It is time to stop quivering in our boots in pointless fear of the future and just roll up our sleeves and build it.
- Ray Pierrehumbert

Wednesday, October 3, 2007

Trust and Expertise

In a post to the Globalchange list, Fergus points to a remarkable discussion on a British weather geek list regarding the trustworthiness of climate science.

I think valid public perceptions of trustworthiness are absolutely crucial to a functioning democracy. I think that we climatologists get rather less than our due, but, more problematically, that economists get vastly more than theirs.

I don't think credentials or tradition suffice. If they did, the Wall Street Journal editorial page (among others) would be genuinely conservative, rather than recklessly mad.

So while I have no objection to the topic, I am a little dubious about whether the prominent naysayer with the cute avatar is really motivated selflessly.

More to the point though, I'd like to see comparable attention paid to the validity and utility of advice from economists.


Fergus said...

Of course, if there was a bona fide climate scientist who was a member of the forum - which, btw, does have meteorologists at its core and produces some great forecast and free graphics material - then the 'geeks' could be better informed: any volunteers? (not you Michael, you're too 'wired'...)

Bruno said...

I trust climate scientists far more than I trust economists. Of course, I'm a lawywer, so you can't trust anything that I say.

Michael Tobis said...

Bruno, let me begin by not trusting that you are a lawywer.

Rob M said...


I am a skeptical contributer to Netweather (Captain_Bobski's my name on there), and I was wondering whether you have read through the comments and, in particular, what you thought of the discussion in general.

I certainly think of myself as being skeptical for selfless reasons, in that I genuinely question the science rather than simply objecting because of any perceived personal impositions. (So, although it is hardly the most flattering word, I suppose you could therefore regard me as a "geek"!)

And I don't question the science because I think climate scientists are idiots or anything like that, either...!


Anonymous said...

Here, here...after all what is a macroecomoic model but a GCM with human beings rather than simple molecules as the ultimate uinit of analysis?

Jim Manzi

Michael Tobis said...

Jim, glad you're still hanging around.

So when do I get to do my PowerPoint pitch? This will only cost you an hour. Time and place of your choice.

Michael Tobis said...

Rob, I am not sure what to make of the discussion. It seems to be a discussion among people who get impressions through journalists even though they are sophisticated enough to be able to go to the IPCC WG1 reports and thence to the primary literature. So the whole thing seems to me so off the rails from the beginning that it's hard to know where to begin.

About what, exactly, are you skeptical?

Rob M said...

Hi, and thanks for the reply!

The discussions on Netweather are among people with varying depths of knowledge - there are many who do just listen to the media (which can generally be regarded as a bad thing!), but there are many others, such as myself and Fergus, who spend an inordinate amount of time reading through scientific papers. What one gets out of the papers depends rather upon how well one understands the science, but an impression can usually be gathered even if the details are over one's head.

I suppose my skepticism stems mainly from my experience in other sciences. I am an avid devourer of Physics, most recently String Theory, and I can see a variety of parallels between this and Climate Science. I wonder how well everything that affects climate is taken into account, especially when I see that (according to the IPCC) our level of scientific understanding of almost everything except CO2 is rated as Medium to Low. Fair enough that we have a High level of understanding of CO2, but how sure are we, really, of the cumulative effects of everything else which we understand to a much lesser degree?

I have other issues, but I've rambled on for long enough (for which I apologise) so I shall leave it at that for now.

Kind Regards


Michael Tobis said...

Rob, please state what it is you are skeptical about, beginning with the sentence "I am skeptical about X".

For all you know, I agree with you. The only substantial thing you said is "how sure are we, really, of the cumulative effects of everything else which we understand to a much lesser degree?" and the answer has to be that the error bars are usually the plot.

Any sense in which your acceptance of the uncertainty characterizations in the IPCC literature might constitute "skepticism" escapes me.

Rob M said...

I am not sure I can give you exactly what you want without using some verbose or tortuous grammar - you say you want a comment like "I am skeptical about X", implying that "X" is a fact about which I am skeptical. The thing is that I am actively skeptical about the broad catchall that is generally called "AGW Theory". That skepticism is borne of questions I have about facts rather than skepticism, necessarily, of the facts themselves.

(Forgive me if this all sounds rather guarded and defensive, but I have found that I have to be very careful about what I am saying to avoid misinterpretation.)

My last post can, I suppose, be reworded to say this:

I am skeptical about the proposed degree of certainty that mankind is having a significant effect on the environment (cited as 90%+) is legitimate, when considering the fact that we have less understanding of most climate-related processes than we have of Man's input. It also seems that the largest error margin is associated with the area of which we have the highest level of understanding (Anthropogenic sources) - some of the areas of which we have little understanding (such as solar effects) have relatively tiny error margins. How can those error margins be justified in the context of "Little Scientific Understanding"?



PS - I suppose you could say, as shorthand, that I am skeptical about error bars.

Michael Tobis said...

The thing is that I am actively skeptical about the broad catchall that is generally called "AGW Theory".

You should be. There is nothing that could reasonably be called that either in the colloquial or the formal sense. Of course, the word "theory" should be avoided altogether in these discussions because of the gulf in meaning between scientific and lay uses of the word.

I am skeptical about the proposed degree of certainty that mankind is having a significant effect on the environment (cited as 90%+) is legitimate

Presumably you mean "climate", not environment. Otherwise I must presume you are posting to a discussion on the wrong planet.

Can you provide some argument for your skepticism, or do you merely not like the result?

I suppose you could say, as shorthand, that I am skeptical about error bars.

This is yet a third thing. You seem to believe that total uncertainty is the sum of individual uncertainties. You may wish to apply a small amount of statistical reasoning to conclude that uncertainties do not sum.

You seem to believe that there is a direct mapping between uncertainty in the amount of forcing and the degree to which a phenomenon is understood. However, in the extreme case, a phenomenon may be almost totally mysterious and yet be known to have a very small impact.

Rob, to be frank you are not asking questions that strike me as either well-informed or constructive, despite your claims that you know what you are talking about.

Please either take the trouble to back up your claims, or take them elsewhere.

Rob M said...

EDIT - I was not aware that I made any claims. I had only explained the cause of my skepticism.

To be honest, Michael, I am not the slightest bit interested in continuing this discussion if you are going to proceed in such an unpleasant manner. Whenever I have a discussion with someone I don't know I always treat them at first with some degree of respect and deference, until such a point as they prove themselves to be either worthy or unworthy of it.

I originally posted to ask a genuine question about your thoughts on the discussion about which you felt a need to write a blog post. Your reply was rather sneering, if I may be so bold, and so I replied to clarify who was involved in the discussion. It is sometimes nice to get an "expert" view on things, but when the experts treat you with such disdain one wonders why one asks.

You ask me to phrase my skepticism in the form of basic questions, but the issue cannot, for me, be broken down into such manageable chunks (or at least not ones that fit your criteria). You refuse to answer an honest question unless it is phrased exactly how you want. And then, despite the fact that I have tried to give you what you want, and been very polite about it (I thought), you still end up by calling me "uninformed" and unconstructive, then tell me basically to "shape up or ship out".

If you want to convince skeptics and doubters that the IPCC view is right then you could at least treat them with some dignity and respect. I shall take my questions elsewhere, thank you very much.

Yours in disillusionment,


Michael Tobis said...

It is difficult to defend a position against someone who is willing to attack it from a position of vague discomfort but isn't actually willing to assert a clear position or engage the evidence.

Fergus said...

Michael; as far as I have worked this out over the past months, Rob is sceptical about the relative forcings of CO2 and other forcings, in particular the natural ones. The doubt seems to lie in the conclusion that the forcing attributable to CO2 can confidently be asserted to be 'x', (within a range), given that some of the other forcings have considerably uncertainty attached to both the likelihood of their attributed strength and the strength of the underlying science.

There is a secondary concern, that there are a sufficient number of variables about which confidence is relatively low, that the net product of the sum of these uncertainties could, feasibly, imply that the contribution from CO2 has been overestimated.

My apologies to Rob if this is a misrepresentation.

AK said...

Hi Michael...

I'm going to post here, despite the age of this thread, because my comment is right on-topic. I hope you'll forgive a bit of wordiness.

I've been chewing over your answer to my question #2 at Wired/Correlations, regarding the greenhouse effect, and I finally figured out what I was missing.

The key problem is that most of the pictures used give the wrong impression. They portray the atmospheric greenhouse as a single layer, which leaves no room for "how many bounces it takes before it gets out. That dominates the surface temperature".

It wasn't so much that I didn't know about the balance of radiation and re-radiation, but that I hadn't thought through all the implications because the pictures kept leading me astray.

It seemed to me, that since the area around 15 microns was already "saturated", doubling CO2 would only have an effect at the edges, since everything is already being absorbed at around 15 microns.

I see it now (light bulb over head), what matters isn't the IR coming from the ground, but the effective temperature of the source of the IR coming to the ground. By shortening the attenuation path length (is that the right term?), doubling CO2 raises that temp.

Which might not matter except that the same thing happens at the top. Looking from the point of view of a satellite measuring the effective temp at each wavelength, the attenuation path length is shortened and the effective temp is reduced. Thus the whole system has to warm up to balance incoming energy.

Thus, doubling CO2 has an effect all the way across the 15 micron peak, rather than just at the edges.

Now, to explain this to somebody else in the same boat I was, I need a picture. And there's nothing. The Wikipedia page on the Greenhouse Effect didn't tell me that, and the pictures don't really give any clue. I'd probably have a hard time using them to explain what I said above.

I tried the first 1000 images from Google on Greenhouse effect, and even the best of the crop were pretty useless: 1 2 3 4 5 6 7 (Venus) 8 9 10 11 12.

One is moderately useful, as it shows some radiation out at 15 microns, and if it were side-by-side with another for doubled CO2 it might have lead to an understanding.

What I'm thinking of, however, is starting with something like this and modifying it to fit. It needs two layers, one near the ground absorbing and re-radiating to the ground, one at the top, radiating upwards, with radiation back and forth between them.

Now map the spectrum from perhaps 7 to 50 microns across the bottom, with the layers moving upwards and downwards in concert with the net attenuation at that wavelength. Ideally it would scale to the actual level of average temp, but anything topologically correct would probably get the point across.

Getting fancy, add vertical lines from a satellite looking down at 15 microns, perhaps 13.5, and 12, with numbers where they cross the top absorption/reradiation layer. To get really fancy, the layers could be colored, the upper one blue shading to white where it rises and gets colder, the lower one red shading to orange where it lowers and gets warmer. (Changing the ground to brown since we don't care about its outgoing radiation.) Then two of them, side by side, one for 1xCO2 and one for 2xCO2.

I wish I had the skills and software to produce something like that (I can see it in my head, for whatever good that does), if I had seen it anytime since Kyoto first came on my radar horizon it would have solved my problem understanding CO2 saturation (or lack thereof) and greenhouse warming. I wonder how many other people would be helped by such a pair of pictures.

Of course, a viewer would already have to understand enough about the atmosphere (lapse rate, etc.) and it would still leave detailed questions about modeling, but it could help.

Of course, if you know of any pictures even somewhat closer to my new understanding than the ones I found (see above) I would certainly be grateful if you could point me to them. (Although with nothing at Wikipedia, I'm guessing there isn't.)

Anyhow, to get back on topic, there seems to be a sort of "forbidden zone" (sensu quantum mechanics) of scientific explanation between the simple stuff for journalists and the equations for the experts. My impression is that many scientists outside Climatology and radiation physics are somewhat taking the experts' word for this sort of thing, which makes me very nervous. Probably many others have the same problem.

However, finally getting an explanation for one of my issues makes me a lot less nervous about the others. I do think there's a crying need for more technical explanations for real skeptics (as opposed to tendentious opponents).


Michael Tobis said...

AK, thanks for your thoughts.

My idea is that it's a difficult request.

Nothing prevents you from picking up undergrad textbooks, and the small audience for this sort of thing makes it unlikely that much will fill the gap besides undergrad textbooks.

The trouble is that these will intoduce you to the actual science (in this case radiative transfer) and not to the questions that come up in informing policy.

However, there is little choice in the matter. You can't really understand the perturbations to the system more than you understand the system.

AK said...

On topic but not on the previous subject, this page came up in a discussion at a non-professional blog.

"What happens after the GHG molecules absorb infrared radiation? The hot molecules release their energy, usually at lower energy (longer wavelength) radiation than the energy previously absorbed. The molecules cannot absorb energy emitted by other molecules of their own kind. Methane molecules, for example, cannot absorb radiation emitted by other methane molecules. This constraint limits how often GHG molecules can absorb emitted infrared radiation. Frequency of absorption also depends on how long the hot GHG molecules take to emit or otherwise release the excess energy."

Whether or not it's correct, it's certainly confusing. My response was to point to the date, but I'm wondering if there's more that could be done?