So says Science. But for the life of me I can’t see why. Hat tip: CB and (!) LM.

Its based on preliminary results from ACEX. Which says… drilling revealed that the latest Paleocene to earliest Eocene boundary interval, well known as the early Eocene Thermal Maximum (EETM), was recovered. During the EETM, the Arctic Ocean was subtropical with warm surface ocean temperatures. I’m not quite sure why this is supposed to be a problem for the modellers though.

Very few people run climate models back then; I don’t suppose the boundary condtions are known very well. So quite why the conclusion has climate modelers stumped I’m unsure. On the contrary, I would have though a bit of new data on what condtions were actually like then might be helpful.

Comments

  1. #1 Benjamin Harrison
    2006/06/05

    Perhaps one might consider it a reference, in some ways, to continuing confusion over the forcing of the PETM? Of course, what models appear to have been run on the subject were stymied, to a degree, prior to the presentation of these drilling results.

  2. #2 James Annan
    2006/06/05

    AIUI (BICBW) the models all struggle to reproduce such a strong polar warming without also having implausibly hot tropics (where there is also some data), for any boundary conditions. But of course these conditions are huge extrapolation beyond 2xCO2, and none of the data are particularly secure. Eg I read something recently about a tropical(ish) core where the authors didn’t even seem to know where the core location was, back when it was formed! Furthermore, different data analysis methods gave wildly different temperature estimates.

    Oh, here you go:

    http://groups.google.com/groups/search?hl=en&q=author%3Aannan+core+bice&qt_s=Search

  3. #3 Lubos Motl
    2006/06/07

    That’s a very good explanation, William. You’re not baffled because you would never have the idea to even think about the question. ;-) Very funny. Do you think that the physical laws were invalid 55 million years ago so that a disagreement is OK?

  4. OT about HuffPo. My cursory search found no way.

    You might email them and beg at the contact us tab.

    Or it could be like the Mafia. Once in, you’re in.

    You might try changing your name and moving to a third world country, or to an unihabited Arctic Island. I understand that beach front property of great potential value is opening up there all the time.

    Good luck!

  5. #5 TokyoTom
    2006/06/08

    Guys like Lubos will never be satisfied with modelling until you’ve essentially recreated the Earth and can play with it (speed it up, tinker with inputs, etc.).

    Unfortunately, we’ve only got one Earth, Lubos. Shall we keep on tinkering with it blindly until the modellers have finally created another Earth, to which we could then move after we’ve messed up the one we’ve got now? That would be dandy with me, but meanwhile there will be all of the changes in the meanwhile to deal with, and costs of moving house once the new Earth is ready.

    Even without a perfect model at present, aren’t we getting results that are robust enough to justify actions to mitigate possible serious negative developments?

  6. #6 Lubos Motl
    2006/06/09

    Of course that I can’t be satisfied with a climate model if it completely fails in a description of the situation 55 million years ago. Such a failure all but proves that the model is wrong and any approximate agreement of it with reality today is a pure coincidence. Eliminating conjectures and models that has been falsified is a main feature of what we call “science”, TokyoTom. But it’s probably too complicated a concept for you.

  7. #7 Eli Rabett
    2006/06/09

    Darling Lubos, would you care, for example, to point to a map of the world 55 million years ago, and if you can, how confident are you of its accuracy

  8. #8 Lubos Motl
    2006/06/10

    Sure. It’s essentially the fourth picture here:

    http://geology.com/pangea-continental-drift.gif

    I am 90% confident that the picture is more than 85% correct – by 85%, I mean the percentage of the surface of the Earth where the binary function “land or ocean” agrees in between the picture and reality.

    Have you heard of continental drift? We can obviously reconstruct 55 million into the past very well. Geologists actually try to reconstruct the continents as they were 2 billion years ago which is 40 times more than what you find “impossible”. Look at some supercontinents:

    http://en.wikipedia.org/wiki/Supercontinent
    http://en.wikipedia.org/wiki/Gondwana

  9. #9 Anonymous
    2006/06/11

    Eli – I hope I’m not interruption your conversation with Lubos, but here is a nice map of 50 mya. A less pretty one from 55 mya is here.

    I think we have a fair picture of the Earth about then. India had yet to collide with Asia and produce the Himalayas, much of Eastern Europe and Western Asia were underwater, the Atlantic was a smaller pond, and the Arctic Ocean was only connected to the rest of the Ocean by the narrow sea between Greenland and Scandanavia and the Turgai straight, but aside from that, not so dissimilar to the present.

  10. Eli – That anonymous comment was actually from me.

  11. #11 Eli Rabett
    2006/06/12

    Ah yes, Lubos the old sweetie is less than certain. Progress.

  12. #12 John Fleck
    2006/06/14

    William –

    Finally got around to reading the paper in question over the weekend. Here’s what it says:

    “palaeoclimate models simulating the early Palaeogene world with 2,000 p.p.m.v. of CO2 in the atmosphere[6]underestimate Arctic Ocean summer SSTs by at least 15 °C for the PETM and 10 °C for the surrounding late Palaeocene and early Eocene”

    and

    “The models consistently predict pole-to-Equator temperature gradients of 30 °C (ref. 29).”

    where:

    [6] Shellito, C. J. , Sloan, L. C. & Huber, M. Climate model sensitivity to atmospheric CO2 levels in the Early-Middle Paleogene. Palaeogeogr. Palaeoclimatol. Palaeoecol. 193, 113-123 (2003)

    and

    [29] Huber, M. , Sloan, L. C. & Shellito, C. J. in Causes and Consequences of Globally Warm Climates in the Early Palaeogene (eds Wing, S. L., Gingerich, P. D., Schmitz, B. & Thomas, E.) 25-47 (Geological Society of America Special Paper 369, Boulder, Colorado, 2003)

    [Ah, interesting. But how well are Arctic summer SSTs known? Not very, I would suspect… do they say? -W]

  13. #13 Meyrick Kirby
    2006/06/18

    Lubos, models tend to have different time scales in mind. Economic model that try to predict inflation, at best only go a few months ahead. Are you suggesting that central banks, who are very interested in inflation forecast, should just give up?

    I know theoretical physicists live in that nice neat world of universal laws, but the rest of us who live in the more fuzzy disciplines have accept that things are not totally universal (e.g. studies conducted on US markets don’t always translate well to other markets)

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