dslack, thank you for the technical insight into the subject. It's great to have a more scientific viewpoint, rather than subjective judgments or blind faith.

One thing I didn't quite follow. I understand that astronomical causes can generally increase and decrease global temperature by 2-3 degrees C in regular cycles attuned to regular changes in Earth's orbit. When such a rise happens, CO2 is aspirated into the atmosphere in amounts sufficient to cause a greenhouse effect. This effect results amplifies the temperature rise by nearly 10 degrees.

If atmospheric temperature increases (presumably regardless of their cause) increase the amount of CO2 in the atmosphere, and a CO2 increase causes a temperature rise, what stops this cycle? It sounds like the temperature would simply keep on increasing, unless more powerful outside forces intervened. This increase would maybe asymptotically go to a limit, but if it takes 800 years for the effect to become noticeable, I would expect it to be far from the limit for a while.

You indicate that astronomical causes change overall temperature by about 2-3 degrees. Then 800 years later temperature begins increasing by another 10 degrees as a result of raised CO2 concentration in the atmosphere. So at the end of the astronomical cyclical "heating up" the temperature is more than 10 degrees higher than at the beginning. However, at this point there is a great deal more CO2 in the atmosphere and therefore Earth is much more "efficient" at saving solar heat. Since the temperature/CO2 concentration cycle is self-perpetuating to some extent (a 2 degree increase in temperature is enough to aspirate enough CO2 into the atmosphere to cause a nearly 10 degree temperature increase), I would expect that temperature would not drop to a level close to the original at the end of this astronomical phenomenon (I'm guessing Earth orbiting closer to the Sun). Therefore, global temperature should continue increasing, with a rate of increase going up and down in cyclical fashion.

I would appreciate it if you could help me in this. You seem to have a more thorough background on this subject than most people I have talked to.