Bishop Hill Moore realist
Aug 11, 2012 Climate: Sceptics Greenpeace founder turned eco-realist Patrick Moore is interviewed at the Washington Times. I want to scream every time I hear some idiot journalist discussing the climate wars as if they are a dispute over whether carbon dioxide is a greenhouse gas. I think Moore may share my frustration.
What most people don't realize, partly because the media never explains it, is that there is no dispute over whether CO2 is a greenhouse gas, and all else being equal would result in a warming of the climate. The fundamental dispute is about water in the atmosphere, either in the form of water vapour (a gas) or clouds (water in liquid form). It is generally accepted that a warmer climate will result in more water evaporating from the land and sea and therefore resulting in a higher level of water in the atmosphere, partly because the warmer the air is the more water it can hold. All of the models used by the IPCC assume that this increase in water vapour will result in a positive feedback in the order of 3-4 times the increase in temperature that would be caused by the increase in CO2 alone.
Many scientists do not agree with this, or do not agree that we know enough about the impact of increased water to predict the outcome. Some scientists believe increased water will have a negative feedback instead, due to increased cloud cover. It all depends on how much, and a t what altitudes, latitudes and times of day that water is in the form of a gas (vapour) or a liquid (clouds). So if a certain increase in CO2 would theoretically cause a 1.0C increase in temperature, then if water caused a 3-4 times positive feedback the temperature would actually increase by 3-4C. This is why the warming predicted by the models is so large. Whereas if there was a negative feedback of 0.5 times then the temperature would only rise 0.5C.
Reader Comments (40)
I thought this was a superb interview (even if I didn’t precisely agree with all Moore’s comments on the climate science). Much praise to Moore for continuing to speak out so effectively.
When can we hope to see him guest-posting on, say, WUWT, or TallBloke, or JoNova, or hey, Your page...
He certaily had some hard hitting comments like:
" If we stopped using fossil fuel today, or by 2020 as Al Gore proposes, at least half the human population would perish and there wouldn't be a tree left on the planet with a year, as people struggled to find enough energy to stay alive."
What is more interesting than his article is the lack of comments (just 5 when I looked). Normally the trolls would be all over it by now with insinuations that Patrick had sold out to Big Oil or the like. Surely this isn't a sign that the CAGW are conceding defeat about public opinion, is it
And all that he says is explicitly there in the IPCC reports; but for some reason you never hear about it.
The Greenpeace he describes is certainly how the movement appeared to me in ~1980 when I was at school. In many ways, it has become what many supporters claim to despise: corporate. Bloated budgets, overheads, employees, the continuing need for funds to sustain themselves, always ready with the corporate line [as if we can't guess it], and a complete inability to stop.
As Moore points out, they will always have a "cause" even if there is no reasonable justification, no enemy, or despised technology. They will find one, or invent one. Good on him for being honest about it, but a science training was always going to put him on a collision course with many activists.
I don't think it's correct to say noone argues CO2 warms the atmosphere. I would suspect a large majority of skeptics agree with the position that CO2 does not warm the atmosphere. This is a primary talking point for many political people, referring to only being 4 parts per 10000.
I would accept that a some people who call themselves sceptics would state CO2 doesn't warm the atmosphere, but a large majority? Not a chance, unless you can back up your assertion with hard evidence.
I don't think it's correct to say noone argues CO2 warms the atmosphere. I would suspect a large majority of skeptics agree with the position that CO2 does not warm the atmosphere. This is a primary talking point for many political people, referring to only being 4 parts per 10000.
Aug 12, 2012 at 3:19 AM | MikeN>>>>>
If you take a look at the well researched empirical data from Nikolov and Zeller, you'll see that the 98% concentration of CO2 in Venus' atmosphere has no effect on that planets temperature, as is the case on Earth.
It's all down to atmospheric pressure and insolation.
They also show that the Atmospheric Thermal Effect (ATE) on Earth is a whopping 133K, a full 100K more than the 33K assumed by the IPCC to be caused by CO2, which in no way could cause anywhere near such a large value of ATE.
There are alternative theories by well qualified scientists - there is NO settled science regarding AGW.
The greenhouse effect in a convective fluid says that the surface temperature is the effective radiative temperature (the temperature it would have to be to emit as much power as it absorbs) plus the average altitude of emission to space (which is a function of greenhouse gases, clouds, and aerosols) multiplied by the adiabatic lapse rate (a property of gases under compression, modified by latent heat from humidity).
It's a simple equation.
T_s = T_eff + AAES * ALR
T_eff is affected by albedo, clouds, solar insolation, etc.
ALR is affected by humidity.
AAES is affected by greenhouse gases.
All three are affected by feedbacks.
This has been mainstream climate science since the 1960s, and it explains Venus, Earth, Mars, and even water ponds with perfect ease. The argument is not about the basic effect, it's about the feedbacks and the natural background variability.
I've no idea what 'most sceptics' believe, there are hundreds of millions and most of them don't comment in the climate blogosphere. I doubt they have any clear views at all. Amongst what I would call the 'active' sceptics, the majority I've seen accept that greenhouse gases do cause some warming. There's a significant fraction (about 5% I'd guess) who don't - following instead one of the 'skydragon'-type theories.
As a physicist, I'm quite sure for myself that they're wrong, but I don't know how to explain why to all of you very easily, and I certainly can't explain it to them. As a matter of principle I support their right to have their say, to put their theories forward, and have them considered seriously. It can sometimes be interesting. But from the point of view of debating with warmists they're also very annoying, as it makes it harder to persuade anyone that scepticism is scientifically valid. There have been numerous occasions when I've just started to make headway persuading some group that not all sceptics are scientific illiterates, when one of them has suddenly appeared and knocked my efforts for six.
But it's something we just have to put up with, as the price for not being shut out of the debate ourselves. Sceptics by definition don't have a party line to stick to. We're not a coherently-defined group, but a collection of individuals acting independently. That's the problem with phrases like "Most sceptics...". We don't really want to be fighting over who's 'in' and who's 'out' on this.
Thanks for the link to this excellent interview. Nice to see some sense in a US newspaper. I look forward to part 2.
PS. I particularly enjoyed:
"join the world-wide struggle against globalization"
I and other people I know agree with RKS. There is no radiative greenhouse effect. There is a pressure effect.
The AGW theory will only be falsified by using basic physics especially the lapse rate. Arguing about feedbacks is a distraction. The concept of feedback is very imprecise.
Nullus in Verba. the physics you describe may be 'mainstream climate science since the 1960s' but in any atmosphere with GHGs it's fundamentally wrong because of a logical fallacy obvious to any engineer but not perceived by far too many scientists.
First we must discount the IPCC's claim that IR from the Earth's surface is S-B for a BB in a vacuum. Because convection and radiation are coupled, radiation can never reach the BB level. What's more if you go back to Kirchhoff, he made his deductions for wavelength intervals, not the overall spectrum.
Thermal equilibrium between the surface and GHG bands is subtle. I've measured it. Most GHGs are in self-absorption and any warmer surface emitter in that wavelength interval will reduce GHG self-absorption, increasing DOWN emissivity. Increased 'Prevost Exchange' reduces surface emissivity.
This strong negative feedback means the real GHE is from reduced surface emissivity forcing more IR emission into the 'atmospheric window' and greater convection. This is new thinking. The IPCC ‘consensus’ means you discount a century of experiment accessible in any handbook on heat transfer.
There can be no CO2-AGW. The GHE is fixed by the first few 100 ppmV of water vapour. As for the planets, because CO2 enters self-absorption by ~200 ppmV, there can be virtually no GHE: it's mostly lapse rate. And as for Venus, how can you get a GHE with an opaque atmosphere?
An additional factor is that the IPCC apparently ignores the effect of mixing gases, summing RF calculated for individual GHGs. This report and its two predecessors shows that when you do incorporate mixing [via HITRAN i presume], once you reach ~10% RH, CO2 self absorption starts at 0 ppmV: http://notrickszone.com/2012/08/11/validating-modtran-for-climate-studies/
PS the 'back radiation' spectra are unreal because the spectrometer cavity is a black body. IR physics is fraught with dangers for those who do not understand it's spectroscopy; line inversion is common..
I am disappointed every time I hear someone, especially a popular sceptical blogger, discussing the climate wars as if there was NOT a dispute over whether carbon dioxide is a greenhouse gas.
The encouragement of reasoned factual dispute is necessary for the success of science.
If you believe CO2 causes warming point me to a CALCULATION of the surface temperatures of Earth and Venus using the radiative greenhouse effect theory..
Spartacusisfree is right there can be NO CO2-AGW., not some nice, safe, don’t rock the boat, little bit of warming.
Hi roger; I went out on a bit of a limb to claim there can be no CO2-AGW because the warmer surface emissivity is reduced by GHGs in self-absorption mode. However, the Gosselin reference shows what appears to be an amazing error by the IPCC, to assume total GHG RF is the sum of the theoretical individual RFs calculated by assuming the Earth emits as a black body, which is impossible, all the energy apparently absorbed at TOA in those bands is directly thermalised AND there is no mixing effect which anyone who has done statistical thermodynamics should realise may be quite significant.
Then we have Hansens's error in claiming we have 33 K present GHG warming when he neglects ~24 K lapse rate warming. This is a factor of 3.7 too high calibration. So, I conclude fairly firmly that even if there were to be direct thermalisation, which is quantum excluded, indirect thermalisation at clouds being much more likely, there can be no CO2-AGW for RH >~10% anyway.
To this we add another amazing deduction, which is that the funny spectrum of clouds, mostly grey body, is because they soak up GHG emission energy and convert it to grey body IR thus further damping total GHE if it is in the atmosphere.
I'm a retired engineer putting all these highly paid scientists right! It seems post-normal scientific education has a lot to answer for compared to what I was taught at Imperial in the 1960s when the process engineering education I received was top notch and has never left me. Just what do they do for experimental heat transfer physics now? Do they cover coupled convection and radiation and the deduction of empirical heat transfer coefficients as I did? I very much doubt it which is why they seem to have gone so wrong.
Aug 12, 2012 at 11:23 AM | Roger Clague writes:
"I and other people I know agree with RKS. There is no radiative greenhouse effect. There is a pressure effect.
The AGW theory will only be falsified by using basic physics especially the lapse rate. Arguing about feedbacks is a distraction. The concept of feedback is very imprecise."
I await your explanation vis-a-vis the 'pressure effect' and how this translates to cooler evenings when our RH (relative humidity) is low, friend.
Remember, sky-dragons, if you're going to re-write how IR radiative/reflective physics work (down to molecule resonance esp. why certain molecules respond to certain EM wavelengths), ALL aspects must be accounted for ...
_Jim
"I and other people I know agree with RKS. There is no radiative greenhouse effect. There is a pressure effect. The AGW theory will only be falsified by using basic physics especially the lapse rate."
The lapse rate is a central component of the basic AGW theory. The mechanism involves both radiation and pressure.
"Thermal equilibrium between the surface and GHG bands is subtle. I've measured it."
It's got nothing to do with radiation between atmosphere and surface, it's to do with radiation between atmosphere and outer space. You're fighting a strawman.
The temperature of the middle atmosphere is controlled by radiation to space. If it radiates less energy than the Earth as a whole absorbs, things warm up. If it radiates more, things cool down. So the temperature of the middle atmosphere 5 km up settles at T_eff = -21 C at which it radiates just the right amount. It's the middle atmosphere that radiates to space, and not the surface, because the atmosphere is opaque to IR, because of greenhouse gases. Without greenhouse gases, it would be radiation direct from the surface to outer space that controlled the temperature, which would be -21 C at the surface and would get even colder than that with altitude.
But because it's the layer 5 km up that settles at -20 C, and - yes - because of the pressure difference between there and the surface, the surface is 5 km * 6.5 C/km = 33 C warmer. The cause of the difference in temperature between the two levels is mostly down to the pressure difference between them. But the difference in altitude between the two is mostly down to greenhouse gases. You can't ignore them.
It's not entirely your fault - the warmists have been giving the wrong explanation for years, and are badly confused about it themselves. But please, do try to at least understand the theory you're arguing against. That other one was thrown out by proper scientists around 1904.
"Its the middle atmosphere that radiates to space.." Yes, the more infra-red active gases present in the middle layer, including more CO2, the more energy is lost to space. Therefore the increasing CO2 content in this layer offsets any positive feedbacks at the lower layers by day, and actually causes the atmosphere to cool more at night than would otherwise be the case.
CO2 is not a 'greenhouse' gas. If you want to attach an emotive label, then 'refrigerator' gas is just as good, because of its atmospheric nighttime cooling effect.
Hi Nlluius in Verba: I am unconcerned with middle and upper atmosphere because it must take care of itself by the jet streams controlling where energy is radiated to space - need to radiate more, the jet streams move nearer the poles; no flat slab model can work.
What we see at TOA is mainly from self-absorption in the lower and middle atmosphere: it starts at very low concentration; ~200 ppmv for CO2, probably significantly higher/more rounded for water vapour and other GHGs with complex IR spectra. There is no DOWN IR at TOA because DOWN emissivity falls with altitude above the cloud level; this is because IR thermalisation is indirect, the GHGs acting as a heat transfer medium. That thermalised energy is dispersed to the atmospheric window, hence clouds are a major negative feedback for true IR absorption, a fifth of that claimed in the models.
My real argument is that the GHE is from suppression of IR band emission for self-absorbing GHEs at the Earth's surface, no CO2-AGW is possible and the GHE is determined by water vapour, the dominant species. This explains all the evidence without having to cheat in the hind-casting as done now to get the imaginary positive feedback.
As for the IPCC's failure in other areas, e,g not accounting for mixed GHGs, is between the modellers and their creator for it is now emerging from other iconoclasts!
"Yes, the more infra-red active gases present in the middle layer, including more CO2, the more energy is lost to space."
No, because it's higher up, and therefore colder (due to the lower pressure). Colder gas radiates less.
"I am unconcerned with middle and upper atmosphere because it must take care of itself"
I have no idea what your comment means. It appears to be a random selection of sciencey words strung together. So long as you're happy, though...
Nullius in Verba is right.
Aug 12, 2012 at 5:11 PM | Edward Bancroft:
"... Yes, the more infra-red active gases present in the middle layer, including more CO2, the more energy is lost to space. Therefore the increasing CO2 content in this layer offsets any positive feedbacks at the lower layers by day, and actually causes the atmosphere to cool more at night than would otherwise be the case. ..."
And, we have satellite imagery to back this up? This would also be a good meteorological tool. We have, BTW sat imagery for WV, but I don't think the 'bulk' of thermal radiation is from the atmosphere rather it would seem to occur from land mass surfaces (and surface water!)
http://weather.rap.ucar.edu/satellite/displaySat.php?region=ABI&itype=wv&size=large&endDate=20120812&endTime=-1&duration=6
_Jim
Spartacus
I have asked you before not to input your own theories onto threads.
Last warning.
Quote: "a warmer climate will result in more water evaporating from the land ".
I'm kinda thinking a warmer air "over" the land or sea will NOT increase evaporation "from" the land or sea.
The sun's radiation heats the earth directly, not the atmosphere above it. Same with the ocean.
It's not entirely your fault - the warmists have been giving the wrong explanation for years, and are badly confused about it themselves. But please, do try to at least understand the theory you're arguing against. That other one was thrown out by proper scientists around 1904.
Aug 12, 2012 at 4:18 PM | Nullius in Verba>>>>>
Sorry I didn't respond earlier - seem to have some sort of temporary cookie problem with my Chrome browser which stopped me from commenting again on this particular thread.
You appear to show greenhouse gasses, and therefore man made CO2, as the primary climate driver - in other words AGW.
Have you actually read the paper by Nikolov and Zeller, and fully studied their maths and empirical data. You have, after all, been quite happy to show us your own hypothesis, which still awaits empirical proof.
You will find their theory has absolutely nothing to do with adiabatic lapse rate.
If you find it wrong, then give us a proper critique as to where and why it is incorrect, instead of arm waving and dismissing empirically based scientific research out of hand.
Regards,
"You appear to show greenhouse gasses, and therefore man made CO2, as the primary climate driver - in other words AGW."
No I don't. I show that the greenhouse effect exists, that it's real physics, and the physics is dependant on greenhouse gases. (Mainly water vapour.) I say nothing at all about the magnitude of response to any change. I say nothing at all about the many other factors affecting climate. I say nothing at all about how feedbacks might or might not magnify those changes and other factors.
The argument for catastrophe has a hundred steps, and the physics of the greenhouse effect is just step 1. The warmists like to pretend that if you accept step 1 then all the rest follows automatically, and that rejecting catastrophe means you're rejecting step 1, but it isn't true.
Their weaknesses are on all the subsequent steps, which is why they like to concentrate attention on step 1 where they're strongest.
Believe it or not, I started writing my response to Moore's two articles yesterday (before I saw this post, today ... and just tried - unsuccessfully - to post a "Reference" so as not to disrupt the flow of this thread!) So I hope readers will forgive the following shameless plug:
For those who may be interested, I have highlighted some differences between Muller and Moore - and why I have added Moore's Confessions of a Greenpeace Dropout: The Making of a Sensible Environmentalist to my must read list (but not Muller's latest opus).
Also of potential interest in this same post, is a 2006 Open Letter I found from Moore to Bob Ward, during the course of Ward's "tenure" with the RS. It warmed (you should pardon my use of the word!) the cockles of my heart!
A tale of two “converts”: Richard Muller & Patrick Moore
P.S. Bish, if you see this, could you delete the truncated "Reference" which makes very little sense at this point. Thanks.
"Some scientists believe increased water will have a negative feedback instead, due to increased cloud cover."
I, for one, have noticed that it's warmer when the sun's out...
Nullius in Verba: I show that the greenhouse effect exists, that it's real physics, and the physics is dependant on greenhouse gases. (Mainly water vapour.)'
True. However, the IPCC assumes (1) denuded IR bands at TOA prove absorption by GHGs of IR radiation emitted by the Earth's surface in those bands and (2) that that IR is constant, the black body level for an isolated body in a vacuum.
However, (1) GHGs self-absorb thermal IR so TOA emissivity in those bands is by definition <<1 and (2) is contrary to a century of experiment which proves that in an atmosphere, convection, conduction, evaporation and radiation are coupled so radiation can never reach the black body level..
Add in the incorrect assumption that TOA DOWN emissivity = 1 and the models create a perpetual motion machine of the 2nd kind, 40% energy increase which, coupled with imaginary cooling by extra cloud albedo, gives imaginary 'positive feedback'.
The real GHE is because emissivity and absorptivity of a radiating body in any wavelength interval are operational: Kirchhoff taught this. At the Earth’s surface, GHGs reduce emissivity in those IR bands in turn raising its temperature because fewer sites are available to transfer energy to adsorbed gas molecules or radiation. The mechanism is subtle and dependent on the GHGs being in self-absorption, ~200 ppmV for CO2, ~900 ppmV for water vapour. The GHE is a fixed level, set by the latter.
Mr. Moore neglects to mention the ice albedo feedback: ice is good at reflecting solar radiation, but when it warms it melts, and the ocean or land left behind absorbs more, leading to further warming.
This is another of those so-called "positive feedbacks". It is contributing to the enhanced warming in the models Mr. Moore cites.
tilting --
It's a matter of degree, though. According to Hansen et al., "Earth's Energy Imbalance and Implications (2011)", such an effect is responsible for an average forcing of less than 0.2 W/m^2. Relatively minor in the grand scheme of things. [Data file is here.]
Hi HaroldW,
I think you may be confusing forcings and feedbacks (easily done!). Hansen's number refers to the present day forcing caused by black carbon and other aerosol emissions falling on snow & ice. This is defined as a forcing because it is a direct radiative effect from the emission.
The radiative effect gives rise to a change in temperature, and stuff that happens in response to the change in temperature (e.g. changes to water vapour and clouds) tend to be defined as feedbacks, positive or negative. Snow & ice melt in response to warming, and that's the feedback I was referring to.
To see how the strong the different feedbacks are in the models Mr. Moore is talking about, there's an IPCC chart (scroll down to Fig 8.14).
P.S. The snow & ice feedback I'm referring to is identified as 'A' in Fig 8.14 - trust a scientific chart to be simple and intuitive ;-)
tilting --
You're correct, that was a mistake on my part. The factor named "snow albedo" in Hansen et al. is the warming due to darkening of snow (& ice presumably) due to aerosols, notably black carbon. I misread the name.
So, what is the actual feedback from melting? Most places which encounter this phenomenon, not surprisingly, are polar, with the associated low insolation.
Hudson did the math for Arctic sea ice: "[T]he globally and annually averaged radiative forcing caused by the observed loss of sea ice in the Arctic between 1979 and 2007 is approximately 0.1 W m−2; a complete removal of Arctic sea ice results in a forcing of about 0.7 W m−2, while a more realistic ice-free summer scenario (no ice for 1 month and decreased ice at all other times of the year) results in a forcing of about 0.3 W m−2."
Hudson notes that the 0.1 W m-2 figure for ice agrees with Flanner et al.*, who assess snow effect as approximately equal to that of ice. So double Hudson's sea-ice forcing of 0.1 W m−2 -- which gives 0.2 W m-2.
Still relatively small.
* Sorry, I couldn't locate a non-paywalled version for Flanner et al.
Hi HaroldW,
I guess it depends what you mean by small :-)
I think the numbers you mention actually agree broadly with the IPCC chart. Here's why: feedbacks are measured in terms of Wm-2degC-1 (in other words, for each degree of warming, what's the additional radiative forcing provided by the feedback mechanism?). Let's say that the Arctic warmed by about 1degC between 1979 and 2006, setting aside the measurement debate for the moment. So on the basis of your numbers that's a feedback of around 0.1Wm-2degC-1. And that's just for the sea ice, not including the feedback from melting land ice and other albedo changes. So it's in the same ball park as feedback parameter 'A' in Fig 8.14.
The figure shows it in relation to the water vapour, cloud and lapse rate feedbacks - whether you think it is small or not is up to you. I guess the point I wanted to make is that it's not totally insignificant, and it's a common-sense mechanism that pretty clearly causes a positive feedback, like water vapour.
Hope that helps...
tilting -
Over the same 30-year period, GHG forcing increased by approx 1.3 W m-2. So the 0.2 from Arctic albedo effect seems small in comparison (15%).
By the way, when using the linear-feedback ansatz, as that is couched in terms of global average forcing and global average temperature, one shouldn't use Arctic warming but global. That's somewhere around 0.5 K over the 30-year period, which would make the feedback parameter around 0.4 W m-2 K-1, still within the range of figure 8.14. However, that ansatz seems even less plausible as ice continues to melt despite relatively stable temperatures; the albedo feedback seems to possess a "momentum" term and is not simply a linear function of temperature. Plus, it is natural that further melting will be at more northerly latitudes and thus at lower average insolations, hence the feedback parameter (to the extent that it's meaningful at all) will tend to decrease with remaining ice. [Along the same lines that the snow-ice-albedo feedback was very much greater at the last glacial termination.] Trying to fit static equations to time-varying systems is an exercise in optimism. I'm optimistic myself, but one must concede limits to the applicability of a fixed model such as the linear-feedback ansatz.
Thanks for pointing out the global/arctic temperature correction, HaroldW, I shouldn't have made that mistake. Gosh, rapid-response blog science is risky :-)
But your correction just makes the arctic sea ice feedback twice as strong. That doesn't make me feel better.
Let's go back to the chart - safer because it is based on calculations that incorporate the nonlinearities and inhomogeneities you rightly point out. You say the albedo feedback ('A') is small, but it is as large as the cloud feedback ('C') in several of the GCMs.
And yet Mr Moore implies that all the amplified warming in the GCMs is due to 'C'. Furthermore he's claiming that 'C' could be negative rather than positive (I think: maybe so) and in fact so negative it more than offsets 'WV' + 'LR' + 'C' (I think: hmm...need more convincing before I put money on that!).
So in summary, we seem to agree Mr. Moore neglects a positive 'water' feedback that is contributing to the numbers he cites. Whether it's insignificant... well, I for one think it's not to be sniffed at :-)
tilting -
"rapid-response blog science is risky :-) " ... agree, cf. my blunder a couple of posts further up :)
With regard to the numerical value of 'A' (albedo feedback) - evaluating the differences over the 1979-2008 period, one gets 0.4 W m-2 K-1 . However, it's not at all clear whether 1979 was (for ice albedo) much different from say 1900, based on [admittedly qualitative] historical accounts; computing over the longer period gives a much reduced value. As I wrote above, linear-temperature-feedback doesn't seem to be a good fit for ice albedo; compare Hudson's figure 3 [citation above] to global average temperature...
"And yet Mr Moore implies that all the amplified warming in the GCMs is due to 'C'. Furthermore he's claiming that 'C' could be negative rather than positive (I think: maybe so) and in fact so negative it more than offsets 'WV' + 'LR' + 'C' " [Last 'C' should be 'A', perhaps?]
Moore says, "All of the models used by the IPCC assume that this increase in water vapour [HW: I interpret this as 'WV'+'LR'+'C'] will result in a positive feedback in the order of 3-4 times the increase in temperature that would be caused by the increase in CO2 alone." So he's not attributing all the amplification to 'C'. He goes on to say, "either there is some equally powerful natural factor that is suppressing the warming that should be caused by CO2, or CO2 is only a minor contributor to warming in the first place." I agree with Moore that a 3x amplification doesn't seem to be consistent with observations.
Moore says "Some scientists believe increased water will have a negative feedback instead, due to increased cloud cover." Going back to my first point, I think he's ignoring the other water-based feedbacks that are uncontroversially positive, and overegging the cloud feedback pudding.
Anyway, let's not while away the time on semantics - I've a beer to catch. Thanks for the discussion, and cheerio!
"I think he's ... overegging the cloud feedback pudding."
Wouldn't be the first time that's happened. But the GCMs seem to be overestimating sensitivity, and that's one good place to start looking.
Thanks for the discussion. Enjoy your pint!