Why belief in CAGW (Catastrophic Anthropogenic Global Warming) is not currently justified by the standards of the scientific method

http://hockeyschtick.blogspot.com/2012/05/why-belief-in-cagw-catastrophic.html

A post today at the Paths to Knowledge blog notes that belief in CAGW is not justified under the scientific method because no peer-reviewed study as ever falsified the null hypothesis that global warming is substantially natural.But, the reverse is not true. A recent peer-reviewed study has shown that the null hypothesis [warming is substantially natural] has a statistically significant higher probability of being true than the CAGW hypothesis. Therefore, belief in CAGW is not currently justified by the standards of the scientific method. The IPCC attempts and fails to falsify the null hypothesis using circular reasoning, as noted by Dr. Tim Ball:

Computer models are key to the IPCC circular argument. They're programmed to the assumptions of the hypothesis, and therefore produce results that confirm the hypothesis. The problem is, nature hasn't cooperated.