[E. Pluribus Unum]

What does that have to do with whether or not recent increases in atmospheric CO2 are attributable human activity?

If the effect of CO2 is orders of magnitude lower than the effect of water vapor, then it doesn't matter.

Atmospheric CO2 levels have been orders of magnitude higher than today and the world did not end as you claim it will, plus humans weren't around to contribute to the high CO2 levels, so they must by your definition have been "natural."

[edsheppa]

If the effect of CO2 is orders of magnitude lower than the effect of water vapor, then it doesn't matter.

Are you saying water vapor affects CO2 concentrations? Or that it affects human activities that emit CO2? Unless the answer to one of those is yes, then it has nothing to do with the question I'm interested in.

If you don't have anything relevant, please don't post to me.