Counterpoint - Climate Models Are Unreliable Therefore Science Cannot Prove Human Activity Causes Global Warming

UPDATE:  A credible challenge to one of the provisional truths of science:

A Climate Of Belief - The Claim That Anthropogenic CO2 is Responsible for the Current Warming of Earth Climate is Scientifically Unsupportable Because Climate Models are Unreliable by Patrick Frank, Skeptic Vol 14(1), 2008.

More on global warming:  Scientists Did NOT Fudge Data To Prove Global Warming, February 24, 2011.  See also The Storms Over Climate Change.