Dallas Cowboys Stadium Seating and Atmospheric CO2

Ryan Scott Welch says:
January 28, 2014 at 7:09 am
The lag of CO2 after temperature changes is quite variable: 800 +/- 600 years during a glacial-interglacial transition, several thousands (up to 5000) years for the reverse transition, 50 years for the MWP-LIA transition, halve a year for the short term variability (2-3 years) and a few months for the seasons. That is because a lot of different processes all with their own time frame are involved. The longest time frame is the deep ocean circulation and the area occupied by ice sheets or vegetation, the shortest by the formation of new leaves in spring and their death in fall.
how can we know that humans contribute more than 50% of the increase of CO2 since the start of the industrial revolution
Because humans emitted twice the amount of CO2 per year as the measured increase in the atmosphere, each year of the past at least 50 years. For the period before 1960, we only have ice cores with a resolution (filtering) of about a decade, but that too shows an about twice amount of CO2 emitted by humans compared to the increase in the atmosphere:
http://www.ferdinand-engelbeen.be/klimaat/klim_img/temp_emiss_increase.jpg
BTW: made a mistake, the accumulated human emissions didn’t start at zero in 1900, neither did the accumulation in the atmosphere. That would cause a small upward shift of both curves, more for the emissions than for the increase in the atmosphere…
Anyway, here the detailed accumulation/sink rates for the past 50+ years of accurate measurements:
http://www.ferdinand-engelbeen.be/klimaat/klim_img/dco2_em2.jpg
The variability around the trend is caused by short term temperature variability (El Niño, Pinatubo) and is a modulation of the sink capacity of nature for the increase of CO2 in the atmosphere. The trend is from human emissions…

richardscourtney says:
January 28, 2014 at 6:07 am
Box of Rocks:
What I am looking for is a calculation that show that the amount of energy lost by a control volume (c.v.) of 1 cubic foot to it’s surroundings can be returned to the c.v. by the CO2 molecules in the c.v.. Nothing more, nothing less.
The GHG theory postulates that When the c.v. cools – it losses energy and that the CO2 molecules with in the cv can convert enough of the earths outgoing radiation to usable energy to either maintains the c.v.’s temperature or raise it.
So there should be an equation or mathematical model that will allow some one to calculate the required energy conversion that the CO2 molecule must do to for the theory to work.
That way, the left side can equal the right side and voila an answer…

please show me thermodynamically how t.hat 0.04% can contribute more than 0.04% of the GHE backed up with calculations.
Well, I could — pretty easily, in fact, since CO_2 is a lot more than 0.04% of the GREENHOUSE GASES that absorb significant amounts of LWIR AT ALL, because O_2 and N_2 simply don’t, much. Or, you could invest $25 or whatever and purchase Grant Petty’s “A First Course in Atmospheric Radiation”, which I’m looking at as I type, and save me from retyping it into this itty-bitty window. Or I could refer you to the numerous places where this has been discussed and gone over on WUWT and elsewhere — the issue isn’t the absolute concentration of GHGs in the atmosphere, the issue is the mean free path of photons in the LWIR bands that those molecules strongly absorb and emit in. Of course then I’d have to teach you enough quantum theory to understand the idea of a molecular cross-section, and that’s pretty difficult.
It’s a shame that your eyes don’t see using LWIR, as if they did we wouldn’t even be having this conversation. The reason that we are is that you look out your window on a fine, sunny day or clear, starry night, and — you can see straight through that atmosphere “to infinity”! It is transparent! On a low humidity night, you can see detailed features of the moon almost as if there is nothing in between the moon and you! And this is for the whole atmosphere, all the oxygen, nitrogen, and everything else (but water vapor and sometimes particulate smoke and smog and so on, which can actually attenuate even visible light pretty strongly).
You look through this clear atmosphere and say to yourself gee, if I can see through the whole thing like it wasn’t even there, how could a gas at a concentration of 0.04% possibly matter?
If you saw in LWIR, however, it would be a completely different story. The mean free path of LWIR light varies with wavelength, but in the strong CO_2 absorption bands it is order of 1 to 10 meters. That means that photons here only go distances ranging from tens of centimeters to tens of meters before being absorbed by a CO_2 molecule. That’s quite similar to trying to see through a fog in the visible bands — you can easily see things 1-10 meters away, but as you get further than that, fewer and fewer photons reach your eye directly from the object you are looking at — most of them are diffusively scattered along the way. No matter which way you look, you see a nearly uniform grey once you try to look farther than photons can travel without a near-certainty of being scattered multiple times. You only see these scattered photons.
This isn’t precisely what happens with CO_2, because in a fog the light is scattering more or less elastically off of tiny water droplets, not inelastically off of molecules, but again, that has little effect on what you “see”. If your eyes were sensitive to the entire LWIR blackbody band (and indeed, saw it in different colors across its spectrum) you’d see even relatively distant objects in certain colors in the “transmission windows” where no atmospheric molecules have a particularly strong cross-section, but other colors would be absorbed almost immediately — “white” objects up close would become colored as you look at them far away not unlike the way our own atmosphere reddens distant objects via Rayleigh scattering. And in the strongly absorbed CO_2 wavelengths the atmosphere would be completely, totally, opaque, 0.04% or not.
What goes on then is complicated — basically most of the absorbed energy is transferred to surrounding air molecules, but in local equilibrium the CO_2 eventually absorbs and reradiates equal amounts of radiation in these bands effectively diffusing the radiation into all directions in rough thermal equilibrium with the temperature at their height. Even this is more complicated than the simple picture suggests, as the absolute density of molecules decreases with height, so even at a constant concentration the mean free path grows as photons diffuse upwards. Eventually the photons reach a height where the probability of a photon emitted in the upward direction reaching “infinity” (escaping the atmosphere) is no longer essentially zero and the energy that is being transported is lost.
But a significant fraction of the energy being given off as radiative loss by the surface of the Earth is returned to the surface of the Earth in the strongly absorbed bands. This isn’t really subject to much argument — while your eyes cannot see it (leading you to commit the sin of saying silly things) it is easy to measure it and photograph it. Indeed, people who are trying to measure things like atmospheric water vapor concentration — where water vapor is transparent, or nearly so, in the visible bands — have to look for it in its strongly absorbing bands as those are precisely the strongly emissive bands (Kirchoff’s law). However, those bands overlap with the bands associated with CO_2 and so one has to perform subtractions of CO_2-linked downwelling radiation in order to extract pictures of overhead not-yet-clouds.
This is straightforward technology, and is an important aspect of predicting the weather. It is a key part of what satellites have to do in order to measure things like atmospheric temperatures from the top of the atmospheres and do things like take those nifty LWIR photographs of weather patterns you can easily find on lots of weather sites — a good way of tracking weather fronts at night when one cannot see them, a good way of measuring the temperatures of the higher clouds in those fronts at the same time. In CO_2 absorbed bands, overhead satellites pretty much cannot see the ground. The atmosphere in these bands is opaque and all that one picks up is diffusively multiply scattered, re-thermalized radiation from the upper part of the troposphere where photons finally start to escape. This radiation is correlated with ground features, but only on a very long lateral length scale — nobody is going to e.g. pick up the localized heat signature of individual humans in these bands.
If you actually want to learn something about this (instead of darkly suggesting that downwelling radiation violates some law of thermodynamics — which is absurd and false) you could read:
http://www.coe.montana.edu/ee/jshaw/publications/Physics_IRCloudImaging_EJP2013.pdf
which is a very interesting, completely global-warming-neutral paper that describes a lot of the physics and of course has many photographs taken in the LWIR bands. Figures 9 and 10, for example, are very illuminating. This isn’t controversial — it is straight up engineering. If you want to take pictures of stuff in the LWIR, you have to explicitly deal with the fact that the atmosphere is not at all transparent in much of the LWIR band associated with the Planck curve for temperatures around 288 K plus or minus 30 K.
The other thing you should really do is work through the single-slab atmospheric model. Willis presented it as the “steel greenhouse”, but it is a common example and a very good version of it is given in Petty (one with user-variable shortwave/visible and longwave/IR absorption coefficients). When one makes the atmosphere perfectly transparent to short wave radiation, and perfectly absorbing/re-emitting of long wave radiation, one gets the steel greenhouse limit of greenhouse warming of 1.2 x T_{gb}, 1.2 times the greybody temperature that the planet would have with no greenhouse effect at all and perfect absorptivity. Real planets will be strictly less than this — the Earth is closer to 1.1 times the greybody temperature.
As Willis points out, the real issue isn’t “a trace gas cannot produce significant greenhouse warming” — that argument is long since lost to direct observations, to photographs and spectrographs of downwelling radiation and upwelling radiation that clearly show the enormous impact of the gases in between the surface and infinity on the transmission of radiation — it is that the Earth’s atmosphere is a complex nonlinear system with multiple feedbacks that lead to a more or less stable mean temperature — there is no pathway to runaway warming visible in the geological record, and while there are indeed pathways to runaway cooling, even that is apparently limited by sufficiently powerful constraints that glacial eras are not “permanent”. It is by no means clear that the simple linear assumption of more CO_2 equals more warming PLUS POSITIVE feedbacks from things like water vapor are correct. It is absolutely unclear that we know how to disentangle the natural variation in the climate record from human effects, as well. Nonlinear open systems mix everything up and are often highly oscillatory around their local quasi-equilibrium (stuff having to do with attractors in high dimensional spaces).
In the end, though, articles like the top article do the skeptical argument no favors. By their nature they promote an argument that is utterly false, and easily demonstrated to BE false by direct spectrographic photographic evidence. Hard to be falser than that — directly falsified by evidence. That just gives those that think that they understand this to the point where they overstate the argument for warming, also in the teeth of contrary evidence, an easy way to promote a logical fallacy that is nevertheless highly persuasive, that if SOME people on your “side” promote one idiotic argument, the entire argument being promoted is wrong. Logical fallacy or not, why give them this sort of free shot?
BEFORE posting things that are simply wrong or almost deliberately misleading, why not take the time to learn some of the physics? And I mean learn it, not mouth words that you do not understand that you’ve heard somewhere that others have told you “refute” the GHE itself.
Hard to “refute” a photograph, at least in my opinion.
rgb

philjourdan says:
@Colorado Wellington – Go Spurs??? You do realize they are just a boot attachment on a cowboy? 😉
Watch out, Phil! One more joke about football and we will all be sent to the principal’s office.

Would it be more effective to use a computer-screen PIXEL coloration app. to convey the CO2 concentration? I am in the process of random;ly adding 400 colored dots to an area of one million dots, appropriately colored to reflect Nitrogen, Oxygen, “trace Gases”, and CO2 . . . .
Here’s a thought on the whole Climate System: Attempting to impose order on Chaos is a fun and interesting Fool’s Errand (:- o .

I’d like to show my incredible level of ignorance here, if you don’t mind. I gather that the “warming” contribution of CO2 is that it reflects the long wave radiation that is emitted by the Earth back towards it. If that were the case, then wouldn’t it not also reflect the long wave radiation that is emitted by the Sun and travels to the Earth back into space? Certainly the solar energy is not all in short wave lengths, thus it would seem reasonable that CO2 is reflecting heat back into space that would otherwise penetrate through the atmosphere. If that were the case, then isn’t it likely that greater concentrations of CO2 would reflect move heat back into space from the Sun that it does back to the Earth? I would think, over time, that a build up of CO2 would, then, cause cooling rather than heating, especially in a low solar activity period. Any ideas what the CO2 level concentrations were just prior to the onset of an iceage?

Tom O says:
January 28, 2014 at 11:05 am
I’d like to show my incredible level of ignorance here, if you don’t mind. I gather that the “warming” contribution of CO2 is that it reflects the long wave radiation that is emitted by the Earth back towards it. If that were the case, then wouldn’t it not also reflect the long wave radiation that is emitted by the Sun and travels to the Earth back into space?
There is only a small overlap between the incoming IR radiation of the sun and the outgoing IR radiation from the earth. CO2 has a band in the incoming radiation, but water vapour is already the large absorber in that range. Another band of CO2 is in the near-zero energy overlap band of incoming and outgoing radiation, so that doesn’t have much influence. The curves can be seen in the .ppt show at slide 25 in:
http://ist-socrates.berkeley.edu/~budker/Physics138/Alyssa%20Atwood%20Atm%20Spec5.ppt
The main absorber of incoming visible light is water vapour, CO2 hardly plays a role. And clouds are the main reflectors, both upward (sunlight) and downward (IR)…