A superb opinion piece published recently in The Australian graphs one scientists conversion from AGW believer to skeptic after failing to find evidence. David Evans is the self-confessed rocket scientist who wrote the custom carbon accounting model (FullCAM) that measures Australia’s carbon credit in the land use change and forestry sector. In disagreeing with mainstream science as represented by the IPCC he is among those that Professor Garnaut indecorously refers to as ‘dissenters’ here or even ‘deniers’ here.
Below are quotes but the full report is well worth reading as an example of the evidential mindset. In this view, climate models are very low on the pecking order of evidential support, and direct evidence for AGW is lacking.
But since 1999 new evidence has seriously weakened the case that carbon emissions are the main cause of global warming, and by 2007 the evidence was pretty conclusive that carbon played only a minor role and was not the main cause of the recent global warming. As Lord Keynes famously said, “When the facts change, I change my mind. What do you do, sir?”
There has not been a public debate about the causes of global warming and most of the public and our decision makers are not aware of the most basic salient facts:
…1. The greenhouse signature is missing. We have been looking and measuring for years, and cannot find it.
…2. There is no evidence to support the idea that carbon emissions cause significant global warming. None. There is plenty of evidence that global warming has occurred, and theory suggests that carbon emissions should raise temperatures (though by how much is hotly disputed) but there are no observations by anyone that implicate carbon emissions as a significant cause of the recent global warming.
3. The satellites that measure the world’s temperature all say that the warming trend ended in 2001, and that the temperature has dropped about 0.6C in the past year (to the temperature of 1980). Land-based temperature readings are corrupted by the “urban heat island” effect: urban areas encroaching on thermometer stations warm the micro-climate around the thermometer, due to vegetation changes, concrete, cars, houses. Satellite data is the only temperature data we can trust, but it only goes back to 1979. NASA reports only land-based data, and reports a modest warming trend and recent cooling. The other three global temperature records use a mix of satellite and land measurements, or satellite only, and they all show no warming since 2001 and a recent cooling.
4. The new ice cores show that in the past six global warmings over the past half a million years, the temperature rises occurred on average 800 years before the accompanying rise in atmospheric carbon. Which says something important about which was cause and which was effect.
None of these points are controversial. The alarmist scientists agree with them, though they would dispute their relevance.
…The world has spent $50 billion on global warming since 1990, and we have not found any actual evidence that carbon emissions cause global warming. Evidence consists of observations made by someone at some time that supports the idea that carbon emissions cause global warming. Computer models and theoretical calculations are not evidence, they are just theory.
Credit to Geoff Sherrington for spotting this.
131 responses so far ↓
So a modeller is now complaining about other modellers? I wonder if Stockwell or McIntyre would like to audit FULLCAM.
Bet not.
Thanks David for this great piece.
And congratulations for the new nice look (+ enhanced functionality) of your blog.
Thanks Demetris. An upgrade was long overdue. Cheers
Luke, I would be interested in posting a review if you send one in. Cheers
I’ve downloaded and read the full article by Evans, and I must say I’m not that impressed:
- First, anyone who would describe himself as a “rocket scientist” either has an exaggerated sense of his accomplishments, very little respect for the technical level of his readers, or both. This attitude doesn’t engender any trust in me.
- Secondly, having programmed a carbon-accounting model (land-use change and forestry sector) doesn’t really imply scientific credentials on climate dynamics. So this credential doesn’t really provide any cover either. Evans’ training is in mathematics, computing and electrical engineering (http://www.sciencespeak.com/). See the deep connection to the atmospheric physics of climate? Neither do I.
So let’s just evaluate the presentation on its own merits:
1) “The greenhouse signature is missing.” Unfortunately, I have been unable to find any other source for this concept of a “missing greenhouse signature”, other than Evans’ article and re-hashes of the same. In my readings in textbooks of atmospheric physics, the story goes roughly like this: Additional CO2 increases the radius of the photosphere at 15-micron wavelength infrared; this means that the effective radius of radiation for that radiation is at higher altitude then before, and thus will reflect a cooler temperature for radiation; thus less radiation escapes to space, so much is reflected downward. How this is supposed to be translated into a hot spot is unclear to me, and I would like a reference more authoritative than that of a computer programmer: In other words, someone who can actually explain the physics, not just do the accounting.
2) “There is no evidence to support the idea that carbon emissions cause significant global warming.” There is also no evidence to support the idea that it’s NOT causing significant global warming. However, the difference is that global warming is an expectation arising from the atmospheric physics that has been studied for over 100 years (older than quantum mechanics or relativity). If a radiative forcing were NOT occurring due to an increase in CO2, one would really have to wonder why it wasn’t happening. It is basic philosophy of science that you can NEVER prove a theory true, you can only try to disprove it: If you succeed in disproving it, you’ve shot it down, and congratulations! But if you don’t, you’re stuck with it as being the best theory available - unless you’ve got a better one that is also consistent with the rest of physics.
3) “Warming trend ended in 2001.” Climatologists don’t look at year-to-year trends, but decade-to-decade trends. The world is the most complicated thing in the world, with lots of subsystems and cycles and noise. It’s a bit silly to expect a monotonic increase. What I find impressive is the IPCC’s graph at http://www.grida.no/climate/ipcc_tar/wg1/figspm-4.htm , where they’re able to estimate the contributions to climate change from CO2, sulfate aerosols, volcanoes and solar variations. When they add them all together, it’s a very good qualitative match: noisy, but reasonable.
4) “The new ice cores show… the temperature rises occurred on average 800 years before the accompanying rise in atmospheric carbon.” First, there’s nothing particularly new about the ice-core analysis: It’s been known for quite as long as I’ve been looking into the global-warming matter, so at least several years. Secondly, no one has claimed that CO2 initiated previous warmings: In the current period, it is because human beings are measurably adding CO2 to the atmosphere (we’ve added 35% in the last 150 years) that there is a warming effect. In the absence of this addition, you wouldn’t expect any driving from the CO2, the increase is the result of heating of the ground and the waters.
But there IS an additional effect which does tie in: The warming of the Earth, although initiated by the orbital variations (Milankovitch cycles) lasts longer than would otherwise be expected, and this IS attributed to the effect of the CO2. The out-gassing of the CO2 results in a warming that increases and extends the temperature increase that was initiated by a completely different mechanism. This is commonly understood in scientific discussions of global warming, so it is interesting that our brave “rocket scientist” doesn’t seem aware of it. Maybe it wasn’t on his list of talking points.
Likewise, Evans lies about Gore, saying “Al Gore made his movie in 2005 and presented the ice cores as the sole reason for believing that carbon emissions cause global warming.” In fact, what Gore said was that there was clearly a link between them, and he very carefully said, “I don’t want to get into the details of the causality.” Not surprising: I just DID get into the details of the causality, and it is a bit subtle - like a lot of scientific reasoning. You don’t believe me? Go back and watch the movie: Gore is rather careful on that point.
The rest of the article just adumbrates the points already made (in my view, wrongly). He asks for proofs of a theory, which are never possible. (Prove, please, that E always = mc^2. While you’re at it, prove quantum mechanics.)
The only real point that he brings to the table is the question of the “greenhouse signature”, which I have never seen discussed by any other independent source (in other words, articles that are not just re-hashes of this very article). I would be willing to re-consider the significance of this point if someone can explain to me in detail the exact nature and the size of this so-called signature; and to participate in comparing that quantitatively to the expected uncertainties in tropospheric temperatures.
In the meantime, I will point out that science is full of surprises, so sometimes a problem in evidence will linger for years until it is resolved. (As happened in 2004 or 2005, when a tropospheric temperature trend that had been a thorn-in-the-side for a decade was resolved by someone finally noticing an algebra error in data reduction.) This always makes people unhappy, but the scientific issue is then, “Do you have a better explanation?” You don’t abandon a working scientific explanation for a nothing, and what the greenhouse-effect deniers have right now is exactly a nothing: no self-consistent model that matches basic atmospheric physics.
Neal:
Thanks for providing a counterpoint to the Evan’s article. I was actually surprised that he didn’t point out all theother indicators that suggest that catastrophic AGW may not be as supported by observable data as many would like, viz., Ocean temperatures, “clean” SST, Antarctic ice coverage, hard to find detailed explanations of the physics behind sensitivity estimates. However, what also remains the case is that a strong AGW proponent has somehow changed his mind. You may not be persuaded, but he certainly seems to be persuaded.
Bernie,
The fact that someone developed a section of a program does not mean that he was ever convinced of the the framework or knowledgeable of the science behind it. You have only his say-so that he was a strong AGW proponent. So I discount all that: What really matters is not his sincerity (which cannot be measured over the internet) but the cogency of his arguments.
And my evaluation is that his arguments are rather weak. It’s the same old stuff that you can see on any skeptical website, unaffected by any attempt to find the scientific explanation to an apparent contradiction. The history of science is filled with paradoxes, which are eventually resolved by efforts to uncover the truth, not by abandoning rationality.
The fact that he trots out these old-warhorse paradoxes make it clear that he hasn’t made the slightest effort to clarify his understanding. These are explained in lots of places.
If you want to discuss your issues, it would make sense to handle them one at at time.
Neal,
the MODELS that predict dangerous warming currently invariably have the so-called HOT SPOT in their output. Sorry if you can’t find references to it.
Maybe you need to read the IPCC report again. They have a really neat set of graphics that show what the MODELS think the tropical troposphere should look like for several different causes of warming. Neither the graphic for GG’s nor the graphic for all forcings match observations.
It is one of those FALSIFIED moments for a major part of the models.
By the way, have you checked the background for all the modellers working on climate?? Then there is Hansen’s own credentials. Climate Science is new enough that there just aren’t that many highly qualified LETTERED ones around!! I get a kick out of it every time a believer claims that if you don’t have a degree in it you don’t have any qualifications!!
Maybe you can be the one that compiles the necessary credentials for Climate Scientists and enforces the rule!! No LETTERS no OPINION!!
You state:
“But if you don’t, you’re stuck with it as being the best theory available - unless you’ve got a better one that is also consistent with the rest of physics.”
Basically you are saying we should act like every WAG that scientists come up with should be treated as FACT and ACTED UPON!!
I’m sorry, but, you are WRONG!! Just because something is the best GUESS doesn’t make it actionable in any way other than to think up more ways to study it and gather more DATA!!
Your #3. Sorry, just because they have massaged their guesses for years so they seem to make a little sense is NOT proof and is NOT good science.
Your #4. Just because no scientist dares to make this claim currently does not mean they didn’t make it in the past!! There are still people who were taught the old religion that still believe this!!
Basically you need to start dealing with reality and not your own straw men!!
Finally, have YOU recomputed the atmospheric sensitivity now that it is commonly understood that the premise for the old computations, that many people still use, is WRONG?!?!?! You do a lot of deprecation and arm waving and offer no real data. One attempt was presented on this blog. 2 other papers last year attempted to correct this. Unsurprisingly they all were DECREASING it for very good reasons. Even GISS data isn’t showing anything earth shaking in spite of the CLAIMS!!
(I’m still waiting for a commercially navigable Northwest Passage!!)
As for how careful Gore was in his movie, I keep talking to people who think glaciers calving are a sign of global warming. Care to comment on the fact that glaciers calving can be growing, in relative equilibrium, or even melting??
How about a comment on the Hockey Stick??
How about a comment on mosquitoes moving north and causing more disease?? A lot of Canadians were really surprised to hear they didn’t have a summer mosquito problem in their swampy melt seasons!!
Care to comment on how a temperature rise of 5C/100 years is going to raise the sea level enough to inundate New York and the rest of the global coastlines with 20ft of water in this century or even the next?? The IPCC disagrees also!
Oh yeah, I loved reading about the special effects guys who did a styrofoam mock up of a glacial coastline for “A Day After Tommorow” recognising their work in Gore’s DOCUMENTARY!!
Gores movie was pure propaganda with the facts overridden with BULL!! Anyone still defending that pile is DESPERATE!!!
When you get some real, useful facts let us know.
Neal, While your observations seem accurate, I think David cleverly covered himself against a rebuttal on most of your points with the para I quoted:
“None of these points are controversial. The alarmist scientists agree with them, though they would dispute their relevance.”
Commenting about his qualifications many would find distastefully elitist I believe. It was after all an opinion piece.
The greenhouse signature has been claimed to be found by Harries for CO2 and CH4 and for water vapor by Soden, and we have raised some of the questions around this potentially direct evidence on this blog. I hope to do more on these. Claims of greenhouse signatures have been made for patterns of ocean warming, tropoopause rising, tropical troposphere heating and other regional changes. I don’t know where these ‘proofs of AGW’ stand right now, but the upper troposphere heating one arguably runs against AGW since Douglass et. al.
But I think you raise good points on what to do when we don’t have good theories, and I would like to steer any comments away from the science issues and onto the quality of evidence contributed by issues, if possible.
David Stockwells last blog post..AGW: Where is the evidence?
David,
I mention the issue of qualifications ONLY because Evans called himself “the rocket scientist”. In other words, “Trust me, I really am smarter than you, and all those other climate scientists as well.”
From my point of view, the issue with respect to those particular points he mentions is not “relevance” but “mis-interpretation”.
I think there are many things that can be considered “signatures of the greenhouse effect”, so if someone has a specific one in mind, it should be clearly stated. In fact, one site that talked about such a signature identified it as exactly that which was found when the data-analysis error for lower-tropospheric temperature trends (that I mentioned in my first posting above) in 2004. So if somebody has something specific in mind, it would be helpful to specify a reference which describes it unambiguously. As I mentioned, the first N pages in google I found referring to this point were all re-hashes of Evans’ own article.
kuhnkat, if you have a particular graph of the IPCC report in mind, please specify it. IPCC AR4 is hundreds and hundreds of pages long, so I don’t want to print it out; and it’s hard to search on PC.
David,
I’m also unclear on what you mean by this: “… I would like to steer any comments away from the science issues and onto the quality of evidence contributed by issues, if possible.”
Evans’ issues are interpretations. If you want to stay away from the science issues, what quality of evidence can you be talking about?
Neal, I think David was being droll. Please see latest post re evidence and his letter.
David,
I’m afraid I don’t find such applications of Bayesian statistics helpful. I find it easier to evaluate arguments in terms of logical coherence than to try to turn degrees of coherence into Bayesian probabilities.
Hi Neal, go for it if you have another meta-method.
I have already done so, in my first evaluation of Evans’ arguments, on July 22: I don’t find them convincing.
kuhnkat, you seem a little upset at Neal’s post – all those caps and !s. Not necessary.
Our host runs a rather civil blog here. Despite the fact that I disagree with most of what he says, I haven’t ever been treated discourteously, which I appreciate. And Neal J. King clearly knows his physics, as demonstrated by his detailed posts on other threads here.
So get a grip. Care to discuss any of your points individually (and calmly)? Take your first, for instance: “hot spots”. They come and go in the real atmosphere and they come and go in model outputs, right? Do they match up? No, not in a rigorous manner, although broad scale regional patterns are in general agreement (IPCC Fig. SPM 4) Does this “falsify” the models? Yes, if you are (mistakenly) trying to use the global models to predict regional effects in detail. No, if you are using the models to predict the long-term climatic response to increased CO2 forcing.
You say: “They [the IPCC] have a really neat set of graphics that show what the MODELS think the tropical troposphere should look like for several different causes of warming. Neither the graphic for GG’s nor the graphic for all forcings match observations.”
See:
http://www.realclimate.org/index.php/archives/2008/05/tropical-tropopshere-ii/langswitch_lang/in
and references therein for a detailed discussion of comparisons of tropical tropospheric measurements and model outputs. Bottom line (I think I’ve got it right): Yes, there are discrepancies, but these discrepancies (a) are diminished by recent re-evaluation of the data, which had, and still has, known problems, and (b) the remaining problems exist regardless of the nature of the forcing, so they (the discrepancies) cannot be used as an argument against enhanced CO2 forcing. That is, physical theory generally implies that the tropical temperature profile adhere to the moist adiabat, but the data do not strictly conform. Whatever the problem is, it applies either to the analysis of the data or to a general theory of tropical tropospheric conditions, regardless of the hypothesized forcing. The experts (whose opinions you are free to dispute, but only with relevant physical arguments) suspect the data analysis, which is not trivial. In either case, CO2 forcing is not discredited.
With regard to “proof”: I could bore you with many instances in which the correct scientific conclusions were drawn on the basis of what you might call “circumstantial evidence”. It’s common in the natural sciences, and has a pretty good track record, especially when the the evidence is built (and tested) over many years (as is the case for AGW). Smoking guns? Lucky to find them. No excuse for denying the evidence.
David: I’m a little surprised that you are so enthusiastic about Evans’ op-ed, which is a pretty pallid recycling of some feeble arguments, no? (In other words, I agree with Neal J.)
Thanks for reading this.
(Corrections and thoughtful comments are appreciated.)
Hi Pat, Nice to see you back. I do not have much time for the venting common elsewhere and appreciate my efforts are noticed.
Perhaps I need to explain the angle on this more. If you read the longer article of David it explains more about how evidence has led to evolution of his thinking, and I was more interested from that angle. I don’t want to get into science arguments that are covered elsewhere, and want to stay focused on the modeling and statistics aspects of things which are the blogs theme. Climate change to me is a vehicle for exploring these (niche) things.
I thought David’s article was well written in that he covered himself well against rebuttals, it was personable and readable. Whether arguments have been made before is not the point.
There are a lot of directions this could go. For example, circumstantial claims that you mention. While you defend circumstantial cases, I seems to me that AGW is a circumstantial case, and the lack of direct evidence is not widely known. Research directions that could possibly have provided direct evidence such as Harries and Soden seem murky and lack lustre. So there is a whole discussion around direct and circumstantial evidence in the AGW case that seems nipped in but by blithe assertions such as “No denying the evidence.” or “CO2 forcing is not discredited”.
I understand people are used to talking that way, but I liked the way David stepped back a bit and talked about the evidence.
A similar long discussion could take place about the temporal ordering of CO2 and temperatures. I think I am aware of the issues, and that no distinction is logically made by the temporal order between AGW vs not AGW. However, CO2 always lagging temperature must alter a balance of evidence, as after all, if CO2 were to lead temperature in the ice cores in all cases then it would be the basis of a strong claim by AGW people. As it is the exisitng explanation seems post hoc. Responding that this is an old argument and David doesn’t understand the science misses his point that the conventional explanation seems to be a convoluted way of explaining away a troubling piece of evidence. David thinks AGW science hasn’t fully responded to this variation.
I could go through more example but this comment is long enough. If I have explained it better I might turn it into a post. Thanks
Yeah kuhnkat: See that key with the 1 and the ! on it. Do us a favor and flick it off.
David,
I see better what you’re getting at; however, in my opinion there is a lot less than meets your eye.
For example, you and Evans talk about the “lack of direct evidence” for the greenhouse effect: there’s no “proof”. But in actuality, in rather few cases is there “proof” for even a well-attested scientific theory. This is why the the test of a theory is the fact you are not able to “disprove” it.
Example: Let’s look at Newton’s theory of universal gravitation, prior to the age of rockets. How would you go about proving that the force on Saturn from Jupiter is GMsMj/r^2 ? You can’t measure these forces directly and you can’t measure the masses directly. If you examine the force between the Sun and the planets, you find the T^2/R^3 relationship - but the masses of the planets cancel, so you can’t measure the actual force.
Now, at some point, perturbation theory was developed, and you could begin to take into account interplanetary forces and try to make consistent assignments of mass values - but I bet there were a lot of mistakes made. Today’s skeptics would have had a field day with their “model calculations” and “parameter fitting” and outright errors in the mathematics. And yet, a couple of hundred years later, we recognize that, despite these errors and fixes, that in fact this effort was in good faith and was ultimately successful - despite the lack of “direct evidence” for the magnitude of the interplanetary force.
Why were they able to proceed? Because they were willing to work with what they could derive: Kepler’s laws falling out as a consequence of Newton’s, and also a lack of conflict between what can be derived and what can be measured. Sometimes, that’s all that you can get. Experimentally, you cannot prove that nothing will ever exceed the speed of light; nor can you experimentally prove the Heisenberg uncertainty principle. What you can show is that no experimental results to date violate these concepts, and that conclusions derivable from these principles do not conflict with experiment. Can that be considered “proof”? I don’t think so: It can be considered a very strong argument, particularly if you think the ideas are plausible anyway. But real “proof” is something that is restricted to the realm of mathematics. Arguing that a scientific theory is no good because it hasn’t been proven is like arguing that a president is no good because he didn’t inherit his authority from his father: It’s not part of the framework. (Oops! In the current setting, maybe this isn’t such a great example. Oh, well: stet.)
Focusing on the specific issue of the time-lag between temperature increase and CO2 increase: The issue is only troubling you because you have a particular analogy in mind: “If CO2 is causing temperature increase now, CO2 must have been causing temperature increase earlier.” But if that were the case, then you really would have to answer the question, “OK, whose jets and cars and smoke-stacks were creating all that CO2 earlier? Was there a Dinosauric-Industrial Age that never left any textbooks behind?”
Instead, the actual analogy is: “Just as today, when there is a lot of CO2 in the atmosphere, there is heating towards a higher temperature; so earlier, when there was a lot of CO2 in the atmosphere, there were higher temperatures.” The story is not as plot-line clean as you would like it to be - but a lot of scientific stories aren’t (like the evolution of the eye). The bottom line is still, Does it pose a conflict with measurement? Can you “disprove” the theory?
There is a real difference in the way of looking at thing, which is interesting. No-one, (at least not me) is arguing that AGW has to be proven, or is disproved by lags. It seems like hypo-deductive (HD) mindset is saying — I will believe my theory until you disprove it, no matter how improbable it becomes. The Bayesian updater (BU) is saying — I will change my mind as new evidence comes in. Not right or wrong, just different.
Eg. Lags. First we have some data that says CO2 correlates with temperature. HD and BU agree that there is support for AGW from this. Then we find out that temperature rises before CO2. BU re-balances his probabilities to not-AGW but HD constructs an auxiliary theory to explain away the lag (something like RealClimate’s “In other words, CO2 does not initiate the warming, but acts as an amplifier once they are underway. “). HD says anyone who thinks lags disprove AGW misunderstands the science.
Then we find out CO2 lags temperature not only on the way up, but also on the way down. BU gets even more excited by the stronger evidence that the arrow of causation is T->CO2 not CO2->T. HD constructs another theory, like the data is unreliable, or the temporal order does not matter:
“Just as today, when there is a lot of CO2 in the atmosphere, there is heating towards a higher temperature; so earlier, when there was a lot of CO2 in the atmosphere, there were higher temperatures.”
The HD is the one asking for proof. First you say there is no proof of theories. Then you ask — Can you “disprove” the theory? The BU says there is no proof, only vanishing probabilities to the point where we operate ‘as if’ proof were available.
From what I have heard there are other areas where the conventional theories have become highly improbably given the evidence (Louis Hissink mentions Geology and Cosmology), though I am not familiar enough with them to talk about them.
The point is, that in modeling David Evans’ thought process, he seems to follow the BU scheme and finds that AGW is becoming more improbable as evidence fails to materialize, or what was claimed to be evidence turns out to be premature enthusiasm over flawed analysis (eg. Hockey sticks, positive feedback in GCMs, CO2 spectral line changes, troposphere hot spots). In his longer article he thinks this is a basis for a rational bet against AGW.
You seem to be saying, “AGW is still not disproven”. I would agree and he does too if you read the article. But he thinks the chances against it are mounting.
Further, another example of the operation of the HD reasoners is seen in the attitude from RealClimate in posts such as “Its the Physics Stupid” where despite acknowledging that “remaining uncertainty about whether water vapor feedback would amplify warming in the way hypothesized in the early energy balance models” they they maintain that “the basic prediction of warming is founded on very fundamental physical principles relating to infrared absorption by greenhouse gases, theory of blackbody radiation, and atmospheric moist thermodynamics.” Maybe, but the fundamental principles do not provide strong evidence for AGW in the BU framework for the same reason that the effectiveness of a drug in-vitro does not provide strong evidence of its effectiveness in-vivo. Because there are other factors at play in the real system, including feedbacks, that are uncertain.
The HD reasoner would tend to take the theory as absolutely true, and respond to contradictory data by saying, “Well it is complicated, maybe more than we thought at first, and there were some other factors at play we didn’t anticipate, but our assumptions are intact.” The BU reasoner would say, “I need to change my mind about this theory, its not as good as I thought”.
http://www.bbc.co.uk/sn/tvradio/programmes/horizon/dino_trans.shtml
Neal said:
“Just as today, when there is a lot of CO2 in the atmosphere, there is heating towards a higher temperature; so earlier, when there was a lot of CO2 in the atmosphere, there were higher temperatures.”
The dinosaurs didn’t seem to mind a volume of 5,000 parts per million of CO2 and they were around for 160,000,000 years (versus our great and grand 5,000).
What was the temperature back then? Yep, something like 50C higher. But there was also an atmosphere that was a 12% higher oxygen level, with no polar ice caps and sea levels hundreds of feet higher.
Attributing all of the higher (and more uniform) temperatures to CO2 is naïve, to say the least. It was a different planet.
AGW indeed. Look up Deccan Traps.
Jack Willis,
Increased CO2 is a known influence to temperature trends, not the sole determining factor. I think it’s safe to say that anyone who has spend any time studying atmospheric physics knows that.
What dinosaurs enjoyed or didn’t enjoy is not really the issue: There is no “ideal” temperature, but when the temperature changes from whatever it is to something else rapidly, it puts the different species inhabiting the Earth under extreme stress, collectively. We could lose a whole lot of species in a hundred years or so. In my opinion, this is the real problem, not a little bit of disappearing shoreline.
And human beings have been around substantially longer than 5,000 years.
David,
It is very common for scientific theories and frameworks to have problems. They tend to get fixed over time; either that, or they blow up into something so big and attention-grabbing that the hotshots focus on it and either clear it up or create a new theory.
In this case, you focus on a few issues that are currently open. But if you went back 10 years, I think you would have found different issues that were open - issues that have since been resolved.
If you look up the complete history of the global-warming discussion, as can be found at http://www.aip.org/history/climate/ , you will see that it’s gone through a lot of ups and downs. There have been moments of scientific despair and moments of breakthrough.
A big one occurred in 2004 or 2005: There was an apparently clear-cut result that lower-tropospheric temperatures were not increasing, even though ground-level temperatures had been. The radiosonde & satellite measurements matched each other, but didn’t show a trend. This was a major embarrassment for about 10 years. The skeptics had a field day, and the defenders of the theory had to just scratch their heads and either hand-wave or assert, “Well, something must be wrong with the experiment.”
And in 2004 or 2005, a mistake was found in the experiment: One of the teams that was involved discovered that they had introduced an algebra error in their data-reduction procedure. (Embarrassingly enough, the team leader was Spencer - well-known to be a climatologist on the AGW-skeptical side himself!). When the error was fixed, the temperature trend expected, based on the surface-level measurements, appeared; and that long-standing problem disappeared.
So sometimes you have to have the courage to say that the experiment is wrong!
But how can you have this courage? It’s only legitimate if you are really well-informed about the field and the work being done and the people doing the work. That’s why it’s significant that, throughout that uncomfortable decade, the majority of climatologists, who were completely absorbed in all the results of and discussions on this and other experiments, were convinced that the problem would eventually be resolved in favor of the greenhouse effect: Because they knew that either this one aberrant result was funny, or else that a lot of other results were screwed up; and it was more likely that this one result was in error.
A related story recounted by Richard Feynman: In the field of particle physics, when Lee & Yang predicted that parity might not be conserved in the weak interaction, Feynman kicked himself, because he had read the original paper a few years ago that experimentally “proved” that parity was conserved - and he remembered thinking to himself, “This paper doesn’t prove a damn thing! The whole argument depends on the last data point; and you know that if that last data point were any good [trustworthy], they would have taken another one!” Unfortunately for him, he didn’t take the time to calculate through the consequences of that insight, so Lee & Yang got their Nobel Prizes instead of his picking up another one.
I can summarize my point by saying that if you look into the philosophy of science, as described for example by Thomas Kuhn (see The Structure of Scientific Revolutions), you find that people tend to lock into a framework for doing science in a particular field, and they stick with it until a problem emerges that won’t go away. It is normal to persist, even in the face of apparent contradictions, because most of the time these contradictions are resolved in the context of the framework, or by small modifications to it. When something persists as a problem, it attracts the attention of the brightest and most ambitious in the field, who either earn a feather in the cap by fixing it; or earn a new hat by overthrowing the framework - which happens very rarely. But in the course of what Kuhn calls “normal science”, there is always “bad news” (inconsistencies) and “good news” (resolutions of inconsistencies): a theory that always and only has good news ceases to be an area of research (it becomes part of engineering), and an area that only has bad news becomes a construction zone for a new theory. I would say that climate science is far from being part of engineering, but has plenty of solidity as a real science. People who want to sell a new idea have to make a case that they can cover a very significant amount of what is already understood before they can convince the scientific community to toss out the old framework. The “alternative” ideas which are brought forth by most of the skeptics don’t come close; in fact, in many cases they have been taken from the junk-heap of ideas already considered and discarded over the history of climate science (I refer you to the website at the American Institute of Physics, above).
Hi Neal,
Thoughtful post (23), but wrt “When the error was fixed, the temperature trend expected, based on the surface-level measurements, appeared; and that long-standing problem disappeared.”
Wasn’t the trend expected to be ~1.2 times the GMST trend? Last time I had looked it seemed to still be quite a bit less than the GMST trend estimations. Wouldn’t it be more accurate to say that there is still somewhat of a discrepancy there?
This might seem irrelevant at first sight, but I thought that this issue might be of interest to the blog owner:
http://failingsofhivaidstheory.homestead.com/
Basically there are many scientists out there saying that HIV cannot cause AIDS, but they don’t get much attention. Henry Bauer approaches the issue primarily by examining the numbers and statistics I guess. He also has some extra info on that website and a regularly updated blog.
Apart from that you can find a lot more information on various other websites if you simply google “rethinking aids” or something like that.
HIV “denialism” is very similar to AGW “denialism” but I guess many AGW “denialists” don’t know about them. I personally think it’s currently a much more important issue, that’s not to say GW isn’t important. Just thought that I should mention it… You can remove this comment if it seems too irrelevant.
sadunkals last blog post..Objective approach to 9/11 Conspiracy Theories -Milgram
On second thought, maybe this book is more appropriote:
http://www.amazon.com/Science-Sold-Out-Really-Cause/dp/1556436424
It’s written by a mathematician who’s job was to construct mathematical models about HIV infection.
Mike N.,
My general impression on the lower-tropospheric temperature measurements is that people have been working very hard to get long-term information out of a system that was not designed for that purpose. It’s not just an issue of statistical uncertainties, but of trying to find the systematic problems. Of course, a data-processing error goes even beyond normal systematics, but in general it’s very hard to know when you’ve found all the problems. Especially when the basic problem is that the measurement set-up is not what you would have chosen for the quantities that are now of interest.
So, this is a long-winded way of saying that I think that you can’t expect too much from these measurements. A fuller discussion can be found at RealClimate (http://www.realclimate.org/index.php?p=170 ), but, as a non-professional in the area, I would say that the difference between expectation and results is not significant enough to constitute a real problem.
sandunkal,
For a few years, there was a rather eminent expert on retroviruses, Peter Duesberg, who argued that HIV did not have the signature of being a result of retroviruses. I followed the story for a few years, because it seemed that he was being unfairly treated by more conventional scientists, but couldn’t evaluate the science on my own. As time went on, it seems that his point of view has receded ever farther from acceptance.
One rather nasty side-effect of his raising this intellectual controversy is that it gave a particular idiot named Thabo Mbeki some cause to doubt the connection between transmission of AIDS and sex. He took it upon himself to “disabuse” other people of the conventional understanding of AIDS. By tremendous bad luck, Mbeki happens to be the President of South Africa, so the result of this intellectual controversy is that the program to fight AIDS in South Africa emphasized herbal medicines and de-emphasized condoms and attention to sexual issues generally. The stupendous expansion of AIDS in South Africa has been a direct result.
Of course we must not forget all of the people who suffered needlessly with ulcers because the “consensus” opinion refused to accept that ulcers could be a result of a bacterial infection.
Neal (27), thanks for the links. Last night I almost typed a few lines at the end of my post saying essentially the same thing as the first two sentences in your response, but they wouldn’t have been so succint or clearly expressed. Of course, I think we’d also be in agreement that there are considerable problems with the GMST estimates from the surface record as well. I don’t really consider either to be set in stone in any way.
Anyway, I had a quick gloss over the RC page, checked out their reference to Fu et al 2005, read a little, and went to their reference of Fu et al 2004(a) and see, “GCM studies have predicted a global ratio of ~1.2 (ref.
and a tropical ratio of ~1.54 (ref. 14).” It seems to me that the “expectations” haven’t appeared as of yet, hence my nitpicking of your post. 
As far as how important the discrepancy is, I guess we’ll just have to let them hash it all out.
PS. Another small nitpick, I took a look at the earlier Fu and Johanson 2004 J. Clim, and why do they round to -0.27 instead of -0.266? With a ton of linear extrap. going on even after that, you would think they’d want to keep it as accurate as possible? (it’s only the tiniest sliver, but of course it goes in the direction of the effect they’re trying to show
-Sorry for offtopic again but-
Neal,
The issue is much more complicated than that. I recommend to really investigate it all deeply and then make up your mind, or simply don’t make up your mind. I’ll just say that I don’t trust Duesberg either and that what Mbeki did -no matter right or wrong- takes a lot of courage. But we shouldn’t discuss this any further here. Whoever is interested in the subject can contact me.
Mike N.,
Haven’t looked at the paper, but maybe they felt that the actual uncertainties did not justify the extra precision implied. Recalling, again, that a lot of the uncertainty can be due to systematics rather than to statistics.
sandunkal,
You can call Mbeiki’s insistence on a scientifically controversial view of AIDS as courageous. I call it superstitious - and disastrous for his country, for Africa, and the world.
-offtopic-
Neal,
That’s because you don’t know enough about him or the science behind AIDS. Please read my last comment again. Inform yourself before you join the defaming:
http://www.youtube.com/watch?v=nY_Pu2gvI-4
And please don’t reply here anymore about this subject, I don’t want to ruin the comments but I also find it very hard to keep silent when you talk like that. We can continue here:
http://condeve.blogspot.com/2008/07/aids-niche-modeling.html
Thanks for your restraint. I have been busy on the other web site http://landshape.org/stats and unable to give these discussions much attention.
Returning to the main point:
There are always discrepancies in ongoing scientific research, otherwise the area is designated as engineering. If these persist over time, they catch attention and are either resolved or bring the framework down. This is how normal science works, according to Kuhn’s way of thinking, which is very popular among physicists, at least.
The history of the global-warming discussion fits into this way of looking at things, as laid out in Spencer Weart’s hyperlinked website, http://www.aip.org/history/climate/summary.htm . The field has had plenty of ups and downs, over a period of more than 100 years, but the basic framework has survived, like a canoe down a mountain rapid. With this perspective, I don’t see any reason to consider the current set of discrepancies as anything more than “the current set of discrepancies”.
Raven,
I just realized that you said something interesting on another thread: on posting #88 of “Radiative Equilibrium: Miskolczi Part 4″, you state:
“The basic physics of GHGs are not in dispute and even skeptics agree that adding CO2 to the atmosphere will result in some warming.”
But on this thread, we are talking about Evans’ article, which affirms: “There is no evidence to support the idea that carbon emissions cause significant global warming. None. ”
Please clarify your position regarding Evans’ article.
Neal,
“But on this thread, we are talking about Evans’ article, which affirms: “There is no evidence to support the idea that carbon emissions cause significant global warming. None. ”
Evans’ claim that there is no empirical evidence to be found that supports the notion that carbon emissions cause significant global warming does not dispute the notion that basic physics of GHGs suggest they will cause some warming. It merely states that there is no evidence for it, that in turn might mean that the observations are wrong or that the basic physics employed is too basic or over simplified or something else as yet unknown is not quite right.
Jan Pompe,
That is your point of view. But I am specifically asking Raven to clarify his point of view, because he has stated: “The basic physics of GHGs are not in dispute and even skeptics agree that adding CO2 to the atmosphere will result in some warming.” (emphasis added).
Raven did not say, “The basic physics of GHGs suggest that adding CO2 to the atmosphere will result in some warming.”
So, Raven, please provide your position on this point.
Let’s have a quick look at Dimitris Koutsoyianannis’ hydrology paper
Hydrological Sciences–Journal–des Sciences Hydrologiques, 53(4) August 2008.
One conclusion he reaches regarding precipitation is
“However, where tested, replacement of the modelled time series with a series of monthly averages (same for all years) resulted in higher efficiency.”
A large part of the argument for GHG warming is the model residual when other factors are subtracted. If the models are wrong, the residual is wrong. (Note, the correct residual, if any, can be higher or lower than actual. I have expressed no opinion).
Although not a killer observation, this is just another ecent piece of evidence that questions the AGW concept.
Now, Neal, if you can explain this away with neutral reasoning, I’d be delighted by your diligence.
Geoff Sherrington, #39:
The argument for GHG warming is that, based on the understanding we have of atmospheric physics, it would be extremely surprising if an increase in CO2 did NOT result in a warming - as Raven has admitted: See #36.
But since you bring this up, maybe you could exhibit the full logical & quantitative connection between GHE and precipitation. I am quite sure that there are lots of uncertainties about cloud behavior (for example) that would severely limit a firm prediction on precipitation, based on ANY model - including one that does not assume GHG warming.
- Indeed, according to K’s presentation at http://www.itia.ntua.gr/getfile/850/2/documents/2008EGU_ClimatePredictionPr_.pdf
“According to IPCC AR4 (Randall et al.,
2007) GCMs have better predictive
capacity for temperature than for other
climatic variables (e.g. precipitation) and
their quantitative estimates of future
climate are particularly credible at
continental scales and above.” So IPCC is not vaunting their modeling of precipitation.
- Your argument will be more powerful when a climate model is presented, that does NOT include GW, but better predicts precipitation trends. Got a candidate?
Re #40 Neal,
There is a long-held realisation among virtually all of my scientific colleagues that the main mechanisms of radiation absorption by carbon dioxide and other greenhouse gases in the atmosphere are qualitatively likely, but the consensus varies about quantity and the less quantifiable effects of clouds, etc as has been so often stated in the past.
To the extent that those who rely upon models not adding up, to set the quantity factor, yes, there is a big argument.
When people invoke temperature changes of the magnitude of IPCC because such magnitudes are needed to satisfy the model gap, we tend to part philosophic company because the onus of proof has to be on the proposers. The first step is to show the models are right. This has patently not been done.
I worked in a highly successful mineral exporation team for many years. It was part of my job to evaluate new proposals and to allocate funding to those judged to have the best chance of success. Apart from climate having a temporal component (whereas we worked mainly spatially) there is a lot of overlap in ways of dealing with earth science data.
Because of the stationary nature of our targets, what we set out to show could be modelled again if we succeeded once. Thus, model refinement proceeded on the basis of demonstrated success.
Typically, about one out of 100 - 1,000 anomalous areas we tested would produce a payable ore deposit. Even among those of similar geology, or on a similar mineral field, we did not ever attempt an ensemble approach to “improve the look” of our model.
Instead, we evolved algoriths that we self-calibrated from our measured data. There were few others in the world using some methods so precisely. That is why we succeeded. We stuck to plausible science, we used quality control, we documented, we held frequent seminars and overviews and we had no barriers to communication from bottom to top. At the top there were extremely science-conscious leaders who would not let pass any excuse for science. If we failed to find a goal on a property in a set time, the law required that we pass ownsership to others.
One result of this intensity of science was that nobody who followed us in an audit role exposed significant errors in our work. Sometimes we had passed up a marginal find that became economic in the hands of others because commodity prices improved, or extraction technology. But the mathematical validity of our early models still stands. Some were developed in the 1960s, on mechanical calculators.
We did not develop models for the reason that there was a gap between what we measured and what we thought the models should show. We developed models that found ore deposits, then invented and developed more ways to add support.
Above all, our careers lived or died by our success in returning a corporate profit. A high bang for the buck. We called it accountability. We scientists did not make public pronouncements about the importance of our finds. Stock market rules imposed tight constraints, so that the eventual statement by the Board of Directors was, in blue chip companies, not really questionable. It was certainly not speculative, not designed able to affect the actions/emotions of people before the answers were in.
So, having a career that evolved in those conditions, I must turn your invitation back to you. I am not going to create a new global climate model. But, I am able to form an opinion on those that exist and I will continue to offer opinion until the “gap” is resolved. That can only happen when the standards and methods of modellers improves. The record so far is not at all good. Many people would be out in the cold by now if they had been in “our team” and done what is being done now.
So, Neal, it is up to the AGW believers to convince experienced others that their findings can be used confidently, with a high chance that they are right.
And yes, I have read about all of IPCC 2008 and many of the references as well. So I was well aware of what you note about thermometry being better grounded than hydrology. It’s just as shame that both fail so many tests.
The model has to be right for hydrology as well as for thermometry and Dr Koutsouyannis is the most recent to cast more doubt.
I was intrigued by this definition in Wikipedia.
Pseudoscience is defined as a body of knowledge, methodology, belief, or practice that is claimed to be scientific or made to appear scientific, but does not adhere to the scientific method,[2][3][4] lacks supporting evidence or plausibility,[5] …
Not the whole of climate science and not only climate science. Just identifying our common enemy.
Geoff Sherrington, #41:
The fact is that the climate problem is loads harder than your likelihood-of-mine-worthiness problem:
Having one system that changes in time, due to many variables and dynamics about which you do not fully know and most of which are beyond your control, is much more complicated than having a sequence of static systems.
If you do not believe this, feel free to outdo the climatologists and get your own Nobel Prize: If you succeed in the first endeavor, I’m sure the second will be forthcoming.
In the meantime, deciding to simply not act is also a decision. Waiting for things to become clearer is not like waiting to test the next mining possibility: We don’t have a spare planet, so it’s not just a matter of losing one mining opportunity to a competitor. The analogy to Spaceship Earth is more appropriate: Our best experts are convinced there is a problem. We can implement their proposals; or we can hope that our best experts are wrong.
davids, #44:
I understand the issue. The fundamental problem is that we don’t have multiple Earths which can be subjected to different experiments. And even if we had a few Earths, we don’t fully understand the dynamics which go on that have nothing to do with additional CO2.
This reminds of the situation in astrophysics as well: There are a lot of research situations for which it is impossible to find a second example of anything, so it’s very difficult to test a model. I remember being told about one phenomenon for which the same (rather eminent) astrophysicist wrote three different papers, proposing three completely different explanations. I found this frustrating.
However, just as we have only one universe, we only have one Earth (available to us). We have to make the scientific best out of our situation, rather than just say that “It’s not repeatable, we can’t do science.”
Neal, #43#44,
This acting out of fear will also have a huge cost. It’s not as simple as “We save the planet, or we don’t”. It’s more like “We make huge sacrifices because we’re afraid that the experts may be right, or we wait until the experts give us more plausible reasons to be afraid.” I guess you’re also familiar with Bjorn Lomborg’s proposals.
Panic without strong foundations shouldn’t be the driving force behind global policy changes.
I’ll also go back to Feynman once again now:
“We are at the very beginning of time for the human race. It is not unreasonable that we grapple with problems. But there are tens of thousands of years in the future. Our responsibility is to do what we can, learn what we can, improve the solutions, and pass them on. It is our responsibility to leave the people of the future a free hand. In the impetuous youth of humanity, we can make grave errors that can stunt our growth for a long time. This we will do if we say we have the answers now, so young and ignorant as we are. If we suppress all discussion, all criticism, proclaiming “This is the answer, my friends; man is saved!” we will doom humanity for a long time to the chains of authority, confined to the limits of our present imagination. It has been done so many times before.
It is our responsibility as scientists, knowing the great progress which comes from a satisfactory philosophy of ignorance, the great progress which is the fruit of freedom of thought, to proclaim the value of this freedom; to teach how doubt is not to be feared but welcomed and discussed; and to demand this freedom as our duty to all coming generations. ”
As you said, climate modeling is much more complicated, but I see this as something which makes the experts much less credible and not more important.
#41, Geoff Sherrington:
Nice story…
sadunkal:
- Lomborg’s estimate for the cost to fix the CO2 problem (even though he did not recommend it) was one year’s growth by 2100. In other words, the difference in economic growth would be such that in the year 2100, we would only have developed as far as we would have by 2099 under the expectation of not-acting on AGW.
One year out of 92 is not much of a slow-down.
- Unfortunately, whatever is happening to the world will not wait for us to satisfy 100% of the population, or 100% of the scientific population. On a much smaller percentage of scientific consensus on nuclear weapons, the U.S. proceeded with the Manhattan Project - a project in which Feynman participated.
- So the more complicated the problem, the more you trust the non-experts? I don’t think Feynman would have liked to be interpreted in that way. The point about “not trusting experts” is not to just doubt what they know, but to get deeply into the material. The revolutionaries in science are the folks (like Galileo, Copernicus, etc.) who knew more deeply than everyone else, not people who denied knowledge. Feynman distinguished carefully between having an open mind and having an empty mind.
Neal,
-Really? I’m not so sure about that. Could you send a link or sth. about this. He sure gave me the impression that the difference would be much more if we would focus on more immediate problems like poverty, diseases etc… And I also believe to have heard him say that our efforts won’t be enough to stop the AGW anyway.
- I don’t get why you give the Manhattan Project as an example. You think it was a good thing that they proceeded?
-”So the more complicated the problem, the more you trust the non-experts?”
Is that really how you understood what I said or is it just an attempt to dismiss my argument somehow?
I find this a little too ridiculous, sorry…
- Lomborg, http://sophistpundit.blogspot.com/2006/07/finding-right-question.html:
“Yet, one could be tempted to suggest that we are actually so rich that we can afford both to pay a partial insurance premium against global warming (at 2-4 percent of GDP), and to help the developing world (a further 2 percent), because doing so would only offset growth by about 2-3 years. And that is true. I am still not convinced that there is any point in spending 2-4 percent on a pretty insignificant insurance policy, when we and our descendants could benefit far more from the same investment placed elsewhere. But it is correct that we are actually wealthy enough to do so.
And this is one of the main points of this book.”
- Manhattan Project: It was a necessity of the war effort. Moral issues were put aside entirely, but the question has to do with technical & scientific doubts. There were some, but the experts were allowed to make the decision. Feynman went along with that.
- You said “climate modeling is much more complicated, but I see this as something which makes the experts much less credible and not more important.” But influence is like a see-saw: When the influence of one group (the experts) goes down, the influence of the other group (the non-experts) goes up. Is this what you want, that the people who know less should have increased influence?”
Neal, are you saying temperature is not affected by precipitation? Is this the position of the experts?
thanks, jim
jimdk,
No, what I’m saying is that the IPCC is not claiming great accuracy with their projections of precipitation. So there isn’t much point in dinging them for it.
Analogy: You hire a pitcher for how well he pitches with his best hand, not how well he pitches with his worst hand.
The goal is to get the best insight you can get. Somebody who’s scoring 50% is doing a lot better than somebody who’s doing 0%.
Neal,
I think it is important to distinguish between saying the experts are wrong and saying the experts are exagerrating the certainty of their claims. The latter is definitely happening in climate science and this constant exaggeration of certainty has politicized the debate and made it much more difficult set policy.
In fact, I find the false claims of certainty are simply used as a polictical hammer in order to push for particular policy outcomes. For example, the average left leaning anti-CO2 activist does not like nuclear power yet such opposition makes no sense if the science was actually as certain as they claim.
If politicians have to set CO2 policy they should be given an accurate picture of how little we really know. This will mean that politicians will not be able to justify moving as fast or as radically as many activists would like.
Neal, As a scientist, I would not make a judgement call as to whether finding ore deposits was easier than climatology. Seek the evidence. I acknowledged the extra dimension of time. A scientist would make a comparison of the technical issues with each pursuit, try to quantify them try to balance/compare them. What you have done is an old-fashioned arm-wave without proof.
That is a recurrent problem with modern climate investigation. In essence, your posts here go a long way to making a case for cessation of climate modelling because of unavailiblity of critical data. We used to say that knowing when to enter a project is 30% of the case; knowing when to get out is 70%. Also, we would set progressive benchmarks and withdraw when they were not met.
It is not only difficulty, it a deficiency of methodologic design that plague global warming debate, Who else would write a summary for policy makers before the cited science papers were completed and accepted?
I also disagree with your claim that ….. “There is no “ideal” temperature, but when the temperature changes from whatever it is to something else rapidly, it puts the different species inhabiting the Earth under extreme stress, collectively.” This is a half-full/half empty glass argument, with you the pessimist. It remains to be shown whether temperature flucuations enhance or decrease the populations of genera - and who is to say what is a good genus and was is an unwanted one. Coping with change is an imperative not limited to Homo sapiens. Maybe it is even an integral part of Darwinian theory.
Disagreement also with your assertion in # 18 that ….. “But real “proof” is something that is restricted to the realm of mathematics.” We reached a stage in one region where, by measuring surface magnetic field perturbations, we could predict the size, attitude and depth to the top (to several hundred m depth) of discrete mineral bodies containing magnetite. There was a minimal probaility of being wrong, as we showed by drilling more than 100 of these with 2 or more drill holes. What more “proof” do you need? This was cutting edge geophysical modelling/testing and it was RIGHT. Later we used methods like lead isotopes and the decrepitometry of fluid inclusions to distinguish those that were barren of gold and copper from those which might make mines. It was mutidisciplinary, it was hard, it was intensely mathematical and rigidly controlled and possibly no easier than climatology.
When you drift into discussion of the philosophy of science, (which is about the ultimate stage in the progression of activities of a scientist) I feel that you might like to read the several books about an unrelated namesake, Sir Charles Sherrington, died 1952. Nobel Laureate, twice Pres of the Royal Soc of London, discoverer of cure for diphtheria……. IMO, ranks with Popper. Amazing what he did without supercomputers.
Raven,
I believe that, in the media, there is at least at much exaggeration of our ignorance as there is of our knowledge.
It is still extremely common to see articles and comments saying, “Global Warming is only a theory. No one has proven the greenhouse effect.”
Whereas, as you admitted earlier, even the more skeptical climatologists agree that the greenhouse effect is an actuality.
Ooops, here we go again. I do not admit that the greenhouse theory as popularly expressed is a reality and I have never accepted it. I do accept the physics reported so far, of interaction between radiation of various wavelengths and GHG on a qualitative scale and have major problems with feedback. After all, I did a couple of years of reasearch on hich-powered CO2 lasers and so I am not ignorant of much relevant physics.
I have no interest in proving the ‘greenhouse theory’ because it is wrongly posited. It’s bit like the theory, still popular, that farmers can bury a cow horn of excrement in a corner of a field when the moon is in the right phase, to increase crop yield.
Neal, the pitcher’s worst hand does not affect his best hand. How can we claim confidence in temp models when we have no ability with precipitation which does affect temperature?
#52, Geoff Sherrington:
1) Relative difficulty of ore-deposit modeling vs. climatology: Here’s the hand behind the wave:
- Variables:
For ODM: constant in time and spatially limited. For C: changing in time and spatially covering the entire globe.
- Dynamics:
For ODM: Nothing is changing, so nothing depends on anything else.
For C: Temperature affects wind-speed affects pressure affects humidity affects cloud formation; time-changing inputs such as human-generated pollutants and land-use changes as well as volcanic eruptions…
- Data collection:
For ODM: You can get collect data at whatever spatial intensity you want, and you can go back and apply better instruments if you want.
For C: If you miss the data, or didn’t take it at sufficient frequency (spatial frequency as well as in time), too bad: You can’t go back and get it. Whatever data you have from the past is what it is: No one has invented a time machine for going back to put in-place the instruments you would have wanted to have, instead of the ones actually used, because the people who were in charge at the time inconsiderately didn’t think what the future experimenters would want, and in fact had something rather different in mind at the time. Not to mention those unhelpful trees and corals that didn’t just provide calibrated thermometers instead of requiring detective work to try to sort out different kinds of temperature & precipitation or pH inter-dependencies.
Yes, on balance: I might not find ore-deposit modeling that interesting, but if my life depended on getting the answers right, I’d gravitate towards ODM and not toward Climatology: Climatology looks orders of magnitude harder.
2) “Withdrawing when the benchmarks are not met”: The loss in the event of you withdrawing from a potential mining site is a commercial risk. The loss in the event of an environment that is much worse for human habitation - even if that happens in 200 years - is rather more significant. For you to “write off” that risk is the height of irresponsibility. Is that what the folks planning the Manhattan project should have done? “The problem looks too hard. Let’s forget about it.”
3) “Who else would write a summary for policy makers before the cited science papers were completed and accepted?” My understanding is that the window for considering papers was closed 6 months before the technical reports were essentially finalized; that the Summary was written up after that; and some wording was changed in the technical reports to make the vocabulary and framework consistent.
4) “It remains to be shown whether temperature fluctuations enhance or decrease the populations of genera”:
- http://www.world-science.net/othernews/071022_mass-extinction.htm
- http://www.sciencedaily.com/releases/2004/10/041001092938.htm
- http://www.grist.org/advice/books/2001/12/12/point/
What I have gathered from my reading is that it takes about 1 million years for a really distinct species to evolve. That suggests that any major change that happens on timescales much shorter than that can likely not be adapted-around, if it is a problem. A 2-3 degree change in global average temperature is fairly big (we’re only 5 degrees from the middle of the last ice age), so if that happens over 100 or 200 years, we are asking for trouble.
Already happening: pine forests in North America are being ravaged by pine beetles. Why? Because the beetles are no longer dying in the winter cold, but surviving until spring. Then they come out hungry: http://www.washingtonpost.com/wp-dyn/content/article/2006/02/28/AR2006022801772.html
5) Proof: Real proof is a mathematical concept. From that point of view, not even relativity or quantum mechanics or even hydrodynamics has been “proven” - and any one of them is more of a scientific foundation stone than your ore-deposit model.
6) Philosophy: My interest in philosophy of science runs more towards Thomas Kuhn, as in “The structure of scientific revolutions.”
7) Computers: These days they make progress in quantum field theory using lattice field theory - which is numerical computation applied to QFT. The famous four-color map theorem was proven with computers. Richard Feynman - no slouch at mathematical invention and prestidigitation - advertised numerical integration as the final resolution to complex dynamical problems with differential equations. Computers are used as just a way of doing computations - nothing more, nothing less.
Geoff Sherrington, #54:
“I do not admit that the greenhouse theory as popularly expressed is a reality and I have never accepted it.”
“I do accept the physics reported so far, of interaction between radiation of various wavelengths and GHG on a qualitative scale…”
The second item is the theory of the enhanced greenhouse effect. If you want to actually get quantitative, you can consult:
- John Houghton, The Physics of Atmospheres
- R.T. Pierrehumbert, Principles of Planetary Climate,
http://geosci.uchicago.edu/~rtp1/ClimateBook/ClimateVol1.pdf
The basic physics of radiative transfer is not considered controversial, and is widely used in astrophysics, in studies of stellar structure and stellar evolution. Leading to, among other things, the prediction of supernovae - which have now been observed.
jimdk, #55:
The basic physics of the model is based on the understanding that when there is more solar-radiation power being absorbed than infrared-radiation power being emitted, the build-up in energy will be reflected in the global average temperature: Roughly speaking, the amount of stuff affected, multiplied by the average heat capacity, multiplied by the change in global average temperature, should equal the increase in energy.
What evaporation and precipitation do is to absorb some of that heat and to move it somewhere else. But that is similar to the wind moving heat from one area to another: It changes the local temperature, but it doesn’t affect the overall average (since neither the wind nor precipitation move that energy out into space).
Now, uncertainties in the amount of cloud formation are a problem, because if there are clouds at high altitude, they reflect the solar energy away, which would reduce the input from solar radiation. This is a very well-known issue, which is consistently listed in the IPCC reports as deserving focus, and as being a source of uncertainty. The only ones who don’t seem to be aware of this are the GW-deniers, who keep pretending that they are the only ones who have noticed this “scandal”!
jimdk, #55, part 2:
So there could be substantial uncertainty in the precipitation predictions without that necessarily being a problem for global-average-temperature trend projections.
Neal, #48
- The quote you’ve sent is from his 7 years old book. Lomborg certainly opposes current GW policies very strongly now, since they only became less rational in the last years:
http://youtube.com/watch?v=OU5c78UyWbQ
http://online.wsj.com/article/SB121141221734512357.html
- Maybe it’s because I’ve never been an American but I can’t see the Manhattan Project as a good thing. As far as I know it also left Feynman scarred, he wasn’t so proud of what they had done. I believe you chose a bad example.
- The thing is, the “non-experts” aren’t trying to push a global change, mostly they aren’t pushing anything. So basically there is no influence going on fro