Lord of the (Tree) Rings

One of the issues in the Hockey Stick Graph climate debate is the reliability of ancient tree rings as temperature proxies. Noted Hockey Stick denier Steve McIntyre wants to make a bet, and James Annan, the original climate prediction bettor, has some details.

Via Backseat driving, I see that Steve McIntyre wants to bet over tree rings. His contention seems to be that they are a very limited or perhaps even useless indicator of temperature:

Do any of the warmers want to bet that European tree rings in the very warm year of 2003 did not show very wide rings such as predicted by the MBH assumption of a linear relationship between temperature and ring width?

Or that Sheep Mountain bristle ring widths in the period 1990-2005 were as wide or wider than projected by a linear model - we can define the model, but essentially it’s the linear assumption of MBH.

I’ll bet either.

Regular readers will be unsurprised that I consider this bet idea to be in principle a good one, although no doubt there's a debate to be had over the precise details. I don't know anything much myself about the reliability of tree rings as an indicator of temperature myself, and (especially given the confusion over the NAS definition of "plausible" etc) I would be very interested to find out the real opinions of the experts in the tree ring circus, as demonstrated by their willingness to put their money where their mouths are.

The comments on this post are as interesting as the post itself. My favourite includes this Eli Rabett Damon Runyon quote:

“‘Son,’ my father told me, ‘there will come a time when you are out in the world and you will meet a man who says he can make a jack of hearts spit cider into your ear. Son, even if this man has a brand-new deck of cards wrapped in cellophane, do not bet that man, because if you do, you will have a mighty wet ear.’”