” … there are too many GCMs, and some of them are cr*p … “
I have linked to this post by William Connolley in my Update to this post. I have decided to post it here for several reasons.
Recently William Connolley, whom I assume is a Certifiable Qualified Climatologist, possibly even a “highly respected and prestigious climatologist”, made the following statement:
“First of all, there are too many GCMs, and some of them are cr*p, so much so that they should simply be thrown away.”
in this post at his Stoat blog:
This is not the kind of statement that adds to the scientific creditably of the Climate Change Community. The numbers calculated by the GCMs appear frequently in the IPCC reports. Are we to now assume that the reported numbers are also cr*p? Are all the numbers and nice color graphs in all the reports over the years not correct?
Connolley also states:
“There are 20+ coupled GCMs in IPCC, and we don’t need that many. I don’t know how many we need – certainly more than one.”
I understand that the ensemble approach to reporting climate response is based on the availability of numbers calculated by several GCMs. Based on this understanding I assumed that the required number of simulations by the various GCMs had been somehow scientifically determined. The above statement would seem to indicate that my assumption is very likely not correct. Hopefully, someone does in fact know how many are needed.
Based on the information provided above it would seem that the ensemble approach, and the numbers reported in all the IPCC reports, include cr*py results. Maybe the cr*p cancels out when the ensemble averages are taken. Can cr*p and non-cr*p average out to scientific results that lead to Scientific Consensus?
Models Methods Software 
“Can cr*p and non-cr*p average out to scientific results that lead to Scientific Consensus?”
Statistically speaking, only if it is independently distributed, unbiased cr*p.
My feeling is it fails that test.