9,25 – a factor that could close the global warming debate
Guest post by Frank Lansner (hidethedecline)
The CO2-sensitivity describes the warming effect induced by a doubling of the CO2 concentration in the atmosphere, and is thus the epicentre of the global warming discussion. Estimates of the CO2 sensitivity are very different, and the value range used by IPCC appears unlikely to physically impossible. To show this, I will focus on the factor “Fw” between the total CO2 warming and then the warming from a single doubling of CO2 concentration.
The total CO2 warming effect is obviously many times bigger than the warming from a single CO2 doubling. Example: When changing CO2 concentration from 5 ppm to 320 ppm we have 6 doublings. But on top of these 6 doublings, how much warming effect is introduced when CO2 concentrations are changed from 0 to 5 ppm etc? In the following I use the online model MODTRAN:
Fig. 1. Above is illustrated the warming effect of CO2 for 3 different climatic areas. Zero W/M2 represents the net forcing of the atmosphere fore a given scenario with CO2 concentration set to 0 ppm.
For each area is shown a clear sky scenario as well as a light rain scenario. All other variables in MODTRAN are left as the default values. The results from MODTRAN are total atmosphere outgoing radiation, and thus when changing concentrations of CO2 we get total atmosphere responses incl feedbacks if present.
Fig 1 Shows 6 doublings of CO2 concentration: 5-10-20-40-80-160-320 ppm where every doubling shows warming effect of similar size (–as could be expected due to the logarithmic declining effect of adding more CO2 to the atmosphere).
From the graph above we can see that the total CO2 warming effect today equals around 9 times the warming effect of one doubling of CO2 concentration.
Fig 2. For a better compare between the scenarios on fig1, these are now shown as %-values of the total CO2 warming effect for (Forcing) with today’s concentration of 390 ppm CO2, equals 100%. It appears that clear sky, rainy sky, Arctic area, tropics, subtropics scenarios has a very similar profile indeed and I find that this result shows that we can consider these %-trends to be rather global.
Fig 3. The average global CO2-doubling can now be calculated more accurate to be near 10,8% of the full CO2 warming effect at 390 ppm. (Or, the “CO2-sensitivity” warming effect is around 10,8% of the total CO2 warming effect, globally.)
Thus, the “best estimate” of the factor between total CO2 warming effect and the warming effect from one CO2 doubling – Fw – can be calculated. Best estimate (so far) Fw = 9,25.
CO2-warming-total (K) = 9,25 * CO2-warming-from-one-doubling (K) = 9,25 * CO2 sensitivity (K)
I have used MODTRAN for this result, but it is universal that the doublings must have near same warming effect and thus the individual doubling will have just some fraction of the total value. For now, the factor 9,25 is best estimate.
Hansen – CO2 sensitivity.
Now how does the factor 9,25 between total CO2 warming effect and CO2 warming effect from a single doubling support the viewpoints of James Hansen on CO2 sensitivity?
James Hansen often refers to a CO2-sensitivity of 6 K… 6 K warming effect for each single CO2 doubling:
Fig 4 James Hansens CO2 sensitivity of 6 K gives around 55,5 K of total CO2 effect using the factor Fw = 9,25. As the total warming effect of all greenhouse gasses is assumed to have a warming effect of approx 33 K, the Hansen CO2-sensitivity demands that the total CO2 related warming effect is bigger than all the greenhouse gasses effect combined.
The overall CO2 warming effect is supposed to be around 10-15-2% of the total warming effect of the atmosphere, here we use 15%. Since CO2 is assumed to account for 15% of the total 33K greenhouse effect on Earth, the CO2 total warming effect is around 5 K. So just ONE CO2 doubling of Hansen’s CO2 sensitivity of 6 K has a bigger warming effect than the total warming effect supposed to be possible.
It is therefore highly odd that Hansen’s claim of 6 K CO2 sensitivity has been taken seriously anywhere at any time.
Here the “greenhouse wheel” (see WUWT post Wheel! – – Of! – – Silly!) where supposedly scientists imagine that we by year 2100 can have warming of over 7 K in fact with less than one CO2 doubling to cause this:
Fig 5. To account for their 7 K temperature increase, they must have played with a CO2-sensitivity of perhaps 10 K? So these honourable “scientists” believes that one CO2-doubling might resemble a third of the combined earth greenhouse effect?
IPCC – CO2 sensitivity
Then, how does the factor 9,25 between total CO2 warming effect and CO2 warming effect from a single doubling support the viewpoints of IPCC on CO2 sensitivity?
IPCC AR4 viewpoints for the CO2 sensitivity :
http://en.wikipedia.org/wiki/Climate_sensitivity
IPCC “best estimate” of warming from one CO2 doubling is 3 K.
Using the Fw = 9,25 we learn, that if one doubling warms 3 Km then the total CO2 warming should be around 28 K ( = 9,25 * 3 )
We must then remember again that the total warming effect of the atmosphere is generally accepted to be near 33 K. The warming effect related to CO2 should then be around 85% of the total Earth atmosphere greenhouse gas effect. And without CO2, the atmospheres warming effect should be reduced to 15% of todays atmosphere…. On a globe with mostly water-ocean surface…
The IPCC numbers where each doubling of CO2 represents 3 K it simply does not fit at all with the total warming effect of the atmosphere.
IPCC then claimed:
“Values substantially higher than 4.5°C cannot be excluded..”
Well, 4,5 K for CO2 sensitivity gives a total CO2 effect of 41,6 K. This is 126% of the total earth greenhouse effect, so we could rephrase:
IPCC:
“Values of CO2 related warming substantially higher than 126% of the total greenhouse gas warming cannot be excluded..” …
Idso´s and Lindzens estimates for CO2 sensitivity.
What if we assume that CO2 is responsible for the 15% of the 33K greenhouse warming effect on Earth? This corresponds to 5 K. If true, the CO2 warming from one doubling should be
CO2 sensitivity = CO2warming-total / Fw
CO2 sensitivity = 5K / 9,25 = 0,54 K
So just using the generally accepted knowledge that CO2 sholuld account for around 15% of the total Earth greenhouse effect, and using the also generally accepted knowledge that total Earth greenhouse effect is 33K, then the CO2 sensitivity should be near 0,54K
Idso 1998 suggests 0,4 K, and Lindzen suggests 0,5 K these results appears sound and realistic in strong contrast to values from IPCC and Hansen.
Hansens 350 ppm ”safe level”
Fig 6. When working with CO2 – effect, one cant help wondering what Hansens ”safe level” of 350 ppm CO2 is all about.
Fig 7. NASA´s, James Hansen has claimed 350 ppm to be a safe level of CO2:
– Just 1,5 % less Warming effect from CO2 and we are “safe”.. ?
If CO2 has a total warming effect of 5 K – as previously calculated – the difference between the Hansen “safe level” CO2 warming and todays level is around 0,075 K.
I wonder if the peoble creating the 350 ppm demonstrations knows this?
I wonder how they will react when they find out.
Idso 1998:
http://www.int-res.com/articles/cr/10/c010p069.pdf
MODTRAN:
http://geoflop.uchicago.edu/forecast/docs/Projects/modtran.orig.html
A nice history of source.. and you can see all the contributors to IR signature ( like glint which I forgot about, and earthshine etc );
Problem is the calibration is based on primitive and incorrect assumptions ie incorrect sign in say the “atmospheric window” eg Platnick and Fontenla 2006
Satellite measurements at wavelengths of light corresponding to about 3.7
pm have been exploited for almost three decades. Radiation near this wavelength
(which includes both solar energy and energy emitted by the Earth‘s surface and
atmosphere) occurs in a so-called ”atmospheric window” where the atmosphere
is relatively transparent to such light. Applications are primarily related to cloud
studies, including cloud detectio4 cloud thermodynamic phase, and quantitative
cloud particle size retrievals….
….Fundamentally, cloud information is derived by first converting the
measured signal into a reflectance quantity. Conversion of calibrated 3.7 pm
channel measurements (in radiance units) to reflectance requires knowledge of
the incoming solar energy (specifically the irradiance) in this spectral region.
Despite the ubiquity of 3.7 pm channels, absolute solar spectral irradiance data
comes from either a single measurement campaign in 1969 or models that predict
the solar irradiance spectrum.
In this study, we compare historical 3.7 ,um band spectral irradiance data sets
with the new semi-empirical solar model of the quiet-Sun by Fontenla et al.
(2006). The model has expected uncertainties of about 2% in the 3.7pm spectral
region. We find that 3.7 ,um channel-averaged spectral irradiances using the
Thekaekara et al. observations or previous solar models differ from the new
model by -1.5 to +4.1%
As MODTRAN5 included the Fontenla quiet sun spectrum one would think this would improve the spectral resolution,however the sun also showed it is not constrained by deterministic conjecture and the variance (and error) increased in the declining phase of sc23.
The implications are quite clear in say the cloud fraction where no model has any statistical agreement with the annular datasets, or the seasonal amplitude eg Probst et al.2010.
As HadSM3 performed worst in comparison with observations,and has problematic issues with scaling heights and stratospheric humidity eg Shine et al 2010 it is legitimate to question how certain are when uncertainties are certain, or to put it another way does the Irreducibility of Uncertainty, provide evidence of the certainty of Irreducibility.
Russ – Obviously all doublings cannot have the same huge warming effect incl feedbacks. By showing that pure CO2 effect has 9,25 “doublings” of total effect, this becomes very clear – and I think this information is very relevant.
With this knowledge its very clear that IPCC and Hansen presumes that feedbacks associated with CO2 warming NOW in the present CO2 doubling must be far far stronger than any warming feedbacks related to the rest of the doublings.
This makes it legitimate to ask: What is it about the present CO2 doubling that is so very very extraordinar compared to other doublings. With what evidence can you claim the feedbacks for the present doubling is many times bigger than for other doubling? (Because i showed that they have to be).
K.R. Frank
Thanks Frank,
Other doublings of CO2 could have more or less total temperature impact than the present doubling due to the influence of other gases, as well as various feedback factors (both positive and negative) either entering their effective ranges or reaching their respective limitations.
I don’t have any particular reason that this specific CO2 doubling should have a greater or lesser temperature impact than other prior or subsequent doublings. All I can say for certain is… it’ll be complicated.
Well I am somewhat familiar with the logarithm function; either in the mathematical form:-
ln(z) = (z-1) – (z-1)^2/2 + (z-1)^3/3 + …etc or many other forms.
I’m also familiar with some physical processes that follow the logarithm function in some way. Until recently we all believed that the elapsed time during which a radioactive substance has been decaying was proportional to the logarithm of the fraction of the original material which still exists. Nowadays it depends on what Leif Svalgaard is up to; becasue of solar neutrinos.
The logarithm of the charge remaining on a previously charged capacitor that is shunted by a resistor, also is proportional to the elapsed time.
The Forward Voltage of a semiconductor diode; at some fixed Temperature is roughly proportional to the logarithm of the forward current over a number of decades of current. Even then it isn’t quite that simple; because that current typically consists of a recombination current, and a diffusion current; and the slope of the logarithmic curve is q/2kT for the recombination current; but q/kT for the diffusion current; where q is the electron charge and k is Boltzmann’s constant.
So there are a few well understood physical processes where the observed data matches some form of logarithmic relationship to a very high degree of accuracy.
So now comes another basically very simple physical problem; the relationship between the mean global Temperature of the earth ( just exactly where nobody knows) and the logarithm of the atmospheric CO2 abundance; and of course we all know how well mixed the atmospheric CO2 is so no matter where or when you measure it on planet earth you always get the exact same value; well as a molecular fraction of the local atmosphere of course. For reasons known only to Chemists and Climatologists; this is always referred to as ppmv, even though nobody has any idea what volume they are referring to. Counting molecules does not seem to have occurred to anybody in these disciplines yet.
Now the beautiful thing is that this same logarithmic relationship occurs, if instead of measuring the wherever Temperature, you instead measure the “forcing”; that being some measure of the LWIR radiation that is emitted from the surface or wherever on planet earth; and that “forcing” should itself follow some sort of fourth power of the actual wherever it is Temperature; which of course the CO2 is then going to change; due to the greenhouse effect.
The really clever thing about this well known logarithmic relationship is that it always applies no matter what model of the atmosphere you call on. It applies simply to the effect of CO2 alone; but it also applies (as a function of CO2 doubling) if you have some other GHG like CH4 orO3 or even H2O in the atmosphere.
The relationship function remains logartihmic through thick and thin; only the slope of the logarithmic function changes; no matter how complex the atmospheric components get. This is especially illuminating in the case of H2O; because in the case of global atmospheric conditions; it is extremely common to have from place to place, and from time to time the local Temperature can go through the value Zero deg C or about 273.16 Kelvins. If this should happen where the atmospheric pressure is roughly one standard atmosphere, and there is any H2O in the system; then a remarkably non linear discontinuity occurs, and the water (H2O) can change discontinuously from a vapor in the atmopshere to a liquid or even a solid, and perhaps manifest itself in some new physical form such as clouds; and yet despite all of these perfectly natural phenomena; that happen all the time; the logarithmic connection to the amount of CO2 does not change; well maybe the slope of the curve changes much like the recombination versus diffusion currents in the semi-conductor diode; but absolutely nothing ever disturbs that logarithmic relationship; so regardless of these changes; or irregardless as the case may be; we can still talk about the climate sensitivity to a doubling of the CO2 (JUST THE CO2) . Nothing else matters of course; simply doubling the CO2 in the presence of all those other effects; causes some fixed change in either the Temperature or the W/m^2 “Forcing” or whatever; and maybe the slope will change; but the logarithmic relationship remains robust no matter how simple or how complex the atmospheric condition becomes.
Well assuming that you are still reading this; some of you might be wondering how this system is so robust; despite the fact that so far we cannot model it properly in such a way that future changes can be predicted; or even projected. So robust is this logarithmic relationship for “climate sensitivity” that it doesn’t even matter what the time relationship is between measurement of the CO2 and measurement of the Temperature or the “Forcing”. Go forward or backward in time and it makes no difference to the logarithmic relationship; other than maybe changing the value (slope) of the “Climate sensitivity”.
The complexity of this very simple concept; is one reason why we do not have a definitive curve of either “forcing” or global mean wherever Temperature against the logarithm of the atmospheric CO2 abundance either for the most recent 1/3rd of a CO2 doubling that has been observed; or for the past five or so doublings^-1 that have occurred since the Pre-Cambrian era; based on proxies for those parameters.
But take my word for it; the relationship is truly logarithmic; no matter what.
All this squabbling over what exact effect doubling CO2 has at the 350 ppm level on global temperatures ignores the elephant in the room–both elevated temps and elevated CO2 have proven BENEFITS for plant and animal life.
Ultimately, we do want to know this detail about the climatology of our world. But test-tube studies do not have all the feedback mechanisms of the real live planet Earth. Examination of long-term CO2 and temp records suggest that feedbacks totally cancel the CO2 effect on temps. Of course, that assumes that all or most of our scientists were honest and reasonably accurate in their reported data AND, more critically, the the general assumptions made in the entire paleoclimatology community are considerably mre valid than those of the CRU community.
If you take half the present CO2 you get something like the value in the ice ages. The temperature with half the current CO2 was about 5 K less than now, so you could argue that the last doubling had at least 5 K warming. Why should the next one be significantly less? There is still some snow/ice left to melt to contribute to positive albedo feedback. This example shows that you can’t treat each doubling the same, because there are other variables than CO2.
Also, the last time earth had this much CO2 was in the pre-glacial eras when Greenland had no ice sheet, so it is not really an interglacial in the normal sense any more, I would suggest, because the glacials are probably done with for a while.
Frank Lansner says:
September 9, 2010 at 1:10 pm
…
This makes it legitimate to ask: What is it about the present CO2 doubling that is so very very extraordinar compared to other doublings. With what evidence can you claim the feedbacks for the present doubling is many times bigger than for other doubling? (Because i showed that they have to be).
K.R. Frank
And you did a very fine job of showing exactly that!
That is so preposterous to think there were no (or different) feedbacks last doubling(s), or last century but now has somehow morphed so large that any proper scientists would just bow out at this point and accept the impossibility. But I doubt they will, and so I will continue to refuse to mention them without putting “scientist” in quotes. They probably don’t even deserve so much.
I have taken Dr. Spencer’s simple model and re-written the spreadsheet until I could understand it’s basics and then re-wrote that as a bona fide program so I can easily extend it any amount of time any parameters (even 800,000 years if curious, but it then does crawl) with any feedbacks or lingering effects, radiative and non-radiative as Dr. Spencer points out, and I finally see exactly what you and Dr. Spencer are saying of these feedbacks. The current model are unrealistic, they don’t match the real world data.
I will be curious in the next few years (I hope) to learn what is causing some the effects that are happening as the AMSU data points out, not following co2’s “proven” effects. That very thing keeps haunting me, and I wrote on this above, could it be that co2 has no effect at all after the optical thickness causes all initial radiation from the surface (not inter-atmosphere) to guarantee capture at least once. The warmist sites I visit do not want to even bring up the concept that thermalization and the re-spread across the spectrum every absorption even exists. That seems to be a key. Look very carefully at a spectrum from the surface upward and one from 20 km downward. See the pretty wide “window” where little is interacting. If I’m correct by the second or third bounce the statistical chance of absorption is near zero. Say the initial chance to hit the 13-16.5 µm band of all IR frequencies is 0.30. on second after thermalization and spread the chance of not hitting the “window” is 0.30^2 or 0.09, third is 0.09*0.30 or 0.03. hope you can make sense of that, I’m not very good at conveying my thoughts sometimes.
Now, what if you add a few (co2 doubling) of absorbers. Of course I realize this would apply to h2o too and there is even some crossing from water to co2 in those bands. By that most of a ghg’s effect occurs in the 3-6 or so doublings. That what would cause the double logarithmic that I mentioned above. If you see this as real and can write an article on it, have at it, I would destroy the concept with my words, your much better.
Once again, I thoroughly enjoyed you article!
Jim D says:
September 9, 2010 at 6:08 pm
If you take half the present CO2 you get something like the value in the ice ages. The temperature with half the current CO2 was about 5 K less than now, so you could argue that the last doubling had at least 5 K warming. Why should the next one be significantly less? There is still some snow/ice left to melt to contribute to positive albedo feedback. This example shows that you can’t treat each doubling the same, because there are other variables than CO2.
Also, the last time earth had this much CO2 was in the pre-glacial eras when Greenland had no ice sheet, so it is not really an interglacial in the normal sense any more, I would suggest, because the glacials are probably done with for a while.
———-
Jim D, CO2 changes from 280 ppm at the height of the interglacials to about 185 ppm at the deepest period of the glacials. That should only be -1.8C for GHGs while the global temperature declined by -5.0C. So, the maximum effect for CO2/GHGs is only 35% of the total temperature change.
Greenland’s ice-sheet developed only 2.5 million years ago (CO2 280 ppm). This was the CO2 level for about the last 24.0 million years so CO2 didn’t cause it. How about Greenland moving about 300 kms north due to continental drift over that period instead?
The problem with climate science and those that believe in it is that they refuse to review the actual climate and CO2 history.
Steven Mosher (Sept. 9, 7:00AM 2010)
Busy here but your lengthy response deserves a reply. After reading it several times I have to come to the conclusion its made up goobbledygook. Heres why:
1. Your assertion that skin temperature is an issue is nonsense. The F117 was designed from the ground up with radar(radio) in mind. Radar is not IR. The wavelengths used are much longer, reflection is the key. Modtran is irrelevant.
The only concern with IR is heat seekers, so the F117A’s twin GE404 turbofans vent through thin horizontal nozzles that spread out the heat. The engines generate the only concern for heat not the skin! You say “Long ago ( like when the F117 was built) we could only predict the returns from flat surfaces and we could only build flat surfaces ( of RAm material)”. The use of Ram material or radar-absorptive mesh is also used to shield parts of the plane from radio (radar) reflection. So what is this “returns from flat surfaces”? IR is not the issue. IR given off by the skin of a plane is irrelevant to its survivability. When faced with a heat seeker speed and agility may save you but most certainly not MODTRAN (lol).
2. As you state the only reason Modtran is required because the airforce holds some patents on it. Sounds like a business decision. The truth of the matter is that it is NOT required to build a successful jet fighter. The only thing required is good engineers.
3. You say “Well, the calculations are used throughout the design process.” I say baloney.
4. We really go wacky when remote sensing is dealt with. You say “well any sensor in the sky or space needs to understand what the atmosphere does to the signal.” A sensor does not NEED to understand anything! Then you say “If you emit signal X at the ground hows that get modulated by the stuff between the sensor and the source. Going backwards, if you receive a signal that looks like Y, what does the source actually look like? So tell me how does a signal get modulated by the atmosphere and what is this stuff you talk about? If you receive a signal that looks like y? Are you kidding?
5. “Lowtran stuff started in the mid seventies ( as I recall) which was before my watch. in the 70s, the drive to incorporate all aspect broadband stealth became paramount. hence the F117, B2, F22.
Make sense?” I’d like to see proof of this lowtran, and no, Steven Mosher, you do not make sense.
Bill Illis,
Yes, the point was that other factors are too important to neglect, which is what is being done when one assumes each doubling has the same effect. In the case of the doubling from 190 to 380, ice albedo feedback helped raise the effect to 5 degrees. Going from 380 to 760, ice albedo feedback would be less, but water vapor feedback remains. You can’t rule out 3 degrees.
From what I saw, CO2 was declining gradually (possibly due to chemical weathering and natural sequestration) at 5-10 ppm per million years in the 100 million years before the Ice Ages (as earth was coincidentally cooling) , and it wasn’t till 15-20 million years ago that it dropped below 400 ppm, at which time Greenland was not covered with glaciers. [300 km is not even 20% of the size of Greenland, so I doubt that accounts for much.] CO2 finally reached 280 ppm by 2.4 million years ago when the Ice Ages began with Greenland freezing over. 280 was a kind of tipping point for Ice Ages to exist.
Jim D says:
September 9, 2010 at 8:28 pm
Bill Illis,
Yes, the point was that other factors are too important to neglect, which is what is being done when one assumes each doubling has the same effect. In the case of the doubling from 190 to 380, ice albedo feedback helped raise the effect to 5 degrees. Going from 380 to 760, ice albedo feedback would be less, but water vapor feedback remains. You can’t rule out 3 degrees.
From what I saw, CO2 was declining gradually (possibly due to chemical weathering and natural sequestration) at 5-10 ppm per million years in the 100 million years before the Ice Ages (as earth was coincidentally cooling) , and it wasn’t till 15-20 million years ago that it dropped below 400 ppm, at which time Greenland was not covered with glaciers. [300 km is not even 20% of the size of Greenland, so I doubt that accounts for much.] CO2 finally reached 280 ppm by 2.4 million years ago when the Ice Ages began with Greenland freezing over. 280 was a kind of tipping point for Ice Ages to exist.
Oh come on. The ellipitical orbit of the earth has nothing to do with it? And show me your references for the alledged 5 degree increase. Ice has a significant effect when it covers Canada and Minnesota, but next to nothing at the poles. And if you sum NH and SH polar ice coverage (albedo is unaffected by thickness), it was hasn’t changed, so no effect of albedo over the satellite era when CO2 went up ~[100 ppm].
Frank,
Thanks for the interesting post.
I was wondering you take on Gavin’s recent paper.
http://pubs.giss.nasa.gov/docs/notyet/inpress_Schmidt_et_al.pdf
Several times here (at WUWT) , Phil has offered, that the CO2-Temperature relationship is linear for small amounts of CO2; then logarithmic for medium amounts of CO2; and then square root for large amounts of CO2.
As a physicist ; that leaves me asking; what was it about the Physics that changed, to change the relationship. The answer of course is that nothing about the Physics changed at all; because none of those formulas are tied in to the Physics of why CO2 would raise the surface temperature of the earth; there’s no scientific justification for any of them.
Now that does not mean that you can’t take some sets of data on Temperatures and CO2 and curve fit to try and get some calculated curve to track with the data.
But curve fitting is really only useful to allow estimation of values at (data) locations that have never been measured; by interpolation between points that have been measured.
It certainly seems perfectly reasonable that at small CO2 concentrations, the effects could fit a straight line; and that eventually the data would stray off that straight line; ie the graph becomes non-linear.
But it is a far cry from saying that a relationship is non-linear, to saying that the result is logarithmic. Just because it may take increasing amounts of CO2 to create a temperature change at higher levels; is no justification for saying it is logarithmic; which is a very specific mathematical function. When Physical relationships truly do plot as logarithmic relationships; it is usually a solid clue that some very simple basic Physical (or chemical) process is involved in the effect. A different situation would be the case of the Mauna Loa CO2 data, which shows an upturn in recent years; it has gone non-linear.
That is no cause to jump to the unwarranted conclusion that the relationship is exponential. It might be just a long time constant transition between one linear rate, and another higher linear rate. To call it exponential is to imply that there is a causal process that makes the relationship exponential. There probably isn’t.
But we now have several generations of climate “scientists” who have been taught, and are absolutely convinced, that Temperature (of the earth) is proportional to the logarithm of the atmospheric CO2.
If that were true; then the very smallest amounts of atmopsheric CO2 would have had the greatest effect.
Frank here, has plotted the forcing; which evidently is identical to the Temperature change; despite the Stefan-Boltzmann relationship for CO2 down to 5 ppmv.
So just when did earth have only 5 ppmv of atmospheric CO2; for that matter, when did it have only 160 ppmv.
If we are to believe the logarithmic doubling sensitivity mantra, then the change in atmospheric CO2 from 4 ppmv to 5 ppmv must have created all manner of chaos on earth.
Now I should throw in here the legal disclaimer: I am NOT among those who try to argue that CO2 can’t possibly warm the atmosphere; that is plain silly; as is the argument that CO2 is such a tiny trace amount; so how could it possibly do anything. That too is plain silly. Pure single crystal Silicon has an atomic density of about 5.00 x 10^22 atoms per cc; Germanium is 4.42 x 10^22, so not much in it for those two materials.
It is very common that semiconductor devices; such as CMOS integrated circuits that power our computers, so we can all meet and greet like this; are typically doped in the range of 10^15 to 10^18 atoms per CC of dopant impurities; Boron or Phosphorous often. So that is one part in 50,000 at the 10^18 level, or 20 ppm. Now in contact areas; you might get up into the 10^19 range which is 200 ppm.
So all of modern technology is resting on piddling little trace constituents like that; which make the CO2 laden atmosphere look like a veritable trash heap; compared to silicon semi-conductor devices.
But that said; what is the CO2 really accomplishing. All the books say that high clouds make it warm at night and the higher the clouds the warmer it gets at night; Positive feedback for sure ?
Well there’s two things (at least) we should keep in mind. #1 the LWIR radiation that is intercepted by CO2 or H2O or clouds is NOT detectable by humans, without sophisticated instrumentation. So it most certainly is not capable of warming us.
# 2 ; Anyone who has spent a night in a dry desert; say in Mojave California, knows full well that the temperature plummets at night. Mojave is so dry (the town) that airlines from all over the world have stacked up hundreds and hundreds of perfectly good usable Commerical airliners, at the Mojave airport; because they can store them there out in the open, and they don’t rust away. So when business picks up they can put some of them back into service.
But back to those plummeting Temperatures; what is the message ?
Well the message is that CO2, which is all still there at Mojave isn’t capable of doing a darn thing about stopping the Temperature from plummeting at night; we can’t feel the radiation from the CO2 anyway, so even if it were massively absorbing energy; we would never feel it.
So why do we feel warm on those high cloudy balmy evenings ? IT’S THE WATER !! Those high clouds are there, because during the day, it was even hotter than it is at night and there was plenty of moisture around to both form the clouds, when the moisture rises up to the dew point elevation; and also that humid air is what is stopping us from cooling our skin by evaporation of sweat from our skin; that is why WE feel warm; our cooling system is shut off by the moist air. No we can’t feel the LWIR radiation being sent back by the water vapor either. The heat that we feel was supplied during the day by the sun; it is not supplied at night by the atmosphere.
During the day; the GHG absorption is certainly capturing LWIR emitted from the hot/warm surface, and it delays the exit of that radiation as a result of that absorption and re-radiation (from the atmosphere) process. During that delay time, old sol is continuing to pour in more energy; and it is that solar insolation rate; times the mean propagation delay of the LWIR exit process that creates the GHG warming.
But at night in most places; the sun does not shine; so there isn’t any extra solar input at night to warm the place because of GHG capture delays.
Yes I firmly believe that CO2 is a GHG and that despite its scarcity in the atmosphere it does capture LWIR emissions and tend to allow the sun to warm the surface a bit more. How much as to doublings whether a big doubling from 390 to 780 ppmv or a small one from 5 ppm to 10 ppm; is somewhat irrelevent; because in the end; the water cycle takes over, and clouds simply adjust the net insolation that reaches the surface to warm it; and how much CO2 is present is hardly of any consequence. The effect (that it DOES have) is simply vetoed by cloud variations OVER CLIMATE TIME SCALES.
Jim D says:
”
If you take half the present CO2 you get something like the value in the ice ages. The temperature with half the current CO2 was about 5 K less than now, so you could argue that the last doubling had at least 5 K warming. Why should the next one be significantly less?
”
Good point, but see what happens after the temperature peaks: Temperature returns down to glacial level while CO2 is stil in MAX effect. This is the general picture:
http://wattsupwiththat.com/2009/01/30/co2-temperatures-and-ice-ages/
Therefore, nothing suggests thatCO2 has anything to do with the temperature changes over the ICE ages.
The same goes for the temperatures over the PETM:
http://hidethedecline.eu/pages/posts/petm-ndash-finally-an-example-of-co2-causing-heat-179.php
**
And… if you think that the other CO2 doublings has the same effect as the present, please note what my article shows: 9,25 doublings of 3 – 4 – 5 – 6 K related to CO2 gives temperature changes unrealistically big.
If CO2 had this effect why did the Earth not boil over when the Earth had 7000 ppm (500 years ago?)
etcetc 🙂
K.R. Frank
*******
wayne says:
September 9, 2010 at 6:42 pm
Frank Lansner says:
September 9, 2010 at 1:10 pm
…
This makes it legitimate to ask: What is it about the present CO2 doubling that is so very very extraordinar compared to other doublings. With what evidence can you claim the feedbacks for the present doubling is many times bigger than for other doubling? (Because i showed that they have to be).
K.R. Frank
And you did a very fine job of showing exactly that!
**********
Wayne, thanks! It means a lot that even though i am indeed fumbling a little in the dark here and there when trying to show something new, some people like you can still see where im getting at, and that this is important.
K.R. Frank
Correction..!
If CO2 had this effect why did the Earth not boil over when the Earth had 7000 ppm (500 MIO years ago?)
:-))
DCA engineer says:
September 10, 2010 at 8:44 am
Frank, Thanks for the interesting post.
I was wondering you take on Gavin’s recent paper.
http://pubs.giss.nasa.gov/docs/notyet/inpress_Schmidt_et_al.pdf
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Thankyou, I will look forward to digest this paper! Perhaps i will comment on it on http://www.hidethedecline.eu when I have the chance.
K.R. Frank
George E. Smith says:
September 10, 2010 at 8:50 am
Several times here (at WUWT) , Phil has offered, that the CO2-Temperature relationship is linear for small amounts of CO2; then logarithmic for medium amounts of CO2; and then square root for large amounts of CO2.
*******
Oh boy… Its odd because the fundamental knowledge hereof comes from laboratory experiments?
If true, does Phil show data to back this up.
– Its the square root that is.. … surpricing … to me(!)
Then you write: “If we are to believe the logarithmic doubling sensitivity mantra, then the change in atmospheric CO2 from 4 ppmv to 5 ppmv must have created all manner of chaos on earth.”
Well, below 5 ppm, the “halfing” effect-thing is slightly weaker and weaker.
But your point stands still, of course, a lot should have happened from just small changes.
BUT!
Take the planet pluto. I the later years its surface temperature has risen 3 Celsius! And the exciting thing is: The Pluto atmosphere warmed after minimum distance to the Sun. So with still less light, temperatures rose considerably compared to Plutos extremely cold surface temperature. The best explanation is perhaps, that just sparse number of molecules has been released from Plustos icy actually have a significant eccect?
K.R. Frank
Jim D,
IIRC, Antarctica drifted to its present polar position about 25 million years ago. This made it much easier for the earth to go into ice ages because it is much easier to form a thick polar ice cap when there is a land mass at the pole. The CO2 levels declining might be a function of declining temps rather than vice versa.
Assuming that the feedbacks are going to remain constant in each doubling has no basis in physical science, right? In fact, the nature of the current feedbacks is the biggest question to be solved. It will be interesting to discuss the merits of the various feedbacks that have been proposed for the current doubling, especially Roy Spencer’s work.
It seems that there is general agreement that the direct forcing from CO2 increasing is minuscule, right? With current CO2 level at 390 ppm and increasing at 2 ppm per year, at these rates it will take nearly two centuries for the direct impact of doubling CO2 to generate 1 degree C heat increase. That is an average of about 1/200 degree C increase per year.
This website is interesting:
http://www.ncdc.noaa.gov/oa/climate/research/cag3/na.html
It is a federal government site that permits you to plot temperature trends in the USA. If you plot the last 12 years, the trend is down at about 1 degree F per decade. This means that in the last 12 years we lost heat equivalent to about 2/3 of the heat that will be gained from the direct effect of the next doubling (i.e. roughly the next 2 centuries) of CO2.
I strenuously suggest all you people arguing over the physics of GHGs start reading up on the experimental results of longwave absorption by gases conducted by John Tyndall about 150 years ago and written up in his book “Heat a Mode of Motion”.
For his work with gases begin reading on page 321:
http://books.google.com/books?id=3DUJAAAAIAAJ&pg=PA321&dq=%22heat+a+mode+of+motion%22&output=text
and take about a half hour to educate yourselves. This is very basic physics which were experimentally discovered 150 years ago, folks.
The very first thing that Tyndall discovered is that in very low concentrations of absorbing gases the absorption increases in direct proportion to the gas concentration. Gradually, as complete absorption is approached, the proportionality becomes exponential.
For anyone who thinks they know enough to describe this by quantum mechanical theory if the result obtained does not approximate the experimental results obtained 150 years ago then your quantum explanation, or any other explanation for that matter, is WRONG and you need to go back to the drawing board until your theoretical results match the experimental measurements. Models of reality DO NOT trump physical reality.
CO2 is present in sufficient concentration in the troposphere to bring its absorptive capacity to near extinction. At this point the proportionality required for incrementally more GHG effect is exponential in nature.
George E. Smith says:
“Climate Science is going to be forever stuck in the doldrums akin to ancient astrology”
————
Yes, this stuff may very well live as long as astrology, which was a very well respected science for nearly 3,000 years, and even Newton is said to have delved in it (he was also an enthusiastic alchemist).
The exact nature of the relationship between CO2 and climate is the perfect subject for a debate that may last several thousand years, since nobody has a clue what it is, and proving anybody’s conjectures wrong is a tricky business. The great Ptolemy, a very competent astronomer for his time, also wrote thousands of pages with stuff like the following. How do you prove him wrong?
Just look at all the stuff Saturn can do, for example:
“Saturn makes men averse to women, and renders them fond of governing, prone to solitude, highly reserved, regardless of rank, indifferent to beauty, envious, austere, unsociable, singular in opinion, addicted to divination and to religious services and mysteries; solicitous of the priesthood, fanatical, and subservient to religion; solemn, reverential, sedate, studious of wisdom, faithful in friendship, continent, reflective, circumspect, and scrupulous in regard to female virtue: but, if he be thus conciliated, and not posited in glory, he makes men licentious and libidinous, practisers of lewdness, careless, and impure in sexual intercourse; obscene, treacherous to women, especially to those of their own families; wanton, quarrelsome, sordid, hating elegance; slanderous, drunken, superstitious, adulterous, and impious; blasphemers of the gods, and scoffers at holy rites; calumniators, sorcerers, hesitating at nothing. If conciliated with Mercury, and if in a glorious position, Saturn makes men inquisitive, loquacious, studious of law and of medicine, mystical, confederate in secrecy, fabricators of miracles, impostors, improvident, cunning, familiar with business, quick in perception, petulant, accurate, vigilant, meditative, fond of employment, and tractable: but, if connected with Mercury, and not posited gloriously, he causes men to be frivolous, vindictive, laborious, alienated from their families, fond of tormenting, and void of enjoyment; night-wanderers, insidious, treacherous, pitiless…”
http://www.sacred-texts.com/astro/ptb/ptb62.htm
“”” Dave Springer says:
September 10, 2010 at 1:44 pm
I strenuously suggest all you people arguing over the physics of GHGs start reading up on the experimental results of longwave absorption by gases conducted by John Tyndall about 150 years ago and written up in his book “Heat a Mode of Motion”.
For his work with gases begin reading on page 321:
http://books.google.com/books?id=3DUJAAAAIAAJ&pg=PA321&dq=%22heat+a+mode+of+motion%22&output=text
and take about a half hour to educate yourselves. This is very basic physics which were experimentally discovered 150 years ago, folks. “””
Well old John certainly wrote a funny strain of English. One thing I did notice in his experimental apparatus is that he evidently did his experiments the same way that “the science guy” does his; and emplyed a source of not very long wavelength “heat” that unfortunately is NOT emitted from the earth’s surface or from the atmosphere (of Planet Earth).
Frank Lansner says:
September 10, 2010 at 10:15 am
… can still see where im getting at, and that this is important.
K.R. Frank
Agreed.
Obviously, I was not saying Ice Ages were due to CO2 changes, but one of the things that goes with AGW is that CO2 is tied on long timescales to temperature. This is what I was referring to. When the earth cools, e.g. due to solar or Milankowitch effects, CO2 follows. Either CO2 or temperature can change first, but the other will follow with a lag. It doesn’t contradict AGW.
Someone asked about the log relation with temperature. As in the original post, the line shows that this relation is just an approximation to what you get out of a full radiative transfer model, no more. Such models do not have a log relation built into them, only individual effects of various absorption bands that saturate to various degrees. Each band or line is just a Beer’s law absorption path calculation which is an exponential decay with concentration, so it is not obvious their integrated effect is going to be a log behavior.