Tamino on the Hockey Stick Illusion
Jul 22, 2010
Bishop Hill in Climate: HSI

Tamino has a rave review of the Hockey Stick Illusion up at Real Climate. I'm reading it now.

A few initial observations - there is a lot of discussion of proxy selection rules in Tamino's piece. This is complex for those who aren't embedded in the nitty gritty of the science, but stand back and ask yourself this: if you have over 100 series in your database, and one of these is the fourth most important pattern in the tree rings of a couple of closely related tree species in one area of the western USA, how comfortable are you that this series should form the basis of the temperature reconstruction for the northern hemisphere? The idea that you can reconstruct hemispheric temperatures in this way is deeply unsatisfactory.

Tamino doesn't try to defend the use of the bristlecones. It's not clear why it's worth arguing about PC retention if everyone (including the NAS and Wegman panels) agrees that bristlecones are inappropriate.

The observation that "McIntyre argued that the entire Gaspe series should be eliminated because it didn't extend all the way back to 1400" is wrong. MBH had its steps starting at 50-year intervals. Gaspe should therefore have been in the 1450 step not the 1400 one. There is probably an argument that Gaspe should be excluded because the update that was taken didn't show the same shape (although it was never published and everyone seems to have subsequently forgotten where the actual location of the trees is).

There's a lot of discussion of reconstructions being hockey stick shaped. The critical issue is of course the relative warmth of the medieval and modern periods.

Remembering Matt Ridley's article about straw men? I am criticised for complaining that hockey stick shape proxies dominate reconstructions and apparently I imply "unfairly" so. I explain how the hockey stick shaped series come to dominate the reconstruction, but I don't imply unfairness as far as I remember. Of course, since Tamino doesn't actually quote anything I said that implies unfairness, it's hard to respond in a precise way.

I'm accused of quote mining re the "better for our purposes" quote. Given that I start by saying that an innocent explanation is possible, I'm not sure this is reasonable criticism. I don't think it's a "killer quote" but it was there and McIntyre raised it in his correspondence with Nature, so it needed to be discussed.

There are very few quotes of any kind from the book (go figure), but certainly some I'd like to use on the cover of the next printing:

"A narrative worthy of the best spy thrillers"

"...spins a tale of suspense, conflict and lively action, intertwining conspiracy and covert skullduggery, politics and big money".

My publisher is going to love it.

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