AIG Article

The Australian Institute of Geoscientists News has published online my article “Reconstruction of past climate using series with red noise” on page 14. Many thanks to Louis Hissink the editor for the rapidity of this publication. It is actually a very interesting newsletter with articles on the IPCC, and a summary of the state of the hockey stick (or hokey stick). There are articles on the K-T boundary controversy and how to set up an exploration company.

Reconstructing the hokey stick with random data neatly illustrates the circular reasoning in a general context, showing the form of the hokey stick is essentially encoded in the assumptions and proceedures of the methodology. The fact that 20% of LTP series (or 40% if you count the inverted ones) correlate significantly with the temperature instrument record of the last 150 years illustrates that (1) 150 years is an inadequate constraint on possible models to base an extrapolation of over 1000 years, and (2) the propensity of analogs of natual series with LTP to exhibit ‘trendiness’ or apparent long runs that can be mistaken for real trends. And check back shortly for the code, I have been playing around with RE and R2 and trying some ideas suggested by blog readers to tighten things up.

With the hokey stick discredited from all angles, even within the paleo community itself with recent reconstructions of Esper and Moberg showing large variation in temperature over the last 1000 years, including temperatures on a par with the present day, one wonders why it is taking so long for the authors of the hokey stick to recant and admit natural climate variability. While the past variability of climate may or may not be important to the attribution debate, it is obviously important on the impacts side, as an indicator of the potential tolerances of most species.