Hi Tony, interesting post!
I can only see benefits of more CO2 - primarily greater plant yields! as archaeological evidence points to periods when the earths atmosphere had far greater concentrations of CO2 always coincided with far greater diversity and yields of life ie the cambrian explosion.
Logically it seems that this planet has its own system to deal with atmospheric balancing.
There is however an argument wrt greenhouse gases that may be of interest since it is slowly gathering momentum - slowly mainly due to censorship by omission by the msm.
That is the repeat of the woods experiment by professor Nasif Nahle in a modern rendition of the famous experiment that disproved the erroneous greenhouse effect wrt CO2.
Along the same lines and with perhaps using the false paradigm of the green house effect professor Joe Postma explains why P/4 is also in error. Simply put most dont understand that The sun does not in reality shine at a quarter of its power all over Earth constantly, and therefore P/4 is a meaningless average in this context. Therefore the models are in reality unphysical! http://www.facebook.com/groups/446446425385858/
If the net effect of CO2 is as little as the woods experiment or for that matter Prof Nasif Nahle propounds then it is likely that we are heading for a little ice age whether or not we create more co2 or not. The increase in plant growth as mentioned would of course be a benefit either way.
It appears to be clear that the physics curriculum will at some point be revised correcting the error that purposefully adheres to the mainstream view concerning the green-house effect.