From The Hockey Shtick, word of a new paper that supports Miskolczi’s theory of saturated greenhouse effect. We’ve seen this before, in the form of this graph.
In 2006, Willis Eschenbach posted this graph on Climate Audit showing the logarithmic net downward IR forcing effect of carbon dioxide relative to atmospheric concentration:
The flatter portion of the graph gradually smooths out, as the effect of CO2 forcing becomes saturated with increased concentration. And this graphic of his shows carbon dioxide’s contribution to the whole greenhouse effect:
What’s more, in this new paper there appears to be some evidence for a negative climate feedback, in the form of slightly lowered relative humidity trend, which makes climate sensitivity lower. Relative humidity (RH) is the ratio of the actual amount of water vapor in the air to the amount it could hold when saturated expressed as a percentage OR the ratio of the actual vapor pressure to the saturation vapor pressure expressed as a percentage. The amount of water vapor the air can hold increases with temperature. Relative humidity therefore decreases with increasing temperature if the actual amount of water vapor stays the same. While the study found a slight increase in specific humidity (the mass of water vapor per unit mass of air), relative humidity (near the surface, 2 meter measurement) decreased by 0.5% per decade, resulting in an overall slightly drier atmosphere.
If a positive water vapor feedback response existed in the climate system, you’d expect both the specific and relative humidity to increase with time. It didn’t. This ends up putting the kibosh on the idea of tipping points, and a lack of positive water vapor feedback pretty much takes all the scare out of CO2 induced climate change.
Of note is the issue with station inhomogeneity which apparently had been masking the signal in earlier studies. This study looked at stations individually to determining where such inhomogeneity existed. Here’s an example in figure 3 of their paper:
From THS:
A paper published today in the Journal of Climate finds that relative humidity has been decreasing 0.5% per decade across North America during the 62 year period of observations from 1948-2010.
Computer models of AGW show positive feedback from water vapor by incorrectly assuming that relative humidity remains constant with warming while specific humidity increases. The Miskolczi theory of a ‘saturated greenhouse effect’ instead predicts relative humidity will decrease to offset an increase in specific humidity, as has just been demonstrated by observations in this paper. The consequence of the Miskolczi theory is that additions of ‘greenhouse gases’ such as CO2 to the atmosphere will not lead to an increase in the ‘greenhouse effect’ or increase in global temperature.
Journal of Climate 2012 ; e-View
doi: http://dx.doi.org/10.1175/JCLI-D-11-00003.1
Surface Water Vapor Pressure and Temperature Trends in North America during 1948-2010
V. Isaac and W. A. van Wijngaarden*
Physics Dept., Petrie Bldg., York University, 4700 Keele St., Toronto, ON Canada, M3J 1P3; e-mail: wlaser@yorku.ca
Abstract
Over 1/4 billion hourly values of temperature and relative humidity observed at 309 stations located across North America during 1948-2010 were studied. The water vapor pressure was determined and seasonal averages were computed. Data were first examined for inhomogeneities using a statistical test to determine whether the data was fit better to a straight line or a straight line plus an abrupt step which may arise from changes in instruments and/or procedure. Trends were then found for data not having discontinuities. Statistically significant warming trends affecting the Midwestern U.S., Canadian prairies and the western Arctic are evident in winter and to a lesser extent in spring while statistically significant increases in water vapor pressure occur primarily in summer for some stations in the eastern half of the U.S. The temperature (water vapor pressure) trends averaged over all stations were 0.30 (0.07), 0.24 (0.06), 0.13 (0.11), 0.11 (0.07) C/decade (hPa/decade) in the winter, spring, summer and autumn seasons, respectively. The averages of these seasonal trends are 0.20 C/decade and 0.07 hPa/decade which correspond to a specific humidity increase of 0.04 g/kg per decade and a relative humidity reduction of 0.5%/decade.
The full paper from the Journal of Climate can be viewed at this link.
Scotish Sceptic says:
Vegetation grows by evaporation. It sucks up ground water that would otherwise flow into rivers and pushes it into the air. Take away the vegetation, leave a field ploughed for a few months, cut downt the trees for lower vegetation, and the amount of vaporation decreases leading to rising temperature.
That is why “Urban heating” starts at population densities as small as a few 10′s of people per square kilometer. It’s not the people, so much as what the do to the vegetation.
One curious aspect of the climate debate is that people extrapolate globally what happens locally to them.
Here in Perth, Australia we have the opposite, which I call the Urban Irrigation effect.
People irrigate their gardens, which directly increases atmospheric water vapour and indirectly increases WV by promoting growth of leafy plants and trees that transpire far more than the native plants.
It’s quite striking at this time of year, Gardens are green and lush, but native bushland is brown, grey with just large trees with pale green leaves.
So I agree with the conclusion that urban effects are largely due to what we do to the vegetation.
Statistically significant warming trends affecting the Midwestern U.S., Canadian prairies and the western Arctic are evident in winter and to a lesser extent in spring while statistically significant increases in water vapor pressure occur primarily in summer for some stations in the eastern half of the U.S.
If the warming is in the winter/spring and the WV changes are in the summer, clearly there is no causative relationship. Ie, no evidence for a +ve water vapour feedback.
The only way they can be related is through a common cause and that common cause is likely decreasing aerosols, which would produce both these effects..
response to ged
good question
does dryin’ air mean less precipitation too ?
To those who dispute the notion of Greenhouse gases: The Laws of Thermodynamics only require that net heat energy flow must be from warmer to cooler. The Laws do not require that all energy flow must be in the same direction, only that net flow is from warmer to cooler. There can be a large upward energy flow from a warm surface into cool air by conduction, convection, and radiation, all occuring at the same time. Yet at each point in the air, radiation emission will occur in a spherical pattern—-ie, in all directions equally. That part of the radiation directed at the surface will transfer energy back toward the surface. Some heat will come back toward the surface, even though the net energy flow must be from warmer to cooler.
The overall effect of the various flows of energy cannot be to heat the warm surface by energy from the cool air. Indeed, the warm surface will, on the whole, transfer heat to the cooler air (which will then, overall, radiate that energy to space) as required by the Laws of Thermodynamics. However, the rate of transfer will be slowed somewhat by the “back radiation”, resulting in a longer “dwell time” for that energy in the system. The equilibrium energy content of the surface and air system together will rise. Voila! The Greenhouse effect.
Stated in other words, any process that slows the escape of heat from a system will result in that system having a higher temperature than otherwise. The atmosphere has gases that produce such an effect for the Earth.
This does not mean that the Greenhouse Effect is large nor that rising CO2 is going to cause catastrophic global warming.
MODTRANs does not show the full effect of carbon dioxide. The 2.94 W/m^2 per doubling of CO2 is widely said to be low.
Even Dr. Roy Spencer appears to me to go along with the IPCC figure of 3.7 W/m^2 per doubling of CO2.
However, that does not change the logarhythmic nature of how CO2’s effect varies with concentration of CO2.
As for the drop in relative humidity: In the graph here, most of that occurred so abruptly that it suggests a change in instruments or methods. I would not be surprised by a gradual drop in relative humidity, especially if concentrated to a time period from the early 1970’s to the middle of the last decade, should the cloud albedo feedback turn out to be positive. That is one reason I expect the sum of the water vapor and cloud albedo feedbacks to be less than IPCC expectations.
Another is that what they mention for the cloud albedo feedback sounds strangely high to me – higher than the surface albedo feedback last time I checked.
Smokey says:
February 8, 2012 at 12:38 pm
Gates says:
“There are many tipping points in any chaotic system, each one with the potential of sending the climate toward an attractor, or new center of oscillation.”
If Gates knew what he was talking about he could call turns in the stock market. If he doesn’t know what he’s talking about, he can post here.
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If I could call turns in the market, you wouldn’t want me posting here?
Hmmm…
Calling “turns” in the market is a bit of a fools errand. Best to do what the smart money (i.e. insurance companies and other big investors) do and bet both sides of the market, (a straddle) switching your “long bet” based on the over-bought or over-sold condition in the market. The insurance companies love to sell annuities to you, giving you your measely 5, 6, or 7% returns, while they are betting against you all the time with your money. If the market goes up, they’ve made a tidy return, if the market goes down, they make an absurd return. They dine on fine food and wine, and will gladly give you the table scraps.
The smart money doesn’t try to time turns in the market. They know there will be turns, and they’ll be there to collect on them…all the while, using your money to bet with. A pretty good gig. Those of you in the insurance business–especially the business of selling “annuities” know exactly what I’m talking about. They leverage your money into tidy profits, and could give a wit about “timing the market”.
Daily UAH lower troposphere temperatures fell to -0.415C on January 21, 2012.
http://img811.imageshack.us/img811/3672/dailyuah2006jan12.png
Water vapour levels must have, likewise, fallen off a cliff. The 3 month lag of the ENSO to water vapour levels and temperatures means that the peak low levels should not be reached until the last part of April, 2012.
Robert Brown says: February 8, 2012 at 9:25 am
IR spectra taken by satellites simply let you identify the parts of the spectrum that act as radiative “insulation”, and slow the transmission of heat so that it eventually comes out of the Earth itself from cold matter up high instead of warm matter down low. End of story.
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spectral plot of MEASURED IR up and IR down is here:
http://www.patarnott.com/atms749/powerpoint/ch6_GP.ppt
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Doug Cotton says: February 8, 2012 at 6:31 am
Then there is evaporation of oceans to form clouds and rain. Where does that energy come from if it wasn’t the result of the Sun warming the oceans? What I cannot accept is any concept of radiation from a cooler atmosphere warming a warmer surface.
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Please have a look at these real world documents and then see if you can still say this.
Figure 3 in this document
http://www.patarnott.com/atms749/pdf/LongWaveIrradianceMeas.pdf
shows the measured IR downwards over a few days and nights.
We know the solar output received in the dark is 0
We know that O2 and N2 have very very very little thermal radiation.
So where does all that downward radiation come from (at least 270W/sqm)
It can only be from GHGs.
During the day we receive about 380W/sqm
So the 270W/sqm is additional to the solar irradiance.
Would anyone care to explain where the night time radiation is coming from if GHE is non existent? Note that the nighttime radiation is only 100W/m^2 less than the day (when the sun is beating down!). Since this radiation is positive and hitting earth can you tell me how this does not increase the temperature over what would be present if no GHGs and night time radiation as zero?.
Also have a look at another real world measurement:
Downward longwave irradiance uncertainty under arctic atmospheres: Measurements and modeling
http://www.slf.ch/ueber/mitarbeiter/homepages/marty/publications/Marty2003_IPASRCII_JGR.pdf
Figure 2
sometimes more downwelling radiation at night! Please explain without GHGs.
The published paper “Surface Water Vapor Pressure and Temperature Trends in North America during 1948-2010”, which is the subject of this post, is not very useful because it describes water vapour pressure trends, which is the total water vapour in the atmosphere, the vast majority of which is near the surface. But changes of water vapour near the surface has very little effect on out-going radiation, therefore has little effect on the greenhouse effect.
Our test using HARTCODE (a line-by-line radiative code developed by Miskolczi) shows that reducing the amount of water vapour in a layer at the 307 to 423 mbar lever ( 8 to 9 km altitude) by 20% has 31 times the effect on out-going radiation as the same absolute change of water vapour in a layer next to the surface (848 to 1013 mbar). The actual humidity near the surface is about 20 times greater than that in the upper atmosphere layer, so a percent change of specific humidity in the upper atmosphere layer has 50% more effect on out-going radiation than a percent change of specific humidity in the surface layer. It matters where in the atmosphere the water vapour changed. The change of total surface water vapor pressure tells us nothing about where the change occurred!
In the topics 30 N to 30 S, the specific humidity at 400 mbar best fit line has declined by 0.11 g/kg, or 13%, from 1960 to 2011.
Ged> For there to be a water vapor feedback, relative humidity must stay the same or raise with temperature.
No. What matters is absolute humidity, not relative. It is the interactions of the photons with the molecules that matter, which depends on the number of said H2O molecules; the photons don’t care about how many there are relative to how many there could be.
The point about sfc vs upper air is a good one. I think the pic that KG provides from the FoS is dodgy; humidity measurements from radiosondes are difficult, and unlikely to be consistent over time (oh, and “The climate models assume that water vapour changes only in response to a temperature change” is wrong, as is apparently any statement about GCMs made by skeptics here :-).
Total column WV over the oceans is shown here: http://www.ipcc.ch/publications_and_data/ar4/wg1/en/ch3s3-4-2-1.html Upper troposphere is more complex; see http://www.ipcc.ch/publications_and_data/ar4/wg1/en/ch3s3-4-2-2.html but you won’t like it.
I don’t agree with R. Gates when at February 8, 2012 at 7:29 am he writes:
“The notion of tipping points isn’t at all related to the logarithmic saturation effect of CO2 in the atmosphere, nor its effect specifically on increase water vapor as a positive feedback effect. Tipping points of course come from the notion of pushing a non-linear chaotic system such as the climate into a new state, such that it seeks a new attractor. One must look at the whole system to see how just a little nudge can cause a big change– this is the essence of Chaos. ”
Where the notion of a tipping point enters this current issue is the speculation that the feedback factor (forcing multiplier due to added water vapour molecules per each added CO2 molecule) approaches unity and a runaway ensues. Obviously this paper lends force to the contrary view by reducing the number of water vapour molecules per new CO2 molecule to below where it was previously thought. And in that entirely linear (non chaos) sense a tipping point is even more improbable.
A small nudge causing a big change is the essence of “Catastrophe” rather than Chaos. The point of chaos is that there is no knowing what might lie the far side of a switch to a new attractor; it might equally be benign.
I don’t think anyone has risen to William M. Connolley’s bait where at February 8, 2012 at 2:36 am he writes:
“No. The GCMs make no assumption of fixed relative humidity. That is an emergent property, approximately.”
It certainly has been my understanding that RH was assumed fixed for want of any better data. Or if it wasn’t explicitly fixed its value was closely predetermined by other assumptions. Anyone here know better? Have things changed as modelling has progressed?
It is amusing that you see information and correction of errors as bait. What, I wonder, will you do when you realise that what you have always assumed – indeed, what everyone here seems to assume – turns out to be wrong? Reject the information, I suppose.
http://journals.ametsoc.org/doi/abs/10.1175/JCLI3979.1 says:
“The sensitivity of free-tropospheric relative humidity to cloud microphysics and dynamics is explored using a simple 2D humidity model and various configurations of the National Center for Atmospheric Research (NCAR) Community Atmosphere Model version 3 (CAM3) atmospheric general circulation model (AGCM)… Relative humidity R simulated by the AGCM was insensitive to surface warming. Doubling a parameter governing cloud water reevaporation increased tropical mean R near the midtroposphere by about 4% with a realistic circulation”
What is found from the GCMs (and from theoretical studies) is that you expect RH to stay roughly constant. But this is, as I say, an emergent property: it isn’t an assumption. Similarly, the climate sensitivity is emergent, not built in.
> the speculation that the feedback factor… approaches unity and a runaway ensues
It won’t happen.
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Robert Brown says:
February 8, 2012 at 9:25 am
So don’t get hung up on radiation going up or down, convection or conduction, winds or global oscillations, heat going from warmer to cooler or vice versa, or anything like that. Those things may affect the way the GHG-moderated GHE works, but they do not have any bearing on the question of whether it works at all. All that matters for the latter is the picture of the outgoing radiation that actually cools the Earth — and is the only way heat actually leaves the Earth, so you can completely, totally ignore 100% of the details of how heat moves around the Earth’s surface before eventually being radiated away. That picture leaves one with absolutely no doubt that CO_2 in the upper troposphere is part of the “well-insulated roof” (where the water window is part of the “poorly insulated roof” where the entire spectrum is “the roof”) that one way or another slows the flow of input energy out of the troposphere and hence raises the average temperature of the house beneath the roof.
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Good explanation that any engineer should understand. The “back-radiation” aspect is technically correct, but perhaps not intuitive. For me, the “insulation” analogy is much more intuitive.
maxberanMax Beran says:
February 9, 2012 at 5:18 am
I don’t agree with R. Gates when at February 8, 2012 at 7:29 am he writes:
“The notion of tipping points isn’t at all related to the logarithmic saturation effect of CO2 in the atmosphere, nor its effect specifically on increase water vapor as a positive feedback effect. Tipping points of course come from the notion of pushing a non-linear chaotic system such as the climate into a new state, such that it seeks a new attractor. One must look at the whole system to see how just a little nudge can cause a big change– this is the essence of Chaos. ”
Where the notion of a tipping point enters this current issue is the speculation that the feedback factor (forcing multiplier due to added water vapour molecules per each added CO2 molecule) approaches unity and a runaway ensues.
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If this discussion was about only one specific type of tipping-point, then my apologies. The title of this blog says “tipping points” (plural). There can be many tipping points along the way in the saturation of the atmosphere with CO2. Runaway greenhouse is only one, and probably one of the most unlikely.
Joules Verne, Robert Brown; this is an interesting read, the article and the comments included. To Joules point, if you have a wide-mouth Dewar flask (thermos bottle) on a clear night, low humidity, put a few cc’s of water in it, stretch some plastic wrap over the top (polyethylene is best) and set it on a table outside. After a while, the water will freeze solid because the Earth is about 300K and space about 2K. The water in the Dewar becomes essentially an IR detector and reaches some equilibrium with the field of view. Because of water vapor (humidity), Houston stays warmer at night compared to Austin or El Paso.
Regarding the effects of CO2 on warming, the article is correct in that as a GHG, CO2 is nearly saturated, that is to say, more CO2 makes little difference in the effects of the gas. CO2 and water vapor, in the wavelengths that they absorb, also emit. Using a simple NDIR (non-dispersal Infrared) detector with a bandpass filter for CO2 for example (4.26 micron), one can both detect the absorption of the gas in a system and also the emission of the gas. If the gas is warmer than a reference, the signal from the detector goes up which means that the gas is losing heat and perhaps has transferred heat, when the signal goes down it absorbs heat and energy, However, in a system, the heat of the gas is the temperature of the gas times its partial pressure and specific heat. So, perhaps, if there is more CO2 in the upper atmosphere which emits at both 10 microns and 4.26 microns, and since because of the blackbody curve 10 microns is the emission peak of 300K, and since the Earth’s emission peak is also 10 microns, there is a transference of heat from the Earth to the CO2 in the atmosphere, which is then radiated out to space. Warm CO2 will radiate energy out into space and will be a conductor of heat within the system.
Water on the other hand can be a bigger warming gas because it absorbs at many wavelengths at both short and long. Hydrocarbon gases like methane (natural gas) is very dangerous because the atmosphere is not close to being saturated and methane is a efficient absorber of IR. I think it is interesting that Earth, to have survived with life forms for so long, would have a CO2 cycle or mechanism to balance the good v. the harm it can do respecting life. I think water vapor is part of the mechanism.
The anecdote I observed for years now, and since I viewed the graph of water vapor v. relative humidity shows that my observations are in sync with the data, that is, with increasing water vapor and CO2, vegetation growth has been noteworthy in that we have better lawns. I need to prune my orchard more, have better crops, and the general landscape is greener (in New Hampshire) than it was in the late ’60’s when summers were very hot and dry and winters not so much back then. Perhaps with a slight increase in CO2 vegetation growth will sequester carbon as fast as necessary to maintain a healthy balance. I think a study of tree growth in terms of regional volume (which would include stocking) done while taking into the calculation the history of water vapor, rainfall, and total water in the system would be instructive. I think with a slight increase in temperature, water, and CO2 there is much more vegetative growth. Isn’t that what greenhouse managers do? I think in the environment it all balances out or there would be no life on planet Earth presently.
R. Gates says:
February 8, 2012 at 7:29 am
Tipping points of course come from the notion of pushing a non-linear chaotic system such as the climate into a new state, such that it seeks a new attractor.
This is patently untrue. While the IPCC pays lip service to chaos / nonlinear theory, tipping points are presented as purely linear positive feedbacks. There is absolutely no formulation of any nonequilibrium system pattern, attractors or jumping between attractors. Mainstream AGW theory ignores nonlinear / nonequilibrium pattern processes entirely. Your musings on the subject consist of arm-waving only and are not part of the central AGW narrative which is rigidly linear.
So not only does “snow” not tend to melt on a well insulated roof it will form frost on it even when air temperature is far above freezing. This was an object lesson for me in the power of radiative cooling on dry clear nights although I hadn’t quite forgotten many camping trips to the high desert at Joshua Tree National Monument in the 1970′s and 1980′s outside Palm Springs where you’d roast by day and freeze by night.
Good luck trying to teach the rudiments of why these phenomenon happen when your students aren’t paying through the nose to hear you talk. I’ve had no luck at it. As Yogi Berra said “You can observe a lot by just looking.” Most people see without actually looking, it seems.
One can actually make ice cream at night in the desert, even in the summer, by making your custard and pouring it in a thin layer into a flat pan well-insulated from below, on a very still night with low humidity. The roast by day, freeze by night is nearly standard operating procedure in e.g. the Sahara, where they have 45 degree temperature swings every day.
As for your second remark, I don’t have much luck getting people to learn when what I am teaching fails to coincide with their prior beliefs. Not just on this blog, this is a lifetime observation. I’ve spent — err, really “wasted” — countless hours trying to convince BICCs (Biblically Inerrant Conservative Christians) that the Universe is a bit older than 10,000 years and that we evolved. Trying to explain radiometric dating to them is a real treat, when they are perfectly happy to assert that God just changed the laws of nature so it looks like some rocks are really old and the light of the stars is coming from really far away, but if we really got those laws right we’d get the right answers, namely that the rocks are all antediluvian and perhaps 6000 years old.
Sounds a lot like climate arguments — on both sides. Me, I favor the side(s) supported by the laws of physics the way they are already worked out, until really proven otherwise;-)
rgb
phlogiston says:
February 9, 2012 at 9:22 am
R. Gates says:
February 8, 2012 at 7:29 am
Tipping points of course come from the notion of pushing a non-linear chaotic system such as the climate into a new state, such that it seeks a new attractor.
This is patently untrue. While the IPCC pays lip service to chaos / nonlinear theory, tipping points are presented as purely linear positive feedbacks. There is absolutely no formulation of any nonequilibrium system pattern, attractors or jumping between attractors. Mainstream AGW theory ignores nonlinear / nonequilibrium pattern processes entirely. Your musings on the subject consist of arm-waving only and are not part of the central AGW narrative which is rigidly linear.
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I was responding to the notion that the plural “tipping points” as used in the title of this blog post only refers to a single thing– runaway greenhouse warming. It is this, that is patently untrue.
I’m going to repost this comment from another thread here, because it is very relevant to this thread.
————————————————————–
This is where the analogy gets interesting. Suppose the dam is infinitely high, but it has two rows of floodgates in it. One, at low level, we will call the CO2 floodgates. One, at higher level, we will call the CH4 floodgates.
The water rises until it starts flowing out of the CO2 floodgate. But, the outflow isn’t enough to establish equilibrium before this row is saturated, so the water keeps on rising. Eventually, it reaches the level of the CH4 floodgates. Here, the water has enough of an outlet that the level stabilizes.
Now, we add more CO2 outlets. To make the analogy fit, let’s assume that we had to raise the level of the CO2 floodgates a bit to fit more in. If the CO2 floodgates had previously been sufficient to allow an equilibrium level to be established, that equilibrium level would be pushed higher.
BUT, since the level previously rose to the CH4 gates, and we put more CO2 gates in below that level which are now able to remove higher volumes of water, the equilibrium level will go down.
I hope maybe this analogy will get a read from some people who did not understand what I was talking about on an earlier thread.
Adding CO2 does not necessarily raise surface temperature, because there are other radiative emitters in the atmosphere which have interacted to create the equilibrium temperature.
That is exactly the question everyone is arguing. The warmist hold that the effect is catastrophically significant while the
realistskeptic hold that it is insignificant or made insignificant, by other negative feedback/forcing(s). Since GMT has plateaued effectively 15 yrs, when CO2 emissions are increasing indicates the portion of GHE due to CO2 is insignificant or at least, such a very low sensitivity value, as to appear insignificant.Water in the atmosphere exists in all phases ice, vapor(gas), liguid, as well as various isotopes – light (H2O), heavy (D2O), and radio (T2O). It is not a trace gas but a overpowering, driving component. In it’s cloud form it will regulate climate on it’s own dynamics. These dynamics may respond to CO2 IR broadening or cosmic ray seeding, but quantification has been a tease so far. You, like everyone else, must decide the weight of evidence or lack of evidence. I think you will find the CO2 “glove” does not fit. GK
I was going to ask whether anybody had mentioned Venus. Apparently somebody did, but that mention didn’t make a lot of sense.
The greenhouse effect does not “saturate”. It’s easy enough to demonstrate theoretically using a grey atmosphere approximation. And otherwise you need a really weird woo theory about Venus.
Michael Tobis says:
February 10, 2012 at 6:26 am
‘The greenhouse effect does not “saturate”.’
“Saturation” means the sensitivity to additional amounts tends to zero. Venus actually proves that saturation happens. Despite being 97% CO2, the major greenhouse effect comes from the much smaller concentration of SO2.
Bart says: February 10, 2012 at 9:25 am
“Saturation” means the sensitivity to additional amounts tends to zero. Venus actually proves that saturation happens. Despite being 97% CO2, the major greenhouse effect comes from the much smaller concentration of SO2.
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There are 70 atmospheres of pressure broadening the spectral lines of all GHGs on Venus!! “Saturation” will occur later SO2 is one of the GHGs there are many in the venusian atmosphere including H2O at 100ppm
jjthoms says:
February 10, 2012 at 3:19 pm
I found a plot a few weeks back of emissions from the Venusian atmosphere. Sorry I cannot provide a link, but I didn’t mark it and cannot find it. But, it showed that the major gap taken out of the underlying blackbody spectrum was in the SO2 range. The CO2 gaps were comparatively negligible.