From: "Geo." 

"John Beckett"  wrote in message
news:opro2399jp79do8q9mfqppk5u3l32cmqph{at}4ax.com...

> You could remove all the nitrogen and oxygen from the atmosphere and have
> no effect on the greenhouse effect of CO2 (I think).
>
> The proportion of CO2 is simply not relevant.
>
> The issue merely concerns the probability of whether a photon of infrared
> radiation escaping from earth would be captured by hitting a CO2 molecule.

I hate to sound harsh but your thinking and reality don't agree. If that
were true, Mars would be warmer than earth since it has 300x (that's a
30,000% increase to your way of counting ) the CO2 per square
meter of surface area of the earth.

http://zebu.uoregon.edu/~soper/Mars/atmosphere.html (you need to see this)

The effects of CO2 are additive here on earth, most of our heat retention
is from water vapor, CO2 heat retention is insignificant because the amount
is so tiny. That's why cloudy winter nights are warm and clear winter
nights are the coldest.

Geo.

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