AGU Meeting

[Climate Audit was started on Jan 31, 2005. Prior to its startup I had some notes at a prior website, which John A transferred to the CA blog at its start-up.]

The AGU conference is unbelievably big. I’m told there were over 10,000 people there. The printed program is 512 pages long and for individual papers only lists authors and titles. I was surprised how little attention was paid to climate in the last 1000 years.

Climate in the past 3 million or 30 million years was a big topic, with many presentations from ODP drilling. There were several presentations on the climate effect of the closure of the Panama Seaway (due to plate tectonics). Impressionistically, the plate tectonics people tend to date this about 4 MM years ago and the ODP climate people about 2.8-3 MM years ago. The closure ended Pacific waters moving into the North Atlantic and bringing heat to the Arctic and initiated a long-term cooling through the Pliocene and Pleistocene. The warming in the Holocene (10000-12000 years), including modern warming, is still well short of the Pliocene warm period. The Pliocene is not dinosaur vintage, but is getting to a recognizably modern configuration. But once the Panama Seaway closed, ocean currents had to re-arrange themselves and ultimately the modern Conveyor Belt was established, in which warm waters now come around the Cape of Good Hope. The re-arrangement is a big job, when you think of it. One of Nof’s students presented a poster arguing that one of the big changes in the Holocene has been the opening of the Bering Strait, which even though is very shallow, de-bottlenecks Arctic water.

Bob Carter showed me some very interesting material from his ODP drilling on the east New Zealand offshore. This is the main entry point for cold Antarctic waters into the Pacific – there are surprisingly few entry points. Bob has found that there are fluctuations at all scales – in fact, his data would indicate that changes of 0.8 deg C in a century are pretty much the norm for millions of years and lesser changes (the premise of the hockey stick) would seem to be the exception.

My poster session was on the Friday afternoon and I was reasonably busy. I talked to about 40-50 people. I had visited the poster session for Nonlinear Methods and quite a few of these mathematically oriented people reciprocated. They got the point of the principal components argument almost immediately and you could almost see them laughing at the punchline. I had printed off the computer program from Mann’s FTP site and highlighted the 4 lines that contain the programming error.

People who were not mathematically inclined were intrigued by a graphic showing 8 hockeysticks – 7 simulated and 1 MBH (the same sort of graphic as the one put up here a while ago, but just showing 1 simulation.) Quantity seems to matter in the demonstration. No one could tell the difference without being told. I’ll insert this graphic here in a day or two.

Again, I was surprised how little was on recent climate. There was very little representation from tree ring people. Casper Amman had a presentation describing his emulation of MBH98; he is planning to web up R code, which should be interesting. He outlined many issues pertaining to problems in emulating MBH98 – most of which will be familiar to any followers of our work, but conspicuously made no reference to our efforts. He said that he could emulate MBH98 results, but made no reference to principal components calculations or such esoterica as the MBH98 editing of the Gaspé series. (I’m still trying to get the new data from Jacoby et al., who say that the old data is more “temperature sensitive” and should be used in preference to the new data, which they refuse to archive. LOL)


  1. TCO
    Posted Aug 7, 2005 at 12:50 PM | Permalink

    I would avoid the use of MM as an abreviation. Some people don’t kno it means 10^6. Also you already have MM as an abbreviation for authors. For similar reasons billion can be confusing accross continetnts and one should write out the number.

  2. Steve Sadlov
    Posted Sep 7, 2006 at 7:41 PM | Permalink

    Interesting, when I brought the tectonics stuff, especially the Panama closure, up at RC, a few months ago, they reacted as if I was some high school drop out red neck who learned everything I know from the web. I really think this topic needs more air time, in general. I first encountered it in a Marine Geology course during the early 1980s.

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