THIS PAGE HAS BEEN ACTIVATED AS THE NEW STATESMAN BLOG IS NOW CLOSED FOR COMMENTS
At 10am this morning, the New Statesman finally closed the Mark Lynas thread on their website after 1715 comments had been added over a period of five months. I don’t know whether this constitutes any kind of a record, but gratitude is certainly due to the editor of of the New Statesman for hosting the discussion so patiently and also for publishing articles from Dr David Whitehouse and Mark Lynas that have created so much interest.
This page is now live, and anyone who would like to continue the discussion here is welcome to do so. I have copied the most recent contributions at the New Statesman as the first comment for the sake of convenience. If you want to refer back to either of the original threads, then you can find them here:
Dr David Whitehouse’s article can be found here with all 1289 comments.
Mark Lynas’ attempted refutation can be found here with 1715 comments.
Welcome to Harmless Sky, and happy blogging.
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10,000 Responses to “Continuation of the New Statesman Whitehouse/Lynas blogs.”
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James P, you wrote concerning my suggestion to visit the: “How to disprove Christopher Booker in 26 seconds” thread:
Geez, I have NOT encountered that problem, so I doubt if it is deliberate. Perhaps you may have some system or software clash. Have you tried the usual tricks like restarting your computer, or hitting the refresh button, or trying at a later time?
Hi Peter,
There you go again, with an analogy (6348). This time it is “the coats of paint”.
This was not my analogy, and I believe it is also not a good analogy at all to describe greenhouse warming. In fact, I think that no analogy is needed.
These is a logarithmic relationship, which is well described.
One can always get into theoretical discussions about “how much warming was caused by the first CO2 molecule?”, but these are much like the theological debates during Medieval times concerning “the number of angels that can dance on the head of a pin”.
I have plotted the CO2 concentration in ppmv versus the CO2 greenhouse effect in degrees C, based on Lindzen’s estimate that the natural CO2 greenhouse warming was 5.2C.
http://farm4.static.flickr.com/3577/3557088818_1814518eaa_b.jpg
You see how the logarithmic relationship brings a certain increase in temperature for each doubling of atmospheric CO2 concentration.
The Lindzen and IPCC estimates are ploted for what happens due to the increased CO2 from “pre-industrial” 280 ppmv to a doubling (by 2100?) to 560 ppmv to a quadrupling (when all known and optimistically estimated fossil fuels on this planet have been consumed) to 1120 ppmv.
You say:
The IPCC ‘best estimate’ figure of 3 deg C, for a doubling of CO2, sounds much more plausible.
I say: just look at the chart, and then tell me that the IPCC estimate is “more plausible” than a continuation of the logarithmic relationship according to Lindzen.
It looks pretty obvious to me that there is a strange, unexplained “kink” in the curve, and that the “IPCC ‘best estimate’ figure of 3 deg C, for a doubling of CO2”, sounds anything but plausible.
Why is there this strange “kink”, Peter? Can you explain this scientifically?
Regards,
Max
James P
You are right-the site is very slow to load.
Bob
I note they stopped posting at about the time we suggested contacting the Guardian direct, after they reposted my comment I made to Max here and came up with their silly conspiracy theories again. That coincided with your last very good post. Perhaps the moderator decided to pull the thread, perhaps it is just allowed to die after a week.
Shame about the ya-boo! bullying antics of some of them, as there are a couple of people its worth debating with, but they are being drowned out. ( I assume this email will be reported back to HQ)
Tonyb
Re speed, thank you Bob and Tony for your range of views! The Grauniad blogs feel ‘slugged’ to me – the main articles come up quickly, but the ‘loading comments’ bar takes a lot longer.
I expect if you’ve got a fast connection, it isn’t that noticeable, but my home broadband is only 1Meg, so not very sparkly, although this blog is manageable enough, as it WUWT.
Perhaps the Guardian website was done with FrontPage…
What with Zac Goldsmith and now Oliver Tickell, we seem to be developing green dynasties. (Tony 6337)
It’s ironic, since neither of them has to work for a living, that they should try to arrange the fate of those who do. A bit of deprivation in a part of the world with no facilities and limited sustenance might do them some good…
Good to see that David Whitehouse is still alive and kicking:
http://www.theregister.co.uk/2009/05/22/bbc_whitehouse_climate/
Max,
There is something a bit sad about a climate sceptic saying that something must be true because it is “well described”. What about the IPCC reports? Don’t you think they describe the AGW problem pretty well? So we can wind up the discussion by accepting their very well done description , can we?
If you are claiming to be clear and independent thinker you really need to do a bit better than that!
You obviously like the logarithmic nature of temperature increase with CO2 concentration. It gives you an acceptably low answer. You can say that doubling CO2 gives N degrees and doubling again gives another N degrees.
So we can then come up with a simple mathematical equation which will describe the whole process? Well correct me if you think I’m wrong but its always a good idea to make a simple check of any mathematical equation by plugging in a few numbers and seeing what sort of answer pops out. What happens when the CO2 concentration gets very big? What happens when the CO2 concentration is very small, or tends towards zero?
Now I wouldn’t argue with Prof Lindzen’s attribution of the figure 5.2 degC to the effect of CO2 in the atmosphere. BTW Does he mean at 280ppmv or 385 ppmv do you know? Although for reasons previously explained its not as easy as it might first appear to explain what this means realistically.
However, you might like to just plug the figure of zero, for the concentration of CO2, into your logarithmic equation and you’ll find that “- infinity ” pops out. That a very large negative number!
In this case I do agree with Prof Lindzen. The contribution of CO2 to the climate is not as big as that!.
So if your logarithmic equation gives you a known wrong answer at the limits, might it not be a good idea to ask yourself if it might be giving you the wrong answer at other values too?
Go back to the coats of paint analogy. I first read it some time ago and it was written by a climate sceptic to explain how subsequent coats had much less impact than the first coat. It stood out from the usual crap that is often written on contrarian sites and showed some evidence of an ability to think. And there was me thinking it was you!
So please , Mr Max, put on your thinking cap and don’t come up with such silliness as this equation must be true because all the experts say it is. I very much doubt if they do BTW.
The coats of paint analogy is very much the correct one. You shouldn’t just dismiss it. It will help you get your equation right.
Hi Peter,
Thanks for your last message.
I have put on my thinking cap (as you suggested) and gone through your message several times, but unfortunately it does not answer the question: why is there a “kink” in the curve?
The CO2 concentration / greenhouse warming impact is logarithmic, as the theory tells us.
I do not believe that it makes much sense for us to question the validity of the greenhouse equations, which are based on the logarithmic relationship.
We can discuss what happens at the very beginning of the curve, but this discussion is meaningless and irrelevant; we are not at the beginning of the curve. “Popping in a zero” does not tell us much about what is going on today because we are not at “zero”.
Lindzen has calculated that the “natural” CO2 greenhouse effect (i.e. at the “pre-industrial” CO2 level of 280 ppmv) is 5.2C. You have pretty much agreed to this with your estimate of 3 to 8C.
There is no way that one can have 5.2C greenhouse warming from CO2 at 280 ppmv with a 2xCO2 impact of 3.2C. Put on your thinking hat, Peter, and figure it out for yourself.
IPCC is telling us that the future (greenhouse temperature response to increases in anthropogenic CO2 levels) will be totally different than the past (greenhouse temperature response to increases in natural CO2 levels), and this simply does not make sense.
Please explain scientifically why you think this makes sense, and why there is this “kink” in the curve from natural to anthropogenic greenhouse warming.
Please try to be specific and please do not throw in anymore analogies. Just stick with the greenhouse theory and forget analogies or hypothetical discussions of what happens at “zero”.
Regards,
Max
Max,
I must say that I don’t really undertsand your graph.
For instance how do you calculate that 35ppmv of CO2 is going to produce a temperature rise of over 3 degs? You’ve just fudged the horizontal scale to try to prove a point.
‘What happens at zero’ is something that Prof Lindzen knows is important. It can’t just be dismissed as hypothetical. He’s suggested a figure of 5.2 degs for ‘what happens at zero’ which I wouldn’t disagree with. Your simple logarithmic equation doesn’t give the same answer at all. So I’d say the equation wasn’t 100% right. Wouldn’t you?
Max,
Talking about graphs and kinks, you might just want to cut the BS and just plot the graph of CO2 versus temperature increase as you normally would:
Whose prediction has the smaller ‘kink’ in it?
I know you are going to start to splutter about it being not fair and its not logarithmic etc etc. I know you like your logarithms but I think we have already established that the relationship between temperature and CO2 concentration cannot be purely logarithmic. There may be logarithmic terms in the equation but there must be others to avoid getting a silly answer at the limit of CO2=0.
The question of whether the relationship between CO2 and temperature is linear or logarithmic very much depends on the degree of saturation of IR radiation in the atmosphere.
Going back to our paint analogy suppose that instead of absorbing 50% of the incident light, each layer only absorbed 10%. So the first layer would absorb 10% of the light and let 90% through. The second layer would absorb 10% of that 90% which means 9% of the initial amount and let the rest, or 81% of the initial amount through.
So although each layer has less of an effect than the previous layer it isn’t that much less. So the equations to describe this situation would look much more linear.
On the other hand if the degree of saturation was much higher the equations would look much more logarithmic.
It is quite common for complex physical systems to be correctly described by a mixture of linear and logarithmic terms.
Peter and Max
I don’t want to intrude on your renewed spat with Peter on Co2 (Part 27) especially as a its a holiday weekend here and the sun is shining for a change so I’m off out.
So I will just repost this article from WUWT in which Hansen claimed much the same as Peter. (or is it the other way round?)
Bill Illis posted a good graph of the logaritnmic effect a little way down the article
http://wattsupwiththat.com/2008/12/21/jim-hansens-agu-presentation-hes-nailed-climate-forcing-for-2x-co2/#more-4628
Tonyb
Hi Peter,
Here you come with a linear “smoke and mirrors graph” of a logarithmic relation and then show “kinks”.
Sorry, Peter, this is absurd.
We both know that the greenhouse relationship between gas concentration and warming is logarithmic. Check the equations. To suggest that it is linear is an attempt to re-invent science to make it fit a disaster forecast that otherwise cannot exist.
It is up to YOU, Peter, to show why greenhouse warming from anthropogenic CO2 (as estimated by IPCC) is 4 times as powerful as greenhouse warming from natural CO2 (as estimated by yourself, as well as by Dr. Lindzen).
Is there something special about a molecule of “anthropogenic” CO2 that makes it behave radically differently from a molecule of “natural” CO2?
If so, what is the scientific explanation for this difference?
In a logarithmic relation, how can the first increase from 1 to 280 ppmv result in only 5.2C warming (with a 2xCO2 increase of 0.65C for each doubling) if the next increase from 280 to 560 ppmv is supposed to result in 3.2C warming for a single doubling of CO2?
It simply does not make sense, Peter.
The ball is back in your court, Peter, and, please, forget the paint analogy. Come with scientific principles instead.
Regards,
Max
TonyB
The December 2008 Hansen blurb is interesting in that it really does not say much except, in effect, to re-iterate that “greenhouse gas forcing is accurately known” (hmmm…) and that the 2xCO2 climate sensitivity of 3°C ± 0.5°C is “nailed” (oops!), without providing any physically observed data to support these claims (ouch!).
May not be factual, but sounds good.
Hansen does concede (duh!) that it was cooler in 2008 (omitting the fact that the cooling trend started in 2001), and does not mention the fact that the latest high-tech Argo measurements have shown that the ocean has cooled since 2003 (still brings in that old saw that the ocean is warming).
Then he has two cute toddlers in the act, to give his whole treatise a bit of scientific credibility, before delving into areas where he has no expertise, such as the evils of coal, tar sands and tar (sic) shale.
Forget this bit of junk science.
I did not spend too much time on it and would not recommend that anyone else does, either.
This guy has lost it with his “coal death trains” remarks and (unheeded) calls for civil disobedience.
Regards,
Max
Hi Peter,
Let’s go back to the basic greenhouse science to clear up any confusion you may have on the logarithmic versus linear relation between atmospheric CO2 and greenhouse warming.
Arrhenius Law defines to greenhouse effect of CO2 on temperature
dT = dE / 4 * [sigma] * T^3, where
T is in K
dE = change in forcing
dE = [alpha] * ln ([CO2] / [CO2orig])
where CO2 = atmospheric CO2 concentration
and alpha = 5.35 [Myhre et al.]
and sigma = 5.67 x 10^8 watt / (m^2 * K^4) [Stefan-Boltzmann]
IPCC (SPM 2007) has used this logarithmic relationship to estimate the radiative forcing from CO2 from an assumed pre-industrial level of 280 ppmv in 1750 to a measured level of 379 ppmv in 2005.
Using the above logarithmic equation, IPCC arrives at a radiative forcing from CO2 over this period of 1.66 W/m^2.
You can confirm this by simply cranking in the numbers into the above equations.
IPCC recognizes the logarithmic relation between changes in atmospheric CO2 concentration and resulting changes in temperature due to greenhouse warming.
Why should you quibble with greenhouse science if IPCC accepts it?
Regards,
Max
Max,
You say “We both know that the greenhouse relationship between gas concentration and warming is logarithmic. Check the equations”
Do we? OK Give me an equation that gives a sensible result for the case of CO2=0 and I’ll check it.
No silliness now about angels on pinheads etc. Lindzen knows that the case of CO2=0 can’t jsut be dismissed as hypothetical and I’m sure you do too. Any equation has to give a sensible result at the lower linits.
Hey Peter,
I corrected your linear CO2 greenhouse effect curve (6360) to show the logarithmic relation between changes in atmospheric CO2 concentration and resulting greenhouse warming.
http://farm4.static.flickr.com/3553/3559535020_cbe3ee2ce1_o.jpg
As you can see, once your curve is corrected the “kink” between natural greenhouse warming and assumed AGW (oer ICC) becomes apparent again.
Sorry, but you got a bad grade on that assignment. Check the science first, next time, before drawing a graph, and you will do better.
Regards,
Max
Max,
It isn’t possible,as I’m sure you’ll agree, to do real experiments with the earth’s atmosphere, apart from the one we are all doing by increasing CO2 levels that is, but there’s nothing to stop us all doing thought experiments.
http://en.wikipedia.org/wiki/Thought_experiment
It just occurred to me that you might not be familiar with this concept and which might explain your silliness about angels and pinheads etc. Sure, we know we can never get down to zero CO2 but we can think about the possibility and use the concept to help us work out the correct equations which might govern the relationship between increased temperature and CO2 concentrations.
Perhaps you’d like to explain to us all, in your own words, just why the the increase in temperature has to be proportional to the logarithm of CO2 concentrations?
No falling back on the argument that all the science books say it’s logarithmic. You’re a ‘sceptic’ remember? You need to understand everything yourself from first principles so that you’ll be able to point any mistakes that might be being made.
TonyB,
I see that two of your (tonybrr) comments over at the Guardian were deleted on 19 May, their blog-time; at 10:36 am and 12:35 pm. Since I have not ever noticed you hurl unreasonable abuse, I’m wondering what sin you committed. Do you have copies of your compositions to share?
Hi Peter,
Instead of addressing the glaring inconsistency of a natural CO2 greenhouse warming of 5.2C (up to 280 ppmv) with a projected 2xCO2 anthropogenic CO2 greenhouse warming of 3.2C (280 to 560 ppmv) you ask (6367):
Who is “us all” here, Peter?
I will be glad to explain it to YOU.
It does not HAVE to be logarithmic.
It just happens that the greenhouse theory stipulates that that is the way the relation is (Arhennius, Stefan-Boltzmann, etc.).
I have no reason to be skeptical of the greenhouse theory itself, although (as you say) no one has been able to validate it as yet based on actual physical observations or experiments.
IPCC accepts this logarithmic relation when it calculates a radiative forcing for CO2.
I can accept the radiative forcing factors as estimated by IPCC (Myhre et al.), as well as the calculated CO2 radiative forcing of 1.66 W/m^2 from 280 ppmv (assumed for “pre-industrial” 1750) to 379 ppmv (measured for 2005. These tell me that the 2xCO2 greenhouse impact is around 0.8C.
Lindzen has estimated this at a slightly lower value of 0.65C, which corresponds to his estimate of 5.2C total natural greenhouse warming from CO2.
All of this makes sense to me as the range of theoretical greenhouse warming one can expect from CO2.
What I cannot accept is that anthropogenic CO2 greenhouse warming (from 280 to 560 ppmv) should suddenly be at a much greater rate than natural CO2 greenhouse warming (up to 280 ppmv).
What happens between 0 and 1 ppmv CO2 is of little practical interest, so there is not much point arguing about it. I compared it to the heated theological debates concerning the number of angels dancing on the head of a pin, but you apparently do not like this comparison.
We are now at several hundred ppmv (thankfully for all life on our planet!) and will undoubtedly increase to a value as much as two to three times the current value before fossil fuels have played out completely, so this is the range we should be thinking about when we deliberate what the greenhouse impact will be.
We do know that our planet has had atmospheric CO2 concentrations much higher than those of today in the far distant past with no runaway greenhouse effect, so that the alarmist prophesies of James E. Hansen that we will soon (at 450 ppmv) reach an irreversible “tipping point” appear to be pure fear-mongering without any real scientific basis other than GIGO model studies (which are no scientific evidence in any case).
The basic question to you, Peter, is:
How can we accept (a) that the natural CO2 greenhouse effect was 5.2C (up to the assumed “pre-industrial” CO2 level of 280 ppmv) and assume (b) that the predicted future anthropogenic CO2 greenhouse effect from doubling CO2 (for example from today’s value of 385 ppmv to a projected far-distant future value of 770 ppmv) will cause warming of 3.2C?
It simply does not make sense, Peter. That is your dilemma.
Please explain.
Regards,
Max
Here is an extract from Christopher Booker’s article in today’s Sunday Telegraph:
My congratulations to Barelysane, Bob_FJ, Max and tonyB – and any other contributors from this thread.
Bob FJ 6368
I was specifically responding to one of the cheerleaders who was convinced that the science is settled and that models are more accurate than they really are, so I posted some links. I also suggested they look to their own site before criticising others, because the Guardian itself posted an article in 2000 confirming the Skate surfacing and that there was open water.
I posted this on Harmless Sky a few days later confirming this;
“What is it with the Guardian site? I posted the following at 10.36 this morning only to have it subsequently removed.
Firstly I posted this which confirmed that the Guardian in 2000 agreed with WUWT in that there was open water at the pole.
http://www.guardian.co.uk/environment/2000/aug/23/g2.weather
I also commented that Mefinny2 absolute faith that the science is settled and models are highly accurate wasn’t borne out by this.
This was posted by the met office demonstrating the uncertainty in the science
http://www.metoffice.gov.uk/corporate/recruitment/vacancies/001758.html
“A significant uncertainty in future projections of sea level is associated with dynamical changes in the Antarctic and Greenland ice sheets and a key aspect of this uncertainty is the role of ice shelves, how they might respond to climate change, and the effect this could have on the ice sheets. The goal of the post is to contribute to improved scenarios of sea-level rise, which is an important aspect of climate change, with large coastal impacts.
Specific job purpose
Incorporate a model of ice shelves into the Met Office Hadley Centre climate model to develop a capability to make projections of rapid changes in ice sheets, thereby leading to improved scenarios of future sea-level rise.”
Models are not the foolproof tool often believed. Correspondents who believe they are, will find themselves disagreeing with the IPCC themselves, for Kevin Trenberth, one of their lead authors wrote,
“…the startling climate state in several models may depart significantly from the real climate owing to model errors.”
“Water vapour and cloud play a crucial part if the climate is to be accurately modelled, but as the IPCC themselves admit numerous times, it can’t be achieved.”
“…cloud feedbacks remain the largest source of uncertainty…”
“In climate research and modelling we should recognise that we are dealing with a coupled non linear chaotic system and therefore that the long term predictions of future climate states is not possible.”
I then said here;
“My comments were removed and I can’t post anything at the moment. Are Guardian posters who don’t like certain information able to have it removed?”
Later on (before I was blocked totally) I posted some more information, which was censored, which I think was all or most of the following topics-I didn’t keep a record.
Firstly, this about sea level rises being dictated by the IPCC even though the respective govt agencies worldwide were not finding these rises.
http://www.defra.gov.uk/environ/fcd/pubs/pagn/climatechangeupdate.pdf
This about people having the wool puled over their eyes;
http://www.telegraph.co.uk/scienceandtechnology/5345963/The-scientific-fraudster-who-dazzled-the-world-of-physics.html
“Schön’s fraud was the largest ever exposed in physics; he ended up without a job, and was forced to leave America in disgrace. But the ease with which his fraudulent findings and grotesque errors were accepted by his peers raises troubling questions about the way in which scientists assess each other’s work, and whether there might be other such cases out there.”
This about another job at the Met office;
“As regards their empire expansion, as well as the polar ice modeller they still need because of the ‘considerable uncertainties in the science’, they also need someone skilled in brainwashing us all;
http://www.metoffice.gov.uk/corporate/recruitment/vacancies/dynamics_communicating_clim_change_Sci.pdf
The irony of course was that none of the info was from the alarmist web sites that Peter seems to enjoy so much (aren’t we lucky to have him as a reasonably rational representative of the warmists?) as the links were from the Met office, The Ipcc, The Guardian itself and the UK govt arm Defra.
They were perfectly factual and you have never seen me abusing anyone because I simply don’t do it, so to have these posts removed seems somewhat defensive.
If any of them are reading this it is something I might still take further. I see this as little more than censorship and would like to believe that GM does not know what is going on in his name.
Tonyb
Hi Robin,
To the Guardian blog exchange (Monbiot/Booker story) you wrote:
Thanks for your kind words.
I take my inspiration from none other than that great Australian philosopher and searcher for the Truth, Bob_FJ, who advised me early on in the great AGW debate (in what he remembered from his broken school Latin): NON ILLEGITIMI CARBORUNDUM, which he translated into “don’t let the bastards grind you down, mate”.
Great words of wisdom…
Hats off to Bob.
Max
Max,
You’re a sceptic right? So your statement “I have no reason to be skeptical of the greenhouse theory itself”. seems somewhat curious. I’m starting to think that your grasp of what it really means is quite poor.
Lets just do simple ‘thought experiment’. Suppose for whatever reason some mad scientist, like Blofeld, in a James Bond movie decides to hurry global warming along a bit by inventing a new greenhouse gas. Naturally he needs to know just how much gas to release to warm up the planet by a certain amount. He’s supposed to be an evil genius so may know the correct answer, but lets say he’s not sure and decides to ask you , Max Anacker for some scientific help. A paid consultancy even! Of course you aren’t aware of his evil intentions at the time :-)
You’ll say “sure thing Mr Bofeld”. I have it on good authority that GHGs have an effect which is directly proportional to the logarithm of their concentration. “Can I have my money now please?”
But Mr Blofeld is not ready to sign your cheque just yet. He knows that he hasn’t released any of his new GHG at all and that the atmospheric concentration is therefore zero. He’s just typed zero into his $20 calculator, taken the logarithm and its come up with an error message. He’s smart enough to know that this is because the real answer is ‘minus infinity.’ So, you are telling Mr Blofeld that even before he’s released a single molecule of his new gas he’s created the worst ice age ever known.
However, the world seems just the same and the white cat is purring contentedly on his lap. I’m not quite sure that you’ll end up getting that cheque signed , Max, unless you can come up with something a bit better than that and you’ll have to think fast. Mr Blofeld is not at all happy with you and the sharks in his giant aquarium are looking forward to their feeding time !
Hi Robin,
More seriously, to the censorship you witnessed personally at the Guardian site, I find this disturbing.
I know that other sites, like RealClimate, routinely snip out any posts which contradict the site credo regarding AGW, but I had not seen this censorship of rational dissent at the Guardian site.
I have also not witnessed this on any site that questions the prevailing AGW paradigm, such as WUWT or ClimateAudit.
Maybe Peter is aware of censorship of dissenting views on these sites, but I have not seen this myself.
I like this site, because there is an open dialog, no censorship of opposing views, yet no tolerance of silly OT remarks or personal “ad hom” insults.
This keeps the “cheerleaders” (as you call them) or “pro-AGW trolls” (as I call them) off the thread.
But, in the end, these guys are no more annoying than the bugs that fly into your eyes in the Australian outback, and the motto of Bob_FJ applies very well to them.
Hats off to Peter and the other rational supporters of the AGW paradigm, who are willing to discuss this topic objectively and openly.
Thumbs down on the trolls (from both sides) and the sites that find it necessary to censor out rationally presented dissenting opinion.
Max
Hi Peter,
Instead of defending your belief in a 2xCO2 greenhouse impact of 3.2C, you sidetracked with:
Sorry, Peter. Being rationally skeptical of some of the more extreme model-based predictions of the AGW paradigm does not automatically dictate being skeptical of the greenhouse theory per se.
Your “Blofeld imaginary new greenhouse gas” story is (as you call it) a “simple ‘thought experiment’”.
I would not give Blofeld any advice on the impact of the first molecule of his imaginary new GHG, but might simply suggest that he try emitting one molecule and we could then measure what really happened. Then he could try doubling this with a second molecule, and then with four molecules, and so forth.
What advice would you give the evil Mr. Blofeld, Peter?
The actual situation regarding CO2 as a greenhouse gas on our planet is different from the “first molecule” situation to which you allude: the “first molecule” was there long before any life on the planet or any human beings to engage in “thought games” about either “the first CO2 molecule” or “the number of angels that can dance on the head of a pin”, both fascinating (but wholly impractical and irrelevant) topics of discussion.
IPCC tells us (more on faith in ice core data than on actual physical observations) that “pre-industrial” CO2 levels were at 280 ppmv around 1750.
Scientists tell us that the natural CO2 greenhouse effect was around 5.2C (Lindzen), with a corresponding 2xCO2 impact of 0.65C.
Others (Kondratyev + Moskalenko) tell us this is a bit higher at 7.2C (2xCO2 impact = 0.87C).
You, yourself estimate this at somewhere between 3 and 8C, which fits within the range.
IPCC quotes CO2 radiative forcing estimates that are closer to the K+M estimate for 2xCO2 of 0.87C than to the Lindzen estimate.
Measurements at Mauna Loa tell us that the atmospheric CO2 concentration is 385 ppmv today.
Hadley thermometers tell us that there has been around 0.65C global warming over the entire 20th century.
Solar scientists tell us that 0.35C of this warming can be attributed to solar impact, leaving 0.3C for everything else, which we can attribute all to CO2.
Using this long-term warming from CO2 over the entire 20th century as the basis along with the CO2 levels at the start and end, we can calculate a 2xCO2 impact. It turns out to be very close to 0.8C, so we have a good fit.
If we look at the model assumptions leading to the 2xCO2 figure used by IPCC (and favored by yourself) of 3.2C, and compare these to actual physical observations on clouds and water vapor, we see that the model assumptions have been robustly refuted (in the case of clouds) and shown to be significantly exaggerated (in the case of water vapor).
Correcting the 2xCO2 assumed by IPCC for these actual physical observations puts us back at a 2xCO2 impact of around 0.8C.
This is the theoretical greenhouse impact of a doubling of CO2, which I would be prepared to accept as a rational skeptic, based on all the data that are out there (rather than just climate model assumptions).
You have been unable to explain to me why “natural” CO2 greenhouse warming (5.2 or 7.2C up to a CO2 concentration of 280 ppmv) should be at a much lower 2xCO2 rate than “anthropogenic” CO2 greenhouse warming (from 280 ppmv to 560 ppmv, for example).
Until you do, the “thought experiments” are meaningless and the model-based 2xCO2 impact of 3.2C is not plausible based on the observed facts.
The ball is in your court, Peter, not to come up with hypothetical “thought experiments”, but to show why the suggested 2xCO2 impact of 3.2C is credible, despite all the evidence out there to the contrary.
Regards,
Max