Among the issues most commonly discussed are individuality, the rights of the individual, the limits of legitimate government, morality, history, economics, government policy, science, business, education, health care, energy, and man-made global warming evaluations. My posts are aimed at thinking, intelligent individuals, whose comments are very welcome.

"No matter how vast your knowledge or how modest, it is your own mind that has to acquire it." Ayn Rand

11 September 2017

Climate Change Settled Science: The Atmosphere Absorbs 90% or 29% of Surface Radiation

What difference does it make?  Who cares whether the atmosphere absorbs 29% or 90% of the infrared radiation from the Earth's surface?  Apparently NASA doesn't care, despite the fact that the settled science claims that atmospheric absorption of this radiation is key to the catastrophic greenhouse effect.

Here is a graphic from a  NASA web page:



Note that the surface is here emitting thermal radiation with an power equal to 17% of the solar insolation at the top of the atmosphere up into the atmosphere. Of that 17%, 5% is absorbed by the atmosphere on passage and 12% makes it through the atmosphere into space.  Therefore 5/17 = 0.29 or 29% of the surface emitted longwave radiation is absorbed by the atmosphere.  This warms the atmosphere and it retards the rate of radiative cooling of the surface.  This is the very essence of the so-called greenhouse effect.  That effect is a critical scientific issue and one that the so-called settled science claims to understand well as the basis of its call for drastic action to prevent catastrophic man-made global warming.

This being a well-understood phenomena of the settled science, we should expect NASA to be consistent in proclaiming that 29% of surface thermal radiation is absorbed by the atmosphere.  Does NASA meet our expectations for consistency?  See this NASA Earth Energy Budget from, believe it or not, the same page as the above graphic on atmospheric absorption:



Now the Earth's surface radiation has swollen by 100% to 117% and only 12% makes it out of the atmosphere into space.  Now the atmosphere absorbs (117% - 12%) / 117% = 0.90 or 90% of the longwave infrared thermal radiation emitted by the Earth's surface.  It is much easier to make a claim that man's emissions of CO2 into the atmosphere will have dire consequences when you can present a picture of 90% surface radiation absorption in the atmosphere than when you present it as 29% absorption.  Note that the story for catastrophic man-made global warming is also made to seem more plausible because surface thermal radiation at 117% just overwhelms the rates of energy loss due to water evaporation at 25% and convection at 5%.  If surface radiation is just 17%, then 25% + 5% = 30% is a lot more important.  As I have pointed out in other postings, the loss of the majority the Earth's surface heat by non-radiative means is critically important in establishing a warm surface temperature.

So which is it?  29% or three times more at 90%?  What is actually measured is the rate at which energy is transferred from the surface to the atmosphere and beyond.  Note that in the Earth energy budget schematic, the back radiation from the atmosphere is claimed to be 100%.  If you subtract that from the 117% that diagram says is emitted from the surface, you get a net surface emission of 17%. In this way, NASA believes the Earth Energy Budget diagram and the upper diagram of the atmospheric absorption are equivalent, but the lower diagram sure represents greenhouse effects as more important than does the upper diagram.

What is actually measured?  When you make a measurement of the radiation from the surface from a given altitude, you only know the radiation power transferred from the surface to your measuring instrument.  Suppose your measuring instrument is at the same temperature as the atmosphere at that altitude.  It can then only measure the energy that can be exchanged between two bodies at the respective temperatures.  In other words, the 5% of surface radiation absorbed by the atmosphere would be what your meter would read at the appropriate point in the atmosphere.  If you move your meter outside the atmosphere into space and have it at the appropriate space temperature, then it can read the 12% level of radiation that escaped into space.  What you really know is presumably what is in the upper diagram.

So how does NASA generate the lower diagram with the 117% surface thermal radiation and the 100% back radiation?  It does so by means of the hypothesis that the atmosphere is a black body radiator, as is the surface.  Both radiate energy exactly as they would if they were isolated black bodies surrounded only by space at a temperature of absolute zero.  What is more, they suppose that any body (greenhouse gases mostly) in the atmosphere absorbing surface radiation re-emits it only toward the Earth's warmer surface, none of that is absorbed by other greenhouse gases, and all of it is incident upon the Earth's surface, which then absorbs 100% of that radiation.  This is absolutely wrong.  The exchange of thermal radiation energy occurs through the medium of an electric field and the flow of photons is only as required by the electric field gradient from the warmer to the cooler body.  The 100% thermal radiation from the atmosphere to the Earth's surface is a figment of NASA's imagination.

In the NASA upper diagram of the atmosphere and the power held in it, the sum of that power is 23% + 25% + 5% + 5% = 58%.  In the NASA Earth Energy Budget lower diagram, the atmosphere has an absorbed power of 23% + 5% + 25% + (117% - 12%) = 158%.  Now it is a miracle that the atmosphere can hold more power than the sun is supplying as is claimed in the NASA Earth Energy Budget in the first place, but faith in the authority of the settled science requires us to believe this. The upper diagram, which is much closer to the actual measurements made, does not require us to violate the Conservation of Energy.  Does this not prompt the rational observer to believe that the assumptions made to generate the NASA Earth Energy Budget are wrong?

The atmosphere on average is colder than the Earth's surface.  In the upper schematic, the atmosphere radiates 59% of the solar insolation at the top of the atmosphere out into space.  The atmosphere is warmer in general than is space so this is what we expect both thermodynamically and as a means to conserve energy.  In the NASA Earth Energy Budget, the atmosphere radiates 100% power to the Earth's surface, which absorbs it all, and it only radiates a power of 59% into space.  Consequently, the atmosphere is treated as a black body radiator that radiates with a total power of 159% in the NASA Earth Energy Budget schematic.  This violates energy conservation.  It implies that a molecular gas thermal radiator emits radiation anisotropically, which is contrary to their own statements and viewpoint that bodies emit thermal radiation as though they were isolated in vacuum with a temperature of absolute zero.  They assume that the anisotropic emission heavily prefers emission from a cooler gas molecule to the warmer surface of the Earth, rather than to a much colder space.  In reality, the thermal radiation power absorbed by the infrared-active gases called greenhouse gases is emitted anisotropically, but such that it flows to colder bodies or to cold space.

The real world cares whether the atmosphere is absorbing 29% or 90% of the Earth's thermal radiation.  Indeed, those who make infrared sensing devices care also.  If the atmosphere really did absorb 90% of radiation emitted by bodies at a temperature of 288 K, then it would be much harder to make and use infrared sensors for imaging and for temperature measurements.  Fortunately, the 8 to 14 micrometer wavelength portion of the infrared spectrum is much more than 10% of the emission spectrum for black bodies with temperatures near 288 K all by itself.  This part of the spectrum lies in one of the atmospheric windows in which water vapor and carbon dioxide absorb almost nothing. See my recent post on how infrared thermometers use this portion of the infrared spectrum to measure temperatures of gray body thermal emitters and how the atmosphere is no gray body.  It is very clear from the arguments made there that the claim that the atmosphere absorbs 90% of the Earth's thermal radiation at 288 K is nonsense.  It is the 29% absorption value that makes sense.

The settled science behind Climate Change is full of inconsistencies and violations of science of such a simply understood nature that it is a farce.  Catastrophic man-made global warming is based in a religion and politics, not in science.  This is why its alarmist proponents get so upset when someone, especially a scientist, does not share their unquestioning faith.  Faith is everything for this belief.

No comments: