I think the narrow issue of multi-proxy studies teaches an interesting lesson to folks who like to think of things in terms of Bayesian probabilities.
I would submit that at a bare minimum, any multi-proxy study (such as the one you cite) needs to provide clear inclusion and exclusion criteria for the proxies which are used and not used.
Let’s suppose that there is a universe of 300 possible temperature proxies which can be used and Michael Mann chooses 30 for his paper. If he does not explain to us how he chose those 30, then how can anyone have any confidence in his results?
I haven’t read the paper myself, but here’s what the infamous Steve McIntyre says:
I identified 33 non-tree ring proxies with that started on or before 1000 – many, perhaps even most, of these proxies are new to the recon world. How were these particular proxies selected? How many proxies were screened prior to establishing this network? Mann didn’t say
I think the narrow issue of multi-proxy studies teaches an interesting lesson to folks who like to think of things in terms of Bayesian probabilities.
I would submit that at a bare minimum, any multi-proxy study (such as the one you cite) needs to provide clear inclusion and exclusion criteria for the proxies which are used and not used.
Let’s suppose that there is a universe of 300 possible temperature proxies which can be used and Michael Mann chooses 30 for his paper. If he does not explain to us how he chose those 30, then how can anyone have any confidence in his results?
I haven’t read the paper myself, but here’s what the infamous Steve McIntyre says: