It is generally agreed that, at sea level, the atmospheric pressure is 14.7 psi and that about 0.035% of the atmosphere is CO2 - but what does that mean. This page will present those facts in a slightly different manner.
Note - the first 2 sections are highly technical and fairly boring. However, they are necessary to understand the rest of the document.
Data for the Earth | Metric | English |
---|---|---|
Atmospheric pressure at sea level | 1014 mb | 14.71 psi |
Atmospheric density at the surface | 1.217 kg/m^{3} | 0.07597 lb/ft^{3} |
Total mass of atmosphere | 5.1 x 10^{18} kg | 5.6 × 10^{15} short tons |
Total mass of hydrosphere | 1.4 x 10^{21} kg | 1.5 × 10^{18} short tons |
Mean molecular weight of atmosphere | 28.97 g/mole | |
Specific Heat of Air (typical) | 1.012 J/g*K [2] 1.005 J/g*K [3] | |
Specific Heat of Water - gas (100 °C) | 2.080 J/g*K | |
Specific Heat of Water - liquid (25 °C) | 4.1813 J/g*K |
Table References
1.217 kg/m^3 in lb/ft^3 = 0.075974828 pound / (ft^3)
The equations that describe the atmosphere are relatively complex - mostly because the atmosphere itself is very complex. The most obvious problems are
14.71 psi = 14.71 lb/in^{2} (14.71 lb/in^{2} * (12 in)^{2}/(1 ft)^{2}) / 0.07597 lb/ft^{3} = 27,880 ft = 5.280 miles = 8.498 kilometersWhat this means is that the 100 or so miles of atmosphere above your head contains the same amount of gas as a horizontal tube
Since CO2 is about 0.035% of the atmosphere, that accounts for about 9.8 ft of that tube.
27,880 ft * 0.00035 = 9.76 ft The value found in some references 27,880 ft * 0.00038 = 10.59 ft Current value 27,880 ft * 0.00045 = 12.55 ft Reasonable expected maximum after ALL oil is burned 27,880 ft * 0.00070 = 19.52 ft Burning coal can provide a higher value 27,880 ft * 0.00100 = 27.88 ft IPCC projects values higher than thisUsing historical data, 30 years produced an increase of about 44 ppm. Using that as a basis, and the fact that the increase is linear, the concentration in 2100 should be
369 ppm + 100/30 * 44 ppm = 516 ppm (0.0516%)not more than 1,000 ppm the IPCC is predicting.
Note - the fact that the CO2 increase is linear, while at the same time the amount of CO2 released by humans has grown exponentially, is the primary proof that humans are NOT responsible for the change in CO2 concentration or climate change.
atm-cm at STPGiven a column of gas at STP, this is the length in centimeters.
Note: STP - Standard temperature and pressure - zero degrees C and one atmosphere pressure
When discussing ozone, Dobson Units (DU) are used, partly because Dobson was the first person to study atmospheric ozone and partly because there is very little ozone in the air.
1 DU = 1 milli-atm-cm (also shown as 1 m atm-cm) ozone concentration = 0.3 atm-cm = 300 m atm-cm = 300 DUThis means that all the ozone in a column of air, when placed in a single layer at 0 degrees C and one atmosphere, would produce a layer of gas only 3mm thick.
Without correcting for temperature and pressure, the following are approximate values for CO2 (based on the table above). Corrected values should be about 9% less (because the temperature would be lower).
350ppm 9.76 ft -> 297 atm-cm The value found in some references 380ppm 10.59 ft -> 323 atm-cm Current value 450ppm 12.55 ft -> 383 atm-cm Reasonable expected maximum after ALL oil is burned 700ppm 19.52 ft -> 595 atm-cm Burning coal can provide a higher value 1000ppm 27.88 ft -> 850 atm-cm IPCC projects values higher than this
9.76 ft at 1 atm * 12 in/ft * 2.54 cm/in = 297 atm-cm (when rounded to 3 significant figures)
This demonstration was supposed to illustrate what was GOING to happen, how adding CO2 to the atmosphere would destroy the Earth ... but it actually showed ... without a doubt ... that the atmosphere is already totally opaque.
Let me be very clear about this - their totally bogus demonstration showed that adding more CO2 to the atmosphere will have absolutely no effect - and this was in a propaganda film.
Ok, why do I call it propaganda and bogus
By the way, there may be ways, other than simply blocking IR, that permit additional CO2 to raise the Earth's temperature - but this is the mechanism presented by NOVA.
Please see my "What's Up With the Weather?" page for additional comments on the program.
4,000 Ångstroms = 400 nm
1.98 kg/m^{3} = 0.1236 lb/ft^{3} (Density of CO2 at stp) (14.71 lb/in^{2} * (12 in)^{2}/(1 ft)^{2}) * 100 / 0.1236 lb/ft^{3} = 1,713,786 ft = 324.6 miles = 522.4 kilometersOn Earth, a horizontal column of air at sea level that represents all the air in the column of air above you is 5.3 miles long.
On Venus, a similar column of atmosphere, if located at sea level on Earth, would be about 60 times longer - about 324 miles long.
On Earth, a 10 foot chamber containing 100% CO2 represents the total amount of CO2 between the surface and free space.
A chamber that represents the amount of CO2 on Venus will be about 312 miles long (96.5% of 324).
To be completely clear, these propagandist want us to believe that increasing 10 feet of CO2 to 20 feet will cause Earth to be like Venus which is equivalent to about 1,680,000 feet of CO2.
Air Column | Feet of CO2 | |
---|---|---|
Earth | 5.3 miles | 10 feet |
Venus | 324 miles | 1,680,000 feet |
And you want to know why I am skeptical.
Note - The first calculations in this section assume that the atmosphere of Venus is 100% CO2, and the last calculation uses the value 96.5%. As a result, there is a small error - but with 5 orders of magnitude difference ... it really doesn't matter.
Note - While the spectra of each gas is different, the absorption and emission spectra for a specific gas are usually identical. (The primary exception is fluorescence.) Though it is seldom mentioned, this means that CO2 absorbs and emits IR radiation at exactly the same frequencies. Note however that all the radiation in a spectral line is not at exactly a single frequency, but instead in a small range (band) of frequencies. It is the width of these spectral lines that is affected by temperature and pressure.
Basically, at ground level the spectral bands are at their maximum widths. (Maximum pressure - but not always the maximum temperature.) It is here that CO2 can absorb more energy than it emits. As you get farther from the Earth, the temperature and pressure both decrease and the bands get narrower.
This means that when CO2 emits energy towards space, only some of it will be absorbed by the CO2 above it. However, a very very small amount will not be absorbed because the absorption bands are narrower.
The rate of this cooling is partly related to the mean free path - how far the radiation travels before it is reabsorbed. Basically, the farther radiation travels toward space (lower temperature and pressure) before being reabsorbed, the narrower the absorption band and the more heat is lost to space.
The funny thing is that when this band spreading is taken into effect, it quickly becomes apparent that carbon dioxide is actually the only gas that cools the atmosphere. That's right, without carbon dioxide the atmosphere has no way to release its energy to space and the planet quickly over heats.
Up to about 11,000 feet (top of the troposphere), water vapor provides this capability. But above that level, there are few, if any, gases to cool the atmosphere.
Another point is that as the amount of CO2 in the atmosphere increases, the mean free path for CO2 released IR radiation decreases. This is offset, at least in part, by having more emitters. It is not clear to me if this will have a positive or negative effect. The evidence from Venus indicates that more CO2 will have a cooling effect ... but there is definitely room for more research on this.
Eventually, I plan to develop a page on just this effect. At that time, I may change my position on this ... but I don't think so. The analysis I've done to date is fairly solid.
I have additional original work on