Some climatologists still wrongly say that any hand held IR thermometer will prove global warming back radiation heating. But as we see below, real world experts from both thermometer manufacturing and the ‘hard’ sciences (better skilled in the laws of thermodynamics) have proved this claim wrong.
To lay readers, please be assured, this is not some arcane scientific dispute of no great significance to you and your family. It is a fundamental paradigm shift – the collapse of the greenhouse gas theory (GHE) – the very “science” that underpins man-made global warming and global carbon taxation policies. Recent progress in these matters is in no small part due to a few climate scientists with the gumption to come out and debate. Kudos to them for that despite wagon-circling by their colleagues and the public opprobrium witnessed since the Climategate fiasco.
As such, an important discussion on the supposed greenhouse gas theory has ensued. Top climate experts, Roy Spencer and Judith Curry came out to cross swords with skeptical experts at Principia Scientific International aiming to slay that GHE “sky dragon.” At issue were claims about whether trace gases like carbon dioxide can cause infrared radiation to “back radiate” and add/delay heat at the Earth’s surface making our planet “33 degrees warmer than it would otherwise be.”
As was demonstrated in my prior article, the “33 degrees” claim is well and truly refuted. PSI analysis found that this number is the product of a botched 1981 equation by NASA’s James Hansen who fatally mixed a scalar temperature value with a vector temperature value. Nonetheless, GHE diehard Roy Spencer has followed the lead set in 1990 by his colleague, Dr Richard Lindzen. Spencer claims Hansen’s number fudge offers a “real-world observed “radiative-convective equilibrium” case.”
But this article isn’t about Spencer and Lindzen being duped by Hansen’s dodgy doings. It’s about the very concept that the supposed greenhouse gas effect can “back radiate” heat to our planet’s surface. And to Spencer’s credit he boldly faced up to my colleague, Dr. Pierre Latour, an industry expert in thermodynamics, to test claims for and against this assertion. Their private email debate is published online and it’s not good reading for Spencer fans.
To affirm Latour’s victory colleagues at Principia Scientific International (PSI) contacted the world’s leading manufacturer of hand held IR thermometers, Mikron Instrument Company Inc., for confirmation of Spencer’s misunderstandings that IRT’s prove CO2 and GHE warming. Sure enough Mikron affirmed that IRT’s are set “to evade atmospheric moisture over long path measurements.” This, they say, is necessary to “avoid interference from CO2 and H2O.”  Sadly for Roy, these thermometers therefore aren’t even measuring the gases he claims they are!
Thus, from the “horse’s mouth” the hand held thermometer gambit is well and truly busted. Professor Claes Johnson thereafter also persuaded Dr. Curry to abandon “back radiation.” But unlike Curry, Spencer did not renounce his “back radiation adds more heat” claims. So Latour pressed home the point to explain to Spencer:
“My radio antenna detects and absorbs cold radio waves but it does not re-emit them with higher intensity than it intercepted them. My 1200 w microwave oven heats coffee to boiling; when I turn it off the boiling stops abruptly, within a few seconds. I suppose coffee re-emits some intense (hot) microwaves converted to IR for a while. I think the IR rate drops very quickly when the oven stops and equalizes with my kitchen IR as I drink it. I am not able to determine how long the coffee continues to radiate above background T.
I accept radiation detector surfaces need not be colder than the incident radiation to detect and measure cold radiation. My eyes see ice. My eyes do not re-radiate ice light. Penzias & Wilson detected CMBR = 3.7 K in 1964 with a radio telescope in a warmer NJ. Radio telescopes do not re-radiate CMBR. I suppose warm IR thermometers can indeed measure radiating temperature of colder refrigerators, without absorbing refrigerator radiation and warming further. What does that have to do with whether warm radiators get warmer from cold re-radiation?”
In short, Latour and other PSI researchers argue climatologists need to drop the unphysical term “back-radiation” and more correctly explain that what they mean is “downward” radiation. But that does not per se add to, or delay heat transport. Any such downward radiation can be composed of two or more sources; remember the atmosphere is heated up also by solar radiation. The air absorbs 14% of solar radiation before it touches the surface. Oxygen, water vapor, and dust are the components of the air that absorb directly part of the incoming solar radiation.
As Latour said to Spencer,
“We cannot count the whole percentage of solar energy absorbed by the atmosphere as energy emitted towards the surface as a warm wrapper because it is dispersed immediately to winds, in the form of kinetic energy, to space like thermal radiation, and to other systems like unusable potential energy. However, the main reason other systems do not absorb thermal radiation from the atmosphere is that the wavelength of the emitted electromagnetic energy does not correspond to thermal energy, i.e. it cannot be transferred as heat to other systems, because of redshift. Downward radiation exists, but it cannot warm up systems that are warmer than the air.”
In summary, we find that climate scientists are proven to have grossly erred in perpetuating the myths about the so-called greenhouse gas theory. They were misguided to seek to prioritize their version of radiative transfer theory at the expense of real, complex physics. The delusion over “back radiation” heating is shown to be just another example of how that infant branch of science blew a fuse in seeking to short-circuit Earth’s entire atmosphere to fit the nonsensical greenhouse gas hypothesis.
Until more climate researchers come out of their ivory towers and consult with industry experts better grounded in the hard sciences, then climatology will be condemned as a second rate discipline. But more pointedly for you and me, any “green” taxes based on limiting carbon emissions are now shown to have a very dodgy scientific basis.
 [1.] Mikron Instrument Company Inc., ‘Infrared Temperature Measurement Theory and Application,’ omega.com, (accessed online: September 20, 2011).