I saw a most facinating letter in the Calary Herald today. It basically stated that green house gasses should block a large portion of energy coming from the sun and preventing it from reaching the earth, thus cooling it. A casual observer might shrug and say, “Yeah, that makes sense.” A slightly less concieted observer might wonder what’s wrong with his or her own understanding of the green house effect. Of course, there’s also the observer who would claim that scientists are just lieing.
Someone with more physics background would note that the sun is very hot so it radiates a bunch of radiation along the higher energy end of the spectrum. It only becomes lower energy radiation after it hits the earth’s surface and the energy gets absorbed. Air is then warmed by direct contact with the surface and energy is radiated out again. Of course, the earth’s surface is at a lower temperature than the sun’s surface and so the radiation is mainly in the lower end of the spectrum.
We know that things absorb and scatter different wave lengths of light. It’s the reason the sky is blue. It seems pretty clear that green house gasses probably shouldn’t reflect energy radiated from the sun and the earth equally. If someone has to ask how gasses discriminate between the two and imply that it’s impossible to back up their conclusion, when I know they’re two different areas of the spectrum. I get the feeling that no research has been done and feel inclined not to believe the conclusion. Whereas if someone who’s spent years studying this and probably knows which gasses are better at reflecting what parts of the spectrum tells me that increasing the amounts of certain chemicals will cause the earth to heat up, I can feel assured that this is probably a sound conclusion.
