"Our greatest responsibility is to be good ancestors."

-Jonas Salk

Sunday, August 12, 2007

Dyson Exegesis

Freeman Dyson starts an article with the words "My first heresy says that all the fuss about global warming is grossly exaggerated. Here I am opposing the holy brotherhood of climate model experts and the crowd of deluded citizens who believe the numbers predicted by the computer models". Yet his article is hardly about climate models, or their relationship to experts or citizens, at all.

I personally have no disagreement with the "third heresy", the idea that the USA is at the end of its hegemony, by the way. I actually think this is occurring now, not 50 years hence as Dyson suggests. I have no idea what this has to do with the purported intent of Dyson's essay, though.

The primary practical (as opposed to theoretical) problem our field needs address these days is to identify specific regional trends and risks, to inform adaptation. This is as opposed to the mitigation question, whether and how much to change our behavior to reduce climate impacts.

The question of how much to mitigate or not is not primarily about climate science anymore, but about economics, ecology, and values. Dyson points out that this is not "a problem in meteorology", and on this point, it must be said, he is very much correct. We already know that the global temperature sensitivity to equivalent CO2 doubling is near 3 degrees C.

The fact that this is considered to be in doubt is a consequence of people using meteorological uncertainty as a diversion, in order to avoid the issue for as long as possible. Dyson fails to understand how this is happening. Like most older scientists he lives in an older, more civilized world than the rest of us occupy. So he misunderstands where the controversy comes from.

That said, his position seems to meander: carbon is a land management problem, but it isn't a problem anyway, and we might kick off an ice age and we might not and... Many of the common misconceptions and not uncommon hubris are scrambled together here. This isn't a serious article, it's an intelligent but essentially uninformed rant. Unfortunately I have to call it irresponsible.

It's also a bit incoherent. So I respond below to some of the individual points made without further summary.

Dyson's text is in blue, my responses in black. Hopefully people inclined to take Dyson seriously on this matter will come by here and think again.


PART I Paragraph 2

The models solve the equations of fluid dynamics, and they do a very good job of describing the fluid motions of the atmosphere and the oceans. They do a very poor job of describing the clouds, the dust, the chemistry and the biology of fields and farms and forests. They do not begin to describe the real world that we live in. The real world is muddy and messy and full of things that we do not yet understand. It is much easier for a scientist to sit in an air-conditioned building and run computer models, than to put on winter clothes and measure what is really happening outside in the swamps and the clouds.

Sure...

That is why the climate model experts end up believing their own models.

Um, I must have missed a step here... In fact climate model experts do not particularly "believe" models. Our skepticism is informed and consequently rather complex. Do we believe this, did we capture that... So here Dyson is completely off base.

Paragraph 3

the warming is not global

This is just confusion. He should read my realclimate article on the definition of "global warming".

Paragraph 4

The number that I ask you to remember is the increase in thickness, averaged over one half of the land area of the planet, of the biomass that would result if all the carbon that we are emitting by burning fossil fuels were absorbed. The average increase in thickness is one hundredth of an inch per year.

Per YEAR!!! On every piece of viable land, under economic use or otherwise... He certainly identifies a viable carbon sequestration sink, but the idea of an inch of graphite per century being redistributed on all land everywhere in soil restructuring is hardly a trivial matter to handwave away.

Anyway, notice he is already wandering away from climate modeling and has said very little about it.

Paragraph 5

Changes in farming practices such as no-till farming, avoiding the use of the plow, cause biomass to grow at least as fast as this. If we plant crops without plowing the soil, more of the biomass goes into roots which stay in the soil, and less returns to the atmosphere. If we use genetic engineering to put more biomass into roots, we can probably achieve much more rapid growth of topsoil. I conclude from this calculation that the problem of carbon dioxide in the atmosphere is a problem of land management, not a problem of meteorology.

Well, it certainly isn't an EASY problem in land management. However, I agree with Dyson that the focus on meteorology is misplaced in the mitigation arguments. Climate science is crucial on the adaptation side, but all the focus on it on the mitigation side is a red herring and a vicious one.

What Dyson is proposing here seems at first blush unrealistic to me. Of course I'm always hopeful when a mitigation startegy is proposed that doesn't involve too much disruption. I don't know if he's talked to soil experts or agronomists. What it is, is a very coarse approach to a mitigation strategy.


Let's be pleased, at least, that Dyson acknowledges a problem of carbon dioxide in the atmosphere.

Paragraph 7

When I listen to the public debates about climate change, I am impressed by the enormous gaps in our knowledge, the sparseness of our observations and the superficiality of our theories. Many of the basic processes of planetary ecology are poorly understood. They must be better understood before we can reach an accurate diagnosis of the present condition of our planet.

Well, the topic has suddenly lurched to ecology. This has little to do with climatology. I think I can say that ecologists I know would tend to agree with this, but it has nothing to do with what is normally charitably described as "anthropogenic global warming skepticism". That's not the disturbing part, though. This is:

When we are trying to take care of a planet, just as when we are taking care of a human patient, diseases must be diagnosed before they can be cured.

Yikes! So should the patient keep ingesting the toxin meanwhile?

PART III Paragraph 3

If human activities were not disturbing the climate, a new ice-age might already have begun.

Maybe so.

We do not know how to answer the most important question: do our human activities in general, and our burning of fossil fuels in particular, make the onset of the next ice-age more likely or less likely?


Nonsense. (He wheels out the usual misinterpretation of Broecker's ocean-driven change scenario, but no scientist is expecting any ocean circulation changes to overwhelm the huge warming and kick off an ice age.) This is simply a layman's mistake and totally out of line with the evidence. Here he is simply substantively wrong, and repeating a common misconception.

PART IV Paragraph 2

First, if the increase of carbon dioxide in the atmosphere is allowed to continue, shall we arrive at a climate similar to the climate of six thousand years ago when the Sahara was wet? Second, if we could choose between the climate of today with a dry Sahara and the climate of six thousand years ago with a wet Sahara, should we prefer the climate of today? My second heresy answers yes to the first question and no to the second. It says that the warm climate of six thousand years ago with the wet Sahara is to be preferred, and that increasing carbon dioxide in the atmosphere may help to bring it back. I am not saying that this heresy is true. I am only saying that it will not do us any harm to think about it.

It does no harm to think about it, but it can do a great deal of harm for a celebrated person to speculate in an uninformed and incorrect way. We are changing the overall forcing of the system much more than the shift from 6000 years ago to today. The extent to which this is the case is quantifiable.

Essentially the natural shifts on that time scale amount to moving solar input from one season to another. The climate system responds in interesting ways, ways which, by the way, are replicated by climate models operating from first principles.

Our present forcing operates at all latitudes in the same direction. The system cannot respond identically. Humans are focussed on climate at the surface, but physics cares about the entire depth of the atmosphere; surface conditions are an important but not a dominant component. We cannot replicate a prior natural climate with an atmosphere whose radiatively active components are different than those seen in nature.

The idea that we will drift smoothly into and settle down to a lusher more convenient climate is a fantasy and a rather stupid one. Yes, a blundering near unconscious drunk could, in fact, blunder into a wonderful jet-setters party and be celebrated for his wit and plied with champagne and caviar. This is no reason for him not to sit down and recover his wits; the champagne thing is rather a long shot.

Update: Promoted from comments:


Ugo Bardi said...

Excuse me. I have a question. At some point Dyson says:

In humid air, the effect of carbon dioxide on radiation transport is unimportant because the transport of thermal radiation is already blocked by the much larger greenhouse effect of water vapor. The effect of carbon dioxide is important where the air is dry, and air is usually dry only where it is cold. Hot desert air may feel dry but often contains a lot of water vapor. The warming effect of carbon dioxide is strongest where air is cold and dry, mainly in the arctic rather than in the tropics, mainly in mountainous regions rather than in lowlands, mainly in winter rather than in summer, and mainly at night rather than in daytime. The warming is real, but it is mostly making cold places warmer rather than making hot places hotter. To represent this local warming by a global average is misleading.

I am not sure of whether this is correct or not. Sounds reasonable, but, on the other hand, considering the level of the rest, it may not be. Is this the reason why the higher latitudes are warming more than the lower ones?

My reply:

Thanks Ugo. I'm really astonished that I missed this. I must have been rolling my eyes up a little too high.

The argument you quote is invalid for two reasons.

First, the greenhouse effect never fully saturates; increased optical depth continues to warm the surface long after the atmosphere is essentially opaque to outgoing infrared waves.

Second, for the most part there is little overlap between the absorption bands of H2O and CO2.

The idea that the effect applies "mainly in mountainous regions rather than in lowlands" is particularly astonishing. It is exactly 180 degrees from the truth.

It is the integrated column depth of greenhouse gases that trap the outgoing IR. Mountains, being nearer the top of the atmosphere, experience less greenhouse warming than the surface.

So "particularly in the mountains" shows that the author has never even sat down with the undergraduate level approximation of how atmospheric radiative transfer actually works. It's really quite shocking.

In fact, the high latitudes are more sensitive to warming. However this is not because they are dry but rather, in part, because of the persistent presence of low clouds, (exactly contrary to the tale he is trying to spin) as well as ice-albedo feedback. See, e.g., Holland and Botz

Update 3/29/09: See also: Slicin' and Dicin' with Dyson and Bryson in response to recent coverage of Dyson with reference to an interesting precedent.

Update 1/23/10: See also: Guest Posting: Expanded Dyson Exegesis .

30 comments:

Anonymous said...

Thanks for a typically approachable post. When I first read about this idea of "heresy" -- from Pielke Jr, I believe -- I thought it sounded suspiciously like an attempt to create a straw man.Any thoughts along this vein?

Anonymous said...

Michael,

I just stumbled into your site, in response to Dyson's writing. Your blog gives a good, informative first impression. I will try to catch up with what you have been writing. I am trying to overcome any ignorance I may have on climate change.

I am working with computational models in system's biology, and from my viewpoint, I agree with Freeman Dyson in spirit, although he may be wrong in his speculations. This is because,

1) as a scientist, I know how hard it is to make accurate predictions about the real world. How do you know you don't have chaos in your system? Why could time series of climate change be well predicted by computer models, since they do such a poor job on all other complex systems (meteorology, economics, biology... ) ?

Thus, I wonder if Dyson is not right about what he writes in his first paragraph about science and society. Isn't it favourable to express yourself confident, than saying that you do not know? That is my experience even from a less controversial field.

2) How can the role of the main actor, CO2, be understood without understanding of the in and outflux from vegetation?

3) as a humanist, I react towards the staunch conservatism of the environmentalist movement. Why is climate change necessarily a bad thing? Why could we not find solutions to future challenges? It is as you write a value question. Also, like Dyson I think it is serious that climate change drags public attention away from concurrent, solvable but serious human problems.

These are the problems I have with "scientific consensus" and the media picture. Also, in response to what you write about Dyson's writing:

1) of course the patient must be diagnosed before she can get cured, otherwise we do not know if it is a toxin or not. Would you take chemotherapy if your doctor couldn't say for sure you have cancer?

2) I didn't get your answer to paragraph 3. Are you saying that climate scientists agree that the issue of ice ages are entirely put off by antropogenic CO2 warming, and will not change before previous CO2 levels are restored?

3) How can you say that "..// settle down to a lusher more convenient climate is a fantasy and a rather stupid one"? On what basis? Is it not also a question of values? I find it hard to believe that, given any set of values, it is quantifiable whether a warmer planet will be better or worse.

Anyway, it was interesting to read your comments. Recommended reading? I am particularly interested in understanding the computational nature of climate models (chaos or not), and validity of parameters in them.

Michael Tobis said...

John, thanks for the feedback.

There is a small element of truth to the 'heresy' complaint, in my opinion. People who know climatologists, and people who have a network of trust that extends to us, are understandably offended by the way we are described in some circles.

Unfortunately there is a tendency to overreact. Scientists, specifically climate scientists, more specifically climate modelers, are neither saintly nor infallible. You will rarely see a scientist arguing thus, but you will occasionally see some of our defenders going overboard.

There is more than a grain of truth to some of the criticisms. Many of them apply to science in general, and we are being unfairly singled out; others are specific to us. (Many other common critiques are irresponsible nonsense, don't get me wrong.)

Since we are operating simultaneously in real science and in its twisted political echo, it is somewhat dangerous for us (as political amateurs) to speak for ourselves. Consequently our defense often falls to people who only have an approximate idea of what we do.

I do a fair amount of struggling in writing this blog in how to acknowledge weaknesses in the field without having what I say misused. Most scientists just sit the whole thing out, which is probably for the best.

One of the consequences of the bind we are placed in socially is that the people defending us only have assertions of trust to base their responses on. I think and hope that the trust is deserved on the whole, but sometimes that statement of trust is less nuanced than you'd hope.

See the infamous debate between Bill Nye and Dick Lindzen on Larry King (linked somewhere from this blog) for an unfortunate example of this somewhat overstated trust backfiring.

Note, though, that as I said, the participants in the science are essentially never (except perhaps rarely in error, in the heat of battle with more politically adept opponents) the ones alleging any sort of scientific infallibility.

In summary, in my opinion, this accusation of dogma is entirely a strawman addressed to scientists, but not entirely as addressed to defenders of scientists.

Anonymous said...

I find his double standards annoying. Climate modelers just sit in their comfy offices and never get their hands dirty with real data, and therefore they have an unwarranted faith in their own models, supposedly. Well, what about theoretical physicists like Dyson?

I'm sure Dyson would agree that good theoretical physicists do pay close attention to experimental results, and temper their enthusiasm for their own theories by their contact with data. Yet he doesn't appear willing to extend the same professional courtesy to those doing climate physics. And I daresay that the latter work much more closely with real data, on average, than does the average particle theorist.

Then, too, not all physicists are theorists; there are experimentalists who test the theories. Likewise, in climate physics, there are those who create the models and those who test them. Even if it were true that climate modelers themselves did not look closely at their models' accuracy (and it is not), there are others who do. The case for climate prediction does not rest on the untested faith of those who create climate models.

Anonymous said...

AR4 says probably 30,000 years to the next ice age without anthropogenic influences, based on Milankovitch cycles.

As you point out later, public debates are an exceptionally crappy place to try to get a sense of the science. I'm sure Dyson has slightly broader sources than that, but it sure doesn't sound as if he went to the trouble of reading the AR4 (or the TAR, depending on when he actually wrote this piece), let alone any of the root literature. What would Dyson think of someone who based their assessment of his field on public debates?

Regarding the medical analogy, I recall when I was a teenager that I came down with a very high fever with no other symptoms. Interestingly, they treated the fever but bever did figure out what the cause was. Lots of diseases (or at least their symptoms) get treated even though there's a less than perfect understanding of them.

Anonymous said...

John, it is very interesting how common this sort of religious rhetoric is coming from denialists. It seems to be code for accusing their opponents of being irrational, and probably comes from their view of themselves as hyper-rational. IMHO resorting to it is a sign of a weak argument.

Fredrik, for me the biggest eye-opener was the paleoclimate evidence. I don't find the models un-credible, but they have big fat error bars. In terms of whether a future climate might be preferable, maybe so, but the problem is the transition to that climate and in particular its speed. We don't know exactly what it will take to melt the Greenland and West Antarctic ice sheets, but the early signs are there. The plausible worst-case is 13 meters of sea level rise over a course of several centuries. Another concern is shifting of climate zones (e.g, a northward move of deserts into the existing breadbaskets.) A third is the loss of the non-polar glaciers, which is proceeding apace. Present estimates are that the Tibetan-area ice will be gone by 2050 or so, which will cause all of those big rivers to become largely seasonal (and on the order of 2 billion people to lose a reliable water supply). And then there is ocean acidification, which has the potential to wipe out most life there.

Direct impacts aside, what are the potential socio-political knock-on effects of all of these? To what degree should our society be willing to risk these outcomes? Do we wait until we are sure that the worst symptoms are happpening? That may be a bit late.

Michael Tobis said...

Frederik, thank you very much for your incisive questions, and welcome. You ask too much for me to do it justice all at once, but I will try to visit these issues in the relatively enar future.

There are some misconceptions in what you say, I am afraid.

They have some similarities to those misconceptions common among fair-minded and scientifically literate people in other fields. My problem with Dyson is not that he had such opinions, but that he tried to attach his authority to them without doing serious research.

As far as model-specific reading, best reviews of the field are "A Climate Modeling Primer" by Henderson-Sellers and McGuffie, and "Computer Modeling in Atmospheric and Oceanic Sciences" by Muller and von Storch.

However, I would recommend the serious reader get a broad understanding of climate physics before seriously attempting a critique of the larger models.

These may be superceded by more recent works but I still refer people to "Physics of Climate" by Peixoto and Oort, and "Paleoclimatology" by Crowley and North. I am also very fond of "A Short Course in Cloud Physics" by Rogers, which is a good overview of the physics that are real crux of the problem, i.e., those that present the greatest difficulties in increasing the utility of global climate models.

Anonymous said...

Fredrik, hang on like grim death to your doubts, your uncertainties, your humility and above all your knowledge of your lack of knowledge. Do that, and you will, in your own way, and irrespective of whatever you achieve, be as great a scientist as Dyson, or Einstein, or Bohr or any of them.

Michael Tobis said...

David's comment seems to imply that the person knows most who knows least, which is not a very useful guide.

That said, it strikes me that whatever Dyson is doing here, it is not, exactly, an inspiring instance of humility.

Anonymous said...

I'm surprised you are finding it difficult to spot humility in his essay, try this, talking of himself:

"The moral of this story is clear. Even a smart twenty-two-year-old is not a reliable guide to the future of science. And the twenty-two-year-old has become even less reliable now that he is eighty-two."

If only all scientists had that approach.

Michael Tobis said...

First of all, we are not talking about "reliable guides to the future of science", we are talking about credible risks to the future of the world.

It's not just a little bit arrogant to wave vaguely in the direction of some half baked solution and imply that it proves that everyone on earth but oneself misundertands the problem. A sprinkling of false humility does little to justify this shabby mess of intuitions and self-aggrandizing attitudes.

This isn't a game. If anyone can prove we are wrong, God bless them, and I'll be dancing in the streets.

Dyson hasn't even made a case. He has published a disconnected set of speculations, mostly unfounded.

Until then we shouldn't be treating this as sport. Dyson apparently has been spouting half-baked nonsense about this stuff for years. It's fine for pub talk, but he should never have gone public with it.

I actually don't know what Dyson's claim to fame is, but I am now regarding that fame with some suspicion.

Anonymous said...

Hubris, Michael, beware hubris!

Michael Tobis said...

Some nice observations about Dyson's peculiar effort
here
.

Anonymous said...

Thank you for a thoughtful look at this rather enjoyable heresy. However, I'm sure you must agree that life profoundly affects climate and Dyson's reference to ecology is not mere hand waving.
Dyson is a terrific writer and I will recommend his books, particularly "Infinite In All Directions" and "Disturbing The Universe."
If you get in the mood for a little more heresy try his short monograph "Origins Of Life" where he considers the difference between replication and reproduction, and which one may have dominated early life.

James Annan said...

Just as a small detail, soil management can certainly have a major effect on soil carbon content. I actually did some work on this 15 years ago, but can't remember the details (here if anyone can work out how to find this!). The context of that was (in large part) the ban on stubble burning which was brought in in the UK in the 80s or thereabouts. All a bit of a hazy memory now...but the changes can be of the order of ten tonnes per hectare.

Michael Tobis said...

Ten tons per hectare in one place is interesting. Ten tons per hectare everywhere would buy us a few decades, depending on emissions scenarios and the definition of 'everywhere'. As a further complication we would keep the extra carbon so captured sequestered indefinitely.

I don't think any carbon cycle people are arguing that soil isn't a major player. That doesn't mean the problem is solved!

And of course, a scientist claiming authority should be able to distinguish between cabron cycle modeling and climate modeling.

Michael Tobis said...

Thanks initially to a link from Realclimate courtesy of Gavin Schmidt, this has been by far my most popular article to date. It's srt of a shame, since it's hardly my favorite. (It was almost a no-brainer to write it.)

I've added links to my personal favorites in honor of the new traffic. If this is your first "In It" article I hope you'll explore a little further.

Ugo Bardi said...

Excuse me. I have a question. At some point Dyson says:

In humid air, the effect of carbon dioxide on radiation transport is unimportant because the transport of thermal radiation is already blocked by the much larger greenhouse effect of water vapor. The effect of carbon dioxide is important where the air is dry, and air is usually dry only where it is cold. Hot desert air may feel dry but often contains a lot of water vapor. The warming effect of carbon dioxide is strongest where air is cold and dry, mainly in the arctic rather than in the tropics, mainly in mountainous regions rather than in lowlands, mainly in winter rather than in summer, and mainly at night rather than in daytime. The warming is real, but it is mostly making cold places warmer rather than making hot places hotter. To represent this local warming by a global average is misleading.

I am not sure of whether this is correct or not. Sounds reasonable, but, on the other hand, considering the level of the rest, it may not be. Is this the reason why the higher latitudes are warming more than the lower ones?

Thanks anyway for the excellent post.

Michael Tobis said...

Thanks Ugo. I'm really astonished that I missed this. I must have been rolling my eyes up a little too high.

The argument you quote is invalid for two reasons.

First, the greenhouse effect never fully saturates; increased optical depth continues to warm the surface long after the atmosphere is essentially opaque to outgoing infrared waves.

Second, for the most part there is little overlap between thye absorption bands of H2O and CO2.

The idea that the effect applies "mainly in mountainous regions rather than in lowlands" is particularly astonishing. It is exactly 180 degrees from the truth.

It is the integrated column depth of greenhouse gases that trap the outgoing IR. Mountains, being nearer the top of the atmosphere, experience less greenhouse warming than the surface.

So "particularly in the mountains" shows that the author has never even sat down with the undergraduate level approximation of how atmospheric radiative transfer actually works. It's really quite shocking.

In fact, the high latitudes are more sensitive to warming. However this is not because they are dry but rather, in part, because of the persistent presence of low clouds, (exactly contrary to the tale he is trying to spin) as well as ice-albedo feedback.

See, e.g., Holland and Botz

Anonymous said...

In an interview with Benny Peiser (also a skeptic), Dyson attributes alarmism about global warming to class resentment among British scientists:

http://www.staff.livjm.ac.uk/spsbpeis/Freeman-Dyson.htm


Dyson: "My view of the prevalence of doom-and-gloom in Cambridge is that it is a result of the English class system. In England there were always two sharply opposed middle classes, the academic middle class and the commercial middle class. In the nineteenth century, the academic middle class won the battle for power and status. As a child of the academic middle class, I learned to look on the commercial middle class with loathing and contempt. Then came the triumph of Margaret Thatcher, which was also the revenge of the commercial middle class. The academics lost their power and prestige and the business people took over. The academics never forgave Thatcher and have been gloomy ever since."

The effectiveness of Dyson's storyline (he's a heretic, climate science is all class warfare) makes one think of political scientist David Runciman on the potency of attention-getting political narratives:

"The new information technology, with its cascades of rumour and limitless outlets for personal histories, is more often than not the enemy of informed public discussion. In the face of an endless readiness on all sides to heed the unmediated voice of personal experience, it has become harder to sustain the bigger picture needed for any plausible defence of progressive politics. This shifts politics, inexorably, to the right."

http://www.lrb.co.uk/v27/n11/runc01_.html

Runciman's piece is an analysis of the campaign to repeal the estate tax, but he could just as well be referring to any hopes for instituting a carbon tax.

Michael Tobis said...

For some reason his link goes nowhere, but I think Tidal wanted to link to Smil's article here.

Anonymous said...

How did I miss this one? You may find it odd, but I agree with others that this is one of your better posts. Enjoyed it.

I try to look at a lot of these things by removing the "side" that people are arguing for and thinking "how is this person behaving?", "what categorical arguments are being made, and would they apply them the same way against their own side?"

I wonder, do you devalue Dyson completely? I would assume say, a year ago, you would have said you valued him as a scientist. What makes someone like Dyson chime in with this? I'm always curious what pro-AGW folks think are the motives of Dyson, or Inhofe, or Lomborg, Spencer, etc.

I find "oil money" to be an unsophisticated and unsatisfactory answer. Or, not really an answer at all. I mean, I don't want dirty water and baking tempuratures. Who does? It seems unsatisfying to say that someone argues a position that they don't believe, and is against their own interests.

Michael: I have a couple of random requests-
1. Could you tell me the best known volume of the atmosphere, and the ocean? I've been wanting to get a mental grasp on their comparison. My internet searching didn't come up with a good answer. I'm getting 1.3B cu. kilometers for the oceans, can you confirm?

2. Would you consider as a new post, a similar rebuttal to this page. I don't know anything about the source, may be barking moonbats for all I know. I'm in the middle of going through the links now. If anyone knows valid refuations in one place, it would be you.
http://sweetness-light.com/archive/get-the-facts-on-climate-hysteric-hansen

Thanks. Good post.

Ian said...

A great book is Uncertain Science... Uncertain World by Henry Pollack, (CUP, 2003) which argues that climate models are much more reliable than many of the approaches used for making far reaching policy decisions. This is in contrast to Sonia Boehmer Christiansen (editor of Energy and Environment) who identified distrsut of models as the core belief that links whata\ I call the disparate and inconsistent views of the skeptics.

Marion Delgado said...

The science blogosphere went through all of this with Dyson, years ago, Michael, on RealClimate and with spillovers to at least Rabett Run and I think Open Mind. Maybe more. And those discussions were citing other science blogs. I think there were even magazine articles that mentioned it.

I'm "skeptical" that Dyson went out looking for valid critiques of his formulations, given they were very effectively trashed where wrong (not everything he was saying was wrong, by the way), and yet he's never acknowledged any of it.

As I've said elsewhere, someone should ask him if a typical GCM is more or less accurate than the Bohr model of the atom, and why physicists did so much modeling instead of bundling on their rad suits, heading down to the atomic pile and building the a-bomb with sheer, unmodeled scientific ingenuity.

I also wonder why we're allegedly so innovative at amelioration but so inept at prevention?

Marion Delgado said...

"This isn't a game. If anyone can prove we are wrong, God bless them, and I'll be dancing in the streets."

Yes. If they only knew - it completely infuriates me that I have to deal with so much climate crap - it takes time away from all my pet causes and projects.

When EITB came out, I didn't assign the kind of priority to C02 and AGW that Gore did, actually, but now I do. He was expressing himself mainly as a proxy for what he'd learned from Revelle, but in hindsight it was prescient.

Fortunately, some of the big ones like saving coral reefs and amphibians are tied in with global warming. But really. That we welcomed this to further our Marxist or anarchoprimitivist schemes. That may be the biggest whopper of all the errors they routinely make.

Unknown said...

Well written, intelligent piece. I've modeled in a different field and have sympathy for the problems you face both technically and politically, but I do have my doubts as to the credibility of any model of a system with such extreme dependence on ititial conditions. Isn't it - literally without a Laplacian frame - impossible to accurately model a chaotic system. My opinion after a literature review is that on current evidence anthropogenic emissions are affecting the climate, though in what way it's impossible to tell. Conditions on earth are pretty much optimal and so any change is bad. We should try to sequester as much carbon as possible without neglecting other major problems more likely to kill more people.

Michael Tobis said...

splowman, climate is not weather.

Weather models are very sensitive to initial conditions. Climate models, hardly; ideally, not at all.

Look into paleoclimate modeling for example.

Adirondack Will said...

Michael:
the underlying equations in climate and weather models are essentially the same. They are both approximations to the Navier-Stokes equations, which are in turn approximations to the Boltzmann transport equations (c.f., Chapmann-Enskog theory). The N-S equations are sensitive to IC's. Full Stop. How they are employed in weather prediction vs climate analysis differs significantly. The way they are used in climate ensemble modelling attempts to minimize that sensitivity-- and to a certain extent succeeds. Nonetheless, properly preparing a climate simulation (or ensemble of simulations) is a significant challenge-- and one I think we have not yet fully addressed. Personally, I think that Earth's climate is fairly insensitive to minor perturbations. That however, does not mean that the models are. (BTW, some of the most advanced atmosphere models for climate have been developed by the team of scientists and mathematicians I used to lead in the national labs.) The state of modelling is best characterized as adequate for some kinds of sensitivity studies and analyzing the effects of perturbations of certain parameters. They are by no means adequate for prediction.

Also, climate science consists mainly of three parts: one the one hand, there are people who make scientifically defensible measurements of climate parameters; secondly, there are folks who attempt to bring together existing knowledge from physics, mathematics, physical chemistry, biochemistry, organic chemistry, and biology into complex system-level models. Finally there are folks who attempt to explain what we have seen and are seeing in climate using basic scientific understanding augmented by use of climate models. The last part has been the most visible and has created the most dramatic claims. Unfortunately, some of the folks using the models do not adequately account for their limitations; and they tend to rely on them, even at the expense of underlying scientific principles. My take as a person who had a long career in scientific modelling and leading scientific enterprises is that there are far too many problems with today's best models to allow to bet the farm on predictions based on them.

As to Dyson, I have to say that he was one of the greatest scientists of the 20th century. Much of our deepest knowledge of particle physics, field theories in general, and quantum theory builds on the synthesis he created. Clearly he still has his analytical faculties; and his renowned skepticism that has stood him well throughout his scientific career. I would no longer look to him for innovative genius; but I would take his analysis of scientific disciplines very seriously indeed.

Neither Dyson, nor any serious scientist I know, disagrees that we are and have been in a gradual warming period coming out of the mini-ice age. All the folks I have spoken with in the science community agrees that there is a human contribution to warming. The disagreement is not about the "bare" effect of CO2, but about feedbacks to that effect. It is also about the importance of CO2 versus extraterrestrial forces and natural climate variability. To label folks who point to the evidence supporting fairly negative feedbacks that reduce the effect of CO2 as deniers is divisive and ad hominem in character and does nothing positive.

Adirondack Will

Charles Taylor said...

Adirondack Will, your comment is spot on in its entirety. I am astounded at how little evidence there is to support the predictive claims made by climate simulators. It all seems to be in the noise of the recorded data This discussion needs to return to the peer reviewed literature which should be open to all groups to publish in. And funding should be equally disbursed. Extraordinary claims demand extraordinary evidence to paraphrase Sagan I believe. The extraordinary evidence is lacking.

Michael Tobis said...

You guys are wrong about all that. You may or may not be deniers, but you're quite incorrect.

It's been a while since I played that game. I feel I've put in my time trying to explain why this way of thinking is incorrect. But it is. Maybe I should take another swing at it.