I would like to post a few facts related to global warming as I read a lot of posts referencing things like the accuracy of mathematical models etc. I am a scientist (chemist) and I would point out that the basic arguments for global warming from greenhouse gases has nothing to do with said modeling. The basic agrement for greenhouse warming is:
1. The Sun is hot.
2. Hot bodies like the sun radiate in the visible spectrum.
3. 99.9999999999+% of gases in the atmosphere are transparent in the visible region of the spectrum.
4. The Earth is pretty cool.
5. Cool bodies radiate in the infra-red spectrum.
6. Triatomic(+) gases (CO2, CH4, H20) are not transparent in the infra-red region of the spectrum, they thus absorb radiation from the earth.
7. Absorbed radiation heats the absorbing body (gas).
All these are facts that can be easily demonstrated by experiment using equipment available in most high school physics labs.
The only non-obvious facts are that CO2, CH4 etc. are greenhouse gases and the main atmospheric gases (O2,N2) are not. The greenhouse gases absorb in the infrared region because infrared absorption is due to intramolecular motion (vibration, rotation, and bending). The diatomic gases are too ‘stiff’ to flex this way. An infrared spectrophotometer (a very common instrument) can be used to measure and quantify the IR absorption.
The idea that CO2 in the air is an important determinant of global temperature is actually quite old, it was first theorized by Svante Arrhenius (1859-1927) in a paper published in Philosophical Magazine 41, 237-276 (1896)[1].
He is one of the most respected of scientists and in fact the symbol ‘A’ is used for the activation energy of a chemical reaction in his honor. He even related the concentration of CO2 to the past geological variation in the Earths temperature.
‘One may now ask, How much must the carbonic acid vary according to our figures, in order that the temperature should attain the same values as in the Tertiary and Ice ages respectively? A simple calculation shows that the temperature in the arctic regions would rise about 8° to 9°C., if the carbonic acid increased to 2.5 or 3 times its present value. In order to get the temperature of the ice age between the 40th and 50th parallels, the carbonic acid in the air should sink to 0.62–0.55 of its present value (lowering of temperature 4°-5°C.).’
