Reader and contributing author Ed Caryl sends another essay, and warns it may be controversial for the obsessed among us who insist a catastrophe is coming.
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Is CO2 Warming a Mirage?
By Ed Caryl
There are three levels in the atmosphere where CO2 could act: at the surface, in the troposphere, and high in the atmosphere where radiation to space is greater than thermal absorption. In each location the conditions are different, and the way CO2 acts is different.
At the surface, the CO2 “back radiation” has been a mystery to many, this author included. Some argue that such a thing doesn’t exist, that it is against the second law of thermodynamics. It does exist, but the mechanism does not work very often, or exactly as advertised. This article will throw you some curves, and many numbers, but will stay away from complicated mathematics. Complex math is unnecessary.
First, the basics: CO2 is a three-atom molecule. It can be visualized as one carbon atom with two oxygen atoms attached, one on each side, in a straight rod configuration. As such, it is “non-polarized”, that is the charges on each atom balance, and the charge on the whole molecule appears to be zero as viewed from any angle. Thus, it has only two modes of vibration when excited by infrared radiation (IR). It can vibrate in and out along the long axis, like a rod that has been struck on one end, or it can vibrate parallel to the axis, like a rod that has been struck in the middle.
The vibration mode along the long axis is only excited in an asymmetric mode, where the end atoms move together in the same direction at the same time. The symmetrical stretch, where the oxygen atoms both move away from the carbon atom then back towards it, does not expose any charge, so doesn’t radiate or absorb radiation.
Figure 2. The vibration modes of CO2. From the top, only the 2nd and 3rd modes contribute to CO2’s IR activity. (Source: Chemwiki, UC Davis)
Figure 3 below shows radiation transmitted by the atmosphere. Conversely, that part that is not transmitted is absorbed. Note: only two peaks of CO2 act to absorb radiation that water vapor does not. Those peaks are at 4.25 µm and 15 µm. The 4.25-µm peak occurs at a wavelength that has little long-wave radiation by the earth.
Figure 3: Source Wikimedia Commons.
The 15-µm peak is the only one that is important in the greenhouse gas discussion. The atmospheric transmission at that frequency is such that less than 5% of the radiation gets through a 1-meter path at one atmosphere with the normal amount of CO2. This means that any radiation from the ground at the wavelengths that CO2 will absorb and re-radiate will be intercepted very close to the ground, most of it within a meter. The standard story is that when the energy is re-radiated, half goes up and half goes back down to the ground. But here is the rest of the story:
When a CO2 molecule is irradiated, it takes from 7 to 15 microseconds (a microsecond is 10-6 seconds) before it re-radiates. In air at standard pressure (1000 millibars), the air molecules are undergoing 1010 (10 billion) collisions per second. This means that before the CO2 molecule can get rid of the energy by re-radiating, it has very probably gotten rid of the energy thermally by colliding with other air molecules, oxygen and nitrogen, that do not re-radiate, about 100,000 times. It is true that some CO2 molecules will gain energy by these same collisions, at room temperature about 5% are excited at any time, but most of them lose the energy thermally before they can radiate.
At the surface, the ground is radiating long wave IR into the atmosphere. But, as described above, that radiation does not go very far. Half of it is absorbed in a few centimeters. If “back radiation” exists, some of the energy would be returned to the ground, but on the way back to the ground, CO2 molecules would absorb an additional fraction. That heat is then further absorbed by more thermal collisions with other air molecules. In any case the result is heated air.
This is especially visible above dark, flat surfaces, like asphalt roadways, or flat gravel deserts, if conditions favor, as an interior mirage, as in figure 1. An interior mirage occurs when the air at ground level is hotter than the air above it, making the ground level air less dense, thus with a lower index of refraction. This acts as a crude lens, making things higher up in the background, like the sky, hills, or higher background objects appear as if they were inverted at ground level. The sky or distant terrain can sometimes look like rippling water in this situation.
This phenomenon does not happen everywhere, only where conditions are right to hold the hot air at the surface and where IR heating is high. Any vertical relief, such as sloping ground, trees, grass, brush or other vegetation, will encourage convection and interfere with the radiation, and the warmer air will rise away from the surface. Lighter surfaces and vegetation also have less emissivity, thus there is less IR to interact with CO2. It does not happen over water, ice, or snow. Over those surfaces, another type of mirage happens, a superior mirage.
Figure 4. This is a superior mirage of Point Reys National Seashore seen in the background from San Francisco Bay. The image is not inverted. Point Reys is over 50 kilometers away, and over the horizon from this location. Source: Wikipedia Commons.
A superior mirage occurs when the air is colder and denser at the surface than higher up, and refracts a distant image along the surface, sometimes one that is over the actual horizon, making it visible as in Figure 4. This is an indication that IR heating is not taking place. We know that IR heating will not take place over ice or snow, because both the temperature and the emissivity are low. It does not take place over water because the water temperature and air temperature over it are usually very close. Any heat generated by IR is lost to water evaporation.
What happens to an inferior mirage when CO2 increases? The atmosphere becomes a bit more opaque at the wavelengths where CO2 absorbs energy, and the height where the energy is absorbed lowers slightly. Instead of 95% absorbed at 1 meter, we have 95% absorbed at 80 cm. Only where it is absorbed changes, not how much. There would be little difference in appearance of the mirage, and no difference in heating.
What happens further up in the atmosphere? For that I bow to others. It involves a concept called Local Thermodynamic Equilibrium. Tom Vonk has a good explanation here. The CO2 in the atmosphere is in Local Thermodynamic Equilibrium (LTE) up to about 100 km. If the atmosphere is in LTE, an increase in CO2 does nothing. It is only at the top of the atmosphere that CO2 can radiate heat to space, and more CO2 there will result in more radiation.
At the top of the atmosphere (TOA), if there is more CO2, there is more long-wave radiation to space, and the high atmosphere cools. Google Local Thermodynamic Equilibrium on the web; you will see many articles talking about non-Local Thermodynamic Equilibrium. Many of these are discussing cooling at the TOA by ozone, CO2, and other processes.
Some readers will say that my explanation is wrong; that an inferior mirage is simply from the surface heating the air by conduction. Air is an insulator. There is some heating of the air by convection, especially if the surface is sloping or irregular, but most of the air heating is by radiation.
There is no “back radiation” if the air is cooler than the surface, because heat (radiation) cannot flow from a cooler body (the air) to a warmer body (the ground surface). There is only radiation upward from the hot ground to the cooler air, which is then absorbed by the CO2 in the air. If the air happens to be warmer than the ground, then radiation can flow the other way and heat the ground, but this is rare. For a good tutorial on the subject of heat flow, go to this site, and download Chapter 26 – Heat Transfer.
In summary: The ground surface is heated only by solar shortwave radiation. This heats the ground, which then radiates long wave IR back into the atmosphere. At the wavelengths where CO2 and water vapor are opaque, this IR is absorbed and heats the atmosphere. If CO2 increases, only the height at which this happens changes. This height is very close to the surface, on the order of 1 meter or less. Back radiation only happens if the air is warmer than the ground. At elevations above 1 meter, the atmosphere is in LTE and increased CO2 does nothing. At the TOA, increased CO2 can radiate to space, cooling the TOA.
Increased CO2 warming is nothing but a mirage.
Thanks Ed. It is good for me as an outsider that you made clear that back radiation exists, but that a cooler object cannot influence by back radiation the temperature of a warmer object. Is this correct?
The cooler object can influence by back radiation the temperature of a warmer object, but consider the mass involved. The usual thought experiment uses similar masses of different temperature. In the case of the ground and the air, the masses are different by a very large factor, and in the case of CO2, where the presence of CO2 is 390 parts per million, the masses are different by an even larger number.
For more on this see:
http://www.physicsclassroom.com/class/thermalP/u18l1d.cfm
Nice essay, two points from a layman. Can back radiation from CO2 take place from the first direction of the heat from the sun? In which case would the affect be equal to the back radiation from the Earth? Second what percentage of back radiation can be attributed to manmade CO2?
I hope I understand your questions. “Can back radiation from CO2 take place from the first direction of the heat from the sun”. At the top of the atmosphere, CO2 is radiating long wave IR, the blue area in figure 3. The incoming radiation from the sun is the red area in figure 3. They are at different wavelengths.
But your second question, “In which case would the affect be equal to the back radiation from the Earth?”, the outgoing radiation is equal to the incoming radiation.
Your last question, “Second what percentage of back radiation can be attributed to manmade CO2”. The radiation, where found, is proportional to the amount of CO2, so the percentage will be the percentage increase in CO2, assuming all that increase is manmade CO2. Most of the increased radiation will be at the top of the atmosphere, outward, to space.
You can talk your ass off trying to convince warmists that the CO2 GH effect is practically saturated and any small increase will be completely overwhelmed by even the slightest change in UHI, land use change or clouds, and all they’ll do is wave the logarithmic formula for CO2 radiative forcing and not listen to you. After all, that’s what’s build into the models and the models are god and tell us the future up to 2100, at least when we run all variations we have and average the output. Oh my, oh my, you really can’t use warmist researchers in the productive sector, they would mess up all industrial processes.
Ed
Thanks for an illuminating article. Why C02 is declared a pollutant in the US is beyond my understanding. It is clearly a politcal decision and not science at all .CO2 is not part of any air quality index either and hence harmless to humans . I am with you about the warming effect of CO2 gases being negligible .That is why I feel the very minor global warming from manmade greenhouse gases has always been dwarfed by the cooling from natural planetary cycles and why cooling is ahead for us for the next little while. It will be very interesting over the next several decades to watch the global temperatures go down while CO2 continues to rise . I can imagine the excuses that will be presented why all the warming forecasts failed .The reasons the forecasts will fail is what you quite rightly point out.
The EPA in the US cited the IPCC as scientific authority for its ruling. A big fight in the new Congress and in the courts is starting over that.
Edit: a couple of places, you’ve used “were” instead of “where”.
I despise warmism, but don’t buy the “cool can’t radiate at warm” objections. Cool doesn’t ‘know’ where its output will go. If the CO2 radiation happens to land on a cooler spot, it will warm it, and that same cooler spot won’t have sent as much along the ‘return’ path, so it net warms. If the CO2 output happens to strike a warmer spot, that spot will become even warmer, but its output along the ‘return’ path will have exceeded the CO2 output.
Of course, each “output” cools the source by exactly the energy involved, and the two sources will approach equal temperatures in the absence of other “forcings” or sinks.
While the net result of such exchanges is always warmer cools, and cooler warms, there is no question that the process involves some retro-flow towards the warmer source (unless you’re Prof. Claes Johnson, mathematician, who asserts that a blackbody source can only reflect, never absorb, incoming radiation at lower than its resonant frequency.) So if you’re talking about “radiation can flow” only one direction, you must always precede it with “net”. “Net radiation can flow” is thermodynamically constrained. “Radiation can flow” is not.
PG will need to make the edits.
In the case of heat exchange between the ground at the CO2 in the atmosphere, the masses involved are so different the “net radiation flow” is usually only in one direction, from the ground. See:
http://en.wikipedia.org/wiki/Heat_capacity
If the ground is cooler than the air, it takes a long time, and a lot of heat difference, for the flow in the reverse direction to amount to much. Think about snow in the shade, even on a sunny day. If the air is still, not much happens.
Editted
Just to “clarify” my overall conclusion/opinion, it still matches yours.
Incoming sunlight warms the surface and the air. The total warming is a result of absorption minus (net) radiation. The outgoing 15um band is blocked, but that blockage is compensated by heightened radiation in other bands as that energy is thermalized. The net result is minuscule.
Brian H,
Yes. That is a good point I neglected to mention.
Every time Rob and his girlfriend come by, it becomes real fun here. His Nobel Prize Argument is not quite new but still can be re-used several times.
Well, there you go, Ed. I’m buying both Dana and me plane tickets to the Nobel Prize awards ceremony to watch you accept your prize and shake your hand. You’ve just saved the whole planet.
You forgot the /sarc.
Ed… You really need to write this up into a paper fast before someone steals your work! I’m sure Nature will put this on the fast track and get it published as soon as possible. You’ve literally shattered the science world and overturned 150 years of physics. Your name is going to be remembered along side Newton and Einstein for this seminal work.
You get a gold star for sarcasm today, Rob.
I am surprised. though, that you did not add Mann and Schmidt to Einstein and Newton.
When people are making utterly absurd claims (and others are swallowing them without a modicum of skepticism), sarcasm is a pretty natural reaction.
Pierre… Extraordinary claims sometimes call for extraordinary sarcasm. 😉
DENIER!
Not only that, but he’s disproven centuries-old physics with a simple blog post! Not to mention disproving empirical observations of increased downward IR radiation at the surface and decreased upward IR radiaton at the TOA from the enhanced greenhouse effect.
http://www.eumetsat.int/Home/Main/Publications/Conference_and_Workshop_Proceedings/groups/cps/documents/document/pdf_conf_p50_s9_01_harries_v.pdf
Quite amazing indeed. Though one has to wonder where the skepticism of the skeptics went if they’re to swallow these rather astonishing claims without question.
The center of the CO2 band is at wave number 667. They didn’t look there, and the difference seems to be sloping up in that direction. Try again.
Ed… Are you saying the authors are misleading people by suggesting that CO2 absorption also occurs between the 700-780 wave numbers?
Hmmm… It seems that Kiehl and Trenberth have measurements that don’t agree with your assumptions.
http://citeseerx.ist.psu.edu/viewdoc/download?doi=10.1.1.168.831&rep=rep1&type=pdf
No, I’m not saying they mislead people. But the spectrum at 700 and higher is the edge of the CO2 band. It doesn’t include the peak.
I’m not saying that CO2 has no affect. I’m saying that increased CO2 has little affect. It has done what it is going to do. Remember, the affect is logarithmic, and we are at the top of the curve.
What you’re saying is wrong and contradicted by empirical data. And no, we’re not “at the top of the curve”.
http://www.realclimate.org/index.php/archives/2007/06/a-saturated-gassy-argument/
http://www.skepticalscience.com/monckton-myth-3-linear-warming.html
CO2 logarithmic affect:
http://en.wikipedia.org/wiki/Radiative_forcing
http://wattsupwiththat.com/2010/03/08/the-logarithmic-effect-of-carbon-dioxide/
http://www.junkscience.com/Greenhouse/
http://brneurosci.org/co2.html
http://www.drroyspencer.com/2010/09/on-the-relative-contribution-of-carbon-dioxide-to-the-earth’s-greenhouse-effect/
Of course you won’t believe these sources.
“We reduce the standard atmosphere
tropospheric specific humidity profile by 12%
to ensure agreement between the model and observed
global mean clear sky flux. The need to adjust the water
vapor profile may be due in part to a bias in the
longwave clear sky ERBE data (see Hartmann and
Doelling 1991; Kiehl and Briegleb 1992).”
As usual – when model and data don’t agree, torture the data until it confesses. 😉
Ed stop with the strawman please. I didn’t say the effect wasn’t logarithmic (if you read my article, I specifically talked about the logarithmic effect). What I said was that we’re not “at the top of the curve”. Please pay more attention.
Thank you for this reference, Dana.
I have but one question: To compare observed and modelled spectra, weren’t atmospheric temperature profiles modelled? Weren’t temperatures adjusted in the study to make the modelled and observed spectra agree? In the case of methane, the adjustment could be made to match CO2 but the same adjustment would not fit methane.
The question is, would different assumed temperature profiles produce different results? Are there temperature profile(s) that obliterate any observed radiation contribution of greenhouse gases?
In Chen 2007, observational data were compared to simulations from a line-by-line radiative transfer model. The observational data weren’t adjusted.
Dana and Rob,
Upper atmosphere cooling:
http://www.atmosphere.mpg.de/enid/20c.html
http://www.wunderground.com/resources/climate/strato_cooling.asp
http://www.realclimate.org/index.php/archives/2006/11/the-sky-is-falling/
http://yly-mac.gps.caltech.edu/Reprintsyly/A_RecentPapers/Zjunk/Feldman05.pdf
http://www.nature.com/nature/journal/v283/n5743/abs/283189a0.html
Shall I go on?
Ed, upper atmosphere cooling is a signature of the enhanced greenhouse effect!! Are you trying to disprove your own blog post? Because you’re doing a great job of it.
You beat me to it.
I said that IN the blog post. Read it again.
So what’s your point?
Interesting paper. Last sentence:
“In the future, we plan to extend the analysis to more spatial and temporal regions, other models, and to cloudy cases.”
Let’s see how well the assumptions of the century-old physics of AGW and the models hold up in the non-trivial cases. I think i’m on firm ground when i say that we will see corrections to both.
Thank you, Ed for taking the time to do this. This reflects my thoughts exactly.
Really? Brian, you also overturned 150 years of physics? This is phenomenal!
Any clues why the planet isn’t a lifeless frozen ball of ice?
Water vapor, continually present in the atmosphere and distributed by the winds, prevents excessive cooling of the Earth through the night, making it possible for the Sun to warm the Earth sufficiently during the day, and on the average, habitable.
Thank Heaven for water vapor.
Yes, remember that Venus doesn’t have any water vapor.
On another topic of contention, I note that no one has calculated the influence of sulphur trioxide and water vapor to form sulphuric acid clouds of Venus to contribute to the atmospheric heat of Venus.
I believe that dust particles in Venus’s atmosphere catalyze the oxidation of sulphur dioxide to sulfur trioxide to form sulfurinc acid droplets, when they coalesce to form larger droplets they fall to Venus’s surface, where they are decomposed back to water and sulphur dioxide by volcanic heat. This is the endothermic portion of the cycle.
In this way, Venus’s volcanic heat becomes a permanent part of Venus’s atmosphere. I think the contribution of CO2 in Venus’s atmosphere has been far exaggerated (by J Hansen and others, which is the source of his paranoia about CO2 in the Earth’s atmosphere)
Brian… Without the well mixed GHG’s you have no WV in the atmosphere. Hence, you have a lifeless frozen planet.
I’ve always looked at the greenhouse effect of CO2 in the air as white paint on a dark wall. The first coat (0-100 ppm) makes the wall pretty much white. The second coat (100-300 ppm) makes it more white. A third coat maybe makes it a tiny bit more white, but you can’t really tell. After that you can put on as many coats as you’d like, but it isn’t going to get whiter.
http://www.realclimate.org/index.php/archives/2007/06/a-saturated-gassy-argument/
Rob, you and Dana with your 150 years since Fourier. If all that science is so rock-solid, why do we keep seeing papers with new and unexpected results, and why are there still researchers measuring stuff (granted, only an estimated 1% of climate scientists bother with reality, but still.). So i guess, “the science is settled” for you. In that case, don’t click this link.
http://www.cato-at-liberty.org/the-current-wisdom-better-model-less-warming/#more-25490
Dirk… Give me a break. The Cato Institute? That’s like asking the fox to inventory the hen house.
Give Cato a break!!!
Preservation of a free economy => wealth for average citizens => contributions to greenie weenie groups on which they exist
Free market thinkers only want to preserve the opportunity for everybody to have an acceptable standard of living!
In every controlled economy the only thing we see is serfdom and excessive wealth, with nothing in between!
This is why it is vital to prevent the free world ending up controlled economies!
OK, then go here if Cato gives you a rash.
http://findarticles.com/p/articles/mi_7598/is_20101201/ai_n56547562/
It doesn’t look like they were lying.
“Free market thinkers” only want to keep the funding from oil companies flowing into their pockets.
“MIROC5 reveals an equilibrium climate sensitivity of 2.6 K”
That’s your revalation? That climate sensitivity is well within the IPCC range (2 to 4.5K for 2xCO2)? Stop the presses! /sarc
I’ll never understand greenie weenie economic thinking in my life.
Solar panels + windmills + biofuels = economic death ticket. I’m not buying into it.
There’s no reason to return to the dark ages, none. Those were the days of a short, brutish life. Horrible.
“Solar panels + windmills + biofuels = economic death ticket. I’m not buying into it.”
I’m not buying that green tech is an economic death ticket either. Well said!
“There’s no reason to return to the dark ages”
Wow, I didn’t realize that solar panels and electric cars were around during the Dark Ages.
They might as well have been, life for average people wouldn’t have changed all that much.
Do you realize the electrical requirements just to keep a sanitary water and sewer system working? You can build aqueducts but you can’t make that work for a city with a million people.
Never mind the accouterments of modern society like going to the grocery store or traveling on aeroplanes or playing around with video games or Facebook.
Dana, one thought about wind and solar. If these systems were economically viable they wouldn’t need subsidies. What would happen to the price of these systems if we would have to produce them with the energy they provide themselves? At the moment they are produced using cheaper sources of power.
The price would go up. Drastically. A solar cell (polycristalline silicon) needs as much power to create it as it will produce during 10,000 hours of full insolation (about 1.2 kWh/m^2 solar energy; delivering about 18% of that as electricity. So, when you use solar power for the production, (about 40 US cent, current German feed in tariff) instead of, say coal-powered electricity (about 7 US cents bulk prize), the cost of the cell goes up by a factor of more than 6. (Assuming that energy is the biggest contribution to its prize).
The numbers for wind are probably less drastic but what i want to point out is that the high prize for these systems could not be paid by a society that relies only on them. They are ATM a luxury that we can only afford because we still have cheap conventional energy.
This situation might change in the future, but only if production processes can be made much more efficient. I am optimistic that this can be achieved, but it will also mark the end of the need for subsidies. IOW, the subsidy regime is useless as a means to produce energy, it is only useful to direct the redistribution of money in certain ways. And the time for wind and solar will arrive as soon as they are economically viable. What we are doing now is useless; energetically and economically.
So any technology that requires subsidies is economically unviable?
I guess that takes fossil fuels and nuclear out of the mix too. Maybe Brian is right, according to Dirk we do need to go back to the Dark Ages!
Simple answer : because even a flat gray ball in our orbit has a mean temperature about 4 degrees warmer than 0 Celsius .
Bob… Do you realize that the mean temperature of the moon at the equator is 220K? That’s -53C.
So, I don’t think that argument holds water (so to speak).
I’ve seen a value of 2C for the Moon’s average temperature . In any case , the computation for a flat gray ball stands . Pray show us what sort of spectrum is required to produce such an extremely cold object in our orbit – even colder than the impossibly cold ( given our measured .3 albedo ) 255k asserted for a naked earth .
How Germany, of all places, could be home of any “global warming catastrophe” type of “science” will be the only sociological mystery to me until I die.
Sure, Germany has had her share of “socialist” political thinkers, but these have never had any bearing on the scientific contributions Germany has made.
There’s no explanation. I can understanding it coming from the UK and the US, but there’s no reason why Germany would be in on this.
The reason is the will of the politicians to have a diversity of energy sources to reduce the dependence on gas and oil imports. AGW is used as a convenient scapegoat; it also helps to neutralize the Greens – you get the people to agree on paying outrageous energy prizes and pretend you do it for Gaia. And the best thing is, Germans are fuming about the latest prize hike but blame it on the greed of the big electricity providers (the media nudges them into that direction). In fact, German utilities are not especially greedy – example EON: price to earnings ratio 11, 5.3 % dividend – i see nothing greedy going on there. Germans don’t even know that 70% of the consumer electricity prize are taxes and levies. They’re not paying attention, and the German mass media don’t explain it.
Oh, and most Germans don’t know squat about company valuations, profits, or how the stock market works. We don’t learn that in school. In fact, that’s the very reason most Germans are socialists of one breed or another.
Pielke posts a preliminary analysis of ARGO 2005-2010 (not yet ready for publication) by Josh Willis, with explanations from Josh.
http://pielkeclimatesci.wordpress.com/2011/02/07/where-is-the-missing-argo-upper-ocean-heat-data/
Looks like the rise of OHC is much less than would be expected according to the centuries-old physics of AGW.
That could also explain why it’s not warming. 😉
Ed,
Thank you for taking time to write up a clear and straightforward explanation of so called back radiation. Yes, CO2 does act as an insulator trapping LR – but what is interesting and worthy of examination is:
How much? and to what effect?
Empirical measurement indicates little to nothing from the Man-Made fraction. Shouldn’t we see something outside of historic variation from all our sophisticated measurements?
As DirkH points to lack of predicted ocean heating (ARGO floats); the heating just isn’t happening according to script. Here’s the satellite data of the atmosphere:
http://www.drroyspencer.com/wp-content/uploads/UAH_LT_1979_thru_Jan_2011.gif
That satellite clearly hasn’t been tortured enough.
Honestly, Ed… Do you not possibly see the absurdity of posting a blog article that essentially refutes the basic radiative physics of CO2 that have been established and repeatedly measured over the past 150 years?
Basically you are asking people to believe that your article is correct and 10’s, if not 100’s, of thousands of published scientific research papers on climate change are wrong.
Do you not see how, if any of what you’re saying here is correct, then you have fundamentally changed an entire field of research? …With a blog post.
Rob,
When I started looking into this I found that there were no papers explaining “back radiation”, just hand-waving. One of the first things I discovered was that no one had actually measured the time between radiating a CO2 molecule and when it re-radiates the energy. The two numbers quoted are all I could find. The only numbers available are from measurements of CO2 lasers using pure gas, or CO2 N2 mixtures under pressure. The second number I cite is from a paper where the author lamented that “Further progress in this
field requires experimental determination of accurate values for the vibrational relaxation time of carbon dioxide-air mixtures so that accurate cooling rates in the upper mesosphere may be calculated.”
I suspect that work has not been done at surface pressures because people don’t want to know, or think they already know.
I have not fundamentally changed an entire field of research, because that research doesn’t exist. Perhaps this might trigger some, if only to prove I’m full of it. Sarcastic comments on my hubris don’t cut it.
Really? There are NO papers on back radiation? Did you do a search?
No Rob, not really.
I’ve linked to several papers measuring back radiation (a.k.a. downward longwave radiation). Though to be fair, Pierre seems to have deleted my post with links to 4 such papers. Science of Doom also has some good discussions about it.
http://scienceofdoom.com/2010/07/17/the-amazing-case-of-back-radiation/
http://scienceofdoom.com/2010/10/06/does-back-radiation-heat-the-ocean-part-one/
I didn’t delete it. Posts with too many links get held up by the spam filter and first have to be approved. I’ve approved it. We’re not afraid of anything you have to say, dana. And plus, this isn’t RC. NTZ is a free and open society. We can deal with debate, here. Nobody here is too good or too special.
I’ve been through Science of Dooms posts. The closest he comes to describing back radiation is this:
“Why does the atmosphere radiate? Because it is heated up via convection from the surface, solar radiation and surface radiation. The atmosphere radiates according to its temperature, in accordance with Planck’s law and at wavelengths where gas molecules are able to radiate.
There isn’t any serious theory that the atmosphere doesn’t emit radiation. If the atmosphere is above absolute zero and contains gases that can absorb and emit longwave radiation (like water vapor and CO2) then it must radiate.”
Which I agree with. But that isn’t the level of detail I describe in my post. It ignores the fact that the greenhouse gases absorb, radiate, AND interact thermally with the other gases in the atmosphere, all in a continuous fashion until either the ground, sea, or space intervene.
I stated in another location on this thread, but I’ll repeat it here: Back radiation is NOT the same thing as Downward Long Wave Radiation. Downward Long Wave Radiation is the total Long Wave Radiation one measures if the instrument looks at the sky. Back radiation is that portion of Downward Long Wave Radiation that is due to the upward Long Wave Radiation from the ground.
Ed… I apologize for the sarcasm but what you’re proposing here is nothing short of astounding. What you are claiming DOES in fact dramatically change the field because what you’re claiming is contrary to empirical evidence and contrary to all published science on climate change. If what you are saying is true you would quite literally (not joking!) win the Nobel Prize. In that I’m not being sarcastic. It’s the truth.
Let’s just take a step back and return to reality for a second.
Nobody in the real world disputes the increased greenhouse effect. Not even the ‘skeptic’ climate scientists like Lindzen and Spencer. This is not controversial science in the least. The increased downward IR radiation has been observed (I added links to 4 more papers on the subject, but Pierre seems to have deleted that post).
Bottom line – CO2 warming is real and observed. If you want to argue that the climate isn’t very sensitive to that increased IR radiation (like Lindzen and Spencer do), then at least you’ve got a scientific leg to stand on. But claiming that an observed effect doesn’t exist is just ludicrous.
I’m not disputing the greenhouse warming by CO2. I’m not saying the observed effect doesn’t exist. I agree with Lindzen and Spencer. The downward IR being measured is the total downward IR in the parts of the spectrum where the atmosphere is transparent plus the downward IR that is visible to the sensor from the atmosphere in front of it that is radiating through the gases that are absorbing and re-radiating. Some of that radiation is from molecules far away, and some from molecules only cm away, and all the range between depending on the wavelength. Changing the CO2 amount doesn’t change the total radiation, just the distance on the sides of the peaks.
Ed… What I’m gathering that you are saying is that CO2 has little effect because the CO2 effect is saturated, therefore adding more CO2 to the atmosphere will not absorb any more radiation. Am I right?
This is NOT what Lindzen and Spencer claim. They hang their hat on other mechanisms that provide a negative response to any additional warming from CO2. Cloud effects, specifically, for Lindzen. They both claim that adding more CO2 will, actually, act to warm the planet. They just say that the sensitivity to adding CO2 is very low. Lindzen claims that climate sensitivity is 1/3 of the IPCC low range estimate, again, not because of the CO2 effect being saturated, but because of other factors that will offset that warming.
To be clear, the temperature change is the sensitivity multiplied by the radiative forcing. What Lindzen and Spencer dispute is the climate sensitivity parameter. What you’re disputing is the empirically-measured CO2 forcing. You are not agreeing with Lindzen and Spencer. They don’t dispute the well-known anthropogenic CO2 forcing.
Rob,
First paragraph. Yes
Second paragraph. They are saying that (the first paragraph) plus negative feedback from clouds. Both put the sensitivity at around 1° for CO2 doubling. Spencer found that number from Pinatubo forcing. In his book, The Great Global Warming Blunder, he finds the same sensitivity at 1° and 1.5° using two other methods. You will recall from CO2 is Cool that I found a minimum sensitivity using the temperature change versus the CO2 change of 1°. It is all the factors together.
No, they’re not saying that. Lindzen and Spencer don’t use the saturated gassy argument. Unless Spencer makes it in his book or something, but he’s never made it on his blog as far as I’m aware, and certainly not in any scientific papers.
Sensitivity – yes, they think is low. But they don’t dispute the forcing value, or the amount of downward longwave radiation from CO2.
I could be wrong, but I don’t believe Spencer or Lindzen believe that CO2 forcing can or will have a discernible” influence amidst natural variation.
I recall Lindzen saying, the evidence is that “persistent” changes in climate are all attributed to orbital influences, I couldn’t agree with him more.
Lindzen also describes an “iris” effect comparable to the radiant forcing component of CO2, masking any apparent influence we could measure.
Of course. There are lots of papers that mention CO2 back radiation, but none that go into detail on the mechanism. They just quote Trenberth or talk about quantities without any description of how they arrive at their numbers.
Ed… Have you tried Harries 2001? – Increases in greenhouse forcing inferred from the outgoing longwave radiation spectra of the Earth in 1970 and 1997
That’s TOA, not ground level.
Fine, then try Evans 2006
http://ams.confex.com/ams/Annual2006/techprogram/paper_100737.htm
Or Philipona 2004
http://www.slf.ch/ueber/mitarbeiter/homepages/marty/publications/Philipona2004_IncreasingGhE_GRL.pdf
Evans:
They didn’t measure the radiation flux at two different times. They measured and compared to a model. The model may not be reality. They also didn’t describe any mechanism. They just made measurements. I thought this was interesting:
“4. CONCLUSIONS
Measurements of the downward
radiative flux have been made for several
important greenhouse gases. At mid-latitudes
in summer as compared to winter, our
measurements show that the downward
surface flux from H2O has doubled to 200
W/m2. The water increase causes a reduction
of the fluxes from the other greenhouse
gases.”
They seem to have used their model twice here, doubling any error if the model doesn’t mirror reality.
Philipona has the same problem with increased cloud and humidity and reliance on a model for the earlier time. But both of these papers are measuring Long Wave Downward Radiation, not “back radiation”. Back radiation is supposed to be the radiation back to the ground resulting from upward radiation from the ground. LWDIR is not the same thing. It is the total LW downward radiation from all sources.
I have no idea what this sentence is supposed to mean:
“Back radiation is supposed to be the radiation back to the ground resulting from upward radiation from the ground.”
As for this one: “LWDIR is not the same thing. It is the total LW downward radiation from all sources.”
The whole point of these observations is that they use spectrometers to break up the spectrum so they can pinpoint the increase specifically due to CO2, water vapor, methane, etc.
You’re just going to have to accept that the increased greenhouse effect is well-measured, Ed. That’s reality.
Dana writes:
“Let’s just take a step back and return to reality for a second.”
Great idea. Where is the catastrophic heating from man-made CO2?
Show me something catastrophic in the atmospheric, oceanic, or sea-level rise indicating the margin of man-made CO2 is creating a catastrophe.
Greg… The point is to AVOID the catastrophic. If humanity can’t find a way to address the issue of the enhanced GHG effect, then hang around a few decades and you’ll start to see more clear signs of catastrophic.
In the meantime, we have more than ample evidence to clearly understand we are headed that direction.
Run for the hills! The actual acceleration is -0.13 (mm/yr2).
http://theinconvenientskeptic.com/2011/02/determining-the-true-acceleration-of-sea-level-rise/
I’ve had lots of conversations with John at his site, at Skeptical Science and in private emails. Look, John Kehr is a nice guy but he’s way out of his field of expertise on this subject and applying the same confirmation bias that goes on here.
I’m the guy who got him to stop using the GISP2 data for his header graphic. Not that he isn’t committing the exact same error with his new header… but that’s another story.
You could look at actual peer review research rather than reading a blog posting from someone commenting on something outside their field…
http://www.agu.org/journals/ABS/2006/2005GL024826.shtml
That paper used data only to 2004, and one can’t tell where the acceleration is calculated from. It’s out of date.
Nice paper, but it only goes up to 2004 while John Kehr is looking at 2004 – 2010.
Come on guys! You can’t be serious.
Here again, because someone has published a blog post, which you want to agree with, on a topic WELL outside of his field of expertise you are willing to completely dismiss a large body of published research that is contradictory without even doing any digging? Really?
Once again, this is not skepticism!
Actually I don’t have a problem with Kehr on this one. Sea level rise has been pretty linear over the past 15-20 years because global warming has been pretty linear over the past 15-20 years. As global warming accelerates, so will sea level rise.
Again we go back to my falling off a cliff analogy. The fact that the current data doesn’t tell us catastrophe is imminent doesn’t mean that a catastrophe isn’t forthcoming.
But Kehr is trying to claim that it’s DEcelerating based on the past 6 years of data.
Okay well that’s just dumb. If you want to argue that sea level hasn’t risen as rapidly over the past 6 years as it has over the past 17 years, that’s fine and accurate. If you want to extrapolate that to claim that sea level rise will continue to decelerate in the future based on 6 years of data, then Rob is right, that’s dumb.
Rob,
Yes, I agree with you; let’s avoid catastrophe.
For an engineer like me though, I need to see just what that catastrophe consists of and according to all measurements, as imperfect as they may be, of ocean temperature, sea-level rise, and atmospheric temperature there is no catastrophe occurring.
Show me some of the ample evidence please.
Analogy – let’s say you’ve fallen off a cliff. You’re falling towards the ground, but other than air resistance, you feel fine. You can’t tell that you’re headed towards a catastrophe unless you use a model to predict that (i) you will impact the ground and (ii) the force from the impact is going to have some nasty effects on your physiology.
What you’re saying is that based on current observations alone, we can’t know that a catastrophe is looming. No question there. But we can project that a catastrophe is coming in the future, in a business as usual scenario.
That is the worst analogy I’ve ever seen! By that light I would be afraid to get out of bed in the morning. Your glass isn’t half empty, it’s bone dry.
Ed… It’s actually a great analogy because, based on all the evidence presented in the literature, we have a clear picture of what’s going on. We might not have an exact number for how fast we’re falling, or coefficient of air friction moving past our body, but we know the direction we’re headed. We currently even have the tools at our disposal to stop the fall. The only thing lacking is the collective will to acknowledge our predicament.
What’s the difference between global warmers and Soviet communists?
The Soviets didn’t necessarily want to demolish Western civilization (with H-bombs) to make the West socialist. They would have preferred not to go that route.
Global warmers believe that the only way to make the west Socialist is to demolish Western civilization.
Brian… That pretty much tops the stupidest thing I’ve ever read. Personally, I believe in the power of the marketplace and human ingenuity to both address what is a grave issue and help to create a cleaner, safer, freer world… all at the same time.
“I believe in the power of the marketplace “
Right now the “marketplace” wants fossil fuel. The only way this preference will change is, um, imposed socialism.
Wow. Well, at least Brian didn’t call us Nazis.
Geez Pierre, with friends like Brian, who needs enemies?
Godwin loses.
Brian… The marketplace, in a Libertarian sense of the word, wants the whole world hooked on crack cocaine. That doesn’t mean it’s a good idea.
What I mean about marketplace is the drive to create better solutions that help us all live better lives.
Gotta go to my put off assignments, but, I won’t deny, I just love petroleum. And coal too.
These things help people, I just think they’re fantastic.
I don’t “profit” through their trade (only by the energy they bring), but I just think they’re super duper extra wonderful fantastic marvelous.
[I put my actions into words, too. I was part of the US effort in Iraq 2004-2006 in part so that the world could benefit from Iraq’s oil supply to the free market]
No doubt about it. Oil is an almost magical material! We can turn it into a vast range of products that benefit humanity. It has been the source for the tremendous advancement of human civilization.
That does not diminish the fact that the by product of burning it in the vast quantities it is having a deleterious affect on global temperature. No one wants for this to be the case. I’d be happy as a clam if it didn’t. As mentioned before I’m a licensed private pilot and would love to be spending my time flying instead of debating here.
The science is clear about this. Humanity needs to take the situation seriously.
Greg said… “how me some of the ample evidence please.”
All I can say is, get truly skeptical. Challenge your own position. Go read the research for yourself. Not the blogs. Not just Lindzen and Spencer. There are hundreds of thousands of research papers published on a wide range of climate change issues. Taken as a whole there is no doubt whether we are warming the planet. There are uncertainties about exactly how sensitive the climate is to increased GHG concentration. Those are also clearly defined.
What I stated here a couple of day ago is, we’re making a roll of the dice here. If climate sensitivity is low the effects might not be catastrophic. If they are mid-range (3C) but we continue business-as-usual the effects are going to be bad. If climate sensitivity is high (4.5C+) and we do nothing to mitigate our output of CO2, then we bequeath to our grandchildren what likely amounts to an extinction level event. I’m not making this up. This is what the research tells us.
In that, we have choices. We can’t control what number the dice are going to land on, but we CAN control what numbers the dice won’t land on.
Rob,
Right on. My mind is open. Or at least I try to keep it open but not so much that my brains fall out.
I didn’t pay much attention to CAGW until Climategate and the corruption of climate science. Now I check the science out myself – and I keep my eye on indicators like GATA, sea-level rise, historical and paleoclimatic reconstructions, and weather patterns.
So far, the conjecture that there is a crisis, or even an impending crisis due to man-made CO2 just does not hold water.
Now having said that, does man-made CO2 add to global warming due to its insulating properties? Perhaps. It really depends upon feedbacks within the encompassing climatic system because those feedbacks may be positive, negative, relatively weak or relatively strong.
Perhaps as Ed has stated, the insulating effect of man-made C02 is weak and thoroughly overwhelmed by naturally occurring weather patterns with a historic cyclical pattern because whatever insulating properties CO2 possesses have already been accounted for – we are at saturation as far as CO2 is concerned and adding more will have little to no effect.
Perhaps there is some process in the climactic system that is compensating for the added fraction of man-made CO2 and that process is about to reach its point of saturation and once that happens there will be a tipping point.
Physical evidence so far supports Ed.
But I’m keeping my eye on the measurements anyway.
“Physical evidence so far supports Ed.”
No. Apparently you’re not paying attention. Direct empirical measurements directly contradict Ed.
Seriously guys, you object to being called deniers, but here you are denying empirically-observed data. If you want to be considered skeptics, then start behaving skeptically. Don’t buy into what Ed says just because it’s what you want to hear. I’m sorry, but Ed is wrong. I’ve produced several papers measuring the effect that Ed claims isn’t there.
You need to stop denying empirical observational data and start accepting reality. I know you can’t accept that humans are causing dangerous global warming, but that doesn’t mean you have to latch onto every “skeptic” argument that you come across. That’s the sort of behavior that makes you almost impossible to take seriously. It’s an illustration of extreme bias clouding your judgment.
I think both Dana and I have both shown today, repeatedly, that the physical evidence does NOT support Ed on this one. Not by a long shot! If you’re in with Ed on CO2 being saturated then you stand alone, well isolated from even Lindzen and Spencer.
And what corruption shown in the climategate emails? Can you please point to one that every independent investigation that looked into the matter missed?
Global temp is back to the level of 1979 according to UAH. The simplistic yet stunningly accurate SOI prediction says it’ll drop further. 150 years of AGW science for the gutter.
http://joannenova.com.au/2011/02/the-soi-still-rules/
Counting chickens again I see. Don’t forget, the climate is a very noisy beast and a few months of data does not constitute a trend by any stretch of the imagination.
Oh, and actually Dirk, you’re wrong.
http://www.drroyspencer.com/wp-content/uploads/UAH_LT_1979_thru_Jan_2011.gif
The UAH anomaly is back to the 30 year mean. It’s also back to the peak high between 1979 and 1982. It’s far from being anywhere close to the peak lows of the 1980’s.
Dana, and Rob,
Got to run – trying to get home from work but very briefly two things:
Thanks for the discussion – I find it interesting if utter unconvincing.
I will get back with you after I get home (unless happy hour gets to me first!).
Dana first,
“You need to stop denying empirical observational data and start accepting reality. I know you can’t accept that humans are causing dangerous global warming, …”
Groundless assertions. Please provide data/links etc. And how on earth do you know that I “can’t accept that humans are causing dangerous global warming…” Gee, I had no idea you knew me so well. (just kidding!).
Of course human cause global warming – land use/UHI (we built these cities after all)/industrial particulates/ and of course, CO2. Question in my mind remains – how much warming can we attribute to man-made CO2; or even by what methodology can we come to such a conclusion; and where is the physical evidence of said warming?
Now comes the “dangerous” part. Please give me some feel for this so-called danger. Not groundless assertions but real danger linked to man-made CO2. I am genuinely curious and do not intend the question as a rhetorical question.
Rob,
Leaving aside assertions and arguments of so-and-so said this-and-that so Ed is wrong – can you give me a quick summary of Ed’s technical errors? I apologize if I haven’t picked them up from your previous comments…I’m at work but will go home and re-read for comprehension.
Greg… So you believe that Ed has overturned 150 years of radiative physics? Dana has pointed to several papers on the matter. We’ve both pointed out the actual measured data that show him wrong. I honestly don’t know what more you could want.
I’m even perfectly willing to entertain the idea that Ed might be right. In that case he should be eager to write this up and publish it as a paper. Put it to the test of science. See how far it gets.
If I sit here and try to disassemble Ed’s piece I’m doing little more than what Ed is doing, hacking out a highly speculative response. I’m resting my case on the fact that there is a vast body of science that suggests his results are in error, and I’m trusting the actual experiments and measurements already done in this area that also show Ed is wrong.
Rob,
Here’s a look at the equipment used to measure LW Downward Radiation:
http://www.kousou-jma.go.jp/english/obs_third_div-e/index3rd_top_e.htm
Questions:
1. How far off the ground is this measurement being made?
2. What does the ground under the equipment look like, relative to a black-body?
3. If the mean path before absorbence is 1 meter, and the measurements assume a black-body ground, what will be the affect of 1 and 2 on the LWDWR?
Let me get this straight. You’re saying the effect you’re talking about is not measured because the instruments measuring are too high off the ground?
Exactly. If you read the article, and followed the links supplied, you will see that the effect happens largely within 1 meter of the ground.
And if that’s the case… what are the instruments measuring here:
http://scienceofdoom.files.wordpress.com/2010/06/spectra-h2o-co2-o2-n2.png
Thermal radiation from the CO2 in the air. In the case of the center of the CO2 band, it is radiation from the CO2 within 1 meter of the instrument.
“how much warming can we attribute to man-made CO2; or even by what methodology can we come to such a conclusion”
I wrote about that here:
http://www.skepticalscience.com/empirical-evidence-for-co2-enhanced-greenhouse-effect-advanced.htm
Short answer, we’ve caused about 80% of the warming over the past century and about 100% over the past 40 years (total of about 0.6°C warming so far with another ~0.8°C delayed due to ocean thermal inertia).
“and where is the physical evidence of said warming?”
What, you mean besides surface temperature measurements, satellite measurements, sea level rise, melting glaciers, melting ice sheets, spring arriving earlier, etc. etc.?
“Please give me some feel for this so-called danger.”
It would help if you would be more specific. 2°C above pre-industrial levels is considered the ‘danger limit’.
http://www.skepticalscience.com/monckton-myth-5-dangerous-warming.html
Some consequences:
http://www.skepticalscience.com/global-warming-positives-negatives-intermediate.htm
I’m really interested in this “ocean thermal inertia”. How does that work exactly? How is all that energy hidden in the ocean without raising the temperature of the water?
Sea level rise – The sea level has been rising very slowly since the huge rise at the end of the last ice age. The “Calamitologists” have been predicting a coming huge rise for several years now, and it is not happening.
Melting glaciers – I’ll give you partial credit for that one, but the cause is mostly black carbon, soot. Some glaciers are increasing, especially in South America and lately in Alaska and Northern California.
Melting ice sheets – Lots of controversy there. Pretty hard to melt ice (Antarctica especially) when it never gets above freezing. The edges of Greenland get black carbon also. The last word is not in.
Spring arriving early – Check with the folks in Europe on that. Also the folks in the Southern Hemisphere. In the U. S. of A. it is mostly Urban Warming.
“without raising the temperature of the water?”
I’m really getting tired of debunking this myth.
http://www.skepticalscience.com/Monckton-Myth-1-Cooling-oceans.html
Hell, Dirk even debunked it above by linking to Pielke’s blog post on Willis’ data. ARGO hasn’t measured upper OHC rising terribly fast over the past 5 years, but it has risen (and it’s only 5 years of data).
“The sea level has been rising very slowly since the huge rise at the end of the last ice age”
That’s not even remotely true. It rose very fast at the end of the last ice age, when the planet warmed rapidly. Then it flattened out for thousands of years when temperatures flattened out. Now it’s rising again as global temperatures have risen.
Melting glaciers: read and learn, please.
http://www.grid.unep.ch/glaciers/
“Melting ice sheets – Lots of controversy there.”
Oh give me a break, Ed.
http://skepticalscience.com/Latest-GRACE-data-record-ice-loss-in-2010.html
Spring arriving early – please Ed, do a little research.
Honestly Ed, I can’t believe you’re actually denying the existence of global warming. That’s a rather stunning level of denial, especially for someone who claims to have a science background.
Five years of ARGO data is an eyeblink.
Half the glaciers in the Himalayas are advancing because they are covered in gravel and the soot can’t worsen the situation. One glacier in Argentina is advancing. The glaciers on Mt Shasta are advancing because of increased rainfall. We will need to wait and seeif the recent hard winters will reverse the trend on other glaciers
There are lots of questions on GRACE. And that data is also a geological eyeblink.
Last year in the UK, spring was a month late. Ditto for Germany. But it’s all natural variation.
Ed you need to research global long-term trends instead of only looking at local short-term trends. At least you admit they’re insignificant, which I appreciate. But the long-term global data is easily accessed. I can only lead you to water, you have to make the effort to drink it yourself. I suggest you start with the World Glacier Monitoring Service report I linked.
I read it. It essentially says that the trends date back to the end of the last ice age. That in the past, the glaciers were melted back as far as they are now, and recovered during the little ice age. I’m not seeing a reason for panic.
Brian asked above how Germans could be so demented to make AGW their religion…
To document the sorry mental state of some Germans. In Stuttgart, there have been intense protests against a rebuilding of the central rail station, putting it underground to free city area, and turning it from a cul de sac station to a drive-through station. One of the main objections of the protesters was the felling of trees. Now, 16 grown trees have been moved to avoid them being felled and to appease the protesters. Of course, it’s expensive and the operation had to be protected by police because protesters don’t really want to save trees; they only needed the trees to stop the project.
http://nachrichten.t-online.de/baumverpflanzungen-fuer-stuttgart-21-abgeschlossen/id_44355418/index
I’m a little bit ashamed to report this. It’s a lot like California. But in a way, it’s funny. What does this have to do with AGW? Well, it’s the same people, the catastrophists who protest there, the watermelons. As i said before, a lot of my friends and colleagues are warmists. I try to deprogram them, but it’s hard. Germans are boneheads.
Dirk… To be quite honest, I don’t disagree with you there. Believe me, I’ve had it out with more than one extreme green. There is a rational medium. We had some tree sitters near where I live a couple of years ago that delayed a minor construction project for the better part of a year, even after promises were made to replant X number of trees for each tree removed. Totally useless waste of people’s money and time.
I think you’re not a hopeless case. 😉
But Dirk, I do support people who choose to take part in acts of civil disobedience for reasonable causes. I get bugged by those who choose to do so to, more or less, stroke their own egos in order to save a couple of trees that can be replace. Stopping any progress for the sake of doing it is pointless. Hansen getting arrested protesting the building of another coal fired plant is a rational cause.
Dirk was wrong. There is no hope for you.
I have yet to be able to follow on to Hansen at one of his “coal rallies” and yell into a microphone, “Don’t listen to a thing he says. He’s a lunatic and would make you live in a cave to feed his own ego. Listen to your common sense and tell greenie weenies to take a leap at the moon.”
Hansen and that ilk who try to control patsies and the very weak minded make me want to vomit all over the floor.
People who are willing to stand up for something they believe is important for the well being of future generations makes you want to vomit? Wow.
At this point, I am sorry to say, I think he’s just standing up for his claim to being right.
Examine the history of his hysteria. That came from his studies of Mie scattering of Venusian clouds (he overemphasized the contribution of CO2), and from his thesis adviser, Sagan, who overemphasized methane greenhouse contribution to the warming of an early Earth (neglecting geothermal heat).
Hansen isn’t about to retract anything, (my take on it is) that all of his hype is his fear of being wrong.
As a result of his political clout, he turned his office into a proof machine for his fantasies and a propaganda ministry for them as well.
At the taxpayer expense!
Ed,
What is so radical about your explanation of radiative physics that has summoned comments that you are overturning well-known physics, radiative physics well known for 150 years – I am assuming these comments refer to Arrhenius and IPCC:
“Arrhenius estimated that halving of CO2 would decrease temperatures by 4 – 5 °C (Celsius) and a doubling of CO2 would cause a temperature rise of 5 – 6 °C. In his 1906 publication, Arrhenius adjusted the value downwards to 1.6 °C (including water vapour feedback: 2.1 °C). Recent (2007) estimates from IPCC say this value (the Climate sensitivity) is likely to be between 2 and 4.5 °C.”
Source: Wikipedia.
I thought your post was reasonable and an explanation and expansion of well-understood physics.
I’m still confused how we get to “dangerous warming” considering CO2 is ever increasing (what…391 parts per million now), and with values of 1.6 deg C to 4.5 C for radiative forcing it seems like there is a fair amount of wiggle room in the science for expanded ideas based on radiative physics to better hone in on the real value, and the effect that value has on climate, if that is even possible.
Consider that all these wonderfully well understood physics don’t appear to explain, in themselves, the actual, real atmospheric system, since GATA defies this explanation, ocean levels are not rising faster, storms are not more intense, weather and climate are well within historic bounds, and so forth (und so weiter).
http://chartsgraphs.wordpress.com/2010/08/19/enhanced-uah-channel-5-temperature-anomaly-trend-chart/
It appears quite clear to me there is no danger to humanity that can be identified with our current measuring coupled with our current understanding of the atmosphere that points to man-made CO2. But leaving that aside, what is so radical about what you posted here? I’m really just curious about what I seem to be missing and it seems your critics have either lost patience with me or don’t have and answer.
Thanks again for all you patience and work.
The top of atmosphere flux is the important climate effect for CO2. I produced some simple models to demonstrate it, one of the articles is here:
http://scienceofdoom.com/2011/02/03/understanding-atmospheric-radiation-and-the-“greenhouse”-effect-–-part-four/
(Although best to look through from the beginning of the series to get a better understanding).
Take a look at the “Overlapping Bands” section – where you can see that it’s quite possible to have no change in DLR (back-radiation from the atmosphere) while having a significant change in the top of atmosphere flux (outgoing radiation).
If less energy leaves the planet, then, all other things being equal, the planet will heat.
If you want to demonstrate that more CO2 has no effect (pre-feedback) you need to produce a solution to the radiative transfer equations. See:
http://scienceofdoom.com/2011/02/07/understanding-atmospheric-radiation-and-the-%E2%80%9Cgreenhouse%E2%80%9D-effect-%E2%80%93-part-six-the-equations/
Or show that the radiative transfer equations are wrong.
I don’t think you have done either.
That’s a good point, which is why I’ve linked to papers showing both more downward radiation and less upward radiation.
I would point out the UAH tropical data over oceans. It is -.51, which is the second lowest temperature in the UAH record for January, and just ahead of 2008.
Remember, it all starts in the tropics; the oceans that is, and La Nina is not weakening, it is strengthening, and looks to be a double forming. The MEI is currently at -1.6.
Rob Honeycutt said:
“And what corruption shown in the climategate emails? Can you please point to one that every independent investigation that looked into the matter missed?”
Oh boy, another OJ defense.
And Rob, on sea level rise, you are aware of this?
http://tinyurl.com/2vf34tq
Recall the very large errors from GRACE? How much research has been tainted because of these errors?
DirkH said on 11. Februar 2011 at 15:46
“You can talk your ass off trying to convince warmists that the CO2 GH effect is practically saturated and any small increase will be completely overwhelmed by even the slightest change in UHI, land use change or clouds, and all they’ll do is wave the logarithmic formula for CO2 radiative forcing and not listen to you. After all, that’s what’s build into the models and the models are god and tell us the future up to 2100, at least when we run all variations we have and average the output.”
Which no doubt resonates with a lot of people.
Yet what resonates is irrelevant. Claims need evidence.
In the case of the “standard theory” – solving the radiative transfer equations with convective adjustment – provides results which match the actual measurements very closely.
You can see some examples here:
http://scienceofdoom.com/2010/11/01/theory-and-experiment-atmospheric-radiation/
This is nothing to do with whether or not GCM’s can “predict” the future. That is another question completely.
Radiative theory is conceptually reasonably simple but computationally very challenging – at least to do it “line by line” – that is, considering absorption and emission from every line from every molecule at each height in the atmosphere.
No doubt many people will continue to believe it’s all made up, but the standard equations to solve the problem can be seen in any standard textbook on atmospheric physics. And that’s what’s used in the models.
So take a look at the equations as shown in:
http://scienceofdoom.com/2011/02/07/understanding-atmospheric-radiation-and-the-“greenhouse”-effect-–-part-six-the-equations/
And
a) prove that they are wrong, or
b) prove that solving them gives a different result
At least, that’s what a skeptic would do.
Hi SoD. I don’t think it’s all solved. Why would Miskolczi or these guys:
Wu, Liu:
“A new one-dimensional radiative equilibrium
model for investigating atmospheric
radiation entropy flux”
http://rstb.royalsocietypublishing.org/content/365/1545/1367.full.pdf
continue working on it. Unfortunately, the Wu/Liu paper disappeared behind the paywall… it was free last time i checked it. If you have a way to access it, do it, it’s interesting. The authors say their model resolves the discontinuity at the surface, see fig. 2.11, p.16 here:
http://www.geo.utexas.edu/courses/387H/Lectures/chap2.pdf
I would add:
c) looking at the parameters and what their estimates are.
Mindert Eiting on 12. Februar 2011 at 10:07:
“I would add:
c) looking at the parameters and what their estimates are.”
That’s a good point. Which really comes under b), but we can put it under a new heading if you like.
The absorption/emission parameters are stored in the HITRANS database, most of the data in there comes from spectroscopy measurements in the lab, and has parameters like:
-wavenumber of line position (the central wavenumber/wavelength of absorption)
-line strength (total absorption associated with the line)
-line width (how the absorption falls off away from the central wavenumber)
Then we need to know the changes in the line shape with pressure and temperature. Pressure changes by a factor of about 5 in the troposphere (1000mbar to 200mbar), temperature by a factor of around 0.75 (288K – 215K) – this changes the absorption characteristics, as the line width has a pressure and temperature dependency.
The other parameters are:
– the concentration of each absorber at each height
– the temperature profile vs height (this affects emission)
There are two basic approaches to solving the equations:
1. Line by line – extracting every last line out of the HITRANS database – within the wavelengths of terrestrial emission this is many hundreds of thousands of lines – and solving the equations for a given temperature profile through the atmosphere
2. Because line by line takes so much time – band models. These are parameterizations of the line by line characteristics. They have been a staple of solutions to the radiative transfer equations for a few decades. Many papers compare the band models to the “real measured line by line values”
In any case, there are many published results for the line by line solution. These are the benchmark.
Therefore, for c) you need to demonstrate that the spectroscopic values in the HITRANS database are flawed.
SofD: Sorry about the moderation delay. As you were commenting for the first time; first comment had to be approved. Happened to be nighttime here in Europe. Thanks for weighing in.
No problem, understand moderation delays.
Science of Doom,
Thank you for taking time to weigh in – you have provided me some homework as I will read this post thoroughly and go back and read your web some more.
DirkH on Februar 2011 at 16:57:
“I don’t think it’s all solved. Why would Miskolczi or these guys:
Wu, Liu:
“A new one-dimensional radiative equilibrium model for investigating atmospheric radiation entropy flux”
http://rstb.royalsocietypublishing.org/content/365/1545/1367.full.pdf
continue working on it. ”
Actually you said that the climate models were preprogrammed to show the “logarithmic result” rather than the “saturated result”.
Miskolczi actually fully accepts the radiative transfer equations. He believes that water vapor acts as a feedback mechanism.
So if we consider a “pre-feedback CO2” which is all the author is talking about – and all I’m talking about – Miskolczi is fully with the standard textbooks. As are Lindzen, Spencer, Christy.
I will have a look at the paper you cite and comment later.
SoD… Thanks for stopping in here and offering your expertise.
I always appreciate your “just the facts, ma’am” approach supported by your clear understanding of the full body of research.
DirkH suggested that the paper, “A new one-dimensional radiative equilibrium model for investigating atmospheric radiation entropy flux” by Wu & Liu indicates that current radiative transfer theory is still in need of work.
The paper is freely available here:
http://www.ecd.bnl.gov/pubs/BNL-82119-2009-JA.pdf
As many people here, including DirkH and the author of the article, are well-versed in the field of radiative transfer I look forward to a summary of what the paper demonstrates about the standard theory regarding radiative transfer.
Afterwards, I will make my comments and the readers can compare.
Thanks for the link, SoD.
David Archibald on climate and energy security
http://wattsupwiththat.com/2011/02/12/david-archibald-on-climate-and-energy-security/#more-33809
The benefits of CO2
The Science and Public Policy Institute has released a ground-breaking book chronicling the many benefits of atmospheric CO2 concentrations. The 55 benefits discussed are drawn exclusively on the peer-reviewed literature.
http://wattsupwiththat.com/2011/02/11/the-benefits-of-carbon-dioxide/
Perhaps the writer of the article can also explain the significance of CO2 absorption around 600 cm^-1 (16.7 µm) and around 740 cm^-1 (13.5 µm).
You asked him but I’ll speak, these are degenerate and dissipate energy only through the rotational and translational modes, and therefore infinitesimally to the total k.e. (the temperature) of the surrounding medium.
The article provides a very helpful clue:
“At elevations above 1 meter, the atmosphere is in LTE and increased CO2 does nothing.”
This clarifies that the writer of the article doesn’t know what LTE (local thermodynamic equilibrium) means.
Because below 1m the atmosphere is also in local thermodynamic equilibrium.
There is an explanation here:
http://scienceofdoom.com/2010/10/24/planck-stefan-boltzmann-kirchhoff-and-lte/
To saving some clicking, here is a quote from Vardavas & Taylor, Radiation and Climate, Oxford University Press (2007):
“When collisions control the populations of the energy levels in a particular part of an atmosphere we have only local thermodynamic equilibrium, LTE, as the system is open to radiation loss. When collisions become infrequent then there is a decoupling between the radiation field and the thermodynamic state of the atmosphere and emission is determined by the radiation field itself, and we have no local thermodynamic equilibrium.”
Professor F.W. Taylor is a Professor of Physics at Oxford University with many published papers. The book is part of a series: “International Series of Monographs on Physics-138”. No doubt that because Prof. Taylor’s current interests are climate science his writing on this subject is clearly inferior to random people who might claim something different.
Luckily I also dug out a quote from Thermal Radiation Heat Transfer, by Siegel & Howell, McGraw Hill (1981):
“In a gas, the redistribution of absorbed energy occurs by various types of collisions between the atoms, molecules, electrons and ions that comprise the gas. Under most engineering conditions, this redistribution occurs quite rapidly, and the energy states of the gas will be populated in equilibrium distributions at any given locality. When this is true, the Planck spectral distribution correctly describes the emission from a blackbody.”
Strangely they say the same, even though they are not climate scientists.
Understanding when a gas in not in LTE can be more helpful. From the same Siegel & Howell:
“Cases in which the LTE assumption breaks down are occasionally encountered.
Examples are in very rarefied gases, where the rate and/or effectiveness of interparticle collisions in redistributing absorbed radiant energy is low; when rapid transients exist so that the populations of energy states of the particles cannot adjust to new conditions during the transient; where very sharp gradients occur so that local conditions depend on particles that arrive from adjacent localities at widely different conditions and may emit before reaching equilibrium and where extremely large radiative fluxes exists, so that absorption of energy and therefore populations of higher energy states occur so strongly that collisional processes cannot repopulate the lower states to an equilibrium density.”
I add my own less accurate but more easily understood definition:
“Molecules banging into each other a lot so that normal energy states apply.”
The writer then cites Tom Vonk, who has an entertaining piece with ideas unknown to anyone who studies, teaches, or writes textbooks about, atmospheric physics.
The real story, quite simple, is that radiatively-active gases like water vapor & CO2 absorb energy from radiation and share it thermally through collisions. This is “absorbing energy”.
But according to Tom Vonk this can’t happen because then the atmosphere wouldn’t be in a state of LTE. Or would. I can’t work it out. I wasn’t sure whether it was Zeno’s Paradox revived, or a joke..
If that’s the case by the way, then the writer of this article is also wrong about what happens in the lower atmosphere as Tom Vonk claims that more or less CO2 can’t do anything because somehow equilibrium means that energy can’t be absorbed or can or something. Yet the author of THIS article says:
“This means that before the CO2 molecule can get rid of the energy by re-radiating, it has very probably gotten rid of the energy thermally by colliding with other air molecules, oxygen and nitrogen, that do not re-radiate, about 100,000 times.”
This statement is actually correct, but conflicts with the Tom Vonk view. *Luckily*, Tom Vonk also doesn’t believe that more CO2 can affect anything, so it’s all good..
Siegel and Howell restrict their attention to radiation exchange of gray gases within enclosures, do they not?
Brian G Valentine on Februar 2011 at 03:23:
“Siegel and Howell restrict their attention to radiation exchange of gray gases within enclosures, do they not?”
Do you want to know if the book will help you learn atmospheric physics?
It’s good background reading. The reason I got it out of the university library was because I scanned in the relevant pages from six textbooks on heat transfer to prove that the writers of heat transfer textbooks and professors of the discipline actually believed that radiation from a colder body was absorbed by a hotter body. Then one of my favorite commenters said that I had “cherry picked” the books!
And said if I read a proper book on heat transfer it would be a different story. And recommended Siegel & Howell. You can see the results at:
http://scienceofdoom.com/2010/10/07/amazing-things-we-find-in-textbooks-the-real-second-law-of-thermodynamics/
I won’t ruin the suspense by saying what Siegel & Howell said on that subject. But I digress.
Was this the reason for your question? You want to know the best textbook to read to learn about atmospheric radiation?
Siegel and Howell is a good book, we used it for the standard grad engineering course in radiation heat transfer. They’re discussing the use and possible breakdown of the LTE approx in a much different sense (namely, it’s possible to bound all the energy within an enclosure).
SoD
Pops up all over the place.
I was the one who recommended that he read Siegel & Howell.
I get the impression that he hadn’t heard of the book before I mentioned it.
He then made the bizarre claim that I had not read it.
It should be all there in the item from his site.
SoDs main aim in life was to prove that a cold object can HEAT a hotter object.
I think he has now reconsidered this as being at the very least questionable so he now puts heat in inverted commas “heat”.
He confused em radiation with heat and so radiation going from cold to hotter surfaces he used to call heat.
The word Heat as used in thermodynamics is quite different to its vernacular use.
SoD named a number of engineering textbooks which had used the vernacular meaning.
I asked him why he did not include any physics textbooks in his sample.
I think perhaps SoD might now agree that I have consistently used the word in the orthodox physics manner.
SoD also seems to have switched his emphasis to TOA explanations of the Greenhouse Effect which is the most plausible version
Brian G Valentine on 13. Februar 2011 at 02:43 – replying to my question about the significance of CO2 absorption around 600 cm^-1 (16.7 µm) and around 740 cm^-1 (13.5 µm):
“You asked him but I’ll speak, these are degenerate and dissipate energy only through the rotational and translational modes, and therefore infinitesimally to the total k.e. (the temperature) of the surrounding medium.”
Would you like to state the transmittance from surface to TOA through CO2 (at current concentration) at these wavenumbers?
And compare it with the transmittance at 667 cm^-1?
Do you know how it will change with increasing CO2 concentration?
“Would you like to state the transmittance from surface to TOA through CO2 (at current concentration) at these wavenumbers?”
I could report it as an exponential, but I honestly don’t know how good the approximation would be.
“Do you know how it will change with increasing CO2 concentration?”
I think the composition is too dilute to use the ordinary band broadening approximation of the response to increasing (partial) pressure of a component in a gas mixture.
So I can’t say much, although Beer’s law would fall off (as a linear relation between absorbance and concentration) at wavenumbers that do not correspond to the maximum absorption.
Brian G Valentine on 13. Februar 2011 at 04:44:
“Siegel and Howell is a good book, we used it for the standard grad engineering course in radiation heat transfer. They’re discussing the use and possible breakdown of the LTE approx in a much different sense (namely, it’s possible to bound all the energy within an enclosure).”
You should prove your claim.
The whole point about LTE is that it is for a system which is open to radiation loss. Therefore, not in an enclosure. You can see in their definition they don’t put that constraint on it.
I did get the 1981 edition out of the library and have since returned it. Luckily, I have the 1971 edition in soft-copy and their section on defining LTE comes right after a section about radiation through the atmosphere.
Why don’t you actually state your case if you have one.
1. What is LTE?
2. What is its relevance to this subject?
3. Is the atmosphere in LTE in the 1st meter of atmosphere off the ground?
4. Is the atmosphere in LTE anywhere?
5. How does the atmosphere absorb and emit radiation?
6. Which equations define the absorption and emission of radiation in the atmosphere?
I asked Brian G Valentine:
“Would you like to state the transmittance from surface to TOA through CO2 (at current concentration) at these wavenumbers?..”
He said:
“I could report it as an exponential, but I honestly don’t know how good the approximation would be.
“Do you know how it will change with increasing CO2 concentration?”
I think the composition is too dilute to use the ordinary band broadening approximation of the response to increasing (partial) pressure of a component in a gas mixture.
So I can’t say much, although Beer’s law would fall off (as a linear relation between absorbance and concentration) at wavenumbers that do not correspond to the maximum absorption.”
But you have already claimed that CO2 at the wavenumbers in question is irrelevant. Well, that is how I interpret your statement:
“..these are degenerate and dissipate energy only through the rotational and translational modes, and therefore infinitesimally to the total k.e. (the temperature) of the surrounding medium..”
If you can’t state the transmittance and how it will change how come you are so confident about the irrelevance of CO2 around these wavenumbers?
I look forward to some values. Or an order of magnitude, or something..
1 “What is LTE?” (1st variation of) (the local potential) = 0 (Prigogine)
2″What is its relevance to this subject?” The use of equilibrium approximations
3 “Is the atmosphere in LTE in the 1st meter of atmosphere off the ground?” no
4. “Is the atmosphere in LTE anywhere?” no
5. “How does the atmosphere absorb and emit radiation?” as a graybody
6. “Which equations define the absorption and emission of radiation in the atmosphere?”
OK, we have the source function for a particular frequency v
Iv= Jv/Kv, the ratio of emission to absorption coefficient.
For a scattering atmosphere we have
Iv(azimuth and longitude angles) = integral over angles(Phase function of angles) x(intensity of the angles) sin (azimuth) d(azimuth)d(longitude)
and for an atmosphere at LTE we have
Iv= the Planck function of (T) at v
Good night and happy *VALENTINE’S* day to all.
To help people understand the complexity of the absorption band of CO2, you can see the “Zenith Transmittance” through the atmosphere due to CO2 as a function of wavenumber (667cm^-1 = 15um):
http://scienceofdoom.files.wordpress.com/2011/02/co2-zenith-transmittance-petty.png?w=499
I’ll try and place it here, not sure whether I can..
What is zenith transmittance? It is the effect of the absorption only of CO2 through the whole atmosphere from the surface.
You can see there is a large area of absorption which can be affected by more CO2.
You can see the same effect in the results of a line by line model which shows the difference between pre-industrial levels of CO2 with 2x that value – as a function of wavelength. In the graph from W.D. Collins (2006) at:
http://scienceofdoom.com/2010/05/12/co2-an-insignificant-trace-gas-part-eight-saturation/
This is why I asked the author my earlier question of 13. Februar 2011 at 02:32.
Brian G Valentine on 13. Februar 2011 at 06:05:
So you have a different view of LTE from all of the standard works in the field. This includes Siegel and Howell. If you believe all of the standard works are wrong you need to explain why.
When LTE is not present the Planck function of radiation can no longer be assumed. This invalidates all of the satellite measurements – like SST, lower tropospheric temperature from UAH.. And also needs explanation as to why theoretical values of flux and spectral results match the measurements. The theory uses the Planck law.
I also note that you approved of the author’s work (this article) – yet, according to you, he is totally wrong about the subject of LTE.
Here is what Siegel and Howell said (1971) about LTE. For those finding this a difficult subject, note the last sentence:
===
“In a gas, the redistribution of absorbed energy occurs by various types of collisions between the atoms, molecules, electrons, and ions that comprise the gas. Under most engineering conditions, this redistribution occurs quite rapidly, and the energy states of the gas will be populated in equilibrium distributions at any given locality. When this is true, the Planck spectral distribution correctly describes the emission from a blackbody, and equation (1-34) correctly describes the emission from a gas volume element.
The assumption, that a gas will emit according to equation (1-34) regardless of the spectral distribution of intensity passing through and being absorbed by dV, is a consequence of the assumption of “local thermodynamic equilibrium” or LTE. When the condition of LTE is not present, the calculation of radiant transfer becomes much more complex.
Cases where the LTE assumption breaks down are occasionally encountered.”
===
Once again demonstrating that taking a wrecking ball through many decades of physics is a necessary action to demolish the standard theory of radiative transfer in the atmosphere.
Negative. The issue is, the definition of T.
Prigogine and De Fay and others go to great lengths to define a consistent thermodynamics (as opposed to a thermostatics) without reference to T.
As Gerlich and Tscheuschner elaborate upon, “temperature” in the atmosphere is a quantity that has many interpretations as calculated from radiant flux, all that might be said is, there are inequalities that hold on the various interpretations of T.
Evidently, the integral that I gave as definition of Iv is the integral Planck evaluated to produce his famous distribution, making a well known assumption about the quantum of action. Here the assumption of an “equilibrium” defines a T.
Brian G Valentine on 13. Februar 2011 at 08:14:
One step at a time.
You *claim* Siegel & Howell agree with you?
I’ve *quoted* from Siegel & Howell to demonstrate that they don’t agree with you.
So prove your case. Demonstrate where Siegel & Howell state that LTE is not true in the lower atmosphere.
You say “Negative” with no evidence. You cite names with no references. You “move on” from your original claim without proving it.
It all might sound impressive to the many people who already believed that CO2 has “no significant effect” and are just looking for an intellectual prop, but I am a skeptic.
If you have something to say, take the time to say it properly.
If you make a claim, demonstrate some support for your claim.
1. Siegel & Howell. Where do they support your claim?
2. You are saying that Vardavas & Taylor are wrong?
3. What are your references for Prigogine and De Fay? And when did they overturn classical theory about LTE in the atmosphere?
Brian G Valentine from 13. Februar 2011 at 02:43:
I look forward to you backing up your as yet unsubstantiated claim of why CO2 absorption is insignificant around wavenumbers 600 cm^-1 (16.7 µm) and around 740 cm^-1 (13.5 µm).
I have provided the zenith transmittance values in this area showing that they are appreciably less than 1. And appreciably more than zero.
The obvious consequence, of course – more CO2 will have a pre-feedback impact on atmospheric transmittance.
I await evidence of your claim. Hopefully, so do some of the other readers.
SofD
Thanks for presenting this formidably solid case. You know your stuff.
For the readers who SofD is engaging here, I’d say it’s time to do one of the following:
1) back up what you claim, or
2) If you need more time to go through the material, just say so – or
3) Say uncle, and be thankful for the enlightenment.
I certainly am.
I can’t back it up. So I am obliged to admit I was wrong.
I never used to sum over those wavenumbers as part of the contribution of total transmittance and now I have been enlightened
Tomorrow I’ll probably know less than I did today!
Science of Doom,
I will concede that my reliance on Tom Vonk was a mistake, but it was a beginning point. The article was an attempt to provoke questions on the CO2 problem, a harder look at some basic stuff concerning CO2. There is a lot of reliance on models, simulations, and theoretical calculations, and not enough on making real-world measurements. The exact relaxation time of CO2 at normal pressure and concentration, for instance, is not known with any accuracy. Does that relaxation time change with concentration? These are fundamental questions that need answers.
There is also a problem with the downward radiation measurements. The measurements are done ignoring the fact that the ground around the instrument is radiating upward. Usually the instrument is a couple of meters above ground. A proper measurement should be made with the sensor at ground level, in the middle of a sizable “black body” area, like an asphalt parking lot, or alternatively, the middle of a white area. Or, do both and look at the difference. Then we might know more about “back radiation”.
As to what happens on the sides of the CO2 absorption peak: yes, it gets wider as the concentration goes up. Yes, the transmission distance gets longer on the sides of the peak. But I have some questions of my own: What does pressure broadening at the surface do to the situation? The peak isn’t a constant width as you go up through the atmosphere. It is wider at the surface, then as TOA is approached, it gets narrower and splits into many individual lines. Won’t this increase the upward radiation and lower the downward radiation? Just for the simple reason that the pressure broadened sides can now radiate freely past the narrower peak higher in the atmosphere, and the upper atmosphere is blocked by the broader peak lower down. What is the possibility that this negates the effect of any CO2 increase?
Thank you for your time and attention to this subject. We are all learning something, and I hope we can learn more.
P Gosselin on 13. Februar 2011 at 12:16
“SofD
Thanks for presenting this formidably solid case.”
Thankyou for your courtesy. Very much appreciated.
Ed Caryl:
First of all, thanks for your kind response. Especially as I have ferociously ripped into your article.
It’s ok to have questions. But unconventional to claim the solution to a difficult problem when you don’t understand the theory.
For example:
1. Why is the theory of radiative transfer embraced in every textbook on atmospheric physics?
2. What solutions to the radiative transfer equations exist?
You need to know the answers to these two questions to write an article claiming that standard theory is wrong. Well, you don’t *need* to know it to write an article..
In books like “A First Course in Atmospheric Radiation” by Grant Petty (excellent and recommended), you can find that 95% of radiation at 667cm^-1 CO2 is absorbed within 1 meter (at 1000mbar). And everyone who works in the field of atmospheric physics knows this (well, maybe a few can’t quote it, or forgot it or don’t know the exact number). Yet, they embrace a different solution (to you).
I would want to know why.
If the fact that 95% of radiation at 667cm^-1 is absorbed within 1m is known to all and sundry why don’t they see the obvious?
There’s a reason. At least, you should search out the reason to find out what it is.
“There is a lot of reliance on models, simulations, and theoretical calculations, and not enough on making real-world measurements. ”
I expect you will find this is incorrect. In every area of climate science that I have investigated I have found a huge body of experimental work.
See, for example, an unrelated article on measurements of ocean emissivity: http://scienceofdoom.com/2010/12/27/emissivity-of-the-ocean/
Now, if you want to find out that changes that result in atmospheric radiation, pre-feedback, from doubling CO2 how will you find it out?
What experiment will you do?
In fact, the theory of radiative transfer has a huge body of experimental work behind it, as does absorption and emission of radiatively-active molecules. And an absolutely massive body of experimental work has been done on the spectroscopic properties of all these gases.
It is legitimate to apply a well-proven theory to find a solution to a future scenario that we cannot create in the lab.
And as with all theories there are areas where theory and experiment do not match. For example, the continuum absorption of water vapor.
“There is also a problem with the downward radiation measurements. The measurements are done ignoring the fact that the ground around the instrument is radiating upward.”
If you take an FT-IR and measure the spectrum of the atmosphere then integrate up the spectrum you find it matches the pyrgeometer measurement pointed up at the sky. (So long as you integrate across the bandwidth of the pygeometer).
Why doesn’t the spectrum of the FT-IR reveal significant radiation at 11um? The ground radiates very significantly at 11um (as you can see by reviewing spectral results from top of atmosphere).
Because the FT-IR is pointing at the sky and the construction of the FT-IR blocks all the radiation from the ground.
Same as a pyrgeometer pointing up at the sky.
You can see some FT-IR measurements in:
http://scienceofdoom.com/2010/07/24/the-amazing-case-of-back-radiation-part-two/
and some very careful measurements of upwards surface radiation, downward surface radiation in the EBEX experiment in:
http://scienceofdoom.com/2010/07/31/the-amazing-case-of-back-radiation-part-three/
What you are claiming is that researchers with decades of experience are making schoolboy errors in measurements or happily working on the basis that “it’s probably fine, someone else probably checked this”.
There are 100’s of papers on how to do correct radiometer measurements, how to correct for this effect and that effect. Very very very dull stuff. But people research it and write papers on it.
For example: A Field Intercomparison Technique to Improve the Relative Accuracy of Longwave Radiation Measurements and an Evaluation of CASES-99 Pyrgeometer Data Quality
S. P. Burns, J. Sun, A. C. Delany, S. R. Semmer, S. P. Oncley, and T. W. Horst
“Techniques for improving the relative accuracy of longwave radiation measurements by a set of pyrgeometers [the Eppley Laboratory Precision Infrared Radiometer (Model PIR)] are presented using 10 PIRs from the 1999 Cooperative Atmosphere–Surface Exchange Study (CASES-99). The least squares–based optimization technique uses a field intercomparison (i.e., a time period during which all the PIRs were upward looking and set up side by side) to determine a set of optimization coefficients for each PIR. For the 10 CASES-99 PIRs, the optimization technique improved the standard deviation of the difference of downwelling irradiance between the PIRs from ±0.75 to ±0.4 W m−2 (for nighttime data). In addition to presenting the optimization method, various PIR data quality checks are outlined and applied to the PIR data. Based on these quality checks, the measured case and dome temperatures of the CASES-99 PIRs were all reasonable. Using the 10 CASES-99 PIRs, simple estimates of the average nighttime net radiative flux divergence within the layer between 2 and 48 m were determined and resulted in cooling rates over a range from 0 to −1.3°C h−1, depending on the assumptions made for the upwelling irradiance at 2 m. The effect of the coefficient optimization on the calculated net radiative flux divergence is explored.”
It won’t be difficult to find 100 more papers on this amazingly boring subject.
Following on from my last comment to Ed Caryl here is a question that is important:
——How to find the research you want? How do you find out if it has been done?
This is difficult and challenging.
Research is scattered.
Sometimes the work was all done and all the problems resolved to the satisfaction of people in the field in the 1800s or the early 1900s or the 1940s..
In this case it is hard (impossible) to find papers on it online or on Google scholar, or even via academic databases.
In this case the theory and the results are usually buried away in boring textbooks in a university library.
Suppose we are considering a more up to date subject.
Usually I try and find a few chapters in a textbook in a university library and read the basics. Then a few more textbooks because the first textbook almost never explains it so I understand it fully.
Without the textbook background, papers are hard to understand. Papers are written for people in the field, so they assume that you have a solid grasp of the work already done.
Next, or if I think I already understand it reasonably well, I start looking for papers.
Others can probably write much better ways of doing “literature surveys”. My methods are ad hoc.
First, search Google Scholar. Many papers are now listed in Google Scholar on the right as pdfs – and usually these pdf results are actually freely available. Luckily, I have access to academic papers anyway.
So I find a paper and have a read. Usually the abstract is the hardest thing to read. Strange, maybe that is just me.
Once I have found a paper and it has something relating to the subject matter that I am looking for, as I read I find a citation which seems to be pre-existing work that is something I need to understand first. So I look that up, and find the paper, and start reading.
Usually, I end up with 5-10 papers open on my pc, some fully read, some partially read. The first paper often never gets finished because the papers I found afterwards are more interesting, or make my head hurt so much.
During this process I start looking for the *foundational paper* cited. This is very important. For example, studying the cool skin of the ocean I found that Saunders 1967 and McAlister 1969 were usually cited. So I read those.
Once you have a few foundational papers you are set.
You can look them up in Google Scholar and click the “cited by” link and find all the papers that cite these foundational papers.
Also along the way, new “foundational papers” are written which cover off some other aspect, or introduce a new method, or new theory or new results. You can see that these are considered important because most of the papers after that date also cite these newer papers.
Like I said, my methods are ad hoc, and I would probably fail “literature review 101”, but I thought it might help people to at least see how to “find out stuff”.
The alternative is “not finding out stuff” and although that’s easier, it’s a lot less interesting at the end.
And if you believe no one has studied it or measured it or tested it – you will usually be wrong.
Thanks taking the time to respond as you have. There’s plenty here for all readers to heed as the discussion moves. I have to admit I was not very familiar with your site, just a vague recollection that Steve McIntyre had recommended it a year or so ago. Will book mark it and drop by regularly. I went through some of your previous writings and found them to be solid and liked what I saw.
In somewhat agreement with what Ed has said, I believe there are a lot of things implicitly or explicitly assumed in theory as well as experimental measurements that are taken to produce other results that depend upon the assumptions made.
One of the most glaring assumptions I know of right now is the assumption of “well mixed gases throughout the troposphere.”
From the kinetic theory and bounds of atmospheric temperature and diffusivity of carbon dioxide in the atmosphere, I don’t find that the assumption that a gas of molecular weight 44 is distributed uniformly to the “top of the atmosphere” to be very good on an annual basis anyway.
Does a lot hinge on the validity of the assumption? Yes it does, but from what I see in the actual measurements (which are all over the map) there’s a case to be made either way.
Anyway I think Ed is right in his implication that there is a lot more modeled than there is measured
Brian G Valentine on 13. Februar 2011 at 23:38:
“In somewhat agreement with what Ed has said, I believe there are a lot of things implicitly or explicitly assumed in theory as well as experimental measurements that are taken to produce other results that depend upon the assumptions made.
One of the most glaring assumptions I know of right now is the assumption of “well mixed gases throughout the troposphere.” ”
Nice to see you going on record as *knowing* this is a *glaring assumption*.
I hope the blog owner flags your future confident claims as suspect.
“..but it can at least be said that the most recent analyses of samples obtained in balloon flights up to between 25 to 30km show no indication of any appreciable increase in the proportion of lighter gases. It must be emphasised that 100km is only a lower limit to the altitude at which diffusive separation first becomes important..”
From the last citation below, you can read the whole paper. It is from 1949.
You can find a basic discussion of the subject in “Physics of Atmospheres” by Houghton (1982): Chapter 5 – The Middle and Upper Atmospheres. (And probably many other textbooks).
Here’s a few papers on the subject (I provided a link to the last one so you can have a read, it’s free and published 62 years ago so you have a bit of catching up to do in your research):
– Does Diffusive Separation Exist in the Atmosphere below 55 Kilometers?
D. W. Hagelbarger, Leslie T. Loh, H. W. Neill, M. H. Nichols, and E. A. Wenzel, Phys. Rev. 82, 107–108 (1951)
– Diffusive Separation in the Upper Atmosphere,
Hedin, A. E., and A. O. Nier (1965), J. Geophys. Res., 70(5)
– Mass Spectrometric Investigations of the Atmosphere between 100 and 227 Kilometers above Wallops Island, Virginia
Meadows-Reed, E., and C. R. Smith (1964), J. Geophys. Res., 69(15)
– Some Phenomena of the Upper Atmosphere
Sydney Chapman (1951) Proc. Phys. Soc. B 64 833
– A review of CO2 and CO abundances in the middle atmosphere
LOPEZ-PUERTAS Manuel, LOPEZ-VALVERDE Miguel A., GARCIA Rolando R., ROBLE Raymond G.,
Abstract for interest:
A review is presented of CO2 and CO in the middle atmosphere. Knowledge of their abundances is important for understanding the thermal budget and transport processes of the middle atmosphere, and for its remote sounding. For both CO and CO2, several techniques have been used to measure their abundance. Significant improvements have occurred over the last two decades with high quality satellite data now available from the Atmospheric Trace Molecule Spectroscopy (ATMOS) and Improved Stratospheric and Mesospheric Sounder (ISAMS) experiments. The CO2 observations are well explained by models that account for diffusive separation, but a small overestimate above 95 km still remains. TIME-GCM calculations suggest a large depletion in the polar winter, down to near the stratopause which is as yet unconfirmed but which could be significant for remote sensing. The CO observations confirm the basic features of the seasonal and latitudinal variability predicted by dynamical models, particularly the enhancements in polar winter. However, the models underpredict the mesospheric CO abundance at mid-latitudes by a factor of 1.5-3 and fail to reproduce the strong latitudinal and vertical gradients in the polar regions. A reduction in the OH abundance from standard chemical models may partially solve this discrepancy. Finally, a comparison of simultaneously measured CO2 and CO in the upper mesosphere/lower thermosphere with models suggests an eddy diffusion coefficient about 2-3 times smaller than those currently used.
– The Earth’s Upper Atmosphere
Bates, D. R., Monthly Notices of the Royal Astronomical Society (1949), Vol. 109, p.215
Free link:
http://adsabs.harvard.edu/full/1949MNRAS.109..215B
I just looked these up on Google Scholar, took 20 minutes, most of the time spent in pasting in the citations.
Enough said.