1. The Little Molecule That Could(n't) ?
Man made C02 based global warming is all about the magical properties of "the little molecule that could ! " After first giving carbon dioxide the magical properties of being able to absorb and hold excessive heat energy released by the Earth at night climate scientists now claim that over time this will cause a global temperature rise of such proportions that we will all eventually suffer the effects of a wildly overheated Planet.
The Final Solution concocted, adopted and promoted by the world leaders? - we have to reduce or eliminate our burning of carbon based fuels so as to stop the continuing rise of C02 in our atmosphere and we must replace our energy needs with sustainable "green" alternatives like solar and wind power. Even better, we should strive to actually capture and sequester C02, reducing atmospheric concentrations back to levels that we used to live (and thrive apparently) in. Scientists vehemently disagree.
Here's the key to the whole argument - it all comes down to whether Carbon Dioxide actually does capture heat energy in the form of IR waves released by the Earth and somehow actually retain that heat at Earth level by permanently overheating the air and / or sending the energy straight back to the Earth as a new / reversed direction IR wave. If this doesn't happen, then literally EVERYTHING that we're being told to do is WRONG and we may have set ourselves on a world course that will eventually do far more damage than good. Why would we need to cut fossil fuels if generating C02 is simply not important (and may actually be beneficial to plant growth).
This paper looks at the spectral environment of C02 affecting its ability to absorb and emit infrared heat emitted from the Earth. The tool for this comes from a basket of well known thermodynamic formulas that describe the electromagnetic properties of heat waves in relation to the materials (such as C02) that they interact with. These formulas are thankfully available in the form of online calculators. We are interested in the Wiens formula and Planck's formula.
This paper will use Wiens and the Plancks to calculate temperatures and absorption probabilities of atmospheric C02 being bombarded with Earth-sourced infrared heat waves.
We need to know exactly what are the spectral properties of C02, particularly its IR absorption properties, as it has to capture IR heat hitting it before it can redirect it anywhere. The science of spectroscopy has clearly shown that carbon dioxide is quite specific in the wavelengths of electromagnetic energy that it will absorb (and conversely in what wavelengths it ignores).
It turns out that its absorption properties are extremely limited - spectroscopy has shown that C02 absorbs only three wavelengths of electromagnetic energy and cannot absorb any of the rest of the spectrum. These wavelengths (actually seen as peaks of small ranges) are at 2.3 um, 4.5 um. and 15 um., all apparently detected within the overall IR spectrum (2 to 25 um) released by the Earth during night time hours.
The problem with stating the 2 to 25 range if infrared is that it is actually too broad and in particular it doesn't show the specificity of the actual gas or in particular, the actual temperature the Earth must be to release compatible IR that can be absorbed by the gas hovering above.
The image above shows the performance of C02 under the full barrage of IR light. Peak 1 / 2 are actually just within the range of incoming IR energy from the Sun, represent very hot states electromagnetic radiation and don't really play a roll in the much cooler outgoing range heat IR as depicted by the second curve (255 K / Earth temperature). This leaves 4.5 um playing a small roll in the overall C02 affected exhaust spectrum and 15 um playing a fairly significant roll. So what emits 4.5 um and / or 15 um infrared?
Imagine a black rock sitting out in the middle of a green field of grass. Above this black rock is an atmosphere composed of nitrogen, oxygen, helium, water vapour and trace gases that include C02 present at a level of .04% of the total volume. Imagine a cloudless day that allows full sunshine to beam down upon our black rock in a manner that when Sunset occurs, the rock is sitting at a temperature of that is say, 50 C. The rock now has 12 hours to cool back down to a temperature of say, 10 degrees Celsius before the next day's Sun begins to heat it up again.
It drops in temperature because it radiates heat to outer space in the form of IR waves. The nature of the waves depend mostly on the temperature of the rock (which we assume to be a perfect emitter called a black body). These electromagnetic waves are characterized by specific wavelengths dependent on the temperature of the rock at the time they are released. They can be calculated from our formulas. Let's do the exercise.
Let's look for the Rock temperature required to produce waves that are 15 um.
1. At 50 C wavelength of IR = 8.967 um.
2. At 40 C wavelength of IR = 9.254 um
3. At 20 C wavelength of IR = 9.885 um
4. At 0 C wavelength of IR = 10.609 um
5. At - 20 C wavelength of IR = 11.447 um - (spectrum above shows 255 K with peak at around 11 um.)
6. At -40 C wavelength of IR = 12.43 um
7. At - 50 C wavelength of IR = 12.986
8. At -70 C wavelength of IR = 14.264 - slight absorption ?
9. At -80 C wavelength of IR = 15.003 - peak absorption = -112 F OR = 193 K.
10. At -100 wavelength of IR = 16.736 - slight absorption?
BUT HOW ABOUT 4.5 um ? Can the Rock get hot enough to emit IR at this wavelength?
1. At 100 C wavelength of IR = 7.766 um
2. At 200 C wavelength of IR = 6.124 um
3. At 350 C wavelength of IR = 4.650 um - absorption probable
4. At 400 C wavelength of IR = 4.305 um - absorption probable.
BUT HOW ABOUT 2.5 um ? -
Well, without all the to-do given to the above two wavelengths, the rock would have to be 900 degrees Celsius to do this. That's 1600 Fahrenheit for you Americans or 1173 K for you scientific types.
SO, IT APPEARS THAT THE ONLY WAY WE CAN DELIVER COMPATIBLE IR WAVES TO THE C02 WAITING ABOVE US IS TO COOL OBJECTS TO RIDICULOUSLY LOW TEMPERATURES (-80 C) OR TO RIDICULOUSLY HIGH TEMPERATURES (350 C OR 900 C). SEEMS RATHER UNLIKELY SINCE EARTH SELDOM REACHES ANY OF THESE EXTREMES AND IF IT DOES THEN IT IS EXTREMELY LIMITED.
PLANCK'S LAW SAYS THIS SCENARIO DOESN'T REALLY HAPPEN. HE SAYS ALL BODIES RADIATE A RANGE OF WAVELENGTHS INCLUDING THE COLD WAVELENGTHS SUCH AS 15 UM AND EVEN THE HOT WAVELENGTHS SUCH AS 4.5 OR 2.3 UM. PLANCK'S FORMULA IS ALSO AVAILABLE IN AN ONLINE FORMAT.
TO REPEAT THIS FOR EMPHASIS - THIS MEANS THAT A "WARM" EARTH WILL RADIATE UP A QUANTIFIABLE AMOUNT OF COLD 15UM RADIATION OR EVEN A QUANTIFIABLE AMOUNT OF OF HOT 4.5 OR 2.3 RADIATION.
IF TRUE, THIS MEANS THERE IS A CONSTANT SUPPLY OF IR BEING SENT FROM A COOLING EARTH TO THE SKY. IF TRUE, IT MEANS THAT WE WILL GET IR IN THE ATMOSPHERE AS A CONSTANT THING AND NOT JUST IN ANTARCTICA WHERE IT'S COLD ENOUGH TO GENERATE 15 UM OR A VOLCANO THAT MIGHT GENERATE 4.5 OR 2.3 UM.
THE CONCEPT OF BLACK BODY / PLANCK TYPE "RANGE" SPECTRUMS ARE DISCUSSED HISTORICALLY AS WELL AS PRACTICALLY IN THE FOLLOWING BLOG. HOPEFULLY THIS WILL GIVE PERSPECTIVE TO THE SITUATION.
WE NOW ASSUME YOU'VE GRASPED THE CONUNDRUM OF SINGLE TEMP / SINGLE WAVE OR SINGLE TEMP / RANGE OF WAVES CONCEPTS. IS IT ONE OR THE OTHER? CAN IT BE BOTH AT THE SAME TIME?
THIS BRINGS US TO THE TWO "SCHOOLS OF THOUGHT" CONUNDRUM. THE LINK BELOW WILL SEND YOU TO THE BLOG DEDICATED TO DISCUSSING THIS ARGUMENT. THE ROUTE YOU CHOOSE TO FOLLOW IS IMPORTANT AS IT AFFECTS YOUR CONCLUSIONS ON ABSORPTION AND BACK HEATING AS WELL.