There is one thing i find strange in the article from ericlp :
http://www.pbs.org/wgbh/nova/transcripts/3310_sun.html
Water vapor is the most powerful greenhouse gas there is. Yet it seems that it is only cooling the earth because of global dimming according to the article and does nothing to warm the earth because of that same capability of reflection, but then pointed downwards towards the earth. I find that strange. Because clouds themselves have an cooling effect, drawing energy away during formation and when raining, the rain when fallen on the earth's surface, needs to evaporate again. This evaporation can only happen when the ground or surface heats up, feeds energy to the water to vaporize again. But at the same time, water vapor high above absorbs infrared energy, and retransmits that IR again but in all directions. Some IR coming from space , back into space. If i understand correctly, that is what is the covering effect or mirror effect what is mentioned when writers of articles mention the IR light is reflected back into space.
But there is also an enormous amount of IR transmitted from the earth, gets absorbed up in the sky by that same water vapor and is partially absorbed and transmitted down towards the earth again.
Now i think i can assume that the same thing is happening to CO2.
It reflects IR back into space and it reflects IR back to the earth.
An optimistic calculation based on the not entirely accurate idea that IR (infrared) radiation is absorbed from one direction and retransmitted in any direction. :
If 50 percent of the IR radiated from the earth surface is coming back to the earth. And 50 percent of the radiation from the sun is reflected back to outer space, The sun would still be responsible for the heating of the earth.
If the earth is not loosing all the acquired energy at the same level it is receiving, that heat energy is accumulated in the earth surface and atmosphere.
What i would like to know is what is that energy normally used for ? I would think cloud formation.
What has man done to create a situation that all that heat energy is not used in a natural cycle ? Is it large scale agriculture ? Global deforestation ?
Cities that heat up because of man made heat and store heat energy, thereby increasing the amount of heat energy stored in the earth surface ? Before i get accused of being a tree hugger who wants everybody to live in caves. That is not the case. I just want to have a clear picture.