Global warming is not caused by CO2

[bellfreeC]

>> Results 1 - 12 of about 12 for svensmark OR cosmoclimatology <<

Hey, another twelve...
Results 1 - 12 of about 12 for hitran.
I will list the most exciting(in relation to this thread\questions)
and then the scary part from my own archives.


CO2 saturation point?
MODTRAN here is a basic mathematical tool to calculate radiation profiles in
certain kinds of atmosphere, using the HITRAN database. ...
https://www.physicsforums.com/showthread.php?t=231437 - 93k - Cached - Similar pages

Lasers Text - Physics Forums Library
Modtran is a wonderful program for simulating transmittance through the
atmosphere google Modtran and Hitran. Redbelly98. Apr17-08, 09:31 PM ...
https://www.physicsforums.com/archive/index.php/t-225471.html - 15k - Cached -

Global warming case frustrating Text - Physics Forums Library
One does need to have good information on molecular absorption - such as the hitran database. Care should be taken to make sure proper resolution and ...
https://www.physicsforums.com/archive/index.php/t-174215.html - 26k - Cached -

CO2 saturation point? Text - Physics Forums Library...
basic mathematical tool to calculate radiation profiles in certain kinds of atmosphere, using the HITRAN database (http://cfa-www.harvard.edu/hitran/). ...
https://www.physicsforums.com/archive/index.php/t-8259.html %253Cbr%2520/t-231437.html - 22k -


Radiative transfer to space affected by atmosphere? Text - Physics
...The atmospheric absoprtion depends on pretty much everything, there's good
computational models (LOWTRAN/MODTRAN/HITRAN) out there, some of which are public ...
https://www.physicsforums.com/archive/index.php/t-220110.html - 7k - Cached -

Observations About Global Circulation Models
Therefore collisionnaly induced emissions/absorptions (and no it is neither 0 nor negligible) are ignored because they are not in Hitran . ...
https://www.physicsforums.com/showthread.php?t=214063 - 37k - Cached -



In the interview below, in-cites correspondent Gary Taubes talks with Dr. Laurence Rothman of the Harvard-Smithsonian Center for Astrophysics about his highly cited paper,
[HITRAN stands for HIgh-resolution TRANsmission molecular absorption database, and it goes all the way back to 1961...]
"The HITRAN molecular spectroscopic database and HAWKS (HITRAN Atmospheric Workstation): 1996 edition"
...
What’s been the biggest surprise over the last 40 years?

'Well, one of them is how many things man is putting up there. It makes my job never-ending. I just added a new molecule to the database that I can’t even pronounce. It gets a little strange. We have all these new gasses that replace CFCs, which attack the ozone, but the new gasses are long-lived and have other effects. They become greenhouse gasses. The only solution is to have fewer humans."

In addition, in regards to the chart;
http://www.atmos.umd.edu/~owen/CHPI/IMAGES/transir.gif
Andrew linked, you can clearly see the "shoulder" for CO2 and which way the window shuts.
MrB.

How accurate are the HITRAN measurements?

We require these things, because of the instrumental capabilities of NASA satellites, to have incredible accuracy. That means we want to know line positions to one part in 10 million or even better. That’s a tough demand. We want to know the intensities to better than two percent. That’s tough, too. There are so many sources of error. For example, the pressure and the temperature in the cells that we’re using to measure these quantities. We’re pushing the envelope.

 

[Phrak]

In this thread we are discussing the mechanisms by which CO2 might have a strong warming effect. We are not discussing of whether the IPCC is a corrupt institution. If you would have read more of my contributions, you would BTW know that I cannot be said to be a strong defender of their scientific attitude either. But we are not discussing that by itself here and the Earth forum is not the place for it. If you want to talk about the study of how human relations affect publications, and you have some material, this might be posted in the social sciences forum. If you have a political statement to make, you can do that in the politics forum. But we don't do conspiracy theories here (even if they are true, I'd say). We don't care about who did what in the IPCC honestly. We try to discuss the mechanisms by which CO2 can heat or not, the earth, based upon measurements and calculations and so on. Not about who said what, and who was told to shut up.

Don't get me wrong. I'm not saying that you are right or wrong. I'm not expressing any value judgement about what you have to say. I'm only saying that this is not the place to say it.

You like the word 'honestly.' You have multiple points of--shall I call them errors?--throughout your responses to me. They've been bothering me a great deal. Perhaps you'd like to restate yourself.

 

[vanesch]

You like the word 'honestly.' You have multiple points of--shall I call them errors?--throughout your responses to me. They've been bothering me a great deal. Perhaps you'd like to restate yourself.

Yes, I will restate myself: keep to the scientific discussion of the thread here, and not about the political, sociological and other considerations, for which there are other forums. Is that clear enough ?

 

[vanesch]

It is a semantic point, perhaps. Since we start with a constant flow of energy (radiation) out that is determined by the temperature of the black body, if you have an additional inflow of radiation energy from a black body situated nearby at the same temperature, there is heat transfer to the first. The energy from the first intercepted by the second may be equal to the energy received by the first from the second, but there is definitely an exchange of energy.

Yes. I was thinking of "heat transfer" as the NET balance. Of course at equal temperature there are still photons going from A to B and photons from B to A, but the net heat flow is 0.
I guess we agree upon that. What actually counts, is the net heat flow through the atmosphere (which, as you said, must be fixed, as given by the solar influx minus albedo). The question is, what is the needed temperature of the surface to obtain this heat transfer through the atmosphere.

If we are talking about a blackbody in thermal equilibrium, there has to be a constant source of input energy. Otherwise it keeps getting colder as it radiates. If you move two such objects closer to each other, the temperature of each will rise. If you take two black marbles at the same temperature at distant separation in a vacuum they will cool at the same rate by radiation. If you bring them closer together, they won't get warmer but they will cool at a slower rate.

Sure.

Have a look at http://www.atmos.umd.edu/~owen/CHPI/IMAGES/transir.html" showing the absorption of IR radiation by different gases as a function of wavelength.

I know, I'm not disputing that. What I'm saying is that the required delta-T for a certain net heat flow outward of an atmosphere will be smaller if there is a strong convection, than if not. That's all.

The reason for that is that the convection is an EXTRA heat transport mechanism that brings heat from the lower layers to the upper layers, and as such, one needs a smaller effective delta-T than if this extra heat transport mechanism were absent, and the entire heat flow had to go through radiative transport, layer by layer. This radiative transport remains of course valid, but is now a smaller heat flux, given that part of the heat flux goes in the parallel convection path. Smaller radiative heat flux means smaller necessary delta-T.

Having an atmosphere that will not trap IR radiation definitely cools the surface locally because it removes heat from the local surface. If all it does is redistribute that heat over the entire surface, it will have a moderating effect rather than a net cooling effect. So parts of the Earth would be much hotter and parts would be much colder without the atmosphere - similar to the moon.

Well, redistribution will change the local heat fluxes (although, I agree, the total heat flux is fixed and given by the sun incoming radiation), and this will mean different local delta-T. It is not clear that the average of the delta-T with, and without redistribution should be the same.

For instance, BB radiation goes in T^4. So a body that has very hot, and very cold surfaces, will radiate away much more radiation than a body that has the same average temperature, but uniformly distributed. The reason is that 5 degrees more will give rise to somewhat more radiation, than what is missing with 5 degrees less. It is due to the non-linear T dependence.
In other words, all else equal, you will have a higher average temperature when you "mix well", than when you "heat locally".

 

[Bystander]

(snip)If we are talking about a blackbody in thermal equilibrium, there has to be a constant source of input energy. Otherwise it keeps getting colder as it radiates. If you move two such objects closer to each other, the temperature of each will rise. If you take two black marbles at the same temperature at distant separation in a vacuum they will cool at the same rate by radiation. If you bring them closer together, they won't get warmer but they will cool at a slower rate.

(snip)

NO! NO! NO!

Kirchoff's Law! Review it! Understand it! The third blackbody you introduce in this statement (vacuum --- without a temperature specification) is the temperature bath with which your two black bodies are in equilibrium. There is no net exchange of energy among the three, and no temperature change. If you wish to equilibrate two black bodies originally at the same, higher temperature than CMB with intergalactic space, the rate of cooling can be reduced by whatever fraction of 4 pi steradians each subtends of the other's exposure to the CMB background temperature bath.

You keep taking the first step of the random walk Gamow treats in very simplified fashion for energy transport from the center of the sun to the solar surface; take the rest of the trip --- a "photon" (or the equivalent energy) proceeds by "the drunkard's walk" from the center of the sun to its surface in a time of the order of thousands of years, and you may conclude that infrared proceeds from Earth's surface to space by the same "drunkard's walk," and if you do the calculation you'll find an order of magnitude for "residence time" for this "excess greenhouse energy."

This silly thread has been going on and on and around and around in circles. Results of transmission measurements discussed independently of emissivities aren't going to get anyone anywhere --- let's all do all the applicable physics together at one time, just once, shall we?

 

[vanesch]

N If you wish to equilibrate two black bodies originally at the same, higher temperature than CMB with intergalactic space, the rate of cooling can be reduced by whatever fraction of 4 pi steradians each subtends of the other's exposure to the CMB background temperature bath.

Yes, I guess that was what Andrew was after.

You keep taking the first step of the random walk Gamow treats in very simplified fashion for energy transport from the center of the sun to the solar surface; take the rest of the trip --- a "photon" (or the equivalent energy) proceeds by "the drunkard's walk" from the center of the sun to its surface in a time of the order of thousands of years, and you may conclude that infrared proceeds from Earth's surface to space by the same "drunkard's walk," and if you do the calculation you'll find an order of magnitude for "residence time" for this "excess greenhouse energy."

Indeed. That's the "radiation resistance" you have there: the radiative transfer, layer by layer, of heat energy in the form of photons, converted into molecular motion/excitation/..., and again into photons etc...
The point I tried to make was that having solely radiative heat transport will require a higher source surface temperature, than if you add convection next to the radiative transfer, because convection will transport part of the heat (and hence diminish the required heat flux by radiative transport). This comes down to saying that convection is an extra heat transport mechanism which will give rise to a lower rise in surface temperature as compared to when there would be no convection. However, I admit not having any idea by how much, but I'm pretty sure about the *sign* of the contribution (namely, negative).

 

[Andrew Mason]

NO! NO! NO!

Kirchoff's Law! Review it! Understand it! The third blackbody you introduce in this statement (vacuum --- without a temperature specification) is the temperature bath with which your two black bodies are in equilibrium.

In my example, the two blackbodies are not in thermal equilibrium with a third blackbody. Since their temperatures are constant, the rate of energy input is equal to the rate of energy output. There has to be input energy from some energy source for this to occur, but that need not be a third blackbody.

We assume that Earth is in thermal equilibrium ie. its temperature does not change. This is not true over a short period of time, but it is generally true over a long period of time. All this means is that the rate of energy input equals the rate of energy output. We will ignore the energy input that is stored in the Earth in a form other than heat, so energy output is deemed to be all in the form of radiation into space. Energy input is from various sources: sun, moon, stars, CMB, cosmic rays, Earth's internal core.

There is no net exchange of energy among the three, and no temperature change.

I don't understand what you are saying. What are the three bodies? One cannot be in thermal equilibrium with space. Space, by definition, is devoid of matter so it cannot have a temperature. The rate of outradiation of the blackbody is greater than the incoming CMB radiation. .

If you wish to equilibrate two black bodies originally at the same, higher temperature than CMB with intergalactic space, the rate of cooling can be reduced by whatever fraction of 4 pi steradians each subtends of the other's exposure to the CMB background temperature bath.

You keep taking the first step of the random walk Gamow treats in very simplified fashion for energy transport from the center of the sun to the solar surface; take the rest of the trip --- a "photon" (or the equivalent energy) proceeds by "the drunkard's walk" from the center of the sun to its surface in a time of the order of thousands of years, and you may conclude that infrared proceeds from Earth's surface to space by the same "drunkard's walk," and if you do the calculation you'll find an order of magnitude for "residence time" for this "excess greenhouse energy."

We aren't concerned with the residence time of photons in the sun. We are only concerned with its energy output. Since the temperature of the sun is fairly constant we conclude that the energy input (from fusion in its core) is equal to its energy output.

AM

 

[DEMcMillan]

Originally posted by Bystander:

This silly thread has been going on and on and around and around in circles. Results of transmission measurements discussed independently of emissivities aren't going to get anyone anywhere --- let's all do all the applicable physics together at one time, just once, shall we?

This thread has covered a lot of ground and is now able to consider its title. I will put forward an estimate of the scale of the CO₂ contribution for others to consider and increase or reduce in scale, based upon Bystander’s emissivity theme. I estimate that the effect of the 14% CO₂ rise over the last 30 years is 0.05 + 0.01 ^oC. I submit that the use of HITRAN CO₂ data requires information about local difference in upward and downward longwave flux for its implementation. The line by line models being used, including Modtran, use a balancing system of optical depth and spectrum-wide compensating gray scale to estimate photon scattering back to the surface. The atmosphere radiates on the basis of its temperature, like all other matter. I have pointed out elsewhere that analytical chemistry of stratosphere gases utilizes a program that requires emissivity estimation and “black body” or 1.0 is used. https://www.physicsforums.com/showthread.php?t=261966 . The upper stratosphere (50km, 1mPa) is much warmer than any tropospheric area above 6 km altitude. Therefore it should contribute more to downward longwave radiation than anything but clouds and ground-related inversions (see Andre’s graph on the above thread). Interest in cloud effects has generated measurements of downward longwave radiation. Antarctic data from NCEP/NCAR revisions in figure 2b of http://psc.apl.washington.edu/zhang/Pubs/Zhang_Antarctic_20-11-2515.pdf shows the average was 223 W/m2, a value clearly higher than the outward radiation level of the Antarctic continent. This means that all greenhouse gases will lower temperature by scattering IR photons into space. I added a review of Hansen’s CO₂ doubling estimates and a 69% lowering of his numbers by 50 km earthward radiation equal in emissivity to the surface and now use a nonlinear 14% to lower his current estimate to 0.05 ^oC. I recall an Antarctic IR spectrum showing a positive 13-18 μ peak to support my model but can’t find it. Can anyone help?

 

[Bystander]

(snip)I estimate that the effect of the 14% CO₂ rise over the last 30 years is 0.05 + 0.01 ^oC. I submit that the use of HITRAN CO₂ data requires information about local difference in upward and downward longwave flux for its implementation. The line by line models being used, including Modtran, use a balancing system of optical depth and spectrum-wide compensating gray scale to estimate photon scattering back to the surface.(snip)

Like that --- yeah. And from "scattering back to the surface" it's easy enough to segue back to "random walk/drunkard's walk." The hope was that someone was going to apply Gamow's random walk treatment to the Earth's atmosphere (pick a total path length, mean free path per step) and come up with a "residence time" for energy "trapped" by CO₂ IR bands, multiply that time by the surface radiation flux, divide by atmospheric heat capacity, and come up with an upper limit for the "radiative greenhouse" effect. No such luck --- it's on the order of seconds (single digit seconds --- to maybe 10s if we throw in relaxation times), and is measured in mK at the bottom line. Compare that time to the week, 10 days, 2 weeks implicit in the 30 K "atmospheric greenhouse" we're seeking, and recall the "week, 10 days, 2 weeks" time scales thrown around for atmospheric convection cells, atmospheric residence time of water in the hydrologic cycle, and examine the possibility that there are other mechanisms for retaining the energy associated with a 30 K greenhouse than "clipping" 5 and 15 micron coupons with carbon dioxide scissors and squirreling them away until they expire.

 

[deboss]

Newbie here. I am but a poor humble engineering student. But I seem to recall a chart displaying a temperature oscillation over thirty year periods, thirty years high, then thirty years low. Being an undergraduate student my primary method of finding things is google which doesn't want to help right now. If someone could find I'd be very appreciative. Anyway if there is a non-year based thermal cycle wouldn't performing an average over our arbitrary ten base wind up skewing the data because we're catching only part of one cycle. If my memory is correct and it is a sixty year full cycle then averaging over a hundred years would include two of one cycle but only one and one third of the other. Would this be an option for the temperature difference reported.