"Things You Wouldn't Know If We Didn't Blog Intermittently."
I'm not a global warming skeptic, but as he admits in the first few sentences this is a computer model. As a programmer with a science background I am always skeptical of these kinds of models. They shows us how the programmer of the model believes the carbon cycle on earth works (assuming no bugs). While pretty it isn't the best argument, because how (if at all) the model has been empirically tested against nature is not discussed. Does it accurately predict real CO2 concentrations at various sites across the globe over the course of the year?