Guest post by David Archibald
The greenhouse gasses keep the Earth 30° C warmer than it would otherwise be without them in the atmosphere, so instead of the average surface temperature being -15° C, it is 15° C. Carbon dioxide contributes 10% of the effect so that is 3° C. The pre-industrial level of carbon dioxide in the atmosphere was 280 ppm. So roughly, if the heating effect was a linear relationship, each 100 ppm contributes 1° C. With the atmospheric concentration rising by 2 ppm annually, it would go up by 100 ppm every 50 years and we would all fry as per the IPCC predictions.
But the relationship isn’t linear, it is logarithmic. In 2006, Willis Eschenbach posted this graph on Climate Audit showing the logarithmic heating effect of carbon dioxide relative to atmospheric concentration:
And this graphic of his shows carbon dioxide’s contribution to the whole greenhouse effect:
I recast Willis’ first graph as a bar chart to make the concept easier to understand to the layman:
Lo and behold, the first 20 ppm accounts for over half of the heating effect to the pre-industrial level of 280 ppm, by which time carbon dioxide is tuckered out as a greenhouse gas. One thing to bear in mind is that the atmospheric concentration of CO2 got down to 180 ppm during the glacial periods of the ice age the Earth is currently in (the Holocene is an interglacial in the ice age that started three million years ago).
Plant growth shuts down at 150 ppm, so the Earth was within 30 ppm of disaster. Terrestrial life came close to being wiped out by a lack of CO2 in the atmosphere. If plants were doing climate science instead of us humans, they would have a different opinion about what is a dangerous carbon dioxide level.
Some of the IPCC climate models predict that temperature will rise up to 6° C as a consequence of the doubling of the pre-industrial level of 280 ppm. So let’s add that to the graph above and see what it looks like:
The IPCC models water vapour-driven positive feedback as starting from the pre-industrial level. Somehow the carbon dioxide below the pre-industrial level does not cause this water vapour-driven positive feedback. If their water vapour feedback is a linear relationship with carbon dioxide, then we should have seen over 2° C of warming by now. We are told that the Earth warmed by 0.7° C over the 20th Century. Where I live – Perth, Western Australia – missed out on a lot of that warming.
Nothing happened up to the Great Pacific Climate Shift of 1976, which gave us a 0.4° warming, and it has been flat for the last four decades.
Let’s see what the IPCC model warming looks like when it is plotted as a cumulative bar graph:
The natural heating effect of carbon dioxide is the blue bars and the IPCC projected anthropogenic effect is the red bars. Each 20 ppm increment above 280 ppm provides about 0.03° C of naturally occurring warming and 0.43° C of anthropogenic warming. That is a multiplier effect of over thirteen times. This is the leap of faith required to believe in global warming.
The whole AGW belief system is based upon positive water vapour feedback starting from the pre-industrial level of 280 ppm and not before. To paraphrase George Orwell, anthropogenic carbon dioxide molecules are more equal than the naturally occurring ones. Much, much more equal.
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Nick Stokes (14:24:38) :
Re: davidmhoffer (Mar 9 07:07),
…daily cycle effect of vegetation completely invalidates the guy’s ability…
Yes, it does. Because the fluctuations that he’s seeing have nothing to do with global CO2.>>
He set out to determine if CO2 fluctuated due to local diurnal cycles of vegetation and effects of wind speed on accumulation. He showed that they did. This does not mean he calculateD annual fluctuations in the same way. The fact that he understood the fluctuations caused by these and other factors does not suggest that he neglected them when calculating annual trends, just the opposite.
<>
Really? Are you certain? Because I’ve been reading an awful lot recently about TREE RING DIVERGENCE and how researchers had to perform the “trick” of substituting temperature for tree ring data because the tree rings “suddenly” stopped tracking temperature for no apparent reason right around 1960. What limits tree growth besides heat and moisture? CO2 perhaps? Is it possible that under a certain level of CO2 tree growth is stunted? So perhaps the tree rings and the CO2 are saying the same thing?
SORRY! messed up the edit, I keep forgetting this blog understands html. Last part of post above shoud have read:
Nick Stokes;
Beck’s pre-1960 curves are quite different. There’s no reason to believe the world changed radically in 1960. The logical explanation is that if you sum a random collection of measurements with all sorts of local effects, you measure something quite different to what eg the Scripps sites are measuring now for global CO2>>
Really? Are you certain? Because I’ve been reading an awful lot recently about TREE RING DIVERGENCE and how researchers had to perform the “trick” of substituting temperature for tree ring data because the tree rings “suddenly” stopped tracking temperature for no apparent reason right around 1960. What limits tree growth besides heat and moisture? CO2 perhaps? Is it possible that under a certain level of CO2 tree growth is stunted? So perhaps the tree rings and the CO2 are saying the same thing?
Some noteworthy empirical facts:
1) The oceans as a whole shed more thermal energy through evaporation than through all other processes combined. They cover >70% of the Earth’s surface.
2) The air-sea temperature differential is negative in the global annual-average sense. In other words, on a climatic basis, the sea heats the air and not the other way around!
3) GHGs produce no thermal energy whatsover, but merely redistribute it through radiative transfer and molecular collisions with “inert” atmoshperic constituents. This is a capacitance effect and not a “forcing.”
4) IR absorption by water vapor covers a much wider range of frequencies than the discrete lines of the trace gases. Its highly variable presence in the atmosphere makes the correspondingly wide “atmospheric window” highly variable also, allowing IR to escape to space more sporadically, but no less effectively.
5) As a consequence, the Earth need not heat up to shed any “excess heat” that may be attributed to increased CO2 concentrations and backradiation at certain LW frequencies. It’s the power density integrated over all thermal frequencies–and not just in certain bands–that determines the surface temperature.
In summary, the climatic regulator is found not in the trace gases, but in the rate of the chaotic hydrological cycle. You can argue all you want about various theoretical constructs, but those are the essential facts as evidenced by observations.
Spector (16:05:02) :
That is a very good point. Perhaps the physical chemists amongst us could put that graph together.
Nick Stokes;
Beck’s pre-1960 curves are quite different. There’s no reason to believe the world changed radically in 1960>>
My apologies, I looked at Beck’s graph again and realised that the big drop in CO2 it shows starts about 1950, not 1960. So then I looked up divergence and it turns out that I had THAT date wrong too. Turns out it started showing up about…1950.
I don’t know if this was posted already: during the Jurassic, CO2 was over 2,000 ppm (more than 5x current), average global temp was about 22C (currently 13C) and life was doing wonderfully. How does this compare to the IPCC models?
Other fact: when I was growing plant clones on agar, the incubator was set for maximal growth conditions for plants: lots of light, 30C, 80% humidity and 10% CO2 (that’s 100,000 ppm).
Graph of temp & CO2 over geological period, from geocraft.com, with references:
http://www.geocraft.com/WVFossils/GlobWarmTest/A6c.html
nick
agw is going to raise the T of the surface facilitating more evaporation. Higher up such as the tropopause, which is at a conservation of energy temperature level, you have effectively a higher emissivity caused by increased ghg levels. that means the atmospheric parcel radiates more power at a given temperature. Assuming it was in a relative equilibrium condition prior to the addition of the ghgs then the temperature must drop as it is radiating more energy out – pretty much at a 2x rate compared to the increased absorbed energy.
exactly what happens is a guess. not every surface point has additional h2o available to become vapor. if the upper atmosphere fails to increase h2o vapor, it merely means there is going to be less of a gh effect. the constant relative humidity assumption is made and is supposedly sorta right on average. Of course, the relative humidity is essentially limited to 100% as super saturation results in a “cure” for too much h2o. One can assume that either the rh stays constant or it decreases with T. More surface heat is going to invoke more of a water cycle and absolute humidity will increase and that is the only thing that counts relative to radiative transfer. The water cycle though is simply going to move more power through regions of lower radiative transfer and act as negative feedback. It’s also going to invoke additional cloud formation which results in a net increase in albedo and will cool the Earth down on average as the water vapor cycle is going to be a time of day dependent activity.
George E. Smith (15:06:46) :
“”” Reed Coray (13:47:29) :
George E. Smith (12:11:01) :
According to “Fundamentals of Statistical and Thermal Physics”, Reif, McGray-Hill, 1965, page 385
“A good emitter of radiation is also a good absorber of radiation, and vice versa. “””
And if the latter statement was correct, then spectrally selective solar thermal energy collection panels simply would not work; providing experimental proof of the falsity of that assertion.
George, I first want to state, and I am NOT being sarcastic, that I appreciate the dialog.
However, I don’t think your above statement regarding the falsity of Reif’s assertion is incorrect. A good emitter is not material that radiates massive amounts of power. A good emitter is a material that radiates a large fraction of the power that a black body radiator at the same temperature would radiate. A good absorber is a material that absorbs a large fraction of the power that a black body would absorb–which is all the power incident on it. In this sense, a black body is both a perfect absorber and a perfect emitter. This concept does not imply that a black body can’t absorb energy, and by various means convert that energy into either work or energy in other forms. Thus, the concept that a good emitter is a good absorber does not imply solar panels can’t convert solar radiant energy into electrical energy.
If all materials were perfect reflectors (i.e., any energy incident of the surface is reflected by the surface), then your comment about solar panels would be correct.
The best model I am familiar with for a black body radiator is a small opening in a cavity whose interior walls are at a common temperature. Independent of that temperature, all energy incident on the hole from the outside will enter the cavity and eventually be absorbed by the walls of the cavity. Similarly, all energy incident on the hole from inside the cavity leaves the cavity. Thus the hole is perfectly efficient–both for absorption and emission. This concept does not requre that the amount of energy per unit time entering the cavity must equal the amount of energy per unit time leaving the cavity. The amount of energy incident of the hole from the outside is independent of the temperature of the walls of the cavity. The amount of energy incident of the hole from inside the cavity is a function of the temperature of the cavity walls. Thus, the statement that “A good emitter of radiation is also a good absorber of radiation, and vice versa” does not imply that net energy can’t be absorbed by the body, and hence does not imply solar panels “can’t work”.
George, sorry. Instead of writing: However, I don’t think your above statement regarding the falsity of Reif’s assertion is INcorrect., I should have written: However, I don’t think your above statement regarding the falsity of Reif’s assertion is correct.
Willis Eschenbach,
Not only do they not use readings obviously contaminated by Volcanic CO2 emissions that spike their sensor, they also do not use ANY readings outside of their standard, whatever that is. In fact, their problem last year was they did not have data for 20 DAYS of a month due to this issue and posted a very low reading which they took back after being questioned about its validity. They told us they implemented infilling to deal with that type of issue.
So, just like temperature data, Mona Loa CO2 readings are now partially made up.
That leads me to question what they were doing about loss of data before?? Is it just recently that their standard is causing them to not use a lot of data?? Why would that be??
“”” Colin Davidson (16:15:27) :
Phil (8Mar10, 20:24:16) said:
“Do the math, radiation is the dominant heat loss route from the surface…”
I will use the figure in FAQ 1.1, Chapter 1, WG1, IPCC AR4 (2007), which is from Kiehl & Trenberth (1997).
The energy fluxes from the surface are (all figures are in W/m^2):
Radiation: 390-324 (back radiation) = 66
Conduction: 24
Latent Heat (in water vapour): 78
So, having done the maths (in my country we do it in the plural), the dominant heat loss route from the surface is in fact water vapour. “””
I’ve not spent a whole lot of time trying to evaluate all the thermal processes exchanging energy between the surface, and the atmosphere/space, so I am somewhat dependent on what others have claimed them to be. And Phil has cited some of the numbers that Trenberth gives, and which are enshrined in the official NOAA energy balance picorial chart. And I have to say I am quite suspicious of some of Trenberth’s numbers. Well for a start, I disagree totally with the phony construct of dividing the solar insolation by 4, since the relation between incoming flux, and surface temperature reached is non-linear, so that process under values the peak surface temperatures reached and so under-estimates the LWIR emission.
But they cite 390 W/m^2 for the Surface radiation (total). Well that pretty much corresponds to the BB Stefan-Boltzmann value for a 288K black body.
Next they claim that 350 W/m^2 out of that 390 is absorbed by the atmosphere, and a mere 40 W/m^2 escapes via the “atmospheric window”.
I find that difficult to believe that only about 10.25% of the surface LWIR directly escapes.
In addition to the 350 W/m^2 the atmosphere absorbs, they add another 67 from direct solar input, 24 from convection from the surface, and 78 from latent heat of evaporation giving a total of 519 w/m^2 absorbed by the atmosphere from all sources. In my book, the atmosphere could care less what the sources of that energy are; the source makes no difference to the heating of the atmosphere.
Then Trenberth has the atmosphere emitting 324 W/m^2 earthwards, and 195 skywards; and right now, there is no way I can rationalize that. Unless I am just plain stupid, that result has to be totally wrong.
At any level in the lower atmosphere, where the air density is high enough to have a mean free path, shorter than the mean lifetime of the excited states of the GHG molecules, the energy intercepted by atmospheric molecules is mostly transferred to the ordinary atmospheric gases; by collisions, before spontneous decay can occur. That is why I say that the source of the atmospheric absorbed radiation does not matter; in the end it heats N2, O2, and Ar.
So at any level in that region, where the above is true, the ordinary atmospheric gases emit LWIR thermal radiation in an isotropic angular distribution pattern. That means that half of that thermal emission is directed upwards, and half is directed downwards.
Above that emitting layer, the air density and GHG molecular density is lower, and the temperature is lower; while below that emitting layer, the air density is higher and the air temperature is higher (in general; not talking storm conditions here).
So for the air above the layer, and in particular for the GHG molecules, the lower collision frequency, and velocity, due to the lower density and temperature, results in the GHG molecules above, having a NARROWER absorption spectral width, than the GHG molecules in the emitting layer; and fewer GHG molecules. That means that the absorption coefficient for the thinner colder air above is less, due to Doppler and collision frequency being lower. So some of the upwards emission spectrum that previously got absorbed by the sample layer, will now proceed right on through the higher altitude layer, because of the narrower absorption band above.
Conversely, the atmospheric LWIR emission that is directed downwards, now sees a denser and hotter atmospheric layer and a higher density of GHG molecules, so the absorption coefficient for the LWIR is higher the further down the back radiation propagates; so the absorption band gets wider, and re-absorption is more probable for downward directed radiation, than it is for upward.
So at any layer, you start with an even split of upward and downward radiation, and the upward path is favored over the downward path, by a narrowing absorption band, and lower GHG density; compared to the downward path with its increasing Doppler and pressure broadening of the absorption bands.
So someone is going to have to do some heavy arm twisting, to convince me, that the total atmospherioc LWIR radiation is directed preferentially downwards rather than up wards; so I am in complete disagreement with Trenberth on that score.
One other little burr under the saddle is the idea of treating the downward (back radiation) as a “forcing”, as if it was a bonus to be applied to the incoming sunlight of 168 W/m^2 that Trenberth says the surface absorbs.
Well hold on a minute. The solar spectrum radiation from the sun, finds itself mostly impinging on deep oceanic waters; about 73% of the total earth surface; and an even greater percentage of the extra-polar surface area where most of the solar energy arrives; so that energy passes quite deeply into the ocean, with the highest spectral irradiance portions going deepest.
On the other hand, the 324 w/m^2 that Trenberth claims is back radiation that strikes the surface, is LWIR and virtually all of it, is absorbed in the top 10 microns of the ocean surface (mostly), where it contributes little to the total energy of the ocean, but is most likely to cause prompt evaporation from that selectively heated surface film.
So to treat that source as simply a “forcing”, as if it was just an adjustment to soalr flux, is a bogus assumption as far as I can see.
I am not a supporter of Trenberth’s view of earth’s energy budget.
“”” Reed Coray (18:12:52) :
George, sorry. Instead of writing: However, I don’t think your above statement regarding the falsity of Reif’s assertion is INcorrect., I should have written: However, I don’t think your above statement regarding the falsity of Reif’s assertion is correct. “””
Well Reed, my command of the King’s English may not be all that great; but when I read… “”” “A good emitter of radiation is also a good absorber of radiation, and vice versa. “””
…. in my minds eye, that word (A) can be replaced by the word (Any); at least they are not incompatible claims.
But if I was to replace the word (A) with the word (Some); then the two statements are quite incompatible; but now I would say that the statement was correct; as amended.
But then I’m not so confident that the same result holds true for ‘Mercan, as it does for the King’s English.
But your typo did not throw me off balance.
But since we do have plenty of “lay folks” visiting here; I do try to be as pedantically accurate as I can, to avoid miscommunication. Perhaps the experts may find that tedium; I consider it necessary.
“”
George E. Smith (14:55:45) :
Well at a pinch, I can only cite two references that I have here at my desk. The first is from:- “The Infra-Red Handbook.” Edited by William L. Wolfe, ( Profesor of Optical Sciences, University of Arizona, Consultant to Infra-red Inaformation Analysis (IRIA) Center, Environmental Research Institute of Michigan; and George J. Zissis Director Emeritus of IRIA.
The Handbook was prepared for the Office of Naval Research, Department of the Navy, Washington DC. I have the 1985 Revised Ed. …
“”
Well, I suppose Reif takes the cake for the worst textbook I ever had one or more classes from.
Stefan’s law is the integrated result of Planck’s law over angle and wavelengths(or all frequencies). Emissivity as shown in Stefan’s law is an engineering number. However, when dealing with gases rather than solids or liquids that actually have a Planck continuum of emissions, one can use an emissivity as a function of wavelength with the Planck curve to generate an emission spectra. Actually that emissivity is the spectral absorption and the Planck curve actually becomes the distribution of energy states. where a molecule absorbs in the spectra, it emits in the spectra – assuming that the Boltzman (Planck BB curve) distribution for energy actually has molecules at that energy state for the given T. This is your Kirchoff’s law consideration. An equilibrium is necessary, but it is LTE, local thermodynamic equilibrium, which is necessary to have locally uniform temperatures between the various types of molecules, such as IR absorbers and non IR absorbers. Otherwise, there is no single temperature common to the different molecular types.
Another way to put Kirchoff’s law in perspective is the Einstein coefficients. There’s one for absorption, one for spontaneous emission, and one for stimulated emission (like a laser). If you have a gas at temperature T and are illuminating it with a BB curve at temperature T, you will not have absorption lines and you will not have emission lines, but rather you will have the BB curve. If the T of the gas is higher than that of the BB curve, you will have emission lines. If the T of the gas is less, you will have absorption lines.
In this, Kirchoff’s law really does apply assuming the same temperature, gas & BB radiator. (your thermal equilibrium). It is also by wavelength (or frequency) at each and every wavelength.
NOte, an interesting configuration is to take two concentric spheres with an atmosphere between that is very thin so approximately, the spheres have the same surface area and all downward or inward radiation impinges upon the inner sphere. Set the same temperature for both spheres and you will have radiation going between them and absorption and emission by the ‘atmosphere’ shell. It will be in equilibrium and no net energy will be absorbed or emitted. Now, lower the T of the outer shell down – say to 3 kelvins or 0 kelvins. What you have here is a different equilibrium form so that the outer atmosphere at the outer shell is at the same T as the outer shell and the inner shell area atmosphere is at T, just like that shell. You have a gradient or lapse rate in temperature where the T at any point above the inner shell is determined by the conservation of energy (or power flow in and out of a small parcel) and that includes all mechanisms of energy flow.
the Earth must be in a radiative equilibrium – what comes in must go out on the moderately short term. The Sun is in a hydrostatic equilibrium so that gravitation attraction must be balanced by pressure preventing the Sun from collapsing. At the average orbital distance, the top of the atmosphere radiation amounts to around 1365 w/m^2. That varies by about 90 w/m^2 during the year due to perihelion and aphelion distances. The fact that Earth rotates basically provides a fairly uniform distribution of power (for the most part) over practically the entire surface on a 24 hour average. No rotation or slow rotation would have a significant effect, especially on approximations. That’s one of the many huge problems with Venus comparisons.
One can though get far more out of these simplifications and approximations than one might initially imagine.
for Reed Coray.
“”” Thus, the concept that a good emitter is a good absorber does not imply solar panels can’t convert solar radiant energy into electrical energy. “””
Reed, if you read my statement again, I think you will conclude that my example of a case where Reif’s assertion was incorrect, was a case of a solar thermal collector; not a PEV solar panel.
I even went to some pains to explain the general strategy for designing such thermal solar collectors (which I feel is how most solar energy ought to be gathered (as thermal energy))
If in fact one were designing a PEV solar cell panel instead, then it would be desirable to do the exact opposite surface preparation to reject solar spectral wavelengths somewhat longer than the silicon bandgap wavelength (around 900 nm) in order to minimize heating of the solar cell panel, which will lower the efficiency of the solar cells (by dropping their open circuit Voltage, and ncreasing their reverse leakage currents).
Once again a reason why I err on the pedantic side.
When articles start off with the assertion that “greenhouse
gasses keep the Earth 30° C warmer than it would otherwise be without
them in the atmosphere” , I feel there is likely little to
learn from them .
The -30c null hypothesis is based on the
non-physical assuption that the naked earth would absorb with its
observed about 0.7 absorptivity , yet emit as a black body with an
emissivity of 1.0 . This is a non-physical and mathematically
intractable assumption . A far more realistic and mathematically useful
comparison is that we are about 9c warmer that a gray ( flat spectrum )
body in our orbit . Unlike what Marty Hertzberg calls the “cold earth”
hypothesis , the flat spectrum case is orthogonal to the ratio in the
correlations between the earth’s spectrum and that of the half
millionth of the sky the sun subtends and the that of the rest of the
3k celestial sphere which defines the “greenhouse effect” . See my http://CoSy.com for the
computations in several array programming languages .
Spector (16:05:02) :
In my humble view, this is the rock that breaks the CO2 driven AGW hypothesis. It seems completely obvious that effect of each added parcel of CO2 is almost completely masked by the near 100% IR absorption bands from the CO2 that is already in the atmosphere.
In my view, the AGW proponents would have to present *hard* scientific evidence showing that this logarithmically diminishing effect of CO2 was not true if they wanted to re-establish their case.
I think one might easily demonstrate this CO2 masking by using a couple of overlay transparencies – one showing the pre-industrial absorption bands and an overlay showing the effect of the CO2 added in the modern era.
Try this for size: http://i302.photobucket.com/albums/nn107/Sprintstar400/CO2spectra-1.gif
George Smith. If you care to continue writing, I’d be happy to read what you have to say. However, I think I’ve exhausted my “understanding” of “grey body” absorption and “grey body” emission. So, unless a specific point comes up that I’m almost positive I know is incorrect, I’m going to let this subject go. I still believe it is incorrect to use a T^4 law for emission when the emissivity is a function of frequency. Furthermore, although it’s a matter of semantics, I believe a “grey body” is a surface whose absorptivity and emissivity are equal and independent of frequency. The absorptivity/emissivity of a grey body surface may change with time, but at any instant in time, the emissivity and absorptivity are equal. I may be wrong, but as the saying goes: “that’s my story and I’m sticking to it.”
Again, thanks for the stimulating discussion.
My, My, My. What a confused mess this post is. Either David Archibald doesn’t have the slightest grasp of logical consistancy, or he does and his post is deliberately deceptive. You decide.
He begins with the basic point that without any greenhouse gases in the atmosphere the temperature would be 30 DegC colder. This is not contentious, its basic Thermodynamics. And the known logarithmic radiation behaviour of CO2 is also well known.
Then further down he has a dramatic looking graph of Temp change per 20 ppm of CO2 with this line leaping up from it of ‘cumulative’ temperature change for 6 DegC ‘IPCC’ models. Plotting cumulative temp amd temp per ppm on the same graph? How bizarre!. But gee it looks dramatic.
(by the way, the IPCC DOESN’T HAVE any models. It simply reports on the modeling done by research groups around the world. The IPCC is a REPORTING agency).
Then further down we have the corker. A bar graph of cumulative temp due to CO2 (and CO2 alone!) vs CO2 level and then the ‘Anthropogenic’ component based on 6 DegC models from the earlier graph added on. Makes the Anthropogenic part look all rather outlandish doesn’t it?
Bingo. If no one notices, deception complete, the gullible gulled.
So what is wrong with what he has shown?
Notice how his final bar graph shows ‘Natural’ Warming due to CO2 varying from around 2-3 DegC across the graph. WHAT HAPPENED TO THE 30 DEGC RISE? If the Earth would be 30 DegC cooler without any GH gases, what happened to it on David’s graph?
Simple, he has shown the CO2 ONLY component of ‘Natural Warming’ against the TOTAL warming – CO2, Water Vapour, Methane, Ozone, CFC’s, Albedo Change, Aerosols etc for the ‘Anthropogenic Warming’ section. Not comparing apples with apples. And he has taken the most extreme end of the range of models reported by the IPCC of 6 DegC. The middle of their range is more like 3 DegC.
So, to make his last graph more realistic, it should show the impact of all the factors. At which point his ‘Natural’ warming would be around 30 DegC high. And the ‘Anthropogenic’ component would then rise another 3 Deg C.
The problem for David is that that would be far more accurate but it wouldn’t be dramatic. It might even show that the ‘IPCC’s models are actually consistant with the logarithmic nature of CO2. And he doesn’t want that does he?
Then there is this gem: “The IPCC models water vapour-driven positive feedback as starting from the pre-industrial level. Somehow the carbon dioxide below the pre-industrial level does not cause this water vapour-driven positive feedback. If their water vapour feedback is a linear relationship with carbon dioxide, then we should have seen over 2° C of warming by now. We are told that the Earth warmed by 0.7° C over the 20th Century.” WRONG!!
The models (not the IPCC’s as I pointed out) model water vapour – period. Nothing to do with pre or post-industrial levels. Then he says “we should have seen over 2° C of warming BY NOW” (my highlight).
WRONG! He is trying to sell the line that the warming associated with a certain level of CO2 should all have happened RIGHT AWAY. The models do predict warming of around 2° C from current levels of CO2. But even if CO2 levels where frozen right here it would still be several decades before we reached 2° C. The oceans are still absorbing vast amounts of heat and are lagging behind in the warming. And the 2° C figure is based on the warming impacts of the GH gases. It doesn’t include the countervailing cooling effects of Aerosols (air pollution) – Climate scientists believe around 1/2 the extra warming from GH gases is being masked by the cooling effect of aerosols. So, in a few decades time when humanity has, hopefully, stopped producing air pollution then 2° C seems like dead certainty. Thats why the climate scientists are using the word ‘commitment’ for this rise. Its already locked in and in play. David doesn’t mention any of this.
Finally note David’s reference to weather in his home town of Perth. Don’t look at the world wide, the global picture. Instead have a look at what’s happening in your backyard! Again, wrong thinking.
And by the way David, as a fellow Aussie, over in Melbourne we have seen temperature rise, prolonged drought and terrible bushfires. Did you ever consider that the local climate in Perth may be more affected by the fact that all you weather comes from off the Indian Ocean and may not change as much as regions whose weather is generated over land – local factors producing local outcomes. The Global in AGW means just that. Local can’t be used to judge anything.
So to summarise, David has presented data which as far as I can tell is factually correct. But he has presented it in distorting and ultimately deceptive ways, has not compared apples with apples, has attempted to make an argument by ignoring factors necessary to that argument, has appealed to you to use inappropriate short term thinking and localised ‘my backyard’ thinking.
And he is making the nonsense assertion that ‘The IPCC’ is claiming that ‘Natural Warming’ from Natural CO2 is sooo different from ‘Athropogenic Warming’ from Anthropogenic CO2.
See, if the IPCC and the Warmists can be shown to make such ridiculous claims, surely we can dismiss it all.
But as I have attempted to show here, it is David who has made the ridiculous claim by using lousy and distorting methods and faultu logic to create a false perception in the minds of the readers of his post.
And go back through all the comments on this post. Look at the praise for what David has said. He has achieved his goal.
The gullible gulled!
So, David Archibald. Innocent Fool? Or Smart Nasty Con Man?
You decide?
Mr Archibald,
I find that it is not shown in your essay that an additional injection of C02, into the atmosphere, will either:
1) be a permanent new higher atmospheric CO2 concentration [i.e. at concentration equilibrium]
or
2) cause [whether the new concentration is at equilibrium or not] a logarithmic [or linear or anything in between] increase in atmosphere temperature [either at thermodynamic equilibrium or not].
I see only assertions and/or assumptions that it does.
If you know of any place where it has be shown then please advise. I sincerely wish to understand.
John
Glenn Tamblyn;
The oceans are still absorbing vast amounts of heat and are lagging behind in the warming>>
The argo buoys have been sampling ocean heat for four years now and show a decline in each year. That’s some lag.
Glenn Tamblyn (19:25:01),
Since you gave the rest of us “gullible gulled” the choice to decide whether David Archibald is either an Innocent Fool or a Smart Nasty Con Man, the response of this gullible reader would be neither. David Archibald has written an interesting article, and those two choices are not a sufficient critique. You could have asked him questions directly, and let the rest of us think about the different viewpoints.
My suggestion would be for you to write your own article for WUWT, explaining the situation as you see it.
Because you stated that “David has presented data which as far as I can tell is factually correct,” it could be interesting. But of course, you would be opening yourself to the same pot shots that Archibald and the rest of us gullible folks just got from you.
Also, since Archibald used Willis Eschenbach’s charts, you should consider yourself fortunate that you didn’t level your critique against Willis instead. Smart move.
George E. Smith (18:24:32) :
And I have to say I am quite suspicious of some of Trenberth’s numbers. Well for a start, I disagree totally with the phony construct of dividing the solar insolation by 4, since the relation between incoming flux, and surface temperature reached is non-linear, so that process under values the peak surface temperatures reached and so under-estimates the LWIR emission.
The division by 4 is necessary to determine the average incoming flux at the surface, if you wanted to calculate the local intensity you could scale by cos() but if you integrate over the whole surface you’d still end up with a factor of 4.
But they cite 390 W/m^2 for the Surface radiation (total). Well that pretty much corresponds to the BB Stefan-Boltzmann value for a 288K black body.
Next they claim that 350 W/m^2 out of that 390 is absorbed by the atmosphere, and a mere 40 W/m^2 escapes via the “atmospheric window”.
I find that difficult to believe that only about 10.25% of the surface LWIR directly escapes.
It’s ‘atmosphere + clouds’, average coverage 62% iirc.
In addition to the 350 W/m^2 the atmosphere absorbs, they add another 67 from direct solar input, 24 from convection from the surface, and 78 from latent heat of evaporation giving a total of 519 w/m^2 absorbed by the atmosphere from all sources. In my book, the atmosphere could care less what the sources of that energy are; the source makes no difference to the heating of the atmosphere.
Then Trenberth has the atmosphere emitting 324 W/m^2 earthwards, and 195 skywards; and right now, there is no way I can rationalize that. Unless I am just plain stupid, that result has to be totally wrong.
You’re not stupid but some ‘minor arm twisting’ is in order. 😉 Again it’s ‘atmosphere + cloud’, for your conundrum consider that the base of the clouds are appreciably cooler than the cloudtops.
Something that doesn’t make sense about the believers in dangerous manmade co2 is why do they come here? The science is settled. Take it easy. Put up your feet boys. Forget about defending the ‘settled science’.
Let the science, the data, do the talking.
But wait—the data is doing the talking and showing your predictions from your computer climate models are wrong.
And also, you don’t include the negative feedback from clouds in those computer models. That factor alone shows how wrong you all are.
With that, I can see why you boys are here, and everywhere else in the media, trying to convince everyone to not believe the data that shows you are wrong.
James F. Evans (12:43:34) :
@ur momisugly Henry Pool
Thanks for the reply.
What your reply suggests in a rough and preliminary way is that at 388 parts per million we still have a large & substantial amount of cushion to work with before reaching an upper limit of CO2.
And, if CO2 parts per million has gone up 100 parts or so in the last 150 years, then at this juncture there is no looming crisis.
So, what we need is a refinement and increased resolution of that upper limit of CO2.
This would seem a more clear-cut objective than splitting hairs about whether 395 parts per million of CO2 or 360 parts per million CO2 makes a difference.
And, puts the endeavor more in a pure science realm as opposed to the current situation where political agendas have corrupted the science
Henry@ur momisuglyJames
We agreed that the safe working limit of CO2 is 0.75% or 7500 ppm. This is what the books are saying.
we know that up to 1000 -2000 ppm (0.1.-0.2% ) would be advantageous for life,
promoting crop- and forest growth, provided we can prove beyond doubt that CO2 has little or no real warming effect. We are now at 400ppm or 0.04%. Which brings me back to the beginning:
@ur momisugly David Archibald
Sorry, but I am not sure where this information comes from that
“Carbon dioxide contributes 10% of the effect ”
first of all, how do we know for sure that CO2 is a greenhouse gas?
The trick they used (to convince us) is to put a light bulb on a vessel with 100% CO2.
But that is not the right kind of testing.
You must look at the spectral data. Then you will notice that CO2 has absorption in the 14-15 um range causing some warming (by re-radiating earthshine) but it also has a number of absorptions in the 0-5 um range causing cooling (by re-radiating sunshine). So how much cooling and how much warming is caused by the CO2? How was the experiment done to determine this and where are the test results? If it has not been done, why don’t we just sue the oil companies to do this research? (I am afraid that simple heat retention testing will not work here, we have to use real sunshine and real earthshine to determine the effect in W/m3 [0.04]CO2/24hours)
Noelene (16:29:41)
Good question, Noelene. The Carbon Dioxide Information Analysis Center (CDIAC) has this as well as other information. Look here for for carbon data, and here for emissions data. They describe the methods they use.
All the best,
w.