[Under construction. We will add some basic material here as a basis for discussion. Meanwhile, you are welcome to begin adding your comments on this subject.]
235 thoughts on “G. Greenhouse Gas Effect”
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Are we going to cover “greenhouse effect” or “greenhouse gas effect” or both?
@01, Berthold, good point. I will change the title.
The hypotheses of the “greenhouse gas effect” is the process where a combination of IR absorbing gases including Water/vapor/liquid/solid, CO2.CH4. NO2 and others are super insulation and cause the atmosphere to be 33 degrees warmer than would be explained by the “black body “temperature.
How is this done? The hypothesis says that the IRag’s absorb the IR radiation then it is “back radiated to earth causing the earth to be warmer by the resonation of this heat enery.
This is just the tip of the iceberg of the magic caused by the “greenhouse gas effect”
as has been said the truth is in the detail therefore anyone that wants to get into more of the details,please join in. I will be adding more later.
Does the Greenhouse Gas Effect defy physics? Gerhard Gerlich and Ralf D. Tscheuschner wrote a paper which said so. In addition they said:
Global climatologists claim that the Earth’s natural greenhouse effect keeps the Earth 33 C warmer than it would be without the trace gases in the atmosphere. 80 percent of this warming is attributed to water vapor and 20 percent to the 0.03 volume percent CO2. If such an extreme effect existed, it would show up even in a laboratory experiment involving concentrated CO2 as a heat conductivity anomaly. It would be manifest itself as a new kind of `super insulation’ violating the conventional heat conduction equation. However, for CO2 such anomalous heat transport properties never have been observed.”
Comments would be welcome.
@4, Craig, Here is an “experiment” that might be worth thinking about.
The planet Venus has an atmospheric pressure about 100 times ours and 96 % of that atmosphere is CO2 (with very little water vapor). While we are about 90 million miles from the Sun, Venus is the next rock in, about 60 million mile from the Sun. The surface temperature of Venus is about 900 degrees F or about 480 degrees C (while the Earth’s T is about 15 degrees C and as you pointed out has already been raised by about 33 degrees C by the modest GHG effect we presently enjoy).
This experiment suggest that, yes, CO2 can act as an insulating blanket and also that “too much of a good thing” might have dire effects for our Planet.
@5, Eric,
Be realistic. The high temperatures on Venus are only partially caused by carbon dioxide. The Galileo probe showed the thick clouds containing sulfuric acid strongly absorb infrared wavelengths of 2.3 microns. Thus, Venus’s high temperature may be entirely explained by direct absorption of incident light, rather than by any greenhouse effect. The infrared absorption lines by carbon dioxide are also broadened by the high pressure on Venus, making any comparison with Earth invalid.
@ Ed, Please, your suggestion that
“Venus’s high temperature may be entirely explained by direct absorption of incident light” is absolutely indefensible.
Consider the Earth’s present average albedo of 0.30. This means that about 0.7 or 70% of the incident light that is hitting it is being absorbed. Now if the albedo of Venus even the minimum possible, 0.0, so that 100% of the incident light is absorbed, as you really suggestion that this change in light absorption could explain why the surface temperature of Venus is 900 degrees F !!! Yes, indeed, one of us should be more “realistic”.
NASA has determined that the heating of Venus is not a “greenhouse gas effect” I will find my copy of this report and any other related data that they provide to document this. I believe that this was publiched in the late 1990′s.
Having read G&T and exchanged E-mails with them , I am finding their work to be much more creditable than the Work presented on The Science of Doom who try to discredit G&T.
While there is lots of physics presented on The science of doom , they never come up with proof that the GHG effect exists.
@7 Eric, sorry my reference was wrong. Galileo went to Jupiter. Here is a reference summarizing the Venus greenhouse effect:
http://aas.org/archives/BAAS/v33n3/dps2001/354.htm?q=publications/baas/v33n3/dps2001/354.htm
It says both CO2 and sulfuric acid clouds are important.
In reference to DR. Eric’s comment on CO2 having an insulation value ,I’d suggest that he look up it “thermo conductivity” and compare it to dry N2 , O2, Argon, and N2+ O2 in the atmosphere . The data shows that CO2 conduct heat better than N2,O2, Argon, thus it is a poorer insulation. If CO2 were a super insulation it would be put in Multi panel “storm windows” and get R values in the 20-30 instead of 8-10 with dry air. Argon and Krypton have been used in storm windows to improve the insulation values however they are higher cost and not enough benefit to compensate for the cost.
Craig, if you want to cite Gerlich and Tscheuschner, you need to show why the response of Halpern et al is wrong.
It’s a bit choppy because of using extracts from behind the paywall, but if I can follow it, so can you.
http://climatephysicsforums.com/topic/3292392/1/
@ 9 Ed,
Yes both the major gas CO2 and Sulfuric acid affect the GHG effect of Venus, but neither of these chemicals have anything to do the light absorption as you stated. Even if Jupitor has an albedo of zero (100% absorption) (who cares where the the Galeleo went), how could you suggest that this albedo affect could explain Venus’s temperature of 900 degrees F.
What I am doing here, of course, is examining your understanding of the albeto effect of albedo – since I know realize you have been so confused in you understanding of the GHG effect and the way we express its magnitude. Perhaps you also have another definition for the term, albedo. If so, lets find out now so we don’t also waste time there. Again, how could very strong absorption of the Sun’s light on Venus possibly explain its temperature?
@12 Eric,
Please save your unfounded personal criticisms for elsewhere. We agreed this debate is not to be about us, but you have continued to attempt to make it personal. Reread our agreement if you need to:
http://climateclash.com/2010/09/15/introduction/
Your comments are completely out of order.
Atmospheric Greenhouse Effect:
Once a sufficient amount of atmospheric absorbing gases (called atmospheric greenhouse gases by convention) are present, they reduce the radiation transmission to space enough so that convection becomes the dominant mode to transport energy from the surface (and from absorbed incoming energy) back to a high altitude where it is radiated to space. The only way the energy can be radiated to space from the high altitude is by radiating gases, i.e. by absorbing and radiating gases. Once this situation is encountered, adding more absorbing gases (but not enough to significantly increase the total mass of the atmosphere) does not change the fact that convection is still the dominant heat transport mechanism. However, adding the absorbing gas does raise the altitude of outgoing radiation somewhat. It is this increase in altitude of the outgoing radiation that results in the slight temperature increase.
Once the dominant mode of heat transport is convection, the atmosphere will form and maintain (on the average) an adiabatic lapse rate. This lapse rate is a temperature gradient due to the cooling effect of rising gas in a dropping pressure (due to gravity). The outgoing radiation has to equal the incoming absorbed radiation unless the temperature is changing, here we consider the case where the temperature has leveled off for simplicity (as it has on Earth for the last decade or so). In that case, the match of radiation out to absorbed radiation through a particular “effective” altitude (it is more complex due to being spread out, but the same in principal) determines the temperature of the gas at that altitude. This temperature, set only by the amount of absorbed incoming radiation, is then added to the lapse rate time altitude, and this gives the ground effective temperature.
You can think of this effect as a radiation insulating, but convectively open atmosphere. If the gas immediately above a selected height (or above the ground) absorbs the radiation, the absorbed energy is transmitted to the surrounding gas by molecular collisions, but likewise the surrounding gas also transmits energy to the absorbing gas, also by molecular collisions, and the local radiation absorptions and emissions will nearly balance. Keep in mind the convection, not radiation, is what controls the gas temperature. The emission is the source of what is called “back radiation”. The back radiation is not a source of added heating; it is in fact a radiation insulation effect. Moving the radiation out to space to a higher altitude, and adding the effect of the lapse rate are the source of extra heating.
@5, Dr Eric.
The outgoing radiation from Venus occurs at about 50 km altitude due to the large thick atmosphere and high atmospheric greenhouse gas content. The albedo of Venus is about 0.7, so even though it is closer to the Sun than Earth, the absorbed solar energy is only about 170 W/msq. It is mostly absorbed in the clouds and atmosphere, but about 17 W/msq reach the surface. The large winds mix the atmosphere so that a adiabatic lapse rate is formed and maintained. The lapse rate is found from -g/Cp for the planet and atmospher, and is near 8 C/km. at low altitudes, and slightly changes on the way up due to large changing temperature. Adding the temperature found from the absorbed radiation at the outgoing altitude and adding the lapse rate time altitude to the ground, we actually get the correct ground temperature.
There needed to be a large amount of greenhouse gas to move the outgoing radiation to high altitude, but since the atmosphere is about 100 times as dense as Earth’s, only a modest fraction of the gas needed to be greenhouse gas. The excess had little to do with the high temperature. There is no runaway greenhouse effect for Venus, but there may have been in the past. That has to do with removing water from the surface, not reaching a high temperature.
@3 & others,
Please quit quoting G&T. They get most of the story correct, but miss the whole point I make in @14, which is the cause of the atmospheric greenhouse effect.
@ 13 Ed.
I just read the agreement you referred to and I am in COMPLETE COMPLIANCE with it, I am doing my very best to discuss the science on which the outcome of this debate depends. When you say that I am “out of order” for pressing you on a specific scientific points, are you then acting as the Judge, as well as the Defense and the Webmaster? Is this indeed a soviet style show trial?
I have indeed noticed that when you come out of your administrative office and join us in discussions of a purely scientific nature, that you make some really bit booboos (I would be glad to point one or two more of these also if you would like me to) and I can imagine how embarrassing that can be when challenged. Nevertheless, just as I have to try to explain my statements when asked to and, it seems to me that you do also.
Now, for the record, I am indeed now pressing you to explain that one statement specific statement you made in your comment #6 about. Note that the question concerns science only and specifically climate science and in particular the notion of albedo. So again here it comes that scientific question:
Please explain how could very strong absorption of the Sun’s light on Venus possibly explain its temperature? – even if its albedo went to a maximum value of 0.0?
To the Jury: to you see anything other than science being discussed here. Is this question “out of order” in any sense whatsoever. I can understand why Ed might not like to have to have to explain his statement, but he did say it, right?
See his exact comment #6 above. It concludes with
“Thus, Venus’s high temperature may be entirely explained by direct absorption of incident light, rather than by any greenhouse effect.”
Ed, I’ll wait for your response and see if you either answer my question of again declare it to be “out of order”.
While I have asked you very few questions previously, I know you have asked me a very large number of them. So if you feel I am treating you unfairly now by asking you this one question, please do look back at your long list previous questions and tell me, as precisely as I have here, which questions have not been responded to (or worse still entirely ignored, as you have done so far to my single question).
One final note Ed : please do not consider this message to be “irrelevant verbage” or being “out of order” – unless you are looking for a way out of this debate so that you can go home. As you know, you started this debate with a distinctly political swipe suggesting that AGW stands for Al Gore Warming (others might not know this because you quickly removed it when I reminded you of our agreement described at http://climateclash.com/2010/09/15/introduction/.) Therefore, one might understand that your commitment to this debate might now be greatly reduced since the 2010 election is over. So why not take the credible road, Ed, explain your recorded remark concerning the albedo of Venus, and show us all that the “Great Debate” is really just about science and not politics.
Ed and Eric,
Please read my writeup. Both the amount of absorption (the only source of the energy for the temperature except for added volcanic addition which is almost certainly small) and the atmospheric greenhouse effect, which is needed as a radiation insulator, along with gravity and mass of atmosphere mass (therefore height), cause the high heating on Venus.
You are both partially correct, but you both hit only part of the issue. The exact same effect exists on Earth, but the small mass and thus height of the atmosphere, limit what can happen with even several times the added CO2. In fact the water vapor feedback (as cloud variation) probably limits the gain due to CO2.
@ 17.
While Ed and I both might appreciate any help you all might be able to provide concerning the question direct I put to Ed in my comment #16 above, I am still waiting for Ed’s response to which I will be obligated to give highest priority of consideration.
@16 Eric,
I am sorry you are incapable of reading simple English. Our agreement says clearly that we are not to make personal attacks on each other. I am not making any administrative decision about this. This is merely my opinion and I will let our jury decide. Then you said:
You went way beyond mere “pressing” me on scientific points. You took a personal shot at me and I challenged you on it. Are you so jumpy that you have to claim an Administrative foul? You fully well I am not making any “Administrative Ruling” on this matter.
You are fully aware I focus my administrative actions on enhancing your ability to have a fair debate, keeping the website running, the discussions organized, and making sure all sides get a fair shot at presenting their arguments.
Meanwhile, I have more important things to do than to get into pissing match. Besides, Leonard knows more about this topic than both of us put together.
I suggest you study Post #6 because you have just lost this phase of the debate whether you realize it or not.
@ 19 Ed,
Please!!! Drop the self-righteous stuff. You suggested here that I can’t read plain English and in post 6.106 you suggested that I don’t understand simple mathmatics. If I can stand and defend myself against these little digs so can you. Come on Ed, buck up or, as they say, get out of the kitchen. Perhaps Leonard, for example, who you seem to require for this and previous responses might like the job? (Just a thought here to help out of your current dilemma).
But enough of the silly pissing match stuff which both of us profess to abhor. Lets get back to business, OK?:
The Prosecution still has a simple request on the floor, that is still waiting for a response from Ed. That request is simply to explain the conclusion Ed shared with us to today in his comment #6 above which was:
“Thus, Venus’s high temperature may be entirely explained by direct absorption of incident light, rather than by any greenhouse effect.”
That’s it. No personal attack involved here. I am looking forward to this explanation of why Venus’s temperature is 900 degrees F, so Ed, the floor is yours. And please feel free to use all the addition help you can find, including Leonard’s, of course.
Dr Ed @6-106, Nov 3rd, 3:33pm:
“I am beginning to think you [Dr Eric] do not understand mathematics. ”
Dr Eric @12, Nov 4th, 9:29pm:
“What I am doing here, of course, is examining your understanding of the albeto effect of albedo – since I know realize you have been so confused in you understanding of the GHG effect and the way we express its magnitude. Perhaps you also have another definition for the term, albedo. If so, lets find out now so we don’t also waste time there. Again, how could very strong absorption of the Sun’s light on Venus possibly explain its temperature?”
Dr Ed @13
“Please save your unfounded personal criticisms for elsewhere. We agreed this debate is not to be about us, but you have continued to attempt to make it personal. Reread our agreement if you need to:
http://climateclash.com/2010/09/15/introduction/
Your comments are completely out of order.”
I do not see how Dr Eric’s comments can be out of order and Dr Ed’s previous comments on another thread were not. Is there some subtle part of the definition of “personal attack” which indicates that like behaviour is unlike in its nature as a personal attack depending on the belief of the author regarding AGW? If not, it seems to me that Dr Eric is well within the parameters set by Dr Ed by his example, and still more so by his cohorts who have been downright, and unjustifiably rude on occasion.
I remind Dr Ed of his claim that, ” Thus, Venus’s high temperature may be entirely explained by direct absorption of incident light, rather than by any greenhouse effect.” (@6) Could he please be less precious, and explain how even with an albedo of 0.0, and hence a 43% greater absorption of incident light than Earth, Venus could have a surface temperature 2.56 times greater than that of Earth (735 degrees K, vs 287 degrees K), and hence approx 43 times greater surface energy?
Dr. Ed,
It does require an atmospheric greenhouse effect. Dr. Eric is correct as far as that part of the statement goes. Dr Eric’s response, which implied to me that the CO2 was a thermal insulating blanket was also not completely right (it is a radiation insulator, but convective conducting, and required the lapse rate to complete the picture), so both of you lose a partial point. Please move on from here. You are both going to be partially correct at times and wrong at others, so please do not take the loss of a single issue personally.
Dr. Eric,
I know it seems the responders are more on the skeptics side than not. I have asked for other supporters for you to come in more. However, I will support the science I consider correct for both sides.
@11 Adelady
I wasn’t citing G&T because I necessarily agree with them, I was simply asking for comment on their conclusion that AGW defies physical and thermodynamic laws.
@23 Sorry delete “AGW” and replace with “greenhouse gas effect”.
“Comment on their conclusion that AGW defies physical and thermodynamic laws.”
Well, G&T’s conclusion arises from their initial postulate that gases that absorb radiation don’t also emit it. As far as I’ve been able to work out, that’s very close to magic. So I wouldn’t set much store by their conclusions.
@20 full response:
1. I made a mistake in my @6. (I too hastily replied without thinking through the details and assumed a reference I read was correct and afterward realized both I and the reference were wrong.)
2. I immediately acknowledged by mistake in @9, although I admit I did not fully explain my mistake.
3. Like everyone who engages in battle, I win some and I lose some. This is part of the game and I accept it. (When I engaged in sailing competitions, I won some races and I lost some races. I learned from my losses but focused on the bigger picture. Overall, I won many world class championships, in spite of losing some races.)
4. My mistake in @6 was due to my haste and has nothing to do with my “understanding” of the atmospheric greenhouse effect as Dr. Eric wishes to assume. (Since I am the “defense” here, my job is not to elaborate into the explanation area but to focus on the problems with the “prosecution” case … which I have summarized in 6@152 and 6@164, wherein I claim Eric’s hypothesis has been invalidated.)
5. Regarding my “understanding” of the atmospheric greenhouse effect, I fully agree with Leonard’s explanation in @14. I cannot improve upon his explanation. I admit he is a better scientist than I am in this subject area. I believe I already stated my position in earlier parts of ClimateClash, that the basic, no-feedback, greenhouse effect Climate Sensitivity of CO2 is about 1 C, a number that seems to be agreed upon by scientists on both sides of the AGW issue.
6. I am also on record as disagreeing with Dr. Eric’s Claim #11 regarding the feedback effects that result from CO2 changes. I will get into this subject in much more detail when it becomes relevant to dispute Eric’s claims in this regard. That is when we will test our mutual “understanding” of the atmospheric greenhouse effect. This is not the place to get into this battle. We will be anxiously awaiting Dr. Eric’s presentation on this subject first.
7. Finally, I maintain Climate Clash is not about me or Eric or our “understanding” of this subject area. We have expert scientists aboard and I view my job is to make the best use of their “expert testimony.” Somewhat similar to being a defense attorney, I do not claim to be an ultimate authority. (Good grief, Lindzen and many others are way beyond me.) And whatever expertise I have or do not have has nothing to do with whether or not AGW is true or false … any more than an attorney’s experience has anything to do with whether or not his client is truly guilty. Which is why it is irrelevant to get into any sidebar discussions about what I may know or not know.
@ 26 Ed,
Thanks for your clarification in pt 1. That simple statement was all that was required in order to withdraw your statement concerning the temperature of Venus.
Concerning points 2 – 7, I don’t see that any responses and even the statements themselves are necessary because, as far as I know, there where no claims to the contrary concerning any of them.
In addition, I know very little about competitive sailing. I focused on basketball and baseball as a young man and also did pretty well (see “awards” in my resume on my website). But excuse me for digression here about my personal life – this debate is not about you and me, as reminded us all of so thoroughly. It is about science and I’m pleased to see that we now appear to be back on that track.
FYI, I am now considering making another major Post that would concern the more ancient period shown in my Figure 1 of Post 6. This would be timely because it also will involve the CO2 Sensitivity term that I have suggested is the major point of quantitative significance in this debate. Also several viewer of the debate have shown keen interest in that era. Before doing that, however, I would first like to ask you if you wanted to provide our next major post first. Please let me know and we’ll be off to a consideration of a distinctly different era and different set of data.
@27 Eric,
I am indeed looking forward to your next post and its discussions. However, we need to first finalize the main issue of your Post #6. In my @164, I claim your hypothesis is invalid. I refer to my summary comment @158. You have not responded to these comments.
After we resolve this issue, I will tell you whether I wish to make the next post or defer to your making the next post.
(By the way, I also played a lot of baseball, grammar school through college, but basketball was definitely not my game.)
Having scanned the different entries I may have missed if anyone brought up the fact that Venus has a very hot core and is covered with volcanoes. It is not a stretch to say that because of the thermo capacity of the very high density of the CO2 atmosphere of Venus and the thick cloud cover of Sulfuric Acid that Venus has not cooled down at the same rate as the Earth. Thus the fact that it is closure to the Sun and receives much more energy , even thou some references say that 72 % of this is reflected back into space ,it is still receiving more energy that the Earth.
Even thou Venus and Earth are about the same size its mass must be far greater than Earth which is demonstrated by the fact that the pressure of the atmosphere is about 90 times the atmospheric pressure on Earth. Thus gravity is keeping the CO2 and sulfuric acid trapped. The effects of these factors of physics should make anyone wonder how we can make a comparison of Earth atmospheric conditions to the conditions on Venus.
The mass of the Earth and the mass of Venus are not that much different. The earth is thought to be 5.9736 E 24 kg and Venus at 4.8685 E 24 kg and a ratio (Venus/Earth) of 0.815
@ 28 Ed,
I will do my best to respond quickly if I can find a few minutes in the next hour. I am presently hustling to complete a few thing before leaving my home in an hour. If don’t do it now, I will in tomorrow morning or late this evening after I return.
Eric
Leonard Weinstein
You can think of this effect as a radiation insulating, but convectively open atmosphere. If the gas immediately above a selected height (or above the ground) absorbs the radiation, the absorbed energy is transmitted to the surrounding gas by molecular collisions, but likewise the surrounding gas also transmits energy to the absorbing gas, also by molecular collisions, and the local radiation absorptions and emissions will nearly balance. Keep in mind the convection, not radiation, is what controls the gas temperature.
Fully subscribed .
This is not different from saying that the troposphere is in LTE (Local Thermodynamic Equilibrium) and that a variation of any IR active species concentration (H20 , CO2 , CH4 , O3 etc etc) provokes a variation of the mean path length of IR photons . This leads to the variation of vertical temperature gradients .
I prefer this formulation but it is equivalent to what you wrote .
This of course instantly falsifies all popular GHE explanations that IR active molecules “store heat” or “capture heat” etc .
However I would add one comment and it is that this effect can be quantified if and only if the troposphere is in radiative equilibrium .
This is obviously not the case and this is one of my main issues with GHE along with the “feedbacks” that are mostly just qualitative vague hand waving .
A short comment to G&T
I never use their paper .
Not because there would be something wrong – almost everything they write is correct and they know more about physics than any average climate scientist .
Especially their demonstration that plugging a surface temperature integral in the Stefan Boltzmann law (the famous -15°C and CO2 heating of 33°C) is absurd for a rotating sphere out of radiative equilibrium , is perfectly valid .
But the problem is that despite saying plenty correct things , they don’t prove what they say they prove .
This is due to the fact that the GHE definitions they took and demolished don’t represent all GHE definitions .
All definitions they demolished are indeed wrong but they missed the right one .
Specifically they don’t consider the 2 correct variants of the GHE definition above – L.Weinstein’s and mine which are formulated differently but say the same thing .
So because the title of their paper and the content are not consistent , it is not very useful for the atmospheric GHE even if it is useful for other things like the nonsense of the – 15°C Earth .
@29,
Volcanic activity is not a large fraction of the source of ground temperature. If it was, the outgoing radiation would be much larger than incoming solar, and it is not. The mass of Venus is lower than Earth. The large atmosphere is due to the fact that much of the surface CO2 is in the atmosphere. Earth has more Carbon than Venus, but it is in locked into rock (from shell forming sea life) and dissolved in the oceans. The oceans and distance from the Sun make the two different systems. The thermal convection of Venus’s atmosphere would rapid cool (on a geological time scale) any large unbalance. See my write up @14 for the actual cause of Venus’s surface temperature.
The reasons that some bodies have atmosphere and others don’t appears at first to be due to gravity, but consider this. It appears that scientists have still to figure this out at least in the details.
@31 Eric, Thanks. No hurry. I also have a lot of other business to do today requiring my absence from Climate Clash for several hours at a time. I respect that we each have personal lives to attend to.
@32,
Tom, I agree with you. I stated it the way I did because I thought it was more easily understood by all. I did mention that it was LTE in a previous comment somewhere. However, I do believe the higher temperature on Earth is partly due to GHG, and would be increased a small amount by more CO2. The reason is that it is clearly so on Venus. Earth has such a small effect, and use of a bogus average temperature makes the accuracy difficult to separate out, so that I am skeptical of positive feedback effects claimed, and clearly skeptical that any change indicated is shown to be due to CO2 increase.
@ 31 continued
Ed,
Please see my responses below shown after each of your 8 points:
1. Historical proxy temperature changes can be explained without invoking CO2 as a driver. You have not shown that CO2 is necessary to explain the historical data.
My response: I can not respond to your first sentence, of course, until I have seen your evidence (note that proof is not necessary) for it. Concerning your second sentence: a agree – I have not yet shown that. But then we are just getting started aren’t we. When we are all on the same page with respect to understanding what is being said in the literature and with respect to important terms and definitions, we will hopefully be able to has a decent discussion on this point pretty soon.
2. Data show changes in temperature always precede their parallel changes in CO2 by ~800 and 2000 years. Thus CO2 cannot be the primary forcing agent for temperature change at the glacial-interglacial scale as you have assumed.
You should look at Thomas Gregory excellent comment this morning in Post #6. He understood what I am said and summarizes it accurately. CO2 certainly does not necessarily or even ever initiate a change in climate direction. After a delay of a few hundred years, however, CO2 follows the new direction and from then on – for many subsequent thousands of year contributes greatly to the subsequent large temperature changes.
Then, your dire warning to humanity has many problems, some of which are:
3. The last section of your Fig. 4, which you have used to support your dire warning, is invalid because it compares two entirely different methods of measuring temperature: proxy ice-core data and modern meteorological data.
Response: Two methods of measurement are better than one as would be ten if we could find them. In addition, of course, some methods only worked during different periods. All should be used and assessed however.
4. The last section of your Fig. 4, which you have used to support your dire warning, is invalid because it makes use of the Fig. 4 “GHG Forcing” (green line) which has no physical validity and which is itself calculated assuming an invalid CO2 feedback.
First, are you possibly overusing the word “dire”. Just the word “warning” might be fine with just a few “dires” throught in occassionally. GHG Forcing does have a physical validity and is used throughout the literature and in the Hansen et al paper under consideration. I am certainly not willing to accept your statement that CO2 feedback is invalid. The evidence to the contrary is so strong that it rarely requires much justification. But if you require a revisit to such basic notions, we will go there in due time.
Which brings us to the null hypothesis. The proper null hypothesis is:
Global climate changes are presumed to be natural unless and until specific evidence is forthcoming for human causation.
5. Neither you nor anyone has yet provided any such evidence.
In a upcoming blog we will be getting into the Age of Man in which such evidence will be extensively discussed. What’s called the Keeling Curve for example, and many other indicators of human causation will be presented. If you are not familiar with the Keeling curves and the associated measurements of that nature being made throughout the world, you might considered reading up about it before we get there – but we will indeed get there.
6. You have assumed without justification that all the temperature changes you see in your data result one way or another from CO2 changes.
This statement is false, I have made to such assumption. Other factors also contribute to temperature changes, as we all know very well.
7. The feedbacks you have assumed in your hypothesis are unphysical and, so far, you have not defended them.
I can not respond because I don’t know what you mean by the word “unphysical”. And I am not asking you to go anal retentive here in coming up with an exact definition. Just tell me what you mean by this word in this case or try another word.
8. You can quickly see the invalidity of your hypothesis if you look at formula (1) of @106, which you approved in @108. Your hypothesis has been invalidated by its very formulation.
Sorry, but I can’t actually see the “invalidity” you describe, so I don’t can not yet respond. And just to help me understand what you are referring to, please expand describe the evidence the invalidity that you say exists here.
We have been discussing the use of ice core data in many parts of the “climate clash” so I figure this reference will cast more light and confusion on the validity of using this type of data as evidence in a “Proof by Scientific Methods” .
“Ancient Evidence That CO2 Does Not Control Climate.”
Submitted by Doug L. Hoffman on Sun, 10/31/2010 – 09:51
a link is available on climate depot.
About #2, please see Tom’s CommentIn my opinion this is the weakest argument in Hansen’s paper. He states,
“Major glacial-interglacial climate swings are instigated
by slow changes of Earth’s orbit, especially the tilt
of Earth’s spin-axis relative to the orbital plane and the precession
of the equinoxes that influences the intensity of
summer insolation [25, 26]. Global radiative forcing due to
orbital changes is small, but ice sheet size is affected by
changes of geographical and seasonal insolation (e.g., ice
melts at both poles when the spin-axis tilt increases, and ice
melts at one pole when perihelion, the closest approach to
the sun, occurs in late spring [7].”
This forcing is “small”, but have to overcome runaway cooling or warming.
He also states,
“Climate sensitivity varies as Earth becomes warmer or
cooler. Toward colder extremes, as the area of sea ice grows,
the planet approaches runaway snowball-Earth conditions,
and at high temperatures it can approach a runaway greenhouse
effect [12].”
So not only do these “small forcings” overcome the CO2 forcings, but they have to be of a magnitude to completely turn them in the opposite direction.
In the one direction (from hot to cold) the magnitude of the CO2 forcing is decreasing, so it is plausable in that direction. However, the other direction (from cold to hot) is much more problematic as the CO2 forcing is getting bigger (a much bigger temperature change for the relative change in CO2).
I am admittedly, not an expert on this, and am obviously interpreting Hansen, but please explain where I am going wrong with this.
Anthony always remember the oceans. When things get chilly, they get even colder as more and more CO2 is absorbed into a cold ocean – so there’s less of the gas around in the atmosphere to have its radiative effect.
When things get hotter, the oceans release more and more of the dissolved CO2, so not only is there a warmer environment, more and more CO2 is free in the atmophere to do its radiative wonderfulness. Not so wonderful is when things get even hotter, and the oceans don’t just give up dissolved gases, they release methane.
Uncomfortable doesn’t even come close.
@40
Yes that is true, but both are in the wrong direction. Neither can turn things around. Less CO2 in the atmosphere means even more cooling. More CO2 more warming. The “small forcings” have to overcome both of those effects.
@37 Eric,
Thank you for your answer. However, would you copy your response over to your Post #6? That is where the discussion of this issue is taking place and where a large number of comments already exist that are relevant to this subject and where people will naturally be looking for your response to my comment in your Post #6. I will respond after you put your @37 under your Post #6.
Thanks.
In my item @38 I reference the follow abstract : Climate scientists continue to be fascinated with the Paleocene–Eocene Thermal Maximum (PETM), which took place about 55 Myr ago. This period of sudden global warming and increasing atmospheric CO2 represents a possible model our present era of warming climate and growing CO2 emissions. Studying the PETM, therefore, may provide insight into climate system sensitivity and feedbacks. Just such a study, reported in Nature Geoscience, found that CO2 forcing alone was insufficient to explain the PETM warming. Scientists speculate that other processes and/or feedbacks, hitherto unknown, must have caused a substantial portion of the warming during the Paleocene–Eocene Thermal Maximum. Simply put, CO2 did not cause the PETM climate change
@40 adelady, you have described a positive feedback in both directions, which is unstable, meaning it would produce runaway in one direction or the other. While this positive feedback may be true for the isolated situation you presented, it is also proof that the positive feedback you describe is either invalid or dominated by other negative feedbacks in the total system. Otherwise, we would not be here discussing this problem.
Why should it be runaway? And it’s not unstable either, certainly not from a human perspective. People haven’t been around for a million years, but these processes involve 10s of millions of years.
Back to runaway. Just think of a maths text book where the cover is an artistic rendition of the shapes of every mathematical function you’ve ever and never heard of. Climate involves lots of things acting on each other in various ways on different timescales. By the time a dozen or more wave, exponential, sinusoidal functions finish their 10-15 million year up-down overlapping positive negative sideways and back interactions and counteractions, we might have a knitting pattern from the graphs but nothing’s been able to run out of control.
And that gets us back to release of geologic carbon. On a planetary scale, that’s “supposed” to take geological timescales to release and reabsorb. It’s certainly reabsorbing at geological rates – but the unabated massive release is overwhelming those very ponderous, gradual processes.
So what you are saying is that the rate of release of CO2 is unprecedented? I am just checking to make sure.
@45 adelady, Thanks. You have proved my point, namely, that your concern about the positive feedback between ocean temperature to CO2 to air temperature is of no relevance to reality. The whole system is so complex that it provides its own internal stability controls.
Now, given the system is so complex that we cannot even describe it, how can you justify your last sentence? …
I claim you have absolutely no way to calibrate or measure whether our CO2 releases are “overwhelming” the system stability. Therefore, it is not a scientific statement.
Anthony What’s unprecedented is that it’s an animal (us) that’s releasing geological carbon in a few human generations.
Normally that’s either volcanic processes (releasing biological carbon sequestered at ocean bottom and relocated through subduction eventually contacting seriously hot material) or an increasing temperature releasing dissolved CO2, and then methane clathrates the whole fam damily from warming oceans. Neither of which happens on human timescales – both take millennia to millions of years.
Ok so the rate is not unprecedented, merely the source. Is this a correct statement?
Dr Ed. Overwhelming?
Let’s start with sequestering carbon by biological processes and converting it to geological carbon. That process continues, peat bogs on land, all sort of processes going on at the ocean floor. Nothing is being done to enhance or speed this process up.
Now look at releasing geological carbon. Massive processes are being applied to convert 100s of millions of years worth of sequestered carbon into airborne carbon dioxide. And this is being done in a quarter of a millennium – not even a quarter of a million years.
Put the release and sequestration processes on the two ends of a see-saw and you clearly have an imbalance. I say it’s overwhelming because I see no way to get the see-saw to budge, let alone move to any kind of balance.
When I see the scientific explanations for planetary processes I see nothing that says my non-scientific observations are wrong. (And I would dearly like to be wrong.)