The second law, and the atmospheric greenhouse effect

[Augustine2004]

Admittedly, I have only a general background, nearly all in college, in modeling complex phenomena. I would be happy to be educated further. Here is my problem: Your paper state,

A recurring element in GT09 is the claim that others neglect the thermal con-
ductivity of the atmosphere, presented in the introductory (“Problem background”)
section covering the first 4 pages of the paper and also Sec. 3.8, as well as elsewhere
in passing. However, they fail to place this in a quantitative context. In fact the
heat flows associated with conductivity are tiny, and hardly different from the value
of zero they repeatedly criticize in the work of others. For example, for a typical
lapse rate temperature gradient of 5 K/km, the resulting heat flow from atmo-
spheric conductivity is about 1.5×10−4 W/m2, (according to Table 5 of GT09) far
less than the 10’s or 100’s of W/m2 associated with other atmospheric heat flow
processes.10

----page 1310

Is it not so that the atmosphere is a chaotic system, so that any neglect of even such a small effect as thermal conductivity may lead to large differences later on? It would make sense to neglect it only if those differences can be averaged out to zero or near zero over sufficiently large time intervals. Maybe there is the definition of climate: average weather, with all chaotic elements averaged out to zero.

[YourMaster]

I've always had a problem with the idea of viewing CO2 as a pollutant (given it's so essential for plant life, which obviously in turn makes it critical for oxygen production). I figured how much harm could a one degree increase in average temperature over the next century really cause? However, the science is pretty solid, and although I've had to wrestle with it, unfortunately global warming is not something we have the luxury of ignoring.

Here's an excerpt from an abstract of a paper that does an excellent job of summarizing the data, and the reality of the situation we face:

Over the last 35 years, our research team has recovered ice-core records of climatic and environmental variations from the polar regions and from low-latitude high-elevation ice fields from 16 countries. The ongoing widespread melting of high-elevation glaciers and ice caps, particularly in low to middle latitudes, provides some of the strongest evidence to date that a large-scale, pervasive, and, in some cases, rapid change in Earth’s climate system is underway. This paper highlights observations of 20th and 21st century glacier shrinkage in the Andes, the Himalayas, and on Mount Kilimanjaro. Ice cores retrieved from shrinking glaciers around the world confirm their continuous existence for periods ranging from hundreds of years to multiple millennia, suggesting that climatological conditions that dominate those regions today are different from those under which these ice fields originally accumulated and have been sustained.

http://researchnews.osu.edu/archive/TBA--LTonly.pdf

I would encourage all who aren't already working in this field to give it a read.

The only thing I would question about the conclusions of this research, is the range of alternatives they present. First, they essentially concede at this point significant damage is already done (and temperatures will continue to increase for some time, even if we could accomplish the impossible, and cut CO2 emissions significantly). Second, the range of alternatives they present aren't very encouraging. We apparently have to either live with an immense amount of catastrophe, or live with a lower (but still substantial) amount of catastrophe. I have to think science can do better. I've heard numerous other ideas, like blanketing areas where the ground is exposed (from melted ice) with white sheets to reflect sunlight. Germany, who once opposed the idea of dumping iron into the ocean to promote plankton growth (thereby sequestering CO2), is now leading an experiment to do exactly that (and IMO it's an extremely promising idea).

[sylas]

Thanks for the responses folks.

I’ll try to answer questions reasonably concisely, but if there’s something I should expand on further, please say so. I’ve not tried to give references for everything, but I have tried to keep my assertions grounded on what is well known and could be checked with reference to general teaching texts on atmospheric physics or other related matters. But it’s still my own work and mostly from memory, so errors are entirely possible. If there’s a concrete claim that looks dubious and for which you’d like more backing, point it out and I’ll double check and respond more carefully.

I’m posting four responses here in rapid succession. This brief general comment, and then answers for questions from shadowmaster, Ausgustine2004 and YourMaster.

Cheers -- sylas

[sylas]

Somehow, this does not present, to me at least, a very compelling argument that Co2 is a culprit that warrants major changes that impact our economic system.
It seems to be more philosophy than real science.
Should we take worst case environmental assumptions and react to that?

At this point I am mainly just trying to explain the related science. Response or reaction is a political/social/economic/etc issue, which is not quite the same. Even people who agree on what we know of the science can reasonably disagree on the reactions.

CO2 stands out as the major driving factor for warming, particularly in recent decades; though of course not the only factor. This is something that shows up independent of questions of sensitivity. There are major uncertainties with some of the other forcings, but nothing else has a plausible positive forcing as much as CO2, by a substantial margin. The uncertainties mean that the total forcing cannot be pinned down accurately; but they do nothing to shake CO2 as primary warming driver. The next most important factors towards positive heating effects are other greenhouse gases, like N2O and CH4.

I would want to see a lot more a lot more validated system modeling before betting that we really understand the complete picture.
As poorly as we understand economics, we know it better than this and we should be careful.
It is possible to generate validated models, and they should be better than the inaccuracies that you have posted above.
Why are they not? What do I miss?

The question of "verification and validation" is of some relevance to software for modeling, and there have been some interesting developments on that area since I was last active in these discussions.

But V&V really isn’t the big issue here. Climate or weather models are necessarily approximations. To see how well the approximations work, you have to compare with some reference; ideally the real system being modeled.

The major issues with this are simply empirical. There are a host of unsolved questions for which V&V of computer models can do nothing to contribute. The outstanding problems are pretty conventional scientific problems. For sensitivity, we need to know a lot more about cloud physics. For time aspects, we need to know a lot more about how energy is distributed within the ocean. We cannot model precisely how atmospheric carbon levels respond to changes in emissions, because the carbon cycle is not fully known. We know empirically that about 40% of emissions are remaining in the atmosphere to drive the rapid increases in atmospheric CO2; and we know that the rest is ending up in the ocean and in terrestrial carbon sinks. But sorting out a precise budget of where it all goes is not known.

We do know some things; but there’s a heck of a lot we don’t know, and the solution to that is to keeping investigating the empirical scientific details of how the world works. Looking at the details of software models is a minor sideline. It is a sideline that is being addressed, and we can look more at that if you like; but really and truly – V&V of models is not going to help anything much until we know a heck of a lot more about what we are modeling.

Cheers -- sylas

[sylas]

Even with the uncertainty in the data, a competent programmer should be able to 'fit' the model with a good desktop computer, and you know the rest of the story. I recall Twiggy suggested a desktop program or something like that, but I think the model would have to be bigger and more sophisticated, yet still linear.

Let me clarify. 'fit' means 'fit the model to the data.' I didn't mean, 'shoehorn the program into your 'puter.'

I’m not quite sure what you are saying here.

Climate models are not "fitted" to data. Climate models work by representing the physics of interactions between atmosphere, ocean and energy. There are a number of tunable parameters, but nothing of the kind that can fit to a time series of data in the usual sense of "fitting".

But this thread is not really about climate models; it is about the physics of the greenhouse effect; and specifically about how heat moves through the atmosphere. There are models used here as well, but they are not climate models. A radiative transfer model for the atmosphere is a much simpler beast than a climate model; and the physics is well understood.

The calculations for an atmospheric radiative transfer model are arduous, but not controversial. There is no fitting involved. The processes are not chaotic. They aren’t "linear" either. There are differences between seasons, and latitudes, and weather conditions. But the differences are not chaotic either. The greenhouse effect for the planet can be quantified to good accuracy, and the forcings of different gases can be calculated. THIS is the kind of calculation that G&T were attempted to disparage in their paper.

You have said a lot about the chaotic atmosphere, which is certainly true, but in a completely different context. It is the flow of the atmosphere as fluid which is highly chaotic. This has very little bearing on the calculations of greenhouse forcings.

Admittedly, I have only a general background, nearly all in college, in modeling complex phenomena. I would be happy to be educated further. Here is my problem: Your paper state,

A recurring element in GT09 is the claim that others neglect the thermal conductivity of the atmosphere, presented in the introductory ("Problem background") section covering the first 4 pages of the paper and also Section 3.8, as well as elsewhere in passing. However, they fail to place this in quantitative context. In fact the heat flows associated with conductivity are tiny, and hardly different from the value of zero they repeatedly criticize in the work of others. For example, for a typical lapse rate temperature gradient of 5 K/km, the resulting heat flow from atmospheric conductivity is about 1.5x10^-4 W/m², (according to Table 5 of GT09) far less than the 10’s or 100’s of W/m² associated with other atmospheric heat flow processes.¹⁰

----page 1310

Is it not so that the atmosphere is a chaotic system, so that any neglect of even such a small effect as thermal conductivity may lead to large differences later on? It would make sense to neglect it only if those differences can be averaged out to zero or near zero over sufficiently large time intervals. Maybe there is the definition of climate: average weather, with all chaotic elements averaged out to zero.

(I’ve taken the liberty of reformatting your quote from our rebuttal. The text is identical, and the formatting will work a lot better. I’ve got the source, and that works better than cut and paste of the pdf.)

No, it is definitely not chaotic in this context. There is no divergence involved; the whole matter of energy transfer is strongly constrained by the fixed energy in and by need for this to balance with the energy out.

The matter of "climate" and "average weather" is not the focus of Gerlich and Tscheuschner’s paper, or our rebuttal. It is simply about the thermodynamics of the atmosphere, and energy balance. The response of "weather" to this is chaotic; but we are not discussing weather, nor responding to claims about weather.

Cheers -- sylas

[sylas]

I've always had a problem with the idea of viewing CO2 as a pollutant (given it's so essential for plant life, which obviously in turn makes it critical for oxygen production). I figured how much harm could a one degree increase in average temperature over the next century really cause? However, the science is pretty solid, and although I've had to wrestle with it, unfortunately global warming is not something we have the luxury of ignoring.

I agree with you on the word "pollutant".

The fact is that benefits of CO2 are not only for plant life. The atmospheric greenhouse effect is essential for keeping the Earth at a livable temperature. CO2 is the main driver of the atmospheric greenhouse effect; a kind of "control knob" for the Earth’s climate. Water vapour has a substantially larger net contribution, but it works more as the "engine" for the greenhouse effect, since humidity is mostly determined by temperatures.

Without CO2 in our atmosphere, the Earth would swiftly descend into an ice age that would make the most recent ice ages look like a tropical paradise.

Many aspects of the Earth are in a happy balance between too much and too little. The end result is a really nice planet to live on. Changing the balance of affairs to which we have become accustomed is going to have consequences.

As far as heating of the planet is concerned, one degree more would be no major problem. Six degrees more would be a big problem. There are two major factors which will determine how many degrees.

• The physics of climate sensitivity – over which we have no control. This is simply a case of not knowing all about the Earth, and how much temperatures would rise for a given forcing.
• The magnitude of the forcing – which we do control (in principle). The largest controlling factor here is CO2 emissions.

The largest contributor to the net forcing is CO2; this also is one which has a long term impact on scales of the coming century. CO2 emitted now continues to have an impact to the end of the century and beyond. Other factors (aerosols, CH4, and some others) have a much more limited time span for their impact. By 2100, the forcing is going to depend on the cumulative CO2 added over the whole century, and aerosols and CH4 added over the preceding decade.

Here's an excerpt from an abstract of a paper that does an excellent job of summarizing the data, and the reality of the situation we face:

[…]

http://researchnews.osu.edu/archive/TBA--LTonly.pdf

Thanks for the link. I had not seen that article previously; it looks like a good overview with a focus on appropriate responses. The author is Lonnie G Thompson, a world leader in Earth Sciences and paleoclimate studies in particular. His CV is staggering.

The only thing I would question about the conclusions of this research, is the range of alternatives they present. First, they essentially concede at this point significant damage is already done (and temperatures will continue to increase for some time, even if we could accomplish the impossible, and cut CO2 emissions significantly). Second, the range of alternatives they present aren't very encouraging. We apparently have to either live with an immense amount of catastrophe, or live with a lower (but still substantial) amount of catastrophe. I have to think science can do better. I've heard numerous other ideas, like blanketing areas where the ground is exposed (from melted ice) with white sheets to reflect sunlight. Germany, who once opposed the idea of dumping iron into the ocean to promote plankton growth (thereby sequestering CO2), is now leading an experiment to do exactly that (and IMO it's an extremely promising idea).

The paper does consider these "other" ideas under the heading "mitigation". Page 167, section headed "OUR OPTIONS", classifies options into: mitigate, adapt, and suffer. The option "mitigation" includes anything to reduce the pace and/or magnitude of changes, which includes the kinds of geo-engineering options you list, as well as the options for reducing existing impacts. Granted, they don't list all the possibilities in detail.

This is getting beyond the scope of looking at the physics of climate; but my own inclination is to be extremely skeptical of deliberately "geo-engineering" climate. In my view, it will inevitably be cheaper, easier and far safer to mitigate by reducing the existing impact rather than by deliberately adding new impacts intended to counter-act existing impacts.

There’s a heck of a lot we don’t know right now about Earth’s climate; and that goes double for all the other various aspects of the planet which help make it a suitable environment in which to live. We cannot hope to modify one aspect without modifying others we don’t anticipate; and for any such engineering process to be significant, we’d have to put in place a process with impacts sufficient to make a difference to the 8 million tons annually of carbon injected into the atmosphere.

Be that as it may, I have no problem with research intended that sheds more light on various proposals for geo-engineering.

As you say, there was opposition in Germany to an experiment on the iron fertilization proposal, and it was initially blocked, but only for a few months. The experiment did eventually go ahead, and the results were very disappointing. You can read about it at Setback for climate technical fix (BBC, 23 March 2009). Extract from the article:

Setback for climate technical fix, BBC news 23 March 2009

Germany's environment ministry had tried to stop the project, which green campaign groups said was "dangerous".

Leaders of the German-Indian expedition said they had gained valuable scientific information, but that their results suggested iron fertilisation could not have a major impact, at least in that region of the oceans.

"There's been hope that one could remove some of the excess carbon dioxide - put it back where it came from, in a sense, because the petroleum we're burning was originally made by the algae," said Victor Smetacek from the Alfred Wegener Institute in Bremerhaven.

"But our results show this is going to be a small amount, almost negligible."

© source where applicable

See also some recent empirical research on the idea: Iron Fertilization To Capture Carbon Dioxide Dealt A Blow: Plankton Stores Much Less Carbon Dioxide Than Estimated (ScienceDaily Jan 29, 2009; and related Nature publication Pollard et al. (2009) linked therein.)

Cheers -- sylas

[Augustine2004]

The question of "verification and validation" is of some relevance to software for modeling, and there have been some interesting developments on that area since I was last active in these discussions.

But V&V really isn’t the big issue here. Climate or weather models are necessarily approximations. To see how well the approximations work, you have to compare with some reference; ideally the real system being modeled.

The major issues with this are simply empirical. There are a host of unsolved questions for which V&V of computer models can do nothing to contribute. The outstanding problems are pretty conventional scientific problems. For sensitivity, we need to know a lot more about cloud physics. For time aspects, we need to know a lot more about how energy is distributed within the ocean. We cannot model precisely how atmospheric carbon levels respond to changes in emissions, because the carbon cycle is not fully known. We know empirically that about 40% of emissions are remaining in the atmosphere to drive the rapid increases in atmospheric CO2; and we know that the rest is ending up in the ocean and in terrestrial carbon sinks. But sorting out a precise budget of where it all goes is not known.

We do know some things; but there’s a heck of a lot we don’t know, and the solution to that is to keeping investigating the empirical scientific details of how the world works. Looking at the details of software models is a minor sideline. It is a sideline that is being addressed, and we can look more at that if you like; but really and truly – V&V of models is not going to help anything much until we know a heck of a lot more about what we are modeling.

But v&v is essentially in part comparing model results to climate observations! You're missing something or being confused.

Thank you for making it clear that atmospheric science is far from being settled, contrary to claims--or what!?

[Augustine2004]

IWithout CO2 in our atmosphere, the Earth would swiftly descend into an ice age that would make the most recent ice ages look like a tropical paradise.

I have to admit that surprised me. So it has been demonstrated beyond reasonable doubt? Where, please?

Six degrees more would be a big problem.

Unsupported assertion? If you did give reference before that I should remember, my apologies.

[sylas]

Without CO2 in our atmosphere, the Earth would swiftly descend into an ice age that would make the most recent ice ages look like a tropical paradise.

I have to admit that surprised me. So it has been demonstrated beyond reasonable doubt? Where, please?

All other factors being unchanged, the atmospheric greenhouse effect raises Earth's surface temperatures about 33 degrees. It's been known since the nineteenth century that water and carbon dioxide are the major contributors to this. Modern quantified work shows that without the CO2, the effect is around 14% reduced (hence, roughly 5 degrees) which is already of the order of the difference with the most recent ice age. But as temperatures cool, the atmosphere can hold less water, which leads to a collapse of most of the greenhouse effect, and expanding ice sheets reflect a lot more of the Sun's light, which drops things further still.

As I described elsewhere in the post you have quoted (msg #36): water vapour, although a stronger greenhouse gas, works as the engine rather than the control, because it is condensable and hence temperatures determine how much water can be held in the atmosphere.

Quantification of this in a readable form is at CO₂: The Thermostat that Controls Earth's Temperature. Some relevant journal articles quantifying the details are as follows:

• Ramanathan, V., and J. A. Coakley Jr. (1978), Climate modeling through radiative-convective models, Rev. Geophys., 16(4), 465–489, doi:10.1029/RG016i004p00465. (journal link, preprint link)
• Schmidt, G.A., R. Ruedy, R.L. Miller, and A.A. Lacis, (2010), The attribution of the present-day total greenhouse effect. J. Geophys. Res., 115, D20106, doi:10.1029/2010JD014287. (journal link, preprint link)
• Lacis, A.A., G.A. Schmidt, D. Rind, amd R.E. Ruedy, (2010) Atmospheric CO2: Principal Control Knob Governing Earth’s Temperature, Science 15 October 2010: 330 (6002), 356-359. DOI:10.1126/science.1190653 (journal link, preprint link)

Six degrees more would be a big problem.

Unsupported assertion? If you did give reference before that I should remember, my apologies.

No problem… as I said back in msg 33 I did not bother with extensive citations in answering your questions, and you are welcome to ask if something sounds dubious. But I think you are already well aware that this number has a lot of support -- even if you personally don't accept it -- so you can probably get references yourself pretty easily.

For a good clear account, I endorse the reference YourMaster gave.

• Thompson, Lonnie G. (2010) Climate Change: The Evidence and Our Options, The Behavior Analyst 2010, 33, 153–170 No. 2 (Fall). (journal link, preprint link).

I'm happy to give pointers like this related to points made in discussion, but I'd like the main focus of the thread to continue to be the basic science behind the atmospheric greenhouse effect, so I'll leave the question of impacts at that.

Cheers -- sylas

-----
Added in edit; a response also to msg #37.

But v&v is essentially in part comparing model results to climate observations! You're missing something or being confused.

Huh? The whole point of the post you quoted is that we simply don't have the observations needed to do V&V!

Thank you for making it clear that atmospheric science is far from being settled, contrary to claims--or what!?

Since I have been making this clear now for YEARS, it's a weird "thank you".

Just to underline the obvious… there's a world of difference between a field of science being settled, and science having made some discoveries in that field which are no longer in any serious doubt.

I don't think you'll ever find anyone anywhere saying anything as silly as "atmospheric science" being settled. Science reporting on this subject has always been completely clear that there are many open questions and unsettled problems; and I too have been clear through years of posting on this subject about the many open questions.

There are, of course, some important discoveries that are settled (in so far as science is ever settled). For example, we know for a fact that the Earth's atmosphere helps keep surface temperatures livable by the atmospheric greenhouse effect. We know that carbon dioxide is an important contributor to that effect, that that raising or lowering atmospheric carbon dioxide levels has a significant heating or cooling effect.

G&T, by claiming to "falsify" the greenhouse effect, are far over into extreme crank physics.

On the other hand, what is highly uncertain is the magnitude of heating or cooling effects, because of the wide open question of climate sensitivity. We DO have strong empirical evidence from many independent lines of investigation which constrain the sensitivity to with certain bounds. But to call that "settled" is inaccurate; people are actively working on refining those bounds and as it stands there is significant uncertainty, being in the range of about 2 to 4.5 degrees per CO2 doubling. The idea of sensitivity being less than 1.5, however, is effectively falsified by many lines of evidence.

Cheers -- sylas

[stsho]

• Edited by a Moderator •

[grmorton]

My real name is actually “Chris Ho-Stuart”. I am listed as one of the six authors on the rebuttal.

Since Sylas has complained about me using his real name, I thought I would respond again to this post of HIS. He can't even recall that he revealed his identity and has complained about me using his real name. He thinks he can tell people what public information he wants them to use.

[Tiggy]

Since Sylas has complained about me using his real name, I thought I would respond again to this post of HIS. He can't even recall that he revealed his identity and has complained about me using his real name. He thinks he can tell people what public information he wants them to use.

Hey moron, has it ever dawned on you that maybe since that time he changed his mind? Maybe he started getting unwanted emails from tin foil hat nutters like you and decided having his real identity out there wasn't the best idea.

I have seen him ask you politely multiple times since then to not use his real name. But you're such a jackass you insist on continuing just for spite. Reason #2764 why you earn so little respect around here.

Enjoy your time in the matrix.

- T

[Tiggy]

Since Sylas has complained about me using his real name, I thought I would respond again to this post of HIS. He can't even recall that he revealed his identity and has complained about me using his real name. He thinks he can tell people what public information he wants them to use.

BTW, here is the campus decorum rule on privacy you agreed to when you joined TWeb

Participant Anonymity/Privacy

In conjunction with our Privacy Statement, please respect the anonymity/privacy of other posters on TheologyWeb. Any member may choose to keep their personal information, such as name and location, from being published on this forum, even if such information is common knowledge elsewhere. Additional personal information, such as occupation, training, background, etc., may be removed if it is not easily obtainable public information elsewhere, can only be referenced by blatantly violating a request for the privacy of a member’s name, or is just generally disruptive to the forum. Once a member invokes this privilege, his reasons for doing so are just as private as the information itself. This section, like the Privacy Statement, can be over-ruled in cases of need to protect TheologyWeb, its members, or other people and/or organizations from intentional or unintentional interference, harm, or deception.

link

- T

[lao tzu]

What the hell, Glenn? It is never a good time to practice being an ass. This is not a useful skill. It does nothing to enhance your reputation, nor does it in any way advance your arguments.

[sylas]

Hey moron, has it ever dawned on you that maybe since that time he changed his mind? Maybe he started getting unwanted emails from tin foil hat nutters like you and decided having his real identity out there wasn't the best idea.

I have not changed my mind, but have been consistent throughout. I have always identified myself when it is relevant -- as in this thread, for example, where I am speaking about a paper published under my own name.

I am not getting unwanted email. My reasons are my own, and they are genuine, and they are personal. It is nothing to do with Glenn specifically, although the kind of behaviour and attitude he and many others display is a part of it in general terms. It has nothing to do with my professional life (such as it is), neither is it a tactic or an attempt to take advantage of a confusion of identities for sock-puppetry or anything of that kind. But there's nothing else going on beyond the simple crudeness that is visible to anyone reading posts in many internet forums.

I appreciate the community here very much. I first joined at a time when I was desperately unhappy, and the community here was a help when I needed it. I don't expect decency and kindness from everyone; but what I did receive was very much appreciated.

I still like it that this is a very open community, where people can be deliberately rude and even cruel with their writings. It is within such contexts that I am interested in supporting and engaging in friendly and constructive engagements -- robust and challenging but fair and respectful of persons -- even across deep differences. I've found it, too!

Be that as it may; my reasons are specifically personal and private, and that is all I need or want to say about it in open forum; given the decorum here. I wish to keep a distinction between my life online and my personal life, and that's all you need to know. So please, don't discuss or speculate, whether you approve or disapprove.

Most people quite naturally use my chosen pseudonym even in this thread. All it takes is a little bit of empathy to see that although I am identifying myself here where it is relevant, I am still continuing to use the pseudonym. Most people just follow that lead. If someone does use my own name, I'll sometimes make a brief request that we stick with the name I am actually using for writing, and there's never been, before this, any need to repeat myself or give any further justification.

Given this continuing refusal of Glenn in particular to simply take a polite request at face value, I guess I need to say more; hence this post.

Glenn's sarcasm about forgetting that I have identified myself previously is unwarranted. Here is a request I gave to Glenn last year, in which I refer indirectly to this very thread, and there are at least two others, where it has been actually relevant. I'm not trying to conceal anything.

A quick personal note: I use the name sylas here. My real name is not secret, and I will identify myself by name in some cases if it is directly relevant; but do much prefer not to use it directly. So everyone -- Glenn especially -- could you please refer to me by the name under which I am writing?

Cheers -- sylas -- who will now return to working on posts dealing with substantive matters with other people who are also taking that focus.