Count the molecules, count the photons; MORE CO2 WILL MAKE LITTLE DIFFERENCE IN GLOBAL WARMING! Gary Young Retired Product Development Manager, Engineer 2007 Using the physics approach of “counting molecules; counting photons” and then analyzing what happens to these molecules based on first principals indicate why little CO2 warming will occur. Counting the molecules: The number of molecules of CO2 can easily be found starting with the weight of the air in the atmosphere at sea level which is 14.7 psi, or equivalent to 10,100 kg per square meter. Air is Nitrogen, Oxygen, water vapor, and trace gases including 380 parts per million of carbon dioxide. By using the molecular weights of the various components of air, the number of CO2 molecules in a one-meter square column stretching to space is about 7.9 x 10^25; or 7.9 times ten to the 25th power. (Scientific notation for 79,000,000,000,000,000,000,000,000, a really large number) Counting the photons: The primary wave lengths of infrared light emitted by the earth and that excites CO2 is about 10% of the spectrum of infrared light, but it is nearly centered in the spectrum where the earth radiates the most. CO2 is capable of absorbing only about a third of the spectrum of the energy radiated by the earth surface. Note that water vapor couples with about 75% of the spectrum and “competes” in much of the same part of the spectrum where CO2 absorbs energy. It can be seen in the 1997 energy balance model by Kiehe and Trenberth, that about 90% of the energy earth radiates is absorbable by all the greenhouse gases. Of the 390 watts of radiation the earth emits at the surface, 40 watts goes directly into space through the atmospheric “window” because no gases can capture it. Of particular note is that 324 watts are the “back radiation” from the greenhouse gas re-emitting photons that are in turn directed back to the earth’s surface. The “back radiation” is an important consideration because the phenomenon greatly mitigates the “shoulders effect” when CO2 concentrations change.
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The Kiehe and Trenberth model is a hypothesis and not a scientific certainty which means that it may be wrong. I prefer the 1997 version before Trenberth went all wobbly trying to find hidden energy. So, the model is as good as any until it is replaced with a verified better model. The infrared wavelength of 14 microns, which is close to where the earth radiates the most, was picked as representative of the energy of the earth’s surface radiation. We know from the laws of physics that these photons have an energy of 1.34 X 10^-20 Joules. (In this case the minus in front of the 20 is scientific notation for the number of places after the decimal including the first number or 0.0000000000000000000134 Joules, a really small number). If we further assume that ALL 350 watts of the absorbable surface radiation energy is concentrated at this wavelength, then we have emission from the surface of about 2.6 X 10^22 photons per second per square meter of the earth The “capture cross section” of CO2, (the apparent size of the molecule that is able to couple with 15 micron wave length photons) is well documented in physics and is 5 X 10^-22. square meters. Therefore, ignoring water vapor and other gases, in order to capture ALL the IR energy emitted by a square meter of the earth requires (only!) 2 X 10^21 molecules of CO2. The earth’s atmosphere already has at least 40,000 times this required number of CO2 necessary to capture all the “greenhouse” causing IR photons leaving the surface of the earth. When I developed this count-the-molecule-count- the-photon hypothesis in 2007, I searched to see if anyone else had come up with something similar. The answer was yes, In June 2006, a retired British physicist, Aubrey E Banner, posted a very similar 2
analysis on http://forum.physorg.com/, a site hosted by Physics Forums. In support of the above analysis, he used the same critical values. His approach was focused on how much energy could be absorbed by current levels of CO2. His conclusion was nearly identical: “The energy of a 14 micron infrared photon is 1.34 x 10^-20 Joules, --- and so the 2 x 10^21 molecules providing the absorption coverage can absorb the energy the earth emits. ----- There are already 8 x 10^25 molecules which could absorb 40 thousand times the energy the earth emits.” Let us now add the effects of water vapor; something alarmists don’t mention. Water actually absorbs in a greater portion of the same spectrum as CO2 where the earth emits greenhouse causing photons. Also, there is on average about four times more water molecules than there are CO2 molecules in the atmosphere. I think it is conservative that the absorptive power of water is five times more absorptive than CO2. For every greenhouse causing photon leaving the earth’s surface there are 200,000 absorbing molecules waiting! Both Banner and I ignored the issue of how many times in one second a molecule of CO2, being greatly diluted in the atmosphere, will accept another photon. The answer is that molecules of CO2 and H2O are able to “relax” and again absorb a photon in as little as 10 ^-10 per second. Banner’s and my absorption analysis was made for only one event a second and for all energy concentrated at 14-15 microns. Since the greenhouse causing photons are leaving the earth at the speed of light, no one knows how many times the energy will be absorbed and then a similar photon is re-emitted. I think ten times is a stretch. Thus, the calculation of having 200 thousand times more molecules only absorbing one photon a second seemed very conservative. The original paper was 40 pages so of course there is a lot more going on such as the mean free path of a photon before it gets absorbed, absorption spectra including “shoulders” which is represented by the HITRAN data base. (I consulted with the Air Force laboratories Detachment at Rome AFB when they first put the data base into a computer program.) When I was in business for large-scale product development, I always liked the term “the bottom line.” CO2 is innocent! The atmosphere already has so many multiples of “greenhouse” absorbing molecules that even doubling the concentration of CO2 from 400 ppm to 800 ppm would not result in a detectable temperature increase.
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Hong Kong, China. Fossil fuels are essential for a better, more beautiful world. There are no energy sources to replace them in many applications. There are good scientists who genuinely think carbon dioxide from fossil fuels is leading to climate change and sea level catastrophes. Other anti-fossil fuel organizations have special agendas.
Good living and healthy environment after use of fossil fuels since the 1800s. 4
Use fossil fuels and nuclear for generating electricity in appropriate countries around the world. Penly Nuclear Station in France. It was planned for very long-term, continuous operations. Pre-approved siting for replacement units at end-of-life for existing units. Two operating units. Two locations pre-approved for future units. France has some of the best nuclear planning in the world.
Very clean coal plant, Comanche Generating Station, in Colorado, USA
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