[sdantonio]

Geof,

I have been trying to think up an argument for what you have said and it finally dawned on me, and the answer was so simple.

You argument is based on conservation of matter, one of the most fundamental laws of physics. And as far as your argument goes it is correct. The earth has a finite amount of carbon and thus a fixed amount of carbon dioxide. This amount hasn’t changed appreciably in 4.7 billion years and still isn’t changing. And it does get constantly recycled from one form to another as you pointed out.

However, taking a large amount of carbon, and turning it into CO2, as with the burning of fossil fuels, which is then dumped into the atmosphere, puts an unusually large amount in a place where it doesn’t belong all at one time. As you pointed out it will eventually get recycled out. However, there is still more than the normal amount in the atmosphere.

Let’s take Aristotle’s argument that a stone sinks in water because it is made of earth and it’s proper place is with other things made of earth and extend it to the human body. You (all of us actually) are approximately 98% water. Having 98% of the stuff in your blood vessels being water is a good thing. The water is where it’s supposed to be. Now lets put 98% water into your lungs, not a pleasant experience (having fallen off a dock as a child before I learned to swim I can vouch that it is not pleasant). There has to be some moisture in the lungs for them to work properly, but nowhere near 98%. Likewise, the excessive CO2 in the atmosphere could be detrimental. Or it could be part of a natural warming cycle.

I’m still in the camp that says we don’t have enough information to tell how much global warming is due to the natural cycle and how much is due to the extra stuff we have caused to be in the air, but there is no harm in being careful about it. The extremists on one side say we are (or have already) pushing the planet past the point where it can recycle and recover. Extremists on the other side say there is no such thing a global warning.

So, just to be safe, I think we should round up all the cows we can get our hands on and have one heck of a CNCzone barbeque.