In Note 4 on the diagram, it is said that the longwave infrared radiation is emitted from the surface of the Earth due to the 168 W/m^2 of radiation from the sun that the surface has absorbed. In Note 5, it states that some of this radiation is absorbed by greenhouse gas molecules with half being emitted in the direction of space and half emitted back toward the Earth's surface. The infrared radiation from the greenhouse gas emission toward the surface is absorbed and the surface gains more heat. This additional heat causes more infrared radiation to be emitted, which again is absorbed by greenhouse gas molecules and half again is re-emitted toward the surface heating it still more.
This is very important in the greenhouse theory because the Earth's surface is desperately cold due to direct solar heating, since the black body temperature corresponding to a thermal power of 168 W/m^2 is only 233.3 K or -39.8 C. Fortunately, the theory claims half of the surface radiated infrared energy that is returned to the surface provides more heating of the surface, which radiates still more energy as it warms, but half of that is returned. In fact, the claim is made that a great deal of heat energy is added to the Earth's surface in this way. Let us examine the frequently cited Kiehl-Trenberth Energy Balance diagram to see how much.
This diagram comes in several versions and the incoming radiation from the sun absorbed by the surface differs somewhat in the various versions. In this diagram, it is 161 W/m^2, or a bit less than the 168 W/m^2 of the IPCC diagram above. The total energy added to the surface by greenhouse gas re-emission is said to be 333 W/m^2 here. This means that greenhouse gases are adding slightly more than two times the energy of the sun to warm the surface. They believe that a factor of two times the solar warming is due to the multiplier effect of greenhouse gas re-emission. Each time a greenhouse gas molecule absorbs ground radiation energy, it sends half of it back to the surface. The surface radiates all of that added energy and half of that half is returned to the surface by the gracious greenhouse gas molecule. The result is a geometric series of one-half raised to a power times the initial heat energy the surface had from the sun. It works like this:
Back Radiation = (161 W/m^2) (Sum from n=1 to infinity of terms 1/(2^n))
The greenhouse gas theory says that the sum of the geometric series is 2. Actually, the sum is 1. I suspect the error arose from the use of a general formula for geometric series which starts with the term for n=0 and one-half raised to power zero is one. The greenhouse gas theorists forgot to subtract this first term of one, which was not in the series they needed to sum. In any case, note that 2 times 161 W/m^2 is 322 W/m^2, or almost the 333 W/m^2 this diagram claims warms the surface with slightly more than twice the power of the sun itself.
There are many problems with the physics of these diagrams. This will not be a general discussion of all of these problems. I will note that it is interesting that the Kiehl-Trenberth diagram allows for some cooling of the surface by evaporation and by thermals or air convection currents, but these apparently become operative only after all of the direct solar warming radiation has already been doubled by the re-emission of infrared radiation back to the surface! One should note that no radiation is emitted by the nitrogen, oxygen, and argon that make up most of our atmosphere in this model. They are warm, as implied by the thermals, but they emit no radiation in their theory. [17 March 2013: Actually, oxygen molecules absorb and emit energy on the border of visible and infrared radiation (found in solar insolation, but not the Earth's emission spectrum) and nitrogen, oxygen, and argon all emit electromagnetic radiation in the very low energy microwave radiation spectrum. These represent very minor amounts of energy, however.]
Another interesting implication is that the absorbing greenhouse gas molecule always re-emits 100% of the infrared radiation it absorbs. It never transfers any energy to nitrogen, oxygen, or argon due to collisions, despite molecular collisions occurring at the rate of 6.9 billion per second at sea level. In reality, such collisions do occur before re-emission does and the absorbed energy often is transferred to nitrogen, oxygen, and argon molecules or atoms, which remain cooler than the Earth's surface under most conditions and times of day.
Another interesting implication is that the absorbing greenhouse gas molecule always re-emits 100% of the infrared radiation it absorbs. It never transfers any energy to nitrogen, oxygen, or argon due to collisions, despite molecular collisions occurring at the rate of 6.9 billion per second at sea level. In reality, such collisions do occur before re-emission does and the absorbed energy often is transferred to nitrogen, oxygen, and argon molecules or atoms, which remain cooler than the Earth's surface under most conditions and times of day.
As we know, heat is not transferred from cooler bodies to warmer bodies. The flow of heat is always from the warmer to the cooler body. This creates a problem since as one ascends in height in the lower atmosphere, called the troposphere, which extends to an altitude of about 15,000 meters, the temperature drops. Where the average surface temperature is 288 K, the temperature at 1000 meters altitude is 281.7 K, and at 5,000 meters it is 255.7 K, or about the same temperature the Earth appears to be as seen from space and assuming it is a black body radiator. Of course it is not a black body radiator, despite the fact that greenhouse gas theorists almost always assume it is. The everyday objects of our lives do emit infrared radiation, but with a reduced efficiency compared to a black body radiator. The Earth's surface is full of everyday objects and materials, none of which are black body radiators. Greenhouse gas theory says that the greatest increase in temperature due to added CO2 occurs at an altitude of 8,000 to 12,000 meters above the equator and the lower latitudes. At 10,000 meters, the gas temperature is 223.3 K. A greenhouse gas molecule at any of these altitudes is colder when at equilibrium with the surrounding gas molecules than the surface of the Earth at 288K. Even if we compare to the black body temperature corresponding to the 161 W/m^2 said to come straight from the sun, the molecules at 10,000 meters are colder than that surface would be and they could not heat it according to thermodynamics principles. Apparently, the greenhouse theorists believe the greenhouse gas molecule absorbs the infrared radiation it is able to absorb and that raises the temperature of the molecule to a higher temperature than the surrounding molecules in the atmosphere at that elevation and before the greenhouse gas molecule has a collision and transfers energy to those surrounding molecules, it re-emits infrared energy to the ground and warms it.
Let us now discuss the properties of a black body radiator. It is a very special cavity with a very thin skin. The volume within the cavity has a very special property. The energy density, or the energy per unit volume of space, is constant everywhere within it. That energy is determined by the photons of various frequencies that are emitted from the walls of the cavity as uniquely determined by the temperature of the walls of the cavity. One of the interesting properties of a black body cavity is that if the interior volume is doubled, then the emission of photons from the walls must also double, assuming the temperature remains the same. Let us examine the distribution of electromagnetic frequencies found in a black body at several temperatures of interest for the greenhouse gas theory of global warming. The diagram below shows the spectrum of frequencies or wavelengths for the sun and for some temperatures similar to that of the Earth.
The spectrum of wavelengths for the sun at 5525 K is shown at the left top of the diagram to have a peak in the visible light part of the electromagnetic spectrum, but also has a long tail in the infrared part of the spectrum. On the right top of the diagram, three spectra of emission energies are shown for black body radiators at 310, 260, and 210 K. These are the smooth lines of violet, blue, and black, respectively. The Earth's surface at about 288 K is closer to the spectrum for a body at 310 K. The blue area filled in within those black body spectra is the portion of longwave infrared radiation from the surface of the Earth which is not absorbed by the greenhouse gases. The wavelengths at which the greenhouse gases absorb radiation is shown for each gas below, as is the sum of their absorptions.
If the Earth's surface is at a certain temperature, then it too will have a black body-like emission spectrum. Now suppose that CO2 absorbs a particular wavelength of infrared radiation out of that spectrum and then re-emits that energy at that wavelength back to the Earth's surface. Can that photon absorbed by the surface raise the temperature of the surface? No. The reason it cannot raise the temperature of the surface is because to do so, the radiative spectrum has to move to the left in the diagram above. The shorter wavelengths on the left correspond to higher frequencies and to higher energies. For the surface to become warmer due to the absorption of the photon from a greenhouse gas, higher energy vibrational states must become occupied in the Earth's surface materials. A photon from a lower temperature emitter cannot warm the surface to a higher temperature because that lower energy photon cannot excite the necessary higher energy vibrational modes. That photon can slow down the cooling of surface at night, since its emission at night will cool the surface and the returned photon will be at a higher energy than the surface is by the time the photon returns. This is the equivalent of the process when we put hot coffee in a thermos, thereby slowing down its cooling rate. But, the returning photons from the reflective wall in the thermos never heat the coffee to a higher temperature than it was at when it was poured into the thermos.
Whether a photon is absorbed by a material or not is dependent upon the electronic and vibrational states in the material which can be excited and the energy of the photon. The fact that a photon is incident upon a material does not mean it will be absorbed. The greenhouse gas theorists recognize this when the material is nitrogen or oxygen molecules, but they assume the Earth's surface can absorb whatever strikes it, at least if it is a low energy or longwave infrared photon. But, just as visible light passes through window glass without absorption, this is not necessarily the case. The light photon is not absorbed in glass because glass has a wide energy band gap in which there are no occupied or unoccupied electronic states. Still higher energy ultraviolet energy may excite available unoccupied electronic states, which in turn will de-excite in time. Until they do, they can warm the glass. But visible light just passes through. The same is the case with some of the low energy, longwave infrared radiation returned from greenhouse gas molecule de-excitations. The Earth's surface will not accept them since the excitable vibrational states are already excited and vibrating assuming that its temperature has not dropped since the returned photon was emitted by the ground. There simply is no available energy state able to accept it. The fact that the greenhouse gas alarmists ignore this fact is a very egregious error.
For another approach to the problem of heating surfaces with black body radiation, let us return to the black body cavity. To make this simple to picture, let us assume it consists of two identical hemispheres which we have put together to make a sphere. We supply heat to the sphere wall to bring it to a temperature T. The power radiating from the black body walls is known to be equal to a constant times T to the fourth power. The interior is full of photons, which are incident upon the walls, which are also radiating photons. Let us image one of the hemispheres is on the left and one is on the right as we look at our black body radiator. When a photon from the right wall is incident upon the left wall, the temperature of the left wall does not go up. It remains constant. An incident photon did not cause a temperature rise. Of course, one may say that the incident fluxes of photons are equal to emitted fluxes, so it is expected the temperature will not increase. But, then if we have supposed that the greenhouse gas molecule that has absorbed a photon from the Earth's surface has not lost energy to a gas collision and has re-emitted the photon at the same energy back to the Earth's surface, then why would the Earth's surface temperature increase any more than the left hemisphere wall temperature would in our black body cavity? The answer is that it would not.
Perhaps you would object that there is something so special about the black body radiator that the Earth's surface cannot replicate it and will act differently. Indeed, there are differences, but it is the analogy to the black body radiator explicitly that is being used in the greenhouse gas theory. The differences of the Earth's surface from a black body radiator are important, but I cannot see how they help to allow one to claim that photons of an energy from the surface's black body radiation spectrum are able to drive the surface to higher temperature than it had when it first emitted a photon of the same energy.
Let us try still another thought experiment. Let us separate our two black body hemispheres ever so slightly so that we have two hemispheres facing each other and they are still at the same temperature. In the greenhouse gas theory, these two facing spheres would heat each other up to a higher temperature! The right sphere would emit a photon and it would be absorbed by the left sphere. The left sphere would then emit half of such photons back to the right sphere and half out into space from the outside surface of the hemisphere. But then half of those emitted from the inside surface would be incident upon the right hemisphere inside surface and be re-emitted toward the left hemisphere. Of course one might say the right hemisphere emits half inward and half outward, but note that in greenhouse gas theory no photons are emitted in the direction of the Earth's interior, despite the fact that they actually are. So assuming the right hemisphere acts like the Earth's surface and the left hemisphere acts like the greenhouse gas, we have set up the same "energy doubling" geometric series between our two hemispheres. The temperature of the right hemisphere must climb. Well, no, it does no such thing. The two hemispheres will remain at the same temperature just as if they were still together as a standard black body cavity. Well not quite. Actually, each will be a very slightly lower and equal temperature.
Let us now take our hemispheres and widely separate them. We will put the right one at a higher temperature than the left and then bring them into close proximity to almost make a spherical cavity. What will happen? The cooler left hemisphere will warm, but neither hemisphere will become warmer than the right hemisphere before they were brought together. The photons incident upon the warmer right hemisphere from the cooler left hemisphere cannot make the initially warmer hemisphere any warmer. Why would they when if we made the left hemisphere the same temperature as the warmer hemisphere, it could not warm that hemisphere. Indeed, the most ideal situation for warming one hemisphere would be to put the two hemispheres back together to make the true black body cavity, but with each hemisphere at a temperature T as we put them together, we would simply wind up with a black body cavity with a temperature of T.
In short, the greenhouse gas theory errs badly about the behavior of black body radiation and radiators. Yes, bodies above absolute zero temperature do radiate photons. But those photons are not always absorbed and they are able to raise the temperature of the absorbing body only if they are of a high enough energy to allow vibrational states to be excited which would be excited in the black body radiator at that higher temperature. The black body radiator requires that the energy levels of its spectrum be occupied and that they be filled to the prescribed extent given by the black body energy distribution for a given temperature. Having many photons incident at an energy level which is already filled, will not increase the temperature of the black body radiator material.
The consensus greenhouse gas theory hugely exaggerates the effect of greenhouse gases. This is not to say that there is no effect. As I have pointed out in a chapter of Slaying the Sky Dragon: Death of the Greenhouse Gas Theory (Stairway Press, Mount Vernon, Washington, 2011), greenhouse gases cool the Earth's surface during the daylight hours and retard its cooling in many cases at night. This is an important, though in no way catastrophic effect, and it has been observed to be happening as the CO2 concentrations have increased. But those effects of greenhouse gases do not violate the conservation of energy and do not require cooler or equal temperature bodies to warm a warmer or equal temperature body.
As I also pointed out in that chapter, the incident radiation from the sun is actually somewhat greater than that claimed in the diagrams above. The temperature of the Earth's surface given that higher energy flux or power density is also much higher than the equivalent black body radiator, since the Earth's surface has a much lower emissivity than does a black body. This means that it cools itself more slowly with radiation than a black body would. As a result, the Earth's surface is likely only about 9 C warmer than one would expect from the incident radiation from the sun. There are many other sources of energy that can account for this much smaller energy differential. Among these are the effects of gravity upon our atmosphere, the heat from the very hot interior of the Earth, the energy due to the tides in the ocean and land due to the moon and other bodies in our solar system, the energy from cosmic rays and dust, the energy from the solar wind, the energy from the interaction of the sun's magnetic field with that of the Earth, and the energy stored in the subsurface oceans and land. The urban heat island effect is also substantial in some areas, though relatively minor across the globe.
Dr. Anderson,
ReplyDeleteWould you care to comment yourself on this reply referencing this blog post of yours?
http://judithcurry.com/2011/01/31/slaying-a-greenhouse-dragon#comment-36485
Pekka Pirilä said on Slaying a greenhouse dragon
February 1, 2011 at 2:40 pm
In response to Hockey Schtick on February 1, 2011 at 2:32 pm:
Ort: no, Bryan’s approach 1 is “no backradiation,” which he dismisses. Approach 2 is that there is “backradiation,” but the colder objects “backradiation” cannot heat the hotter object. This is exactly what materials physicist Charles Anderson explains in detail, and you fail to understand why the absorptivity is effectively 0 by a hotter temperature/frequency/entropy body [...]
The explanation is false. A black body goes never to a state where it would not absorb all radiation reaching it. The absorption leads unavoidably to the transfer of the energy of the absorbed radiation to the heat content of the body. The body is also radiating at the same wavelength, but the rate of radiation is not changed by the absorption. Thus the incoming radiation influences the heat balance of the body.
The same applies very closely also to most surfaces of earth for infrared radiation, because they are almost black in the infrared region.
and also this comment on the same thread:
ReplyDeletemaxwell said on Slaying a greenhouse dragon
February 1, 2011 at 3:11 pm
In response to Hockey Schtick on February 1, 2011 at 11:34 am:
Thanks for that Bryan, Physicist Charles Anderson also just posted an explanation on why “back-radiation” from colder objects does not heat warmer objects: http://objectivistindividualist.blogspot.com/2011/01/blackbody-radiation-and-consensus.html Excerpt: “…If the Earth’s surface is at a certain temperature, then it too will have a black body-like emission spectrum. Now suppose that CO2 absorbs a particular wavelength of infrared radiation [...]
This guy Anderson is a total crank when it comes to the greenhouse effect at least.
First, the whole idea that the ground cannot absorb low frequency light because of vibrational states is complete garbage. The density of states of low frequency motion in a solid (like the surface of the earth) is much higher than the density of high frequency motions. Moreover, the vibrational energies of water and CO2 are several hundred to thousands of wavenumbers. That corresponds to temperatures over 1000 K. You’re telling me that the ground can’t absorb photons corresponding to a temperature of 1000 K? Really?
On top of that fact, what percentage of the earth is hotter than 1000 K? Like the 0.00000001% that exposes lava lakes? So even if the structure of materials like the surface of the earth were such that there was a low density of low frequency motions, the energy from GHG emission could still be absorbed virtually everywhere on the face of the planet!
So this guy can even come up with a meaning, fake physical theory! And you take him at face value?!
Moreover, all this talk about how a colder body can’t transfer heat to a warmer body is only meaningful in the macroscopic limit. Unfortunately, that means when we’re talking about the collisions between molecules, which Anderson does at length, we are in the MICROSCOPIC limit and energy can transfer to a molecule upon a collision, even if that molecule is in a lower energy state. Temperature and heat are not defined for a single pair of molecules, therefore we are not violating the second law of thermodynamics as well! Make an important mental note of this fact.
There are also sooo many collisions happening, that it is very likely energy gets transferred from a kinetically excited O2 or N2 into a state of CO2 or water from which that molecule can decay radiatively. The chances of this processes happening increase as one increases in altitude because collisions become less frequent (density decreases) while the radiative decay rate stays relatively the same. In the stratosphere, the rate can even increase due to increases in temperature.
So all in all, one needs to be slightly more skeptical of these types of claims. To just believe it because it says what you want to hear is not very scientific. In fact, it may be the exact opposite from scientific. Then again, I’m beginning to expect that from some of you.
This is an area in which the mythical black body is supposed to have properties real materials rarely come close to having. Very fine particle carbon black and a carefully formed CuO rough layer on copper do absorb well over very large infrared radiation wavelength ranges, but few materials do.
ReplyDeleteThe FTIR spectroscopy technique is widely used to examine materials and is useful because materials generally have a few resonant vibrational frequencies determined by the chemical bonds in them. Polymers, plant materials, hydrocarbon products, and some minerals are commonly identified and characterized by reflecting IR radiation at wavelengths from 2.5 microns to 25 microns off the material. The absorbed wavelengths excite vibrational states in the material and heat it. The unabsorbed IR wavelengths are reflected and continue to a IR detector. Much of the spectrum from 2.5 to 25 microns commonly shows no absorption for most materials.
The infrared spectrum for a black body at 288K covers the wavelength range from about 3.5 microns to 70 microns with a peak at about 10 microns. Thus, a very large fraction of the spectrum lies in the window of FTIR spectroscopy from 2.5 to 25 microns where we can directly examine the IR absorption of a wide range of materials in many laboratories.
2nd Anonymous:
ReplyDeleteCertainly the ground can absorb some of the radiation from a higher temperature body at 1000K just as it does the solar radiation of a body at 5525K. The problem I was addressing was that a body radiating IR in the low energy end of the black body radiation spectrum cannot provide the higher energy vibrations needed to shift the spectrum to that characteristic of a higher temperature black body radiator.
There may be some interesting issues though for real materials which are not black body radiators and do not actually produce emissions in a continuum of wavelengths as a black body radiator would. For real materials, photons of a low energy can be absorbed, but they will raise the temperature of the body very little and the excited state may de-excite very rapidly since it may not be sustained by the temperature of the body. The effects of such high wavelength absorption on real materials in the Earth's surface are surely much at variance with any analogies to black body radiators. There are many issues of the physics of the climate which scientists should be studying and learning about. Modeling the climate based on black body radiators is really, really nuts. Actual measurements on the real materials of the Earth's surface and of the atmosphere need desperately to be performed to understand the physics. The arguments commonly made in support of catastrophic AGW are completely inadequate. Rather than modeling the climate with insufficient and inapplicable theories, much more effort should be put into experimental measurements of properties needed before any adequate modeling can be performed.
In the argument I gave, I was largely addressing the surface of the Earth as a black body radiator. There are severe limitations in making arguments in that context, including applying some of my arguments to real materials in the Earth's surface. The details of real materials make it difficult to make general arguments while incorporating all those real details. But, this is a very good reason for not assuming disaster will result because very simple and very wrong models have been assumed.
Gas molecule collisions in the lower troposphere are so frequent that an excited CO2 molecule due to its absorption of IR radiation from the surface will in many cases not de-excite with the emission of the same frequency IR. It will transfer energy to other molecules in many cases and much the most often those other molecules will be nitrogen or oxygen molecules. Warming nitrogen and oxygen molecules hundreds and thousands of meters above the surface is not an effective way to heat the surface either. This will put more energy into rising thermals or convection currents as opposed to bringing more energy to the surface.
When there are competing theories in science, the first recourse should always be to experimental evidence that can decide the issue. See
ReplyDeleteVenus: No Greenhouse Effect
The temperature difference between the atmospheres of Venus and Earth is entirely and precisely due to their different distances from the Sun, nothing else--not to the planetary albedo (Venus is covered by dense clouds that reflect much of the visible solar radiation, while Earth is not), not to the IR absorptive properties of the surface (Earth is 70% covered by deep ocean, Venus is solid crust), and above all not to the concentration of CO2 or any other IR-absorbing gas in the atmospheres. So first of all, the evidence of two whole planetary atmospheres undeniably and unambiguously tells us there is no greenhouse effect as envisioned by climate scientists. Secondly, it tells us the atmospheres of both planets are warmed by the same IR portion of the Sun's incident radiation, by direct absorption of that portion in the atmosphere, not by warming of the surface first. The "debate" put forth by Judith Curry and other believers in the greenhouse effect is incompetent in the face of the Venus/Earth evidence. There is no need to waste time now on competing theories, with that overwhelming evidence on hand. The consensus is incompetent, period.
A Conversation with an Infrared Radiation Expert;
ReplyDeletehttp://wattsupwiththat.com/2011/02/13/a-conversation-with-an-infrared-radiation-expert/#more-33954
There are really too many false statements in your blog to address them all in a single comment, so just to concentrate on one - your thought experiment with the hemispheres fails to conserve energy. If you take into account the radiation into empty space, then conservation of energy requires that the warmer hemisphere becomes warmer as the colder hemisphere is moved closer. Try doing the algebra correctly.
ReplyDeleteTom,
ReplyDeleteConservation of energy requires that the sum of the energy in the lower atmosphere, in the outer atmosphere, and that radiated off into space from the atmosphere will be equal in this case. It does not require that the sum of the energy in the inner and outer atmospheres be equal to the original energy absorbed from the sun, while that radiated off into space is ignored.
As far as any major effect on man and the surface of the Earth is concerned, the partition of energy between the lower atmosphere and the upper atmosphere is also very important.
Good article, but the message is hard to find.
ReplyDeleteI think the problem with climate science is that climate scientists persist in believing the only way they can theorize and experiment is by measuring and analysing the atmosphere.
The current IR radiation greenhouse theory seems to say that CO2 can transfer heat by radiation up a thermal gradient. This would be mug simple to prove (false) by experiment in a physics lab. So why hasn't anyone bothered??
If the IR greenhouse theory is nonsense, then climate scientists need to come up with a better theory that can be demonstrated in theoretical phycis, experimental physics, and real world measurements. There is a way to go yet.....
To date I have accepted the "blackbody temperature" part of the climate scientist argument. But on reading about the "Stefan-Boltzmann" Law, it is more of a theory than a law. It appears useful to astronomers trying to predict the temperature of stars based on their color. Is it really intended to be and actually reliable when it comes to temperatures of planets in the sun??
ReplyDeleteAt the base of the usual greenhouse gas hypothesis is a claim that at that moment when the solar radiation has its average daily value, the Earth's surface temperature is many degrees cooler than its measured average temperature. It claims this difference is due to greenhouse gases and develops a theory which predicts a zone in the atmosphere over the equator and lower latitudes at altitudes from 8 to 12 Km which is supposed to be warmer than it actually is. The theory is wrong.
ReplyDeleteThis should not be surprising, since the very theory that starts with the assumption that the Earth is a black body radiator immediately then starts assuming that greenhouse gases are biting large chunks out of a black body radiation spectrum. Indeed, most of the atmosphere is made up of nitrogen, oxygen, and argon gases which do not have the radiation absorption properties of black bodies in the most obvious ways. To this are added the major greenhouse gas of water vapor and the minor greenhouse gases of CO2 and methane which have neither the absorption or the emission properties of black bodies. The water, rock, soil, and vegetation of the Earth's surface do not have the properties of black body radiators either. Then one starts claiming that the minor effects of a minor greenhouse gas such as CO2 will have catastrophic effects upon the climate, when one already has a theory riddled with substantial false assumptions and claims and gross approximations.
The biggest error here is in the initial setup of the greenhouse gas argument. You cannot simply start with that moment of average daily solar radiation on a patch of the Earth's surface and perform all of your calculations. The claimed cooler Earth's surface on that basis is exactly what you should expect. You must examine the complete daily cycle of solar radiation. If you do, you will find no big discrepancy that needs to be explained by positing a strong greenhouse gas effect. In fact, you will find that the greenhouse gas effect of the greatest importance is that it helps a bit to keep us from broiling in the afternoons because it more effectively dissipates heat at that time than any other time of the day. You will also arrive at a new appreciation of just how critically important air convection and water evaporation are in cooling the Earth. In other words, the more important problem is not why is the Earth warmer than some expect when applying black body radiation theory to it, but why is it cooler than it would be every afternoon if than it should be if you applied black body radiation to it.
Hello, thank you for the opportunity to post on your blog.
ReplyDelete1) The complex climate models solve nonlinear partial differential equations as dictated by advanced and well supported physical theories; they mimic weather models (but with limited resolution since they only care about long term global averages), which are much more complex than the simple diagram you mentioned. They use many measured data points from all over the earth and atmosphere. For example, there is a lot of energy released high into the atmosphere (ozone capture of uv and higher energies) which also contributes some downward radiation.
2) Measurements support the global average values shown on that diagram. For example, some places on earth have average radiation coming down from the sky as measured near ground level ("back radiation" measured with an instrument shaded from the sun and pointing upwards, a pyrgeometer) that is over 400 W/m^2. Most locations average in the middle to upper 200s and in the 300s. You seem to be saying that actual measurements taken by many different people around the world are wrong and have been for decades.
3) The non ghg are not merely warmed by "thermals", as you rightfully appear to suggest. The vast majority of radiation absorbed by ghg in at least the first few kilometers of the atmosphere (which is where the majority of the back radiation exists before it drops off to near 0 as we go higher) immediately goes towards heating the surrounding gases (like N2). This is because the rate of interaction of particles at that pressure is high and only seldomly allows the excited ghg to spontaneously emit. Yes, absorbed radiation by ghg does heat the entire atmosphere directly. The Trenberth diagram doesn't say anything that contradicts that. It makes statements on radiation levels that agree with observed results. It doesn't make allegations about temperatures or about timings, nor does it give very many "reasons" on how those numbers should have arisen.
4) the 1/2 + 1/4 + 1/8 ... example you gave is a silly one for any climate scientist to support.
a) First, it is independent of ghg concentrations so would imply the temperature is insensitive to ghg concentrations. Why would someone espousing CO2 global warming claim the atmosphere temp is independent of ghg concentrations?
b) Second, it doesn't follow the math of what happens to radiation (even if we ignore thermodynamics LTE effects mentioned in point 3). Ghg molecules don't just receive from the ground. They receive from molecules above as well, so some fraction of what they send "upwards" comes back to it for another "chance" to be re-emitted downward, and some fraction of what they send downward is intercepted with another chance to be re-emitted back up. [But remember, we can't ignore point 3, and all of this bouncing around of photons with "origination" in the sun a long time earlier (going back in time towards "negative infinity") helps warm the lower atmosphere extra.]
c) Third, this assumes all radiation from the earth upwards is caught right at the ground and at each layer upwards. That too is way off since ghg together don't even cover the full spectrum of radiation (some radiation goes directly into space unimpeded), AND they don't capture that radiation in 1 mm but require many many meters (at our current concentrations in the atmosphere). See CO2 emissivity work by Hottel and later improved by Leckner.
So that infinite series argument could never have been a real argument adopted by any significant number of "CO2" climate scientists.
cont:
ReplyDelete5) That Trenberth diagram doesn't suggest the earth is an ideal blackbody radiator. If you look at the 161 value and add it to the 333, you have about 500, yet only about 400 is radiating from the ground. You also have about 100 that is incident but not absorbed. Remember that these numbers are based on measurements and are global yearly averages. If the numbers up and down didn't effectively cancel, you would have the earth constantly getting much more (or less) radiation than it expelled, and the earth would keep cooking up (or freezing) at a very fast rate. The numbers in the diagram are near stability values because the earth must be in near equilibrium (given that today solar irradiance doesn't ramp up or down to any disrupting degree).
6) You claim that back radiation cannot heat the planet and use the analogy of coffee placed in a thermos -- that blocks any significant heating source that would heat the coffee to near the boiling point of water. You ignore that the thermos and air keep the coffee from going to absolute zero temperature. The atmosphere does not block the sun.
7) You claim that low energy radiation cannot warm the planet, yet that contradicts how engineers (and mother nature herself) use "low energy" radiation on earth to create super hot furnaces and super hot lasers on the planet. We have created temperatures in small regions that exceed the temperature of the sun. Yes, concentrating "low" energy into a small area with little dissipation does serve to keep raising the temperature. Note, that the sun is a constant source of steady energy onto the earth. If we added a strong hypothetical blanket over the earth (or, worse, used reflective mirrors), that allowed radiation in from the sun but not allowed it to escape back out, the earth would melt (unless we found a way to turn all of that energy into useful work). Did you never cook hotdogs outside with aluminum foil when you were young?
8) You claim the earth has no vibrational states to accept low energy radiation (or they are already taken up). What theory or evidence are you using to support that? The earth is huge. It absorbs well in this range. In fact, if you can absorb at a given frequency (common ghg IR), you can generally emit at it. The fact common earth gases can emit IR should be a clue that the "much-thicker-in-energy-levels"/amorphous and much more massive earth can absorb it. In fact, did you forget that the ghg are already absorbing from the earth at those frequencies (wavelengths)? If it can dish it, it can take it.
9) The initial analogy with a left and right hemisphere is not very clear. Can you clarify that? Are you saying the earth cannot be at the current temperature or get even .00001 hotter? You assume equilibrium exists always no matter what? That is nonsensical. More radiation leads to a re-adjustment of values. What specifically do you think you are modeling with those two hemispheres at atmosphere temperatures in our atmosphere?
cont:
ReplyDelete10) You seem to suggest that if you put a "blanket" or mirrors around you, it won't make any difference whatsoever. The back radiation is extra photons hitting the earth instead of going into outer space (ignoring, as you stated for argument's sake, that most of the absorbed photons serve to warm the atmosphere directly). We have these photons on top of the photons from the sun. To use a very crude physical model, if the earth suddenly gains an atmosphere, it will be gaining 1 photon from sun then emitting 1 photon, then later gaining 2 (back radiation and sun), then emitting 2, then later gaining 3, then emitting 3, then later gaining 2.. 3.. 2.. 3.. 4.. 3.. 3.. 2.. 3.. 4.. 5.. 4.. 3.. 4.. etc. When first acquiring this instant atmosphere, radiation leaving into space immediately dropped off to near zero (instead of the old rate when no atmosphere was there). Eventually, an equilibrium is reached where the energy leaving the new atmosphere matches what it gains originally from the sun. This balance is reached because, near the surface, we have worked our way to a very high amount of radiation/backradiation, from which enough manages to escape into space to balance out the sun's input.
11) You separated the two model left and right hemispheres a little, but I have little idea what you are suggesting. For starters, that model is immersed in our atmosphere so is radiated from all directions. The earth is immersed in empty space, heated essentially only by the sun's direct radiation. And did you truly think you were modeling the encompassing atmosphere as a non-encompassing hemisphere onto the other hemisphere?
12) The diagram doesn't cover the internal parts of the earth because that was not the point of the paper. [Notice it also didn't cover the inside of our heads.]
13) You separate the model hemispheres a lot. Again, I am not sure what point you are trying to make. Are you aware that these are immersed in our current atmosphere and so is rather different than the earth?
14) What physical experiment or laws are you invoking to claim that absorbing a photon does not add more energy to the system? If vibrational states could somehow all be filled (and the earth is far from melting), then it would not absorb the photons. Instead the stream of photons would come out the other side of the earth (or scatter/reflect or "push" another off) and be measured in our satellites passing overhead all over the planet (or by a ground instrument). Are you also claiming the satellite instruments are "saturated"? Do you know how silly this sounds? Can you cite a scientific text that claims "vibrational modes" can get filled or that this is happening to the present earth? Don't tell me you are inventing this stuff?
In short, although I probably missed some points I would argue, I think you are really misunderstanding physics and that diagram. If you are a healthy skeptic that has recently started your study of advanced physics and climate science, consider getting the opinion of those with lots of experience. Barry Bickmore (professor living in Utah), a former skeptic and a Republican who realizes "deniers" tend to have political motivations but are tarnishing the long-term viability of the political party, has produced an interesting blog. Skepticalcience and other websites also cover some of the real science to help the many of us who are not experts or even physics majors.
I will reply to your numbered points:
ReplyDelete1) The complex computer models are different than the description given to the public and different than what is taught generally to university educated supporters of catastrophic man-made global warming. The details of these calculations of dozens of models are not available to those of us who have to evaluate the likelihood of the truth of the claims that are made. We start with the publicly espoused models and discussions such as those made numerous times by our government agencies funding the research and supporting the claims, and generally not shouted down by the modelers. Since there are wide variations in the predictions of the computer models, we have to assume that there are many variations in the algorithms used and that makes them difficult to discuss in detail. If the essential physics is different than that broadcast by university professors and by the U.S. government, then I am arguing that the fraudulent arguments normally made are not a justification for the claim of catastrophic man-made global warming. The fact that the claims are made to the American voter on a fraudulent basis would be good reason not to accept government policy recommendations that would hurt the economy and individual freedom of choice. We would have every reason to be distrustful of the more refined computer models whose physics is so little understood that the many models produce many different results.
2) Longwave radiation measurements shielded from the direct solar radiation are made and daily averages vary widely from as low as 50 W/m2 in the Antarctic up to such values as you mention. We have less good pyrgeometer data than we have surface temperature data, so the average downward flux of longwave infra-red radiation is not very precisely known. As noted in my post, a more reasonable estimate of the emitted longwave IR from the surface is 277 W/m2 and at least 20% of that is emitted at wavelengths which are not absorbed by the greenhouse gases. This means that about 55 W/m2 is emitted from the surface straight out into space. This leaves about 222 W/m2 to be absorbed by the greenhouse gases. Much of this energy has to be radiated into space as well as being returned toward the surface, so there is no way that returned can exceed 222 W/m2. That would violate the law of Conservation of Energy. This upper bound energy flux is much less than the 333 W/m2 that the Kiehl-Trenberth diagram indicates. The problems do not end here. Some of the flux of energy striking the surface will be reflected and no such effect is indicated in the Kiehl-Trenberth diagram. For instance, we know that 71% of the Earth’s surface is covered by water and in the range of longwave IR from 3 to 60 µm that a body at 290 K can absorb, water actually does not radiation well over a substantial portion of these wavelengths. The peak of the emission spectrum of a blackbody radiator at 290 K is at about 11 µm. There is a large water window of poor absorption between about 4 and 11 µm, with only one sharp, weak peak in that broad window. Thus, one expects considerable longwave IR reflection from water surface.
3) We agree that gas molecule collisions spread the energy absorbed by greenhouse gases through their IR absorption to the non-greenhouse gases very efficiently. Air convection and transport of energy by water vapor is very much more important than the Kiehl-Trenberth diagram indicates for that reason. I have often made a major point of the rate of gas molecule collisions in the lower atmosphere and how they occur multiple times before a greenhouse gas molecule can re-emit IR radiation.
ReplyDelete4) Yes, the fact that a greenhouse gas molecule will emit radiation groundward almost half the time and spaceward slightly more than half is independent of how many such molecules there are absorbing the IR radiation. I did not claim that the geometric series which is often used in arguments for the public implies that the temperature is independent of how many greenhouse gas molecules are present. This series has been purported to explain how so much surface radiated longwave IR came to be returned to the surface to heat it up. Because adding CO2 cannot change the fraction returned significantly because its effect is already almost saturated, the dependence upon CO2 concentration is a second-order effect not covered by the geometric series rationale. That rationale is wrong in any case because it ignores the fact that the dominant transport of energy is by gas transport, not by IR radiation. Of course the computer models do not just use this geometric series argument, but instead do substitute a layer by layer sectioning model of the atmosphere. In doing this, they become very complex and develop wide disagreements with one another and yet make many common assumptions which are not well-founded scientifically. The fact is that the science is not sufficiently well-known to have any confidence in these models.
I have just become aware that Jose_X made additional comments, which I had overlooked. I will address them now:
ReplyDelete5) The claim that 333 W/m^2 of back radiation is incident upon the surface is nonsense. The energy absorbed by the greenhouse gases is mostly shared with other gas molecules in the lower atmosphere due to the very high frequency of collisions. Near the ground, little energy is actually transported by IR radiation. Similarly, the ground actually cannot transport the 396 W/m^2 shown in the Trenberth diagram to the upper atmosphere by IR radiation either. These two claims in the diagram are highly misrepresentations of reality. IR radiation is the primary means of energy transfer above about 5 km altitude and not below that altitude. This is an average since there are frequency windows in which radiation directly from the surface to space occurs and there are windows in which most of the radiation to space is from 8 to 10 km altitude. If the surface radiates 396 W/m^2 that energy is largely absorbed very close to ground if it is absorbed by either water or carbon dioxide. By the time one gets to an altitude of a mere 5 Km, the average temperature is about 256K and radiation from this altitude is already much less than 333 W/m^2. So where would 333 W/m^2 come from? Indeed, actual average measurements are much lower than this. About 240 W/m^2 is more like an Earth average, though good numbers of this type are still lacking.
6) I do not understand what your point is here. If a thermos of hot coffee were placed in deep space whose temperature is about 4K, than the thermos would slow the rate of cooling of the coffee, but it sure would soon approach a temperature of about 4K. The sun plays the role of the heat source that originally heated the coffee in the thermos. There is no question that that part of the Earth seeing afternoon sun will heat up strongly. Indeed, one of the most interesting questions about surface temperatures is that of why we do not broil every afternoon. Fortunately the greenhouse gases cool us during the afternoon.
7) Concentrating the radiation spectrum of the sun upon a small area should at least be capable of heating that area to the temperature of the sun. It certainly is not relevant that the mirror surface temperatures are much cooler than the sun. Indeed, as radiation spreads out upon leaving the sun, the temperature of objects exposed to it will decrease as the objects become further and further from the sun. Refocusing that radiation upon an object is the equivalent of bringing the object closer to the sun. But how does one focus solar energy to get hotter than the sun? One possibility is that the exposed matter releases nuclear energy much as the sun does. This part I will be interested in looking into more.
8) If the surface of the Earth is at a temperature higher than that of the greenhouse gas molecule radiating energy back toward the surface and that energy is incident upon the Earth's surface, every frequency which the Earth's surface is capable of having excited at that temperature is already so excited. Frequencies of radiation from a cooler radiator are not needed. Given the cooling lapse rate with altitude, there are few cases when the atmospheric molecule radiating energy back to Earth is at a high enough temperature to warm the Earth's surface. There is an effect to some degree as evening comes on in some cases, but cooling effects by greenhouse gases during the day are larger effects. The radiation coming from a hotter body is needed to actually warm the Earth's surface.
ReplyDelete9) The biggest possible warming effect for the Earth's surface would be that in which IR radiation characteristic of the Earth's surface temperature is absorbed by an IR molecule which radiates it back to the Earth before the molecules energy is decreased by a collision with other molecules. This rarely actually happens. But if this is the case, the Earth's surface is already emitting the appropriate flux of photons for its temperature just as one half of a black body sphere would be. The flux of photons from the second half of the sphere cannot warm the first half. What would disturb the equilibrium and this analogy would be a greenhouse gas molecule with a temperature higher than the surface of the Earth. Then, assuming that IR radiation was dominant and not conduction and convection, the greenhouse gas emitted radiation could raise the temperature of the Earth's surface.
ReplyDelete10) As Alan Siddons has pointed out, if what you say is true, one can put a turkey straight from a freezer into an enclosure of mirrors and it will very quickly be cooked. Indeed, given the speed of photons and the multiplication effect upon multiple reflections that you claim, this oven will be totally impractical. It will turn the turkey into a pile of carbon before you can move fast enough to remove it. Fortunately, the laws of thermodynamics save us from this catastrophe.
11) Actually, the two hemisphere model did not have any atmosphere because I wanted to reduce the problem to a simple form that dealt only with radiation and not the added complications of an atmosphere that mostly remove radiation as a significant transporter of energy near the surface.
12) I did not make a big deal out of this, though in understanding the daily, seasonal, and decadal temperature cycles, which are critical, one has to consider the absorption of heat energy in the oceans, soil, and rock of the surface.
13) Again, the thought experiment is simplified to eliminate an atmosphere and to only consider the maximal effect of radiation possible.
14) Actually, I am telling you that a body at a given temperature will only radiate a spectrum as given by its blackbody spectrum and its emissivity at most. You cannot superimpose a spike in that spectrum at the frequency of an incident photon unless the incident photon spectrum includes higher frequency photons from a higher temperature body. If you could do what you think you can, that mirror oven would indeed turn the frozen turkey into a pile of pyrolytic carbon. All of our energy needs would be solved! But, that stubborn old set of thermodynamics principles just keeps popping up and causing us to need those darned fossil fuels. But, it also keeps us from broiling in the afternoon sun and probably keeps us from destroying too many meals, not to mention nations in war. Imagine the weapon systems possible with such photon multipliers. Input 161 W/m^2 of photons and get 333 W/m^2 of photons back in a jiffy even as one loses a bit of energy to thermals and evaporation. Talk about violating physics!
Nice blog post Dr Anderson, and you have dismissed all the objections of your critics.
ReplyDeleteIn time, this view will be seen as the correct scientific theory, not the witchcraft of back radition and MMGW from an imaginary "greenhouse effect"
regards
John
Hey, I just got back to this thread.
ReplyDelete1: Reading over your first response (and thanks for your extensive discussion, which I will read probably tomorrow), I have to ask, (a) what "fraudulent" information are you talking about specifically and (b) are you aware that a number of models are open source software (extensive quantities of Fortran), which means in those cases they are giving you every last detail you possibly could need to evaluate the physics.
Jose_X is responding to my comment:
ReplyDelete"1) The complex computer models are different than the description given to the public and different than what is taught generally to university educated supporters of catastrophic man-made global warming. The details of these calculations of dozens of models are not available to those of us who have to evaluate the likelihood of the truth of the claims that are made. We start with the publicly espoused models and discussions such as those made numerous times by our government agencies funding the research and supporting the claims, and generally not shouted down by the modelers. Since there are wide variations in the predictions of the computer models, we have to assume that there are many variations in the algorithms used and that makes them difficult to discuss in detail. If the essential physics is different than that broadcast by university professors and by the U.S. government, then I am arguing that the fraudulent arguments normally made are not a justification for the claim of catastrophic man-made global warming. The fact that the claims are made to the American voter on a fraudulent basis would be good reason not to accept government policy recommendations that would hurt the economy and individual freedom of choice. We would have every reason to be distrustful of the more refined computer models whose physics is so little understood that the many models produce many different results."
to put it in its full context.
One aspect of the fraud is that having refuted the physics of the generally tractable and presented argument, the more academically inclined catastrophic man-made global warming advocates often claim that the many computer models do not really follow the more tractable arguments commonly presented for a significant warming of the Earth's surface by long-wave IR already once emitted from the Earth's surface and absorbed by water vapor or carbon dioxide. As I said earlier, if this is case, then the model builders should be proclaiming the simpler explanations to be wrong and they should oppose the presentation of these arguments to the public.
Secondly, we are told by numerous scientific societies and by numerous government scientific research funding agencies that the science of catastrophic man-made global warming is well-known, well-established, and unquestionable. Yet, the model predictions vary widely. This is like saying that the theory of gravity is well-understood and we can tell you that the gravitational acceleration at the surface of the Earth is between 3 and 15 m/s^2. Apparently, the fact that the gravitational models all agree that the gravitational constant is attractive rather than repulsive is quite enough that we would have a consensus understanding of gravity if this were the case!
But, it gets worse. The discussion of errors in the physics of various effects often in the models according to the IPCC AR4 report of 2007 gave a breakdown of effects and the error bars on the size of those effects. The error bars were often about as big as what they thought the most likely size of the effect was. Sometimes, they did not know for sure whether the effect was a warming or cooling effect. Many known natural effects whose magnitude is not well known were left out because too little was known about them. All in all, this makes the models predictions very dubious. The selection of considered effects was also indicative of a bias toward showing that man's fossil fuel emissions caused a warming effect of significance.
I have built computer programs to model much simpler physics relating to heat flow, temperature distributions, IR radiation, and x-ray absorption in solids and electron beam transmission in solids. Building even these simpler radiation system models is a very time-consuming task as you seek to give them the ability to deal with real materials. As the model code builds up, keeping track of every conditional loop, every subroutine, all of the boundary conditions, and all of the many points at which you can examine an output parameter to make sure that everything is working correctly is a very time-consuming task. Jose_X would like to impose this task on me for these huge climate circulation models funded by $100s of thousands in my copious free time before I dare state that the claim based on these computer models that the climate effects of CO2 are fraudulently stated as well-known and agreed upon by consensus. It is almost as much work to understand a huge computer model as it is to build one from scratch. Indeed, I would actually prefer to build one from scratch. I am very happy not to take on this unfunded gargantuan task and continue operating my materials analysis laboratory. Consequently, even if a few of the models have made the computer code available, the models are for all practical purposes not available to scientists the government does not wish to fund. NSF has made it clear that it will only fund those who believe in catastrophic man-made global warming and I am sure this is generally true throughout the Obama regime. I am nonetheless justified in my criticisms for the several reasons I have stated above. It is clear that most of the computer models are simply not yet ready for prime time application.
ReplyDeleteI have always imagined there are closed source programs. No doubt that is a failure, but we can stick to what is public and base policy off that.
ReplyDeleteThe first fraud point you mention is reasonable with respect to closed source software. For open source, we could just talk specifically about the program itself and implied physics and not care what is taught by person x or y. Yes, there are many ways to attack a problem and what you teach in a classroom (or what many might consider in papers) is probably not the technical aspects of the most (believed to be) accurate programs. People are optimized to handle problems differently than would computers. That said, I agree with you that, if all we had were closed source software, it would not make sense to talk one thing and then code up another. I was bothered greatly by this, too, when I thought there were no open source models. [Naturally, just having open source is not enough, but I trust in time these will be scrutinized to an increasing degree.]
There are sources of differences across any computer program that wouldn't imply significantly different physics (remember, making 100 year forecasts or even short ones involves engineering tradeoffs, it goes beyond theory to actually coming up with something concrete and dealing with implementation issues). Random number generators are a source of differences and where you apply them is as well. Approximations have implications. Also, different features add different running costs, so there is room for variability by stepping up or down based on resources available and other constraints or analysis desired. There is also the fact a very wide range of data exists, of which likely only a subset is used (different groups would have different reasons to try different data or might even make it a habit of varying that around). Another is that forecasting requires making assumptions because we don't know how much CO2 will be released in the future or what the sun and volcanoes will do.
There are many problems where imperfections are a necessary evil of coming up with a specific number. The difference between a program that requires 1 google years to run and one that runs in days can be decided by the above considerations.
In short, if all we had were closed source, I would understand the skepticism and fear of fraud, but having open source, the burden to prove fraud shifts to the community making the allegation.
>> the science of catastrophic man-made global warming is well-known, well-established, and unquestionable. Yet, the model predictions vary widely.
This fits in to what I just covered.
In the end, one has to judge the science by the science and the computer processing on its own merits based on the specific engineering trade-offs and desired product.
When people say the science is understood, they are expressing confidence in the theory, but it is impossible to measure every drop of water and air to account for the butterfly effect properly going out 100 years.
I sympathize with the variations we are seeing from models and that bother you and many people, but a legit criticism should first consider the specific details of each implementation and judge accordingly. We have the information to do that for the open source models. Yes, I'll repeat, it makes sense to me to weigh policy decisions strongly to the outcome of those open models and not the others.
>> Many known natural effects whose magnitude is not well known were left out because too little was known about them. All in all, this makes the models predictions very dubious. The selection of considered effects was also indicative of a bias toward showing that man's fossil fuel emissions caused a warming effect of significance.
I think if you do the research and come up with competing results you can make a legitimate claim here.
>> As the model code builds up, keeping track of every conditional loop, every subroutine, all of the boundary conditions, and all of the many points at which you can examine an output parameter to make sure that everything is working correctly is a very time-consuming task.
ReplyDeleteNo doubt. There are serious costs to doing this. I hope as a society, we can succeed. Part of the trick is in helping recruit others into your open source approach so that your model can show results in which we can have confidence.
It is a chore to double check the existing models, I agree.
With so many groups having so much interest in the outcome and so much money on the line and accessible for research, I can't imagine money would be the problem if these (special) interests really cared.
>> Jose_X would like to impose this task on me
No, and sorry for appearing to write off the difficulty of the task.
But the reality is that if one group is doing the work and leaving a trail behind and competing groups are not being very competitive, then policy will eventually follow the group doing the work, especially if near term nature cooperates with that group.
>> before I dare state that the claim based on these computer models that the climate effects of CO2 are fraudulently stated
As a fellow human, I understand you want to draw attention to some of these issues and difficulties you are mentioning. It must be frustrating not to be receiving more help.
>> It is almost as much work ...
No doubt, but that is why open source is the way forward for skeptics (and hopefully for nonskeptics alike).
>> this unfunded gargantuan task
You do know there is probably like a trillion in profits being made by the fossil fuel industry yearly (or at least several hundreds of billions). Never mind allotted R&D expenses not included in that figure.
[I agree that all money accepted will be used against you in the future. Sorry about that.]
>> NSF has made it clear that it will only fund those who believe in catastrophic man-made global warming and I am sure this is generally true throughout the Obama regime.
Again, the other side is not poor by a long shot. The profits made are much much larger than what the NSF has to work with. The US people are making the resources available for profit exploitation, even though we are gobbling up resources like if humanity was not interested in living more than a few more generations. We are not showing a sense of moderation or cautious restraint that would more than be due were this almost any other apolitical topic.
The fossil fuel industry perhaps doesn't care (or doesn't doubt, based on their own unpublished research, the position taken by most scientific institutions) or is simply taking advantage of the skeptical volunteers overburdening themselves. I don't know. It's been decades now of the AGW vocal drip getting louder and louder.
There are some organized skeptic groups. It would be a good idea to make it a priority to develop a competing FOSS computer model. You, someone else I just bumped into online, and numerous other skilled individuals are working on their own individual projects. It's time to collaborate more perhaps.
2: [a few more things]
ReplyDeleteReturning quickly to the 1+1/2+.... I have no doubt that many climate scientists do not understand the physics of greenhouse warming. It isn't easy, and climate science covers a wide spectrum of skills.
>> a more reasonable estimate of the emitted longwave IR from the surface is 277 W/m2
If you have formal physics/math and/or measurements (such as downward facing pyrgeometers or other tools) to support this, you should definitely publish the details online in order to help push the conversation in an organized fashion and reach a broad audience.
I do know that the BEST project, among others, has undertaken the task of categorizing, (sanity) weighing, and ultimately concluding that average temperatures are in the 288K range (14 C, which is rather cold anyway), which corresponds to 385 flux range (1 emissivity or anything close to that). Trenberth et al explain why their number is greater than the average temp, but they are within the ballpark.
Even if Trenberth is wrong, it probably wouldn't be too far below the 350 range, I would suspect, given how the average temp corresponds to blackbody radiation of around 385.
>> as low as 50 W/m2 in the Antarctic
Just wanted to clarify that you are talking about one of the coldest places on Earth in Winter, potentially on one of the colder days.
[article]>> [that] this diagram claims warms the surface with slightly more than twice the power of the sun itself.
>> so there is no way that returned can exceed 222 W/m2. That would violate the law of Conservation of Energy.
Let's consider an analogy to see how the idea in Trenberth is possible.
If we have a huge house with a weak electric heater and the house starts cold at 0C, the energy leaving the heater can be very small, but, over time, if the insulation is sufficiently excellent, we can get the house to be so hot that we may need to shut off the heater for very long periods of time. The way we shut off the heater is by quickly moving it outside into the snow through an opening just large enough to allow the heater to be taken out and brought back in so that very little heat is lost in the process (we can use a robot arm to do this efficiently). The result is that, after the equilibrium temperature range is reached, the average radiation from the heater we experience within the house is rather low because the heater remains outside most of the 24 hours (say 3 hr indoors). Meanwhile, the items inside the house have a much higher average radiation flux because they remain at a nicer 23 C all 24 hours.
[The sun's intensity during the middle of the day can be around 1000 in many parts of the world during Summer, but the average is much lower when we consider the full 24 hours and all parts of the earth and year.]
With the atmosphere, it's the same idea. The sun just needs to add enough to balance what is lost into space through what could potentially be a good insulating system.
Energy conservation? Sure, agreement with any calculation or measurement is possible if the energy is retained well. All you have to worry about is that the gain and losses approximately match. Meanwhile, internally to these boundary points, it's possible to enjoy a high radiation/warmth level, eg, at 14 C near the ground.
Also note that in the house above, every radiating object is bathed in radiation from every other object (with average temp maintained thanks to convection). If not, any lone object would just quickly move towards 0K, but they all "recycle" the energy because it hardly leaves the boundary of the excellently insulated house (and later is made up by turning on the heater for 3 hrs).
>> Some of the flux of energy striking the surface will be reflected and no such effect is indicated in the Kiehl-Trenberth diagram.
This is not a big effect, but it sounds like an interesting point.
You should consider writing the researchers, perhaps after you do some calculations yourself.
Jose_X says:
ReplyDelete"You do know there is probably like a trillion in profits being made by the fossil fuel industry yearly (or at least several hundreds of billions). Never mind allotted R&D expenses not included in that figure."
From 2006 through 2010, the five largest oil companies in the US had a net income after taxes of $484 billion and many shareholders expecting their dividends. Had these companies diverted much of this into climate research to dispute the federal government's alarmist claims, they would have disappointed many dividend-seeking investors and angered the federal government. An angry federal government can increase taxes on them, launch still more frivolous investigations of their operations, charge them still more for leases on federal land in the oceans or simply refuse to allow them leases at all, and slap them with still more onerous regulations. The oil companies are in a no win situation. They have concluded that being quiet is best and this is not because man made global warming is based on good science.
On the issue of fraud, here is a very interesting article by Larry Bell at Forbes:
http://www.forbes.com/sites/larrybell/2013/02/05/in-their-own-words-climate-alarmists-debunk-their-science/
Part of the reason I have not responded to your comments earlier is because I have been working on a new article describing the baseline, equilibrium surface temperature of the Earth and the physics behind it. I am polishing that article up now and it will have a great impact in proving my point that the basic physics of the alarmists is sadly lacking.
The new article proves that the baseline surface temperature and the temperature at the bottom of the atmosphere and through the troposphere are just what you would expect. The principal results are:
ReplyDeletethe Earth's surface is not a black body radiator having an emissivity of about 0.5 and therefore a temperature of 288.15K or 15C,
surface cooling is mostly due to evaporative, conductive, and convective cooling, not radiative cooling,
much of the initial radiative cooling is quickly converted to convective cooling a very short distance above the surface,
the lower atmosphere is not in radiative equilibrium with space,
the effective altitude of radiative equilibrium is tied to the upper layer of the water vapor emission layer with a weak ground weighting due to the IR atmosphere window and unaffected by CO2,
back radiation is insignificant,
the static air temperature gradient in the lower atmosphere is 6.49K/km due to the gravitational field
with high convection rising air, the air temperature gradient can rise to as much as 9.78K/km due to the cooling of expanding air as it rises, and
these temperature gradients downward from the effective altitude of radiative equilibrium with space ensure that the bottom of the atmosphere is at a temperature of 288.15K or 15.0C.
See it at: http://objectivistindividualist.blogspot.com/2013/02/infrared-absorbing-gases-and-earths.html
DR. Anderson,
ReplyDeleteI tried leaving a post about Black Body radiation here a couple of days ago, but don't see it and I have not received a reply e-mail. Did you get it? If not I can try again.
I don't need a post, but I would like your views.
Ted Held
I have not seen the comment you refer to having tried to make.
ReplyDeleteDear Dr. Anderson,
ReplyDeleteI was just wondering if you might comment on a simplified question about Black Body Radiation and its effect on Global Warming. I have contacted a number of public voices in the debate and have gotten either evasion or silence. It’s usually evasion, then silence. This is rather disturbing for a science question.
The question bears on what role Black Body radiation has and what factors, if any, negate its effects. Attached in the next post are my calculations for your review. I have assumed that the counterbalancing effects, like albedo, and various atmospheric complexities, are realistically unchanged over the past ten years, twenty years, and maybe 100 years. That leads to isolating the Black Body calculations, which appear to be rather large – 1% to 2% increases in radiative energy loss for 1° or 2° global temperature increases. To be sure, the Earth is not a Black Body. But it still gets cooler at night, every night, meaning that heat is being lost. And the nightly temperature cooling dwarfs the apparent slight average temperature deviations that are published every year. It’s like any temperature deviations we see are simple rounding errors.
Maybe this issue has been covered somewhere on your site or elsewhere on the infallible Internet. But my experience is that it is difficult to find an isolated consideration of this effect. What I find are elaborate discussions of climate, which, while interesting, are largely speculative and based on very short spans of detailed record keeping. This means, it seems, that any Black Body Radiation effects are hidden away somewhere within various algorithms.
I turn to you because you seem responsive as well as credentialed. Maybe you can show me my errors.
Thanks,
Ted Held
Simple Calculations of Black Body Radiation:
ReplyDeleteThe mathematical expression for Black Body Radiation is called the Stefan-Boltzmann equation, an equation known for over a century and taught in every competent college course in thermodynamics:
P = 4πR2σT4
The P in the Stefan-Boltzmann equation stands for the power (energy) that is passively lost by cooling for a perfect Black Body. R is the radius of an assumed spherically shaped body (a simplification used to derive the equation), the σ is a constant, and T is the temperature of the body in degrees Kelvin. Note especially the T4 term.
Here is the question: How is Black Body Radiation accounted for in the various climate models?
For those who are not familiar with the Black Body effect, objects in space, away from incoming radiation or other additive energy source, radiate heat away from them according to their basic average temperature. They cool off. If they are cold, they radiate away less energy. If they are hot, they radiate away more. And the array of wavelengths varies according to the temperature. If they are really hot (compared with normal earth temperatures), the radiation is within the visible range. For the earth, the radiation is largely in the infrared region. But energy is given off regardless of whether it is visible or not. That’s why it gets cooler at night. And it does get cooler at night, meaning that any trapping by way of the greenhouse effect is small (at least within our present experience). Even greenhouses get cool at night.
How big is the effect of Black Body Radiation? Pretty big, actually. Let me show the effect with a couple of quick calculations.
Since the 4πR2σ part of the equation is the same for a given object (especially within a range of a few degrees), it can be treated as an overall constant itself (certainly so within narrow limits), simplifying the equation to:
P = constant x T4
The problem I have is the temperature to the fourth power generates large increases in escaping energy as Black Body radiation with even small temperature rises. Taking Dr. Pierrehumbert’s favored average Earth surface temperature of 280°K (Principles of Planetary Climate by Raymond T. Pierrehumbert, published in 2010 by the Cambridge University Press), we can calculate the energy losses associated with a one or two-degree temperature increase.
280°K P = constant times 6.147 x 109 (choose your own energy units)
281°K P = constant times 6.235 x 109 = 1.43% more energy loss than 280°K
282°K P = constant times 6.324 x 109 = 2.88% more energy loss than 280°K
If we use another arbitrary average earth temperature of 14°C (287°K) we would get slightly different numbers.
287°K P = constant times 6.784 x 109
288°K P = constant times 6.880 x 109 = 1.42% more energy loss than 287°K
289°K P = constant times 6.976 x 109 = 2.83% more energy loss than 287°K
As can be seen, the black Body Radiation effect is robust over the temperature range of interest, regardless of the assumed (or measured) average earth surface temperature. The magnitude of the energy loss is in range of 1.0% to 1.5% for a 1°K temperature rise.
Of course, the calculations are for perfect Black Body objects and most things are not perfect. But the large effect is obvious even ignoring lack of perfection.
Dr. A.,
ReplyDeleteDid you receive my comments I sent on the 15th? If not, maybe you can offer an alternative to the web site posting mechanism and then post my comments yourself if they are worthy.
Ted Held.
Ted, some of your comments did not generate the e-mail notifications I am supposed to receive about comments needing my moderation. Because US manufacturers are ebullient about their chances of making a profit compared to the case when that destroying socialist Obama was President, my laboratory has had a huge increase in demand for materials analysis since the last presidential election and I have not been good about checking for comments with Blogger. For example, your comments of 15 December did not show up in my e-mail as proven by a search for them after you told about them today. I apologize for not giving your comment a posting until now and a reply to come below.
ReplyDeleteThe Power of emission at 281K compared to that at 280K is 1.44% greater.
ReplyDeleteThe Power of emission at 282K compared to that at 280K is 2.89% greater.
The Power of emission at 288K compared to that at 287K is 1.40% greater.
The Power of emission at 289K compared to that at 287K is 2.82% greater.
This is according to my HP 48G calculator which uses a more significant figures in its calculations than most calculators do. The results are only very slightly different than yours were.
Of course the best way to determine the Earth's average thermal radiation output is to use many values for a given area of the Earth ranging between the high and low temperatures of the day and across the seasons. Given the T to the 4th power dependence of thermal emissions, this will not make a trivial difference
Note that a 0.7K temperature difference compared to 288K is only a difference of 0.24% in the temperature. Despite this very small difference the alarmists make a huge fuss over this. Meanwhile, the average difference between the daily high and daily low in the months of April and October in Baltimore, Maryland is 12.8K. The lowest monthly high to low differences are 11.7K. Clearly, every daily high is a catastrophe many times over!
Dr. Anderson,
ReplyDeleteI thought your many readers might be interested in the following. It arose from reference recommendations from former President Obama in an opinion piece in Science magazine a while back. The main one is:
Climate Change 2013, The Physical Science Basis
Working Group I, Contribution to the Fifth Assessment Report
of the Intergovernmental Panel on Climate Change,
Cambridge University Press
This is a huge book, some 1550 pages, start to finish. The book consists of what the editors and compilers describe as the definitive set of technical papers in support of the climate change narrative, with hundreds of authors, directly or indirectly contributing to the papers presented. The book weighs a full 9.0 pounds and contains a host of graphs and innumerable journal references.
Just as a note, I doubt that many people with definite views on Global Warming (pro or con) have read the book. I seriously doubt that President Obama has read the book. Perhaps he has skimmed the summary pages at the beginning. But the balance is beyond the comprehension of most public players. Those with the most ardent views are not, in my experience, able to discuss climate science in any depth. If a person has technical questions, those are ignored or become the subject of adamant hostility. That is because the individuals (public officials or private individuals) actually know almost nothing about the science. This applies to both “sides” of the issue.
The fun starts on page 36 in the next section entitled “Technical Summary.” Now we (the objective readers) are advancing beyond the narrative, hoping to encounter the nitty-gritty details of the science. On page 36 we have a note about the “Treatment of Uncertainty.” Here is a recognition of where doubt might sneak in. It seems from the text that a note on this aspect was circulated to authors suggesting that they “rely on two metrics for communicating the degree of uncertainty in key findings, which is based on author teams’ evaluations underlying scientific understanding.” These are:
• Confidence in the validity of a finding based on the type, amount, quality, and consistency of evidence (e.g. mechanistic understanding, theory, data, models, expert judgement) and the degree of agreement. Confidence is expressed qualitatively.
• Quantified measures of uncertainty in a finding expressed probabilistically (based on statistical analysis of observations or model results, or expert judgement).
This relates to the odd italicized confidence levels printed throughout the texts.
For those that have been raised in a scientific environment, suspicions are immediately raised about these ratings, based, as they are, at least partly on the subjective expert opinions in some unspecified and unknown way. One might assume that the ratings might be skewed differently had skeptics or (horrors!) deniers been included in the rating panels. This little revelation was disappointing for me since I had hoped that this book would contain some unassailable science. After all, our former President has always maintained that this climate science is “settled.” One wonders about the term “settled.”
Finally, as I perused the text, I found a modest index at the back for terms and people. One thing I was interested in finding was the effect of Black Body radiation. As I have posted, Black Body radiation seems to be a possible major climate cooling effect and I wondered how that was fitted into the models and how it was countered in those models. The effect has been known for over 100 years and is codified and quantified by the Stefan-Boltzmann equation. The index of this book has no entry for Black Body radiation, no entry for Stefan, and no entry for Boltzmann. That seems odd, but there it is.
Ted Held.