Why CAGW theory is not “settled science”

In Andi Cockroft’s story yesterday Climate Science and Special Relativity he asked a prescient question:

For the general public that does not have an objective scientific bent, how do you tell virtual reality from the real thing?

Dr. Brown responded in comments, which was so well thought out, it benefits everyone by elevating it to full post status, and thus is presented below. Like The Skeptics Case, I highly recommend this one as a “must read”. – Anthony


Guest post by Dr. Robert Brown, Duke University Physics Department

For the general public that does not have an objective scientific bent, how do you tell virtual reality from the real thing?

That’s a serious problem, actually. Hell, I have an objective scientific bent and I have plenty of trouble with it.

Ultimately, the stock answer is: We should believe the most what we can doubt the least, when we try to doubt very hard, using a mix of experience and consistent reason based on a network of experience-supported best (so far) beliefs.

That’s not very hopeful, but it is accurate. We believe Classical Non-Relativistic Mechanics after Newton invents it, not because it is true but because it works fairly consistently to describe Kepler’s purely observational laws, and (as it is tested) works damn well to describe a lot of quotidian experience as well on a scale less grand than planetary orbits. We encounter trouble with classical mechanics a few hundred years later when it fails to consistently describe blackbody radiation, the photoelectric effect (the one thing Einstein actually got the Nobel Prize for), the spectra of atoms, given Maxwell’s enormously successful addition to the equations of electricity and magnetism and the realization that light is an electromagnetic wave.

Planck, Lorentz, Einstein, Bohr, de Broglie, Schrodinger, Heisenberg and many others successively invent modifications that make space-time far more complex and interesting on the one hand — relativity theory — and mechanics itself far, far more complex than Newton could ever have dreamed. The changes were motivated, not by trying to be cool or win prizes, but by failures of the classical Euclidean theory to explain the data! Basically, Classical flat-space mechanics was doomed the day Maxwell first wrote out the correct-er equations of electrodynamics for the first time. We suddenly had the most amazing unified field theory, one that checked out empirically to phenomenal accuracy, and yet when we applied to cases where it almost had to work certain of its predictions failed spectacularly.

In fact, if Maxwell’s Equations and Newton’s Law were both true, the Universe itself should have existed for something far, far less than a second before collapsing in a massive heat death as stable atoms based on any sort of orbital model were impossible. Also, if Maxwell’s equations and flat spacetime with time an independent variable was correct, the laws of nature would not have had the invariance with respect to reference frame that Newtonian physics had up to that time enjoyed. In particular, moving a charged particle into a different inertial reference frame caused magnetic fields to appear, making it clear that the electric and magnetic fields were not actually vector forms! The entire geometry and tensor nature of space and time in Newtonian physics was all wrong.

This process continues today. Astronomer’s observe the rotational properties of distant galaxies to very high precision using the red shift and blue shift of the stars as they orbit the galactic center. The results don’t seem to agree with Newton’s Law of Gravitation (or for that matter, with Einstein’s equivalent theory of general relativity that views gravitation as curvature of spacetime. Careful studies of neutrinos lead to anomalies, places where theory isn’t consistent with observation. Precise measurements of the rates at which the Universe is expanding at very large length scales (and hence very long times ago, in succession as one looks farther away and back in time at distant galaxies) don’t quite add up to what the simplest theories predict and we expect. Quantum theory and general relativity are fundamentally inconsistent, but nobody knows quite how to make a theory that is “both” in the appropriate limits.

People then try to come up with bigger better theories, ones that explain everything that is well-explained with the old theories but that embrace the new observations and explain them as well. Ideally, the new theories predict new phenomena entirely and a careful search reveals it there where the theory predicts. And all along there are experiments — some of them fabulous and amazing — discovering high temperature superconductors, inventing lasers and masers, determining the properties of neutrinos (so elusive they are almost impossible to measure at all, yet a rather huge fraction of what is going on in the Universe). Some experiments yield results that are verified; others yield results — such as the several times that magnetic monopoles have been “observed” in experiments — that have not been reproducible and are probably spurious and incorrect. Neutrinos that might — even now — have gone faster than light, but again — probably not. A Higgs particle that seems to appear for a moment as a promising bump in an experimental curve and then fades away again, too elusive to be pinned down — so far. Dark matter and dark energy that might explain some of the unusual cosmological observations but a) are only one of several competing explanations; and b) that have yet to be directly observed. The “dark” bit basically means that they don’t interact at all with the electromagnetic field, making them nearly impossible to see — so far.

Physicists therefore usually know better than to believe the very stuff that they peddle. When I teach students introductory physics, I tell them up front — “Everything I’m going to teach you over the next two semesters is basically wrong — but it works, and works amazingly well, right up to where it doesn’t work and we have to find a better, broader explanation.” I also tell them not to believe anything I tell them because I’m telling them, and I’m the professor and therefore I know and its up to them to parrot me and believe it or else. I tell them quite the opposite. Believe me because what I teach you makes sense (is consistent), corresponds at least roughly with your own everyday experience, and because when you check it in the labs and by doing computations that can be compared to e.g. planetary observations, they seem to work. And believe me only with a grain of salt then — because further experiments and observations will eventually prove it all wrong.

That isn’t to say that we don’t believe some things very strongly. I’m a pretty firm believer in gravity, for example. Sure, it isn’t exactly right, or consistent with quantum theory at the smallest and perhaps largest of scales, but it works so very, very well in between and it is almost certainly at least approximately true, true enough in the right milieu. I’m very fond of Maxwell’s Equations and both classical and, in context, quantum theory, as they lead to this amazing description of things like atoms and molecules that is consistent and that works — up to a point — to describe nearly everything we see every day. And so on.

But if somebody were to argue that gravitation isn’t really a perfect 1/r^2 force, and deviations at very long length scales are responsible for the observed anomalies in galactic rotation, I’d certainly listen. If the new theory still predicts the old results, explains the anomaly, I’d judge it to be quite possibly true. If it predicted something new and startling, something that was then observed (variations in near-Earth gravitation in the vicinity of Uranium mines, anomalies in the orbits of planets near black holes, unique dynamics in the galactic cores) then I might even promote it to more probably true than Newton’s Law of Gravitation, no matter how successful, simple, and appealing it is. In the end, it isn’t esthetics, it isn’t theoretic consistency, it isn’t empirical support, it is a sort of a blend of all three, something that relies heavily on common sense and human judgement and not so much on a formal rule that tells us truth.

Where does that leave one in the Great Climate Debate? Well, it damn well should leave you skeptical as all hell. I believe in the theory of relativity. Let me explain that — I really, really believe in the theory of relativity. I believe because it works; it explains all sorts of experimental stuff. I can run down a list of experimental observations that are explained by relativity that could scarcely be explained by anything else — factors of two in spin-orbit coupling constants, the tensor forms and invariants of electromagnetism, the observation of \mu-mesons produced from cosmic ray collisions in the upper atmosphere far down near the surface of the Earth where they have no business being found given a lifetime of \sim 2 microseconds — and observation I personally have made — and of course all the particle accelerators in the known Universe would fail miserably in their engineering if relativity weren’t at least approximately correct. Once you believe in relativity (because it works) it makes some very profound statements about causality, time ordering, and so on — things that might well make all the physics I think that I know inconsistent if it were found to be untrue.

Yet I was — and continue to be — at least willing to entertain the possibility that I might have to chuck the whole damn thing, wrong from top to bottom — all because a silly neutrino in Europe seems to be moving faster than it should ever be aver to move. Violations of causality, messages from the future, who knows what carnage such an observation (verified) might wreak! I’m properly skeptical because what we have observed — so far — works so very consistently, and the result itself seems to be solidly excluded by supernova data already in hand, but you know, my beliefs don’t dictate reality — it is rather the other way around.

The sad thing about the Great Climate Debate is that so far, there hasn’t really been a debate. The result is presented, but no one ever takes questions from the podium and is capable of defending their answers against a knowledgeable and skeptical questioner.

I can do that for all of my beliefs in physics — or at least, most of them — explain particular experiments that seem to verify my beliefs (as I do above). I’m quite capable of demonstrating their consistency both theoretically (with other physical laws and beliefs) and with experiment. I’m up front about where those beliefs fail, where they break down, where we do not know how things really work. Good science admits its limits, and never claims to be “settled” even as it does lead to defensible practice and engineering where it seems to work — for now.

Good science accepts limits on experimental precision. Hell, in physics we have to accept a completely non-classical limitation on experimental precision, one so profound that it sounds like a violation of simple logic to the uninitiated when they first try to understand it. But quite aside from Heisenberg, all experimental apparatus and all measurements are of limited precision, and the most honest answer for many things we might try to measure is “damfino” (damned if I know).

The Great Climate Debate, however, is predicated from the beginning on one things. We know what the global average temperature has been like for the past N years, where N is nearly anything you like. A century. A thousand years. A hundred thousand years. A hundred million years. Four billion years.

We don’t, of course. Not even close. Thermometers have only been around in even moderately reliable form for a bit over 300 years — 250 would be a fairer number — and records of global temperatures measured with even the first, highly inaccurate devices are sparse indeed until maybe 200 years ago. Most of the records from over sixty or seventy years ago are accurate to no more than a degree or two F (a degree C), and some of them are far less accurate than that. As Anthony has explicitly demonstrated, one can confound even a digital electronic automatic recording weather station thermometer capable of at least 0.01 degree resolution by the simple act of setting it up in a stupid place, such as the southwest side of a house right above a concrete driveway where the afternoon sun turns its location into a large reflector oven. Or in the case of early sea temperatures, by virtue of measuring pails of water pulled up from over the side with crude instruments in a driving wind cooling the still wet bulb pulled out of the pail.

In truth, we have moderately accurate thermal records that aren’t really global, but are at least sample a lot of the globe’s surface exclusive of the bulk of the ocean for less than one century. We have accurate records — really accurate records — of the Earth’s surface temperatures on a truly global basis for less than forty years. We have accurate records that include for the first time a glimpse of the thermal profile, in depth, of the ocean, that is less than a decade old and counting, and is (as Willis is pointing out) still highly uncertain no matter what silly precision is being claimed by the early analysts of the data. Even the satellite data — precise as it is, global as it is — is far from free from controversy, as the instrumentation itself in the several satellites that are making the measurements do not agree on the measured temperatures terribly precisely.

In the end, nobody really knows the global average temperature of the Earth’s surface in 2011 within less than around 1K. If anybody claims to, they are full of shit. Perhaps — and a big perhaps it is — they know it more precisely than this relative to a scheme that is used to compute it from global data that is at least consistent and not crazy — but it isn’t even clear that we can define the global average temperature in a way that really makes sense and that different instruments will measure the same way. It is also absolutely incredibly unlikely that our current measurements would in any meaningful way correspond to what the instrumentation of the 18th and 19th century measured and that is turned into global average temperatures, not within more than a degree or two.

This complicates things, given that a degree or two (K) appears to be very close to the natural range of variation of the global average temperature when one does one’s best to compute it from proxy records. Things get more complicated still when all of the best proxy reconstructions in the world get turned over and turned out in favor of “tree ring reconstructions” based upon — if not biased by — a few species of tree from a tiny handful of sites around the world.

The argument there is that tree rings are accurate thermometers. Of course they aren’t — even people in the business have confessed (in climategate letters, IIRC) that if they go into their own back yards and cut down trees and try to reconstruct the temperature of their own back yard based on the rings, it doesn’t work. Trees grow one year because your dog fertilizes them, fail to grow another not because it is cold but because it is dry, grow poorly in a perfect year because a fungus attacks the leaves. If one actually plots tree ring thicknesses over hundreds of years, although there is a very weak signal that might be thermal in nature, there is a hell of a lot of noise — and many, many parts of the world simply don’t have trees that survived to be sampled. Such as the 70% of the Earth’s surface that is covered by the ocean…

But the complication isn’t done yet — the twentieth century perhaps was a period of global warming — at least the period from roughly 1975 to the present where we have reasonably accurate records appears to have warmed a bit — but there were lots of things that made the 20th century, especially the latter half, unique. Two world wars, the invention and widespread use and testing of nuclear bombs that scattered radioactive aerosols throughout the stratosphere, unprecedented deforestation and last but far from least a stretch where the sun appeared to be far more active than it had been at any point in the direct observational record, and (via various radiometric proxies) quite possibly for over 10,000 years. It isn’t clear what normal conditions are for the climate — something that historically appears to be nearly perpetually in a state of at least slow change, warming gradually or cooling gradually, punctuated with periods where the heating or cooling is more abrupt (to the extent the various proxy reconstructions can be trusted as representative of truly global temperature averages) — but it is very clear indeed that the latter 19th through the 20th centuries were far from normal by the standards of the previous ten or twenty centuries.

Yet on top of all of this confounding phenomena — with inaccurate and imprecise thermal records in the era of measurements, far less accurate extrapolations of the measurement era using proxies, with at most 30-40 years of actually accurate and somewhat reproducible global thermal measurements, most of it drawn from the period of a Grand Solar Maximum — climatologists have claimed to find a clear signal of anthropogenic global warming caused strictly by human-produced carbon dioxide. They are — it is claimed — certain that no other phenomena could be the proximate cause of the warming. They are certain when they predict that this warming will continue until a global catastrophe occurs that will kill billions of people unless we act in certain ways now to prevent it.

I’m not certain relativity is correct, but they are certain that catastrophic anthropogenic global warming is a true hypothesis with precise predictions and conclusions. I have learned to doubt numerical simulations that I myself have written that are doing simple, easily understandable things that directly capture certain parts of physics. They are doing far, far more complex numerical simulations — the correct theoretical answer, recall, is a solution to a set of coupled non-Markovian Navier-Stokes equation with a variable external driver and still unknown feedbacks in a chaotic regime with known important variability on multiple decadal or longer timescales — and yet they are certain that their results are correct, given the thirty plus years of accurate global thermal data (plus all of the longer timescale reconstructions or estimates they can produce from the common pool of old data, with all of its uncertainties).

Look, here’s how you can tell — to get back to your question. You compare the predictions of their “catastrophic” theory five, ten, twenty years back to the actual data. If there is good agreement, it is at least possible that they are correct. The greater the deviation between observed reality and their predictions, the more likely it is that their result is at least incorrect if not actual bullshit. That’s all. Accurately predicting the future isn’t proof that they are right, but failing to predict it is pretty strong evidence that they are wrong.

Such a comparison fails. It actually fails way back in the twentieth century, where it fails to predict or explain the cooling from 1945 to roughly 1965-1970. It fails to predict the little ice age. It fails to predict the medieval climate optimum, or the other periods in the last 10,000 years where the proxy record seems to indicate that the world was as warm or warmer than it is today. But even ignoring that — which we can, because those proxy reconstructions are just as doubtful in their own way as the tree-ring reconstructions, with or without a side-serving of confirmation bias to go with your fries — even ignoring that, it fails to explain the 33 or so years of the satellite record, the only arguably reliable measure of actual global temperatures humans have ever made. For the last third of that period, there has been no statistically significant increase in temperature, and it may even be that the temperature has decreased a bit from a 1998 peak. January of 2012 was nearly 0.1C below the 33 year baseline.

This behavior is explainable and understandable, but not in terms of their models, which predicted that the temperature would be considerably warmer, on average, than it appears to be, back when they were predicting the future we are now living. This is evidence that those models are probably wrong, that some of the variables that they have ignored in their theories are important, that some of the equations they have used have incorrect parameters, incorrect feedbacks. How wrong remains to be seen — if global temperatures actually decline for a few years (and stretch out the period with no increase still further in the process) — it could be that their entire model is fundamentally wrong, badly wrong. Or it could be that their models are partially right but had some of the parameters or physics wrong. Or it could even be that the models are completely correct, but neglected confounding things are temporarily masking the ongoing warming that will soon come roaring back with a catastrophic vengeance.

The latter is the story that is being widely told, to keep people from losing faith in a theory that isn’t working — so far — the way that it should. And I have only one objection to that. Keep your hands off of my money while the theory is still unproven and not in terribly good agreement with reality!

Well, I have other objections as well — open up the debate, acknowledge the uncertainties, welcome contradictory theories, stop believing in a set of theoretical results as if climate science is some sort of religion… but we can start with shit-canning the IPCC and the entire complex arrangement of “remedies” to a problem that may well be completely ignorable and utterly destined to take care of itself long before it ever becomes a real problem.

No matter what, we will be producing far less CO_2 in 30 years than we are today. Sheer economics and the advance of physics and technology and engineering will make fossil-fuel burning electrical generators as obsolete as steam trains. Long before we reach any sort of catastrophe — assuming that CAGW is correct — the supposed proximate cause of the catastrophe will be reversing itself without anyone doing anything special to bring it about but make sensible economic choices.

In the meantime, it would be so lovely if we could lose one single phrase in the “debate”. The CAGW theory is not “settled science”. I’m not even sure there is any such thing.


newest oldest most voted
Notify of

If the science is settled, then why don’t we cut all of the funding to the climate scientists ?
They aren’t needed anymore, because the science is settled.
Otherwise, we are just keeping them around to scare us with another over-hyped horrer story.


A ‘friend’ of mine wrote the following: Thought you might find it interesting:
‘………………………………………………Research in fundamental particle physics has culminated in our current Standard Model of elementary particles. Using ever larger machines, we have been able to identify and determine the properties of a whole zoo of elementary particles. These properties present many interesting patterns. All the matter we see around us is composed of electrons and up and down quarks, interacting differently with photons of electromagnetism, W and Z bosons of the weak force, gluons of the strong force, and gravity, according to their different values and kinds of charges. Additionally, an interaction between a W and an electron produces an electron neutrino, and these neutrinos are now known to permeate space — flying through us in great quantities, interacting only weakly. A neutrino passing through the earth probably wouldn’t even notice it was there. Together, the electron, electron neutrino, and up and down quarks constitute what is called the first generation of fermions. Using high energy particle colliders, physicists have been able to see even more particles. It turns out the first generation fermions have second and third generation partners, with identical charges as the first but larger masses. And nobody knows why. The second generation partner to the electron is called the muon, and the third generation partner is called the tau. Similarly, the down quark is partnered with the strange and bottom quarks, and the up quark has partners called the charm and top — with the top discovered in 1995. Last and least, the electron neutrinos are partnered with muon and tau neutrinos. All of these fermions have different masses, arising from their interaction with a theorized background Higgs field. Once again, nobody knows why there are three generations, or why these particles have the masses they do. The Standard Model, our best current description of fundamental physics, lacks a good explanation.
The dominant research program in high energy theoretical physics, string theory, has effectively given up on finding an explanation for why the particle masses are what they are. The current non-explanation is that they arise by accident, from the infinite landscape of theoretical possibilities. This is a cop out. If a theory can’t provide a satisfying explanation of an important pattern in nature, it’s time to consider a different theory. Of course, it is possible that the pattern of particle masses arose by chance, or some complicated evolution, as did the orbital distances of our solar system’s planets. But, as experimental data accumulates patterns either fade or sharpen, and in the newest data on particle masses an intriguing pattern is sharpening. The answer may come from the shy neutrino.
The masses of the three generations of fermions are described by their interaction with the Higgs field. In more detail, this is described by “mixing matrices,” involving a collection of angles and phases. There is no clear, a priori reason why these angles and phases should take particular values, but they are of great consequence. In fact, a small difference in these phases determines the prevalence of matter over antimatter in our universe. Now, in the mixing matrix for the quarks, the three angles and one phase are all quite small, with no discernible pattern. But for neutrinos this is not the case. Before the turn of the 21st century it was not even clear that neutrinos mixed. Too few electron neutrinos seemed to be coming from the sun, but people weren’t sure why. In the past few years our knowledge has improved immensely. We now know, from the combined effort of many experimental teams, that, to a remarkable degree of precision, the three angles for neutrinos have sin squared equal to 1/2, 1/3, and 0. We do need to consider the possibility of coincidence, but as random numbers go, these do not seem very random. In fact, this mixing corresponds to a “tribimaximal” matrix, related to the geometric symmetry group of a tetrahedron.
What is tetrahedral symmetry doing in the masses of neutrinos?!? Nobody knows. But you can bet there will be a good explanation. It is likely this explanation will come from mathematicians and physicists working closely with Lie groups. The most important lesson from the great success of Einstein’s theory of General Relativity is that our universe is fundamentally geometric, and this idea has extended to the geometric description of known forces and particles using group theory. It seems natural that a complete explanation of the standard model, including why there are three generations of fermions and why they have the masses they do, will come from the geometry of group theory. This explanation does not yet exist, but when it does it will be deep, elegant, and beautiful — and it will be my favorite…………….’
Any guesses who wrote it???????????????//

Doug S

Very well done professor. One of the saddest things to me is the lost opportunity in the climate media campaign to educate people on basic science. So much advocacy has been presented to people, falsely under the name of “science”, that I fear we have set back the general populations true understanding of what science is all about. You have presented an honest description of the true nature of science and I’m hopeful that your efforts along will so many other people of good faith will help us recover from this very damaging period of alarmism. Thank you.


I like the use of the term CAGW because it is the certainty of catastrophe that I disagree with, not that humans have affected climate somewhat.


An excellent essay, well deserving of this stand alone posting.

Pull My Finger

Do you ever get the feeling that god just loves to mess with Physicists? You struggle for decades to comprehend and test all these esoteric thories, and just when you think you’ve got… blammo!
Everyone with an opinion on AGW should read this.
Like I stated before, Global Warming is a rounding error.


NetDr – agreed it is important not to let them confuse people by changing the terminology. They are a predicting climate catastrophe due to man made global warming – without MMGW there is no catastrophe. CAGW is good too


Beautifully put, Doctor, thank you. It’s heartening to see such a clear, unequivocal description of the scientific method, and to see it applied to the dogma as it’s presented every day by scaremongers. I shall be pointing people to this…

Greg Locke

Heretic. Stone him, I say.

Dave in Canmore

Hear! Hear! This is the essence of science.

What a demolition job!
“… the correct theoretical answer, recall, is a solution to a set of coupled non-Markovian Navier-Stokes equation with a variable external driver and still unknown feedbacks in a chaotic regime with known important variability on multiple decadal or longer timescales —”
Thank you, thank you.
And now I must away, for I need to get in much wood for the looming, long, cold, southern hemisphere winter.



More Soylent Green!

While there are many useful computer models of various systems, that does not mean that the models are correct. They may work well within certain parameters and when the processes being modeled are well-understood.
However, computer models do not output data. Computer models do not output facts. Computer models do not qualify as “experiments,” but may qualify as “computer experiments.”
Computer models are software and work as programmed. In other words, computer models show various effects of increased CO2 because that’s how the models are programmed and not necessarily because that’s the way the real climate works.

Garry Stotel

Dear Dr Brown,
Heart felt thank you for the article.
I am REALLY tired of this CAGW bullshit. My question is how on God’s green Earth, in open and supposedly democratic societies, globally, such daring lies can exist for so bloody long, and cause so much damage? When CAGW crashes and burns, as it inevitably will, will the world be immunized against such nonsense for a good long while? I have no confidence in that, and I bet that the world will find itself another delusion, scare, religion or pagan belief to be afraid of and to which sacrifices are to be made…

An informal comment on a blog puts to shame the sorry stream of shallow-science, special pleading, and policy-led evidence-making that has marked the past 30 years or so, the troubled infancy of ‘climate science’. It has not been a healthy, vigorous child of a subject. It has been abused by its keepers who have pushed it beyond anything they have a right to claim. Their social science and political collaborators and funders have displayed even more irresponsible behaviour, extending their harm beyond the abstract world of a science, and into the real one in which real children have been deliberately frightened by horrible visions of the future, and real people have faced starvation because bio-fuel destroyed so much food, the price of it went up appreciably. They have also harmed our landscapes and seascapes with absurdly inefficient and extravagant methods for generating electricity, and weakened our economies by diversion of resources from more productive areas in order to provide subsidies for silliness and self-indulgence on a grand scale. They have also poisoned international relations by inventing a new grievance as a source of bitterness and hatred amongst nations – an off-the-shelf we-know-who-to-blame for each and every weather-related catastrophe. We may yet be some way from Peak Loss due to this period of inflated claims for the insights and knowledge of climate science. Mediocre science and superb political manipulation brought us to this. First-class science could help speed up our escape from it. Well done Dr Brown for giving us a glimpse of what might have been, and what might yet take place by way of deeper examination of whether and what substance might be found behind the miasma of rhetoric and moral and intellectual shoddiness we have had to endure for so long.

Excellent. Not only am I going to bookmark it in my “Gold” folder, I’m going to print this out and stick it in my well used copy of Asimov’s “The Relativity of Wrong”

Accurately predicting the future isn’t proof that they are right, but failing to predict it is pretty strong evidence that they are wrong.
[i]t would be so lovely if we could lose one single phrase in the “debate”. The CAGW theory is not “settled science”. I’m not even sure there is any such thing.

I do not wish to loose the phrase “settled science”; I wish to use it as a scientific marker. Use of that phrase in a statement concerning any theory can and should be used by others as a warning label on the quality of the statement.

Big D in TX

Excellent summary, I will be linking this post to friends.

David Walton

This is the single best summary I have ever read of why CAGW is not “settled science” and begs the question, “Is it even science?”
Thank you Dr. Robert Brown.

David Wells

Oh joy! On the Bloomberg site they are in raptures because Spain managed to generate 4,890,000MW from their wind turbines an exultant 2% of their total electrical needs, now isnt that fantastic. Even more underwhelming was Dr Peter Musgrove – Times Letters – foaming at the mouth because Professor Michael Kelly said there were 14,000 abandoned wind turbines in America pointing out that the USA now had 46,000 MW of wind capacity which in 2010 managed to generate unprecendented 94,652,000 MW or 2% of 4,125,060,000 MW. So if wind turbines are the future of renewable energy what is the real future of electricity generation because as 2010 was the best year of wind turbine installations for America at 6810MW at that rate it will take 57 years to reach the current 20% target and by that time rising energy consumption will have risen beyond winds ability to keep up, even if you ignore the intermittance being green is not a solution, solar and wind have already failed and its time to close the door before more good money is flushed down the plughole of subservient belief.
Coal generated 45% of Americas need in 2010 yet President Obama and the EPA are hell bent on no new coal fired generation. In the Presidents own words “even if the science is wrong, its still the right thing to do”. I am glad they dont hang people in the UK any more because I wouldnt want to be tried for a serious crime if the Judge felt the same way about evidence “young man the evidence suggests you are innocent but I believe you are guilty, hang him!”
David Wells

Dermot O'Logical

A thought occurs.
Warmists use the science of x3 feedbacks. Non-warmists use, well I’m actually not sure here, but fill in the blank for yourselves, is it x0.9? – some negative feedback component anyway.
Isn’t this x3 coded into the GISS models somewhere? If so, why can’t we just change it (and only it) to x0.9 and re-run the models from the same point and see if the revision generates something closer to reality.
That might help…

Ian E

Now, how do we get politicians to read this article and actually think about its arguments and conclusions?

Rick Morcom

Superb and wise article. Could be applied to many more things than climate science too – medicine for one…

Greg, from Spokane

CAGW has never been science, therefore there is nothing to be settled.
I like Lindzen’s statement, “Perhaps we should stop accepting the term, ‘skeptic.’ Skepticism implies doubts about a plausible proposition. Current global warming alarm hardly represents a plausible proposition. Twenty years of repetition and escalation of claims does not make it more plausible. Quite the contrary, the failure to improve the case over 20 years makes the case even less plausible…” (bold is mine.)
From: Seminar at the House of Commons Committee Rooms
Westminster, London
22nd February 2012


The science is settled, there appears to be a consensus that the science is not settled, therefor the science is settled. /jk

Steve M. from TN

I’ll admit I usually don’t read every word of every article here at WWUT. Mostly because the topics are so varied, and I’m not able to become expert enough to comprehend everything. OTH, I did read every word in this article (oh, btw, reflective over is probably reflective oven in the paragraph about thermometers). Professor, thank you for being clear and writing this for people who are not experts.

Ken Hall

What an outstanding article and one which absolutely hits the target. It defines exactly what my opinion is regrading the whole pseudo-science of climateology and it’s most religious and devout acolytes.
Let’s get back to pure science until we can actually prove what is happening by collective and individual observation and falsifiable hypothesis tested by repeatable, experimentation, for that IS science.
The IPCC is a corrupt and dishonest political propaganda machine, NOT a scientific body.

Bruce Cunningham

“Keep your hands off of my money while the theory is still unproven and not in terribly good agreement with reality!”
Well said Dr. Brown!


Maybe the thing to do is fund the IPCC based on the success of its predictions.
I wonder how likely the IPCC would have considered an anomaly below baseline in 2012? Fund them like spread-betting. All assessments by “independents” of course!
A nice essay.


Bravo. Well stated and a refreshing pail of water to be thrown on the sleepwalking warmist adherents….not that rational argument ever helped sway fanatics.
Thanks very much for your effort !
Steven Mosher – please take notes and refer back to this often while you play.

Dr. Brown,
You have done a beautiful job of answering my question. As some have mentioned, it should be widely distributed on the internet for the general public to read and understand. Along that line, most internet browsers (people) are not inclined to spend enough time to read and understand the full length of your comment. Maybe you could excerpt some of the eye catching points and submit them to other blogs with a URL to the full article. I think Dr. Curry would like to post it.

Bennett Dawson

After reading this, I realize that I’ve just been “schooled” by a man of science.
Thank you.


It is so sad. So very sad. Witnessing someone actually speaking the balanced truth about our understanding of man-made global warming, as Dr Robert Brown has just done, is as rare as Unicorns.
It is so sickening. My pride in the pure noble pursuit of science and my pleasure from having studied Physics and having played a very small part of how engineering has continued to transform the our way of life, bringing countless benefits to society; all of this has been utterly destroyed by a bunch of “scientific” scumbags who have hijacked my calling, and besmirched us all as no better than snake oil salesman.
Nearing the end of my professional career, this is such a bitter pill to swallow.
High-profile “scientists” like Gleick are doing far more damage than causing embarrassment to the CAGW camp, they have ruined the good name of my professional calling. Somehow I feel we have deserved this. Somehow, collectively we let this happen. Somehow the taxpayer funded gravy train became more important than any principles we ever held. Why are there not more Dr. Richard Lindzen’s and Dr Robert Brown’s around? Why have so few pure science Professor’s spoken up? Why have the “evil” engineers been left to defend their “dirty” machines, “dirty” industrial processes, “dirty” manufacturing, “dirty” resource extraction and “dirty” energy supply, while nearly everyone else has piled on the extremist environmental gravy-train crusade?


Well said! Robert, you presented an eloquent description of what we DON’T know (which is quite a bit) and why it is critical to stay skeptical of any scientific claims.
At the same time, I think it is important to state what we ARE pretty sure of. Using your example, Newtonian mechanics is “settled science” for describing normal-sized objects and normal-sized speeds. No one seriously questions using F=ma to explain cars and bullets and bridges.
Similarly, there are a few things that are “settled science” in climatology. One idea I would put in that category is:

. Everything else kept constant, a doubling of CO2 from recent levels will result in a radiative forcing of ~ 3.7 W/m^2, which corresponds to ~ 1 C in global temperatures.

We understand the IR properties of CO2. We understand sunlight and earth’s thermal radiation. We understand the laws of thermodynamics. We can tweak one parameter and see pretty accurately how it affects global energy balance. One could certainly question whether the number should be 3.0 W/m^2, or that the direct effect should be 1.2 C. But no one should think that the number is exactly 0.0000 W/m^2, or exactly 0.0000 C. CO2 DOES have and effect — even if it comprises only 0.04% of the atmosphere.
However, it is also critical to remember that “everything else being equal” is a HUGE assumption. There are changes in solar input. There are changes in land use. There are changes in earth’s orbit. There are multi-decadal ocean oscillations. There are volcanoes. There are changes in cloud cover as temperatures change. All of these are ADDITIONAL factors in the earth’s climate that ALSO affect the climate.
Anyone who claims that only CO2 is important is, frankly, a fool. Anyone who claims that they understand the whole of the climate well enough to make specific 5-20 year forecasts is deluding themselves. There so many interconnected factors (and completely random factors), that predictions will never be ever close to 100% accurate. It reminds me of a quote from Jurassic Park by Dr Malcom: “Gee, the lack of humility before nature that’s being displayed here, uh… staggers me.”
Conversely, anyone who claims that CO2 is irrelevant is also a fool and is also displaying a “lack of humility before nature”. Nature clearly shows us that CO2’s IR properties have an impact (both through theory and through experiments). The lack of humility that says “I, with my freshman physics class, am right and the rest of science is wrong” is also staggering. “Settled science” is not likely to be overturned by blog posts and garage experiments. CO2 DOES warm the earth.


Dr Brown’s essay could usefully be nailed to the front door of many scientific establishments, starting with that of the Royal Society in London
Nullius in verba!

Willis Eschenbach

Dang. Well done that man!

Rob Crawford

“Keep your hands off of my money while the theory is still unproven and not in terribly good agreement with reality!”
T’ain’t just the money — it’s the liberty. And it’s also that they’d leave the bulk of humanity in abject poverty — and push more people to that state from where they were improving their lot — on the basis of a “theory” that doesn’t hold water.
But, then, their “solution” to CAGW is the same “solution” the same people presented for the “population bomb” and for the “coming ice age” and for dozens of other “problems” which appear to have been found by drawing a scary line projected out into the future. I long ago came to the conclusion that for this group, they’re not concerned with any of these “problems”, but entirely with their “solution” — giving them totalitarian levels of power over the lives of everyone else.

Steve C

As good the second time around as it was the first.
A little more proofreading:
Astronomer’s observe the rotational properties – Astronomers
and observation I personally have made – an observation … (?)
Newton’s Law of Gravitation (or for that matter … – no closing paren
faster than it should ever be aver to move – ever be able to move


Even models of numerous differing oscillations, will line up together for a short time. I believe you have pointed this out rather efficiently. Their models worked for a decade or two and then the natural oscillations started to deviate from their esoteric models and they have been proven failures. It is time for the CAGW community to admit their mistakes instead and modify their models to fit reality. I wonder if they already did that and they actually see an ice age coming; would they fess up to it? Are they most afraid of losing their funding or being wrong? Seems like a position between a rock and a hard place. They have already been proven wrong and are trying to keep their funding coming! This is the definition of Fraud.

Allan MacRae

large reflector over
large reflector oven?

Willis Eschenbach

Tim Folkerts says:
March 2, 2012 at 9:17 am

… Conversely, anyone who claims that CO2 is irrelevant is also a fool and is also displaying a “lack of humility before nature”. Nature clearly shows us that CO2′s IR properties have an impact (both through theory and through experiments).

Thanks, Tim. And just where does nature show us that “CO2′s IR properties have an impact “?
First you say Nature shows us through “theory” … but nature can’t “show us” anything through theory. That’s why it’s called a theory. It’s just a story we made up to explain something … so a theory can’t show us anything. A theory might be able to explain an observation … is that what you mean? And if so … which observation is explained by the theory that CO2 is very gradually warming the earth?
That just leaves us what you call “experiment”. So where are these experiments by which nature “clearly shows us” that CO2 has an impact on the temperature, who did the experiments, where were they done, you know, the usual …
I’m with Satchell Paige on this one. He famously said:

It’s not what you don’t know that hurts you. It’s what you know that just ain’t so.


“I can run down a list of experimental observations that are explained by relativity that could scarcely be explained by anything else.” ~Dr Robert Brown
And that is today’s scientific method in a nutshell. The candor in this statement is respected and appreciated. “We can’t explain it any other way.” This is exactly how Mercury’s eccentric orbit was used to “prove” Einstein’s GR. The academics reported they had exhausted every other possible explanation. And the public dutifully took their word for it, and the nature of space, time and gravity have been settled ever since.
And yet, just as is the case in “climate” “science,” the “anything else” that could explain the material system the science is supposed to be describing, is consistently, serially, and methodically ruled out of every scientific journal and academic institution. On WUWT, it has been called “Omitted Variable Fraud,” and the “Principle of Exclusion.”

Terrific article, while reading it last night I thought it deserved to be elevated to a full post here on WUWT, and am so glad to see Anthony did promote it to a proper place to give it the exposure it requires. Well done Dr. Brown. Your comment should be mandatory reading in every science class.
Too bad it is so long that many who need to read, contemplate and understand its contents will not be willing to invest the time necessary to do that.

Ian E says:
March 2, 2012 at 8:36 am
Now, how do we get politicians to read this article and actually think about its arguments and conclusions?

An old country saying that applies is:
You can lead a horse to water but you can’t make him drink.
The same applies to politicians and activists with the last word changed to think.
You can point them toward wisdom but you can’t make them think.
Until people understand that “accepted science” is always provisional and always includes the unspoken caveat “to the best of our current understanding”, the sooner this charade will be over. All good scientists understand that their “laws” and “theories” are only practical rules of thumb that approximate reality to a useful limit, and are subject to future revision as understanding of the underlying facts increase and experimental evidence (not computer models) disagrees with their expected results.
If a theory cannot even meet the first test of approximating reality is not a theory at all but just a guess that missed the point. As such, the climate models have been repeatedly shown to be far off the mark and should be regarded with the appropriate suspicion regarding their validity based on those failures.

Robin Hewitt

I walk round Friston Forest most lunch times, I take my dogs and a physicist. As stated above, he knows nothing, as soon as he talks science everything is qualified. He can be really annoying like that especially if I am trying to explain the latest WUWT revelation.
OTOH he is very useful when someone in the family needs someone to countersign a document, being a fellow of the Royal College he is entitled to sign himself Doctor, works like a charm.

Richard M

Tim Folkerts says:
March 2, 2012 at 9:17 am
Similarly, there are a few things that are “settled science” in climatology. One idea I would put in that category is:
. Everything else kept constant, a doubling of CO2 from recent levels will result in a radiative forcing of ~ 3.7 W/m^2, which corresponds to ~ 1 C in global temperatures.

Or, not … what about the cooling effect of GHGs? Just discussing the warming effect does not convey the full picture.
Interestingly, even the above “fact” is probably not exactly right. Isn’t the amount of warming dependent on the surface temperature? So, even this number is a variable.


This comparison between physics and climate science reminds me of how WW1 saved saved special realativity. Basically Einstien published his results. Some scientists went into the field to test, but one was German and WW1 had just started, so the Russian eclipse he wanted to observe was out, and the other (an American) got overcast sky. Einstien then noticed his results had an error (a factor of 2) and he published the corrected results, and a few years after the first observation attempts, the eclipses were photographed and the theory shown true. – to the degree of certianty that could be obtained with that equipment.
That is where we are with the computer models, if they are right, then going forward and back in time, they should accurately predict tempurature, if they are wrong, then they won’t.

Michael Palmer

While this is an entertaining read, it is, for the most part, not very topical. It spends most of its time considering how an expert scientist deals with the inconsistencies in his own discipline. The original question was, “for the general public that does not have an objective scientific bend, how do you tell virtual reality from the real thing?”
The final suggestion – to compare earlier climate-model predictions to current observation – is fine as far as it goes. However, even if those predictions happened to be more compatible with current observation, that still would not make the models relevant; they are just exercises in curve fitting and extrapolation.

Willis Eschenbach

Allan MacRae says:
March 2, 2012 at 9:28 am

large reflector over
large reflector oven?

[Thanks, fixed. -willis]

Another day at WUWT – I love it. Steam engines. Sand clocks. Bucket thermometers. Progress.

solar and wind have already failed and its time to close the door before more good money is flushed down the plughole of subservient belief.
I would respectfully differ with this, especially w.r.t. solar. Solar simply hasn’t yet come into its own, but IMO its arrival is at this point inevitable. Last time I looked, the “magic number” for solar was roughly $1/watt of full-sun capacity. On the high side of this number, the amortized consumer cost of solar vs fuel-generated power are break even to lose a bit or even a lot. On the low side of this number, one pays off the initial investment in ever reduced time and reaps longer and longer fractions of the total expected lifetime as pure profit.
This number itself isn’t static. Obviously, break even in part reflects local energy costs — where they are high solar is already “there” as a break-even or better investment with maybe 10-12 year amortization — too long (and too much capital out of pocket) for a lot of people but still economically reasonable. Where they are low the cost of solar has to be even lower to compete. It is also not homogeneous with respect to geography. The Southwest US gets a lot of sun, water to cool conventional plants is scarce and expensive, and the delivery network is large and sparse. In parts of the Southwest it is easily worth it to install solar out on farms and remote ranches.
Over the counter grid-tie systems (that don’t have to store power put resell surplus to the power company by running your meter backwards) are just about $2/watt unsubsidized — around $11000 for 5 kW worth of panels capable of generating anywhere from 500 to 700 kWh per month. At a dime per kWh, that’s $50-70/month return on $11000, and pays off the original investment in around 20 years, maybe a bit longer, leaving you with only 10 years (out of 30 expected years of service life) as “profit”. Not very attractive. With the government subsidy, you knock the cost down by a third, amortize in 12 or 13 years, better but not spectacular.
At $1/watt unsubsidized — $5000 for 5 kW worth $50/month, you pay off the investment in 100 months — call it 120 to allow for the cost of the money — ten years. The next 20 years are “pure income” of $50/month. For humans even 10 year amortization is a bit daunting, although people spend more than this on high tech furnaces and AC units already for equally long payoffs — but for power companies it starts looking very attractive — $600 a year income out of a fully paid $5000 initial investment with a 30 year lifetime is actually pretty nice. Over 30 years, you make at least $2 for every $1 you originally spent, no subsidy.
Now we have to look at another number and ask an important question: Does Moore’s Law apply to photovoltaics?
The strictly empirical answer appears to be yes:
Furthermore, given a conservative estimate of the extrapolated decline in pricing — one that the market is already beating, as large scale installations have economies of scale that already put the cost per watt very close to $1 — in 20 years PV electricity will cost no more than $0.50/watt in 2009 dollars.
While the cost of PV electricity is declining, the cost of mined fuel-based electricity will almost certainly continue to rise, with or without carbon taxes. Sure, you can argue that the price we see is all manipulated, that if we all got out of the way of the eager and productive minions of the big oil barons they would drive the price way down and we could all drive anywhere we like for $0.25/gallon once again, but the strictly empirical data on the rise of the cost of oil and coal is a history of fairly steady (and complex) rise. There is certainly no Moore’s Law for mining natural resources; quite the opposite. The more of a resource one recovers, the greater the cost of recovering the rest. In both cases technology modulates things — a new technology (or higher prices) can restore an “exhausted” mine and make it worth working once again — but in the long run, the low hanging fruit are cheap, and then it gets incrementally more expensive the higher you have to climb the tree to get at it.
That’s why I argue in the top article that there is no crisis no matter what we do about “carbon”, even if the CAGW folks are right! Moore’s Law for PV combined with the rising price of recovering oil and coal mean that we will see a ragged meeting of the cost-benefit of the competing technologies over the next 20 years where the profitability of PV-generated electricity will be greater than that of fuel generated electricity in first the Southwest (where one is really already there in many places with or without carbon taxes or subsidies) and then in increasing areas of the country and the world. In 30 years we will be using a fraction of the fuel we are currently using to generate electricity (although we may or may not still be burning gasoline) not because we are saving the planet, but because only a fool spends more than they have to for electricity. It will be pure economics.
IMO there are a number of other co-technologies that could alter this (conservative, remember) timetable — Andrew has posted a top article not long ago on high capacity low memory zinc oxide batteries, for example. A cheap and high capacity battery would change everything enormously, very quickly. Thermonuclear fusion would change the game and make even solar power passe. One of these days we might wake up and start building thorium salt fusion plants — cheap power, no potential for making bombs. None of these generate CO_2 (although they may have other hidden costs of their own).
There is nothing nice or “romantic” about carbon based fuels. Coal is dirty and dangerous to mine. Oil is far too valuable to burn (ask any organic chemist). Again one can look back in history to where we almost hunted whales to extinction for whale oil — it might well be that there is a whole economy based on whaling or coal mining or drilling for oil today, but in thirty years most of the coal mines will be shutting down, their product almost unused. Oil will still be drilled, but with cheap enough electricity, synthesizing gasoline may well be competitive with mining and refining it, especially if we have to look ever deeper at ever more difficult to extract sources in high risk areas where there are large costs to e.g. a spill. Gasoline is a fabulously useful material, totally granted — it is hard to pack that much energy into that small a space with anything else so controllable — but I could care less if my car runs on gas or if it runs on zinc oxide batteries or if it runs on garbage packed into its onboard Mr. Fusion.
To conclude, by all means pick on wind power, although solar updraft and several other technologies are actually quite attractive and once again are very close — a few clever ideas away — from being more profitable than fuel based resources. But if you think PV solar is “dead” — no, my friend — it is just now coming to life, and if the Moore’s Law curve is continued for another 20-40 years, carbon based fuels will all but disappear by 2050, an easy 50 years away from the projected “disaster” that looks increasingly unlikely given the actual temperature data and probable role of the sun.


Maybe its an American thing (like aluminum vs aluminium) … but isn’t it “a scientific BENT” not “a scientific bend”? A bent refers to having an inclination towards something; a bend refers to being curved?
[Reply: “bent” is correct usage. Article fixed. ~dbs, mod.]