Saturday, March 05, 2011

Consider a Spherical Truncated Icosahedron

UPDATE: A much better title

In the comments, palindrom points to a toy model which has been submitted to EGU.

Over in the wacky world of Huffington Post, a denialist troll posted a link to this odd paper:

http://mee­tingorgani­zer.copern­icus.org/E­GU2011/EGU­2011-4505-­1.pdf

in which Hermann Harde, a laser spectroscopist morphs into a climate modeler, inserts some very good molecular data into what appears to be a rather crude, toy, do-it-yourself planetary atmosphere, and decides the CO2 isn't quite what it's cracked up to be as a greenhouse gas. Can someone who is actually expert at this give an authoritative review of this? (Dammit, Jim), I'm an astronomer, not a planetary atmospheres person, so I don't have the requisite deep knowledge of planetary atmospheres models, but the inquiring minds posting here ought to know ...
John points out the obvious (damn it get to work and post stuff, Eli is gonna retire)
Harde calculates a smaller rise in global temperature (about 0.45 C) as a result of doubling CO2, compared with the IPCC number (3C), by a factor of about 7.

The IPCC result is based on: (1) a rise of 1.2 C from doubled ed CO2 in the atmosphere, causing an enhanced Greenhouse effect, and (2) positive feedbacks (ice-albedo, rising water vapor concentrations) which raise the IPCC estimate to about 3 C +_ 1.5 C.

Harde has calculated only the atmospheric effects, and has ignored feedbacks completely. So his result of 0.45 C should be compared with the IPCC "no-feedback" estimate of 1.2 C. Thus the discrepancy is more like a factor of three, not seven.
but we still got a factor of three, so Eli went and read the damn thing. It was actually quite nice, some original stuff in there like
The propagation length of the sun light in these layers, which depends on the angle of incidence to the atmosphere and therefore on the geographic latitude, is included by considering the earth as a truncated icosahedron (bucky ball) consisting of 32 surfaces with well defined angles to the incoming radiation and assigning each of the areas to one of the three climate zones.
but where the factor of three comes from is easy to see
To identify the influence of the absorbing gases on the climate and particularly the effect of an increasing CO2- concentration on the warming of the earth, a two-layer climate model was developed, which describes the atmosphere and the ground as two layers acting simultaneously as absorbers and Planck radiators. Also heat transfer by convection between these layers and horizontally by winds or oceanic currents between the climate zones is considered. At equilibrium each, the atmosphere as well as the ground, delivers as much power as it sucks up from the sun and the neighbouring layer or climate zone.With this model for each climate zone the temperature progression of the earth and the atmosphere is calculated as a function of the CO2-concentration and several other parameters like ozone and cloud absorption, short- and long-wavelength scattering at clouds as well as the reflection at the earth’s surface.
The problem is that there are only two levels. The greenhouse effect is driven by the increase in the height of the atmosphere from which radiation that can be absorbed or emitted by CO2 can reach space. This cannot be captured in a two level model, which, of necessity has to crudely average over a lot of parameters. Of course some of the devil is in the details, such as how much water vapor, clouds, etc is in the second level. The figure, of course, is from Rabett Run's reply to Gerlich and Tschuschner. Harde's stuff is of a much higher quality than the G&T joke.

Oh yes, this appears to be a bad week for climate denialists. Roy Spencer took five on the nose, two from Arthur Smith and three from Barry Bickmore

24 comments:

Ron Broberg said...

I don't know if this falls prey to a similar error or not - but on a related note, Lansner (reposted at WUWT last fall) used MODTRAN and current greenhouse warming to derive a CO2 sensitivity of 0.54C. I reworked his method some to arrive at 0.67C. Its been puzzle sitting around waiting for me to get smarter. If you care to dig into that can-o-worms, you can find my stuff here:
http://rhinohide.wordpress.com/2010/09/08/lansner-reloaded/

EliRabett said...

Ron, I will take a look. You are right though, there should not be much difference between what you get with MODTRAN and with a line by line code in these circumstances

David B. Benson said...

Ray Pierrehumbert's "Principles of Planetary Climate"

Anonymous said...

Eli, What I would like to know is do the existing models run with a complete line by line absorption for the entire spectral interval that Harde seems to have done. Or do they take slices to speed things up a bit. Cheers, TJ

David B. Benson said...

TJ --- See what R.T. Pierrehumbert has to say in his book.

The actual GCM code is quite complex so as to well approximate a line-by-line approach and still be speedy.

Horatio Algeranon said...

The real question is "Why in the world would anyone expect such a simple model to yield anything better than an order of magnitude estimate?"

0.45C is of the same order of magnitude as 1.2C, so it's not clear (to this mouse, at least) that there is any real "discrepancy".

If anything, Harde's result is a validation of the basic IPCC "bare" CO2 doubling result.

The fact that folks like Harde actually seem to believe that such a result (obtained from a very crude model) is sufficient to raise questions about (to say nothing of overturn) the findings of climate scientists who have done modeling to take into account the many aspects of the earth's atmosphere (based on extensive experimental data) really demonstrates just how absurd the whole "debate" about climate science has become outside the peer reviewed journals.

Anonymous said...

As David Benson kindly explains, all is explained in Chapter 4 of Principles of Planetary climate. I'll also add (for people who want the 6-page version) that my Physics Today article is all the refutation Harde needs. The fact that the AIRS observed spectra of Earth's outgoing radiation exactly matches the computation done by the line-by-line code (which in turn validates the band-averaged codes used in GCMs) makes it impossible that Harde's calculation can be right. If he thinks he has a case, he has to show that he can reproduce the AIRS spectra -- also the similar CO2 features one sees in the Mars TES observations, etc.

Here's an interesting experiment. Both Lucia's and Judy Curry's bloggy things claim to be able to take skeptics argumetns seriously and evaluate them on the merits. Somebody should air Harde's paper there and see if either one is capable of spotting the errors. They're so obvious it wouldn't be saying much if they can, but it would be something.

--raypierre

Eric said...

Eli.

I agree with you that it's 'original' to approximate the earth as a truncated icosahedron, but it's pretty funny. The classic joke is about physicists oversimplyfing this... 'consider a spherical cow'. But the earth already is pretty spherical. Why on earth try to improve on that?

As folks more tech-geeky like to say, lol....!

Anonymous said...

Eli,

Thanks so much for following up on this -- I figured it was nonsense, but it isn't my field.

In any ordinary subject, such as my own, contributions like this can pretty much be counted on to sink without a trace, but in climate studies, I think the relevant community needs to be especially mindful and call out incompetence right away.

Cheers - palindrom.

EliRabett said...

RayP's Physics Today article is available on line. If Eli may make a suggestions, those attending the eau meeting should stop by and talk with Prof. Harde. Take a copy of the AIRS spectra showing the match and maybe some other backup material.

Horatio Algeranon said...

"Elephantary, My Dear Hansen"
-- by Horatio Algeranon

Spherical elephants and Buckyball mice
Isn't climate science nice?
Complex physics ain't required
To prove the scientists should be fired.

H/T Eric

Lazar said...

... who was once as smoothly a varying function as you.

Muoncounter said...

This type of back-of-the-envelope model sounds similar to some of the '50% of LWIR goes up, 50% down' we've heard a lot about on various sensitivity threads on SkS. This familiar xkcd cartoon speaks to the potential value of such expertise.

EliRabett said...

Ray if you think that is a good idea try this train wreck Of course, Judy's contribution demonstrated once again that she is not very clued in.

John said...

One aspect of Spencer's book that nobody has commented on (yet) is the publisher: Encounter Books. A glance at their website will convince anybody that they are an ideologically conservative publisher, that normally takes no interest in scientific questions. Encounter Books (started in 1997) was named for the defunct Anglo-American literary magazine Encounter, which ceased publication in 1991. Encounter magazine suffered a major setback to its credibility in the 1960's when it was revealed that its parent organization, the Congress for Cultural Freedom, was secretly funded by the CIA. In the wake of those revelations, one of the founding editors, Stephen Spender, resigned.

Encounter magazine, because it was a literary magazine, may be dismissed as irrelevant to the present issue. That would be a mistake. Here's how the Encounter/Congress for Cultural Freedom operation worked: a few people at the top knew about the CIA funding link. Farther down the organizational ladder, others did not know, and actually operated on good faith. Encounter magazine actually got some high-quality literary intellectuals to sign on to the "project" by (for example) not requiring its participants to endorse every single action of the US government in the Cold War. But there were some red lines that could not be crossed.

How is that relevant to today's issues? The global warming deniers have set up a large propaganda network. Some of the network can be shown to be funded by fossil fuel interests, some by ideological conservative outfits (The Bradley Foundation, for example.) But not all of it. And once the system is up and running, lots of participants may be unaware of the funding of the denial network. And some are operating in good faith, while some key people are perfectly aware of what who is funding them, and why.

What's the take home lesson here? Encounter Magazine sought to conceal the CIA funding link. Today's AGW deniers seek to conceal the funding link to fossil fuels companies (Koch, Exxon-Mobil) and ideological conservative outfits. In both cases, they were able to recruit and use some honest people who were unaware of the crucial funding link.

susan said...

What baffles me is the size of the Curry audience. This is not a small cabal.

What goes missing is that it requires hard work and skill to become a top scientist. Seems like the kids in school who didn't want to do their lessons are taking over. There are a lot of them and they have a lot of equipment to help them avoid facing the hard work of actually learning something.

John said...

I see that Roy Spencer is now on the Board of Directors of the George C. Marshall Institute, where he joins William O'Keefe, former COO of the American Petroleum Institute.

Of course, this does not address the merits (or demerits) of the argument that Spencer offers. Thanks to Barry Bickmore and Arthur Smith for that.

Steve Bloom said...

GMI has been a principal promoter of Spencer and Christy for some years now, so it's no surprise to see Spencer on the board there. Christy won't join, as doing so would damage his credibility with the Revkins of the world.

Oale said...

considered this somewhat a bit back, but figuring out the grids on the pentagonal sides is a bit difficult, I believe.

Horatio Algeranon said...

It is possible that the Hermann Harde paper is tongue-in-cheek.

It might be just a coincidence, but one of the most famous uses of the icosahedron in science (albeit a regular icosahedron) was by Kepler for his "Platonist polyhedral solar system".

Kepler's use of the icosahedron and other platonic solids was based purely on mysticism.

William Connolley said...

I submit http://scottishsceptic.wordpress.com/2013/11/13/hermann-harde-greenhouse-effect-30-smaller-than-ipcc-says/ for your consideration.

a_ray_in_dilbert_space said...

Susan said: "Seems like the kids in school who didn't want to do their lessons are taking over. There are a lot of them and they have a lot of equipment to help them avoid facing the hard work of actually learning something."

Roy Schwitters, the first and only director of the lab that was supposed to become the superconducting supercollider referred to this trend as the revenge of the C students.

quantpalaeo said...

And so it is published in the ever prestigious Open Journal of Atmospheric and Climate Change.

At 50 pages long, there is too much to wade through to find out what is going on. The two-layer model now has 228 sub-layers in the atmosphere. Not sure what it lacks that it is not a 228 layer model.
Paper claims to include all relevant feedbacks, but the model is obviously far to simple to do anything physically realistic with
processes causing feedbacks.

Hmm. Cloud cover is a function of land temperature. No requirement for humidity. Cannot see how this could possibly go wrong.

http://www.scipublish.com/journals/ACC/papers/846

KR said...

He appears to be using a 228 layer radiation model for spectral effects, but still only using a 2 layer temperature model. And with what appears to be fixed humidity - no feedbacks whatsoever.

Entirely too simple for the conclusions he's drawing.