The catch of CO2 alarmism is that CO2 as an atmospheric trace gas is claimed to have considerable impact on global temperature as a "greenhouse gas", by IPCC estimated to 3-5 C warming upon doubling of the concentration from 0.03% in preindustrial time, with today 0.04%. It is also claimed that this reflects a near saturation (logarithmic) effect of CO2 with additional warming from another doubling being very small. The catch is then that CO2 as a greenhouse gas of very small concentration is claimed to have a big effect up to 0.03% as a very substantial part of an estimated total atmospheric effect of +33 C, but much smaller effect above 0.03% by saturation.
Now, a physical system for which a small cause can have a big effect is an unstable system and as such cannot persist over time. This is like steering your car with a very small joystick sensible to every little shake of your hand. You do not get far with such a control mechanism.
So, if global temperature is largely controlled by CO2 as a trace gas as a very small cause, the Earth faces the possibility of a "runaway greenhouse effect" with huge warming upon doubled CO2. But this is not what we see when observing less than 1 C warming with CO2 raising 0.01% from preindustrial level. The proposed explanation is saturation of the warming effect of CO2 as a greenhouse gas, which then must have been reached already today.
But there is another more natural explanation of the little observed warming from increased CO2, namely that CO2 as trace gas has no (observable) influence on global temperature at all. This is like removing the control function of steering your car from the sensitive joystick to a conventional steering wheel. You can then let your kids play with the joystick as much as they want under an illusion that they steer the car.
This connects to a principle of homeopathy of dilution where the concentration of a substance supposed to be beneficial can be reduced to only a trace while keeping/improving the effect. You can then be a believer, or you can as a non-believer say that the substance has no beneficial effect whatsoever independent of dose.
The catch of CO2 alarmism is thus to claim a big effect from a small cause without runaway effect and then eliminate the possibility that the small cause de facto has only a small effect. This dilemma has not been resolved.
The big effect of CO2 as trace gas is claimed to be demonstrated by its blocking effect (causing warming) on Outgoing Longwave Radiation OLR as the big ditch in the radiation intensity spectrum around frequency 600 as reported by AIRS spectrometers in satellites with the green curve representing OLR from an atmosphere without CO2 as presented by William Happer (time 25.00) (see also article):
The effect of doubling CO2 is represented by a slight broadening of the ditch in red upon doubling as a small effect by saturation. The ditch in OLR causing global warming is thus presented as a big effect up to 0.03% and a small effect upon doubling, as discussed above with connection to homeopathy.
But there is a catch in the above spectrum, since what AIRS de facto measures is the temperature of atmospheric CO2 at the highest level where it can be detected (220 K at the tropopause), which is possible even at trace concentrations, but what is reported is radiation intensity from Planck's Law as if CO2 as a trace gas is blocking considerable amount of radiation. The above diagram is presented as the main evidence that CO2 as trace gas causes considerable global warming, but then without runaway effect. But the diagram can be questioned since it reports something which is not directly measured. Maybe a true OLR has no ditch and so no (observable) warming from CO2. Maybe the spectrometer acts as a ghost detector like that detecting Downwelling Long Wave Radiation DLWR discussed in this post. What do you think?
Happer is a skeptic claiming little warming from doubled CO2 as the slight broadening of the ditch. But Happer seems to believe in its present big effect represented by the green curve without ditch. It would be interesting to hear what Happer says about the possibility that the diagram is the result of ghost detection, and so I have asked him and am waiting for response.
PS1 The fact that an AIRS spectrometer directly measures temperatures and not radiation intensity (like a pyrgeometer) is supported by the fact that it contains both coolers and radiators at 150 K and 190 K. Also recall this post.
PS2 Communication with Will Happer: (see invitation to TNT Radio)
Claes:
Does a pyrgeometer directly record temperature or radiation intensity?
Will:
Claes:
Will:
Temperature is both obvious from our sensations of hot and cold, and at the same time profoundly subtle from a thermodynamic point of view. Here it is intimately associated with the idea of systems in thermal equilibrium, and with the abstract concept of entropy. The most fundamental definition of the temperature of a body in thermal equilibrium is the rate of change of its internal energy with entropy, under conditions that no work is done. This definition is usually too abstract to be of much use.
Ideal Planck radiation has a temperature and has the maximum possible entropy for radiation of a fixed total energy. But it is unusual to find real Planck radiation in nature. Besides having the Planck distribution of intensity over frequency, the radiation must also be completely isotropic. Sunlight can be roughly isotropic inside an optically thick terrestrial cloud, but the spectral intensity is orders of magnitude too weak for the sunlight to be in thermal equilibrium. Except in the interior of optically thick clouds, Earth's thermal radiation is highly anisotropic, and it usually does not have a Planck spectral distribution because of the complicated absorption spectra of greenhouse gases. But cloud particulates are pretty good grey bodies with no sharp spectral features. The particulates absorb, emit and scatter much more powerfully that greenhouse gases. So multiple scattering, emission and absorption of thermal radiation inside optically thick, isothermal clouds can produce radiation which is close to the Planck limit for the temperature of the particulates in the cloud.
Inlägg
One way of looking at the Brightness Temperature graphic is to do away with the solid line (292 K?) and draw an appropriate Planckian curve such that the amount of open area between this curve and the squiggly line is equal on both sides of the curve. This should give some rough measure of the actual "global temperature"... while also showing something else that is important.
SvaraRaderaEven if that Brightness Temperature graphic is correct, what is happening isn't a "trapping of heat"... it's a down-conversion of energy from the absorption bandwidths of CO2, O3 and H2O (note the respective dips in the graphic) to longer wavelengths.
You'll note that to the left of the absorption bands of CO2, O3 and H2O, the squiggly line rises higher than it otherwise would absent those absorption bands. This becomes especially apparent if one draws that Planckian curve mentioned above.
That energy's not being "trapped", it's being thermalized, then transferred via t-v (translational-vibrational) and v-v (vibrational-vibrational) collisional processes, primarily to water vapor, then radiatively emitted.
The more radiative, polyatomic molecules there are in a parcel of air, the more it can cool the system known as 'Earth' via radiative emission to space.
The more monoatomic and homonuclear diatomic molecules there are in a parcel of air, the more they dilute the polyatomics and thus reduce the ability of that parcel of air to cool the system known as 'Earth' via radiative emission to space.
IOW, since monoatomics have no vibrational mode quantum states and thus cannot emit; and since homonuclear diatomics have a net-zero magnetic dipole and thus cannot emit unless that net-zero magnetic dipole is perturbed via collision, they cannot effectively radiatively emit to space.
In an atmosphere consisting of solely monoatomics and homonuclear diatomics, they could pick up energy via conduction by contacting the surface (just as the radiative polyatomics can do), they could convect (just as the radiative polyatomics can do)... but once in the upper atmosphere, they could not as effectively radiatively emit. The upper atmosphere would warm, lending less buoyancy to parcels of air attempting to convect, and thus hindering convection.
And that's how an actual greenhouse works... by hindering convection. Thus the monoatomics and homonuclear diatomics are the actual 'greenhouse' gases.
The polyatomics (H2O, CO2) are the prevalent atmospheric radiative coolants; water vapor acting as a literal refrigerant (in the strict 'refrigeration cycle' sense) below the tropopause; and CO2 acting as a net atmospheric radiative coolant at all altitudes except for negligible warming at the tropopause (where it absorbs a greater proportion of cloud-reflected solar IR insolation and radiation from cloud condensation), as the presentation by Maria Z. Hakuba from NASA JPL and as the Clough & Iacono study show:
https://i.imgur.com/0DTVYkR.png
https://i.imgur.com/IYDjzxX.png
In fact, many high-end vehicles have proportional steering which provides a larger angular wheel movement for a given steering wheel input at low speed, and a smaller angular wheel movement for a given steering wheel input at high speed... thus, if you jerk the wheel at low speed, the vehicle will steer sharply, but if you jerk the wheel at high speed, the vehicle won't overturn.
SvaraRaderaSome call it Speed-Proportional Steering, others call it Speed-Sensing Steering.
You'll note this requires an intelligent (human-programmed) response to vehicle speed so as to alter steering output proportional to steering input.
If we conflate low CO2 atmospheric concentration with low vehicle speed and high CO2 atmospheric concentration with high vehicle speed, we have the same response.
In reality, what occurs in the atmosphere with increasing CO2 atmospheric concentration is a reduction in the extinction depth of the band centered on 14.98352 µm.
The radiation which would be absorbed at high CO2 atmospheric concentration is already being absorbed at low CO2 atmospheric concentration, just in a shorter distance in the high CO2 atmospheric concentration instance.
The thermalization (which is only half the story... see next post) which occurs at low CO2 atmospheric concentration will still occur at high CO2 atmospheric concentration, just in a shorter distance. The net effect in both cases being an increase in Convective Available Potential Energy, which increases convection, which is a net cooling process.
As we will see in the next post, an increasing CO2 atmospheric concentration doesn't imply an increase of 'heat trapping', it implies an increased moderation of atmospheric temperature closer to the 'transition temperature' (not used in regards to phase transition, explained in the next post) of CO2.
{continued in next post}
Note here that the term 'transition temperature' is not used in relation to phase change, but to a change in the role of the given molecular species from net cooling to net warming or vice versa.
SvaraRaderaClimate alarmists claim that CAGW (Catastrophic Anthropogenic Global Warming) can occur because the CO2 molecule absorbs 14.98352 µm radiation, becomes vibrationally excited in one of its bending modes, collides with a nitrogen or oxygen molecule, and imparts that vibrational energy to the translational energy of the other molecule via a process known as collisional de-excitation, thereby increasing atmospheric temperature.
The climate alarmists claim that this process occurs under all circumstances. This represents a violation of 2LoT and the Equipartition Theorem.
CO2 is a dual-role molecule, just as all molecules capable of emitting radiation are.
The 'transition temperature' of any given molecular species is dependent upon the differential between:
1) the combined translational mode energy of two colliding molecules,
-and-
2) the lowest vibrational mode quantum state energy of the radiative molecule.
When 2) > 1), energy flows from vibrational mode to translational mode, which is a warming process.
When 1) > 2), energy flows from translational mode to vibrational mode, which is a cooling process.
Below ~288 K, the vibrational mode quantum state energy of CO2's lowest excited vibrational mode quantum state, CO2{v21(1)}, is higher than the average combined translational mode energy of two colliding atmospheric molecules, therefore the 2nd Law of Thermodynamics and the Equipartition Theorem dictate that energy will flow from vibrational mode to translational mode.
The increase in kinetic energy of atmospheric molecules represents an increase in temperature.
Above ~288 K, the Maxwell-Boltzmann Speed Distribution Function dictates that enough of the atmospheric molecules carry sufficient combined translational mode energy upon molecular collision to begin significantly vibrationally exciting CO2's lowest vibrational mode quantum state.
A graphic, showing the percentage of molecules which carry sufficient kinetic energy at 288 K to excite CO2{v21(1)}
https://i.imgur.com/CxVTcro.png
The conversion of translational mode to vibrational mode energy is, by definition, a cooling process.
This increases the time duration during which CO2 is vibrationally excited and therefore the probability that it will radiatively emit. The resultant radiation which is emitted to space is, by definition, a cooling process.
This 'transition temperature' at which CO2 changes from being a net-warming to a net-cooling molecule is ~288 K, with CO2 acting more and more in its net-cooling mode as temperature increases.
Thus CO2 is physically incapable of causing catastrophic warming, and indeed is a net atmospheric coolant above its transition temperature, in accord with 2LoT and the Equipartition Theorem.
The same concept applies for all molecules capable of emitting radiation. The only thing that changes is the transition temperature at which any given molecular species changes roles from net-cooling to net-warming or vice versa, because each molecular species has different vibrational mode quantum state energy.