I’m off camping for a few days and unlikely to post before Friday which will give me a chance to see some of our gorgeous avifauna (before it’s all roasted on the wing). That’s the good news. The downside is that I may well miss some very important developments in the climate change debate. A debate that I follow with great interest.
The hot topic is the New Hockey Stick. The old one was a potent symbol for the warmists, it was developed by Mann, it showed a very nice constant climate with a sudden upkick of temperature in the twentieth century, it was published by the IPCC, demolished by Steve McIntyre and it seemed to be carefully not mentioned by the warmists for a while.
The new version emanates from Marcott, Shakun, Clark and Mix in a paper published in Science. The reaction from the popular press was dramatic. Essential reading for anyone interested is We’re screwed: 11,000 years worth of climate data prove it.
Marcott is quoted in the article … “I’m curious to see how the skeptics are going to take this paper.”
Some of the smart deniers have had a good look at the science. It seems very shaky. Even more interesting is that this work is the culmination of Marcott’s PhD. In the PhD thesis we have this graph …
Steve McIntyre, patron saint of the anti-hockey stick league, has been scrutinising the underlying data and the methods of torture it has been subjected to.
I will give you the link shortly, but first you will need to know that …
Alkenones are highly resistant organic compounds (ketones) produced by phytoplankton of the class Prymnesiophyceae.
Coccolithophoroids, for instance Emiliania huxleyi, respond to changes in water temperature by altering the production of long-chain unsaturated alkenones in the structure of their cell. At higher temperatures, more of the di-unsaturated molecules are produced than tri-unsaturated [Prahl and Wakeham]. The molecules are resistant to diagenesis, and can be recovered from sediments up to 110 million years old.
The ambient water temperature in which the organisms dwelt can be estimated from ratio of their unsaturated alkenones (C37–C39) that are preserved in marine sediments.
Which makes them useful proxies for temperature. But as well as reflecting temperature a useful proxy must also be accurately dated. If you were to choose your proxies carefully and fiddle with their dates you could get any result you wanted … even a hockey stick.