Hi John,

Your intermediate-level argument doesn't consider CO2 from volcanic sources, which is a common skeptical talking point.

 Of course, it's negligible: 1/250 of the human-caused CO2, on an annual basis (averaged). But it should be mentioned.

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http://volcanoes.usgs.gov/hazards/gas/index.php :

Carbon dioxide (CO₂)

Volcanoes release more than 130 million tonnes of CO₂ into the atmosphere every year.

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Neal

Since you had already claimed it, No.

I'm just making a comment, since I have dealt with this throw-away line before in blog discussions.