required to create very simple one-dimensional models. When you put in the factors whose effects people want to know, the models become complicated. It’s damned if you do and damned if you don’t. If you use the simplified models you want critics will rightly say they are not sufficiently realistic for us to use us a basis for action. If you make the models more realistic then people will say they are too complicated to understand. In this case you cannot create a simple model that explains what is going on and gives useful results. Would you really try to predict the response of a living cell to say, a short chain peptide that you have introduced, from a simple mathematical model? Fortunately the climate system is easier to model than that, but the point is sometimes back of the envelope calculations are of little use.

    As for the the climate model predictions not improving, if the point estimate of CO2 sensitivity of around 3ºC is close to correct then we expect that the point estimates will not change much with model improvements. Some of the range of possible values comes from uncertainties about cloud cover which have not improved much. Some, I believe, comes from non linearities in the model which make it hard to rule out extreme values of the sensitivity purely on the basis of the models. But to the extent that different estimates of sensitivity are independent, the fact that their point estimates and ranges are similar gives us some confidence that the true value of the sensitivity is close to the point estimates.

  43. 543
    Francois Ouellette says:

    Ray, nowhere in any of my posts here did I say that climate change was not a serious threat. Where did you find that? I guess that you assumed that if I criticized climate scientists as being disconnected from the real world, that meant that I thought every thing they did was crap. Far from it! Again, you assign intentions and opinions without quoting!

    I also never claimed that I had “special insight” into climate science. I do have an opinion, but I don’t claim that it is special. I just observe and comment based on my own experience and knowledge. Don’t all commenters here do the same?

    One other thing I did not say was that the reality of climate change is contingent on models. But for once you’ve read my mind correctly. And I don’t see how one could dispute that. All the predictions of climate change for the future are indeed the result of modeling. So all the debate on policy is indeed dependent on the model’s validity. I don’t see that as controversial or even provocative. Indeed, Spencer Wearts tells us that only models can give us answers. That there has been warming in the past is one thing. But we are not worried about past warming, only future warming. In fact, probably the reason why there are so many skeptics is that past warming has been far less than catastrophic, and in fact has probably been more beneficial than detrimental. When we are not faced with a concrete catastrophe, it can be difficult to imagine that one is coming. So it is only natural, and I think also quite sane, to question those predictions.

    Now as a last comment, I will ask how is it that I cannot comment on climate science, and that you can dismiss the work of all STS’ers, who also have Ph.D.s and also spend a lifetime to get to the top of their game. Do you have a special insight yourself? If you feel you can challenge their conclusions, then the game is open to everyone.

  44. 544
    David B. Benson says:

    Francois Ouellette (543) wrote “But we are not worried about past warming, only future warming. In fact, probably the reason why there are so many skeptics is that past warming has been far less than catastrophic, and in fact has probably been more beneficial than detrimental.”

    Past warming has led to world-wide glacier retreat and now Greenland melt. I’m concerned and you should be too.

    Past warming has certainly already become harmful in Bolivia (glacier retreat) and in various Pacific islands (sea level rise). Other examples abound; I dispute that “more beneficial than detrimental” is in any sense factual.

  45. 545
    Ray Ladbury says:

    Note, Francois, that I explicitly said that not all STS studies were garbage. I even have friends in the field. I do have a problem with some of the crap that has been produced by sociologists and anthropologists who know bupkis about the subject matter the scientists study and who do not even share a common language with them. I do not confine this criticism to studies of climate science. There was a real stinker of a study of particle phsicists about a decade ago.
    You claim that current warming is not a concern–and yet current warming is already threatening the polar sea ice, glaciers and permafrost (with all its methane and CO2).
    As to your opinion, you are entitled to it. Whether it is worthy of respect depends on whether it is informed. You’ve given no indication that it is. I take your failure to answer my query about whether you know any climate scientists as a negative. So you are apparently basing your opinion on sociological studies by authors who don’t really understand climate science or climate scientists either. Now given that climate science has been gone over with a fine-toothed come by physicists, chemists, meteorologists–hell even petroleum geologists–and not one professional scientific society or National Academy is in dissent, I don’t think your criticism is all that well founded. And of course, you’ve had nothing substantive to say about the science at all.

  46. 546

    Francois Oullette writes:

    Why would I have such limited experience of science? I’ve been on grant committees that covered the entire Information Technology field in Canada, I’ve reviewed hundreds of proposals. I’ve done due diligence for many technology-based startups, I’ve worked in biotechnology, and I’ve published a few dozen papers and reviewed many hundreds.

    Well, it’s kind of a clue that you don’t appear to understand the difference between science and technology.

  47. 547

    Francois Oullette writes:

    But those two latter fields do not make predictions on which important public policies are likely to be based. In fact the last time evolutionary biologists did that, it was quite a fiasco!

    Great, he’s a creationist, too. Why am I not surprised?

  48. 548

    Francois Oullette writes:

    All the predictions of climate change for the future are indeed the result of modeling.

    When Svante Arrhenius published the first estimate of global warming under doubled carbon dioxide in 1896, he did not use a computer model. Nor did G.S. Challenger in 1938.

  49. 549
    Rod B says:

    Francois, I’m curious: what situation are you referring to with “…last time evolutionary biologists did that, it was quite a fiasco…”?

  50. 550
    Francois Ouellette says:

    [edit]

    Ray Ladbury, there is an election here in Canada, as there is in the USA. I do not know personnally any of the candidates. That doesn’t prevent me from making a choice between them. Does one really need to have climate scientists as friends to understand how they work? I don’t think they work very diffently from most academic scientists, and I have plenty of experience with them. I mean, can we advance the debate or will it endlessly come back to my lack of qualifications? is this a job interview or what? Why don’t you detail how qualified you are yourself? I’m still waiting.

    Your argument that current warming is a concern does not hold. The Arctic melting today is not killing anyone. That it may be a sign of future dangerous melting if the trend continues is a concern. If one made a list of natural or man-made disasters that are killing people TODAY, climate change would be near the bottom. Wars, disease, poverty, etc. are much more harmful today.

    But you infer from this that I do not think that future climate change is not a concern, something I did not say. All I said is that it is difficult for many people to be concerned about something that does not affect them TODAY, and I’m not necessarily talking about myself. But the same can be said of many other disasters. How can one connect to the problem of malaria in Africa when you’ve never seen anyone sick with it?

    Actually, I think the hysterical proponents of AGW, who claim that harm is done today, do more harm than good. By constantly claiming there is immediate danger, and using bad examples like Katrina, or glaciers (who has ever seen a glacier anyway?), they inevitably make fools of themselves, and lose a lot of support from people who just think they are exaggerating. By the same token, the IPCC, by trying to claim exaggerated levels of certainty, just makes many suspicious of such claim. The acrimony with which any criticism is taken doesn’t help either. See how I’m treated here!

    I don’t see what’s wrong in saying that future climate change, the extent of which is suggested from models, is a cause for concern. That being said, the politicization of the debate is also a concern. And, in my view, the fact that most of the knowledge about it comes from a purely academic setting should induce caution. It is my opinion that the culture and dynamics of the academic research institution is not designed, and not ready, to bear the responsibility of giving the final advice about important public policies. I think we need to create other institutions (and the IPCC is a very bad example) to help us through this potential problem.


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