Aug 122008

A recent paper in climate science that has excited comment is D. Koutsoyiannis, A. Efstratiadis, N. Mamassis and A Christofides, On the Credibility of Climate Predic­tions, Hydrological Sciences Journal, 53 (2008). It is available in .pdf format here. The abstract reads:

Geographically distributed predictions of future climate, obtained through climate models, are widely used in hydrology and many other disciplines, typically without assessing their reliability. Here we compare the output of various models to temper­ature and precipi­tation observations from eight stations with long (over 100 years) records from around the globe. The results show that models perform poorly, even at a climatic (30-year) scale. Thus local model projections cannot be credible, whereas a common argument that models can perform better at larger spatial scales is unsupported.

The paper argues that Global Climate Models have underestimated the observed varia­bility of both temper­ature and precipi­tation for these particular stations. The authors acknowledge the limitation of having analysed records from only eight stations: “Whether or not this conclusion extends to other locations requires expansion of the study, which we have planned.” But they contend that the poor performance in the examined locations “allows little hope.” It is interesting that one of these stations is just down the road in Albany, NY, where the change in the 30-year moving average for temperature over the 20th century is roughly -1.5°(C), compared to model predictions of roughly +0.5°(C).

There are active discussions of the Koutsoyiannis paper on both the skeptic site, Climate­Audit, and the consensus site, Real­Climate. I have my own take on these discussions, including a tremendous respect for Steve McIntyre, the author of Climate­Audit. But I am mainly interested in the question of the disinter­estedness of science. Is such disinterestedness even possible any more? Is it worth safeguarding?

  3 Responses to “Koutsoyiannis et al 2008”

  1. Hi Paul, I saw your trackback on the CA discussion.

    I personally feel that we should separate two distinct arenas in these AGW discussions. On one level, we have the high-level, more intellectual and scientific discussions – which in this situation unfolded between Gavin Schmidt, Steve McIntyre, and Dmitri Koutsoyiannis. It may not have been a back-and-forth dialogue, but I think their point-counterpoint blog postings illustrate a more sophisticated level of discussion. It’s very possible that there are intrinsic political bends guiding these discussions, but the players are extremely good at maintaining objectivity and an academic rigor. Sure, the occasional ad hom drops in, but it’s nothing compared to another arena.

    Unfortunately, there exists a much lower arena of discussion, which we see in the comments at CA and to some extent RC. If anywhere there is a palpable political influence occurring, it’s in the comments regularly posted on climate change blogs. For the most part, these partakers are not scientists, but individuals with a vested political interest for or against the science. Their arguments are characterized by a lack of cohesiveness, little logical connection, and an utter vehemence for the opposition. Nothing constructive comes out of these discussions, which is why I’ve significantly lowered my activity commenting on blogs in favor of slowly authoring my own blog where I can be less influenced by passion for the subject.

    I too am sad that discussions have taken this turn for the worst. Unfortunately, it will only get worse. Opponents and proponents have firmly dug in their heels. I’d argue that the AGW-proponents do a better job at remaining objective, and that it’s the opponents who are playing pathetic political cards and using antagonizing tactics, but it is happening on both sides and will likely continue to happen for quite some time. Ultimately, it is inevitable that we move to a higher-efficiency, more conservation-minded economy, and once those changes occur and the AGW-opponents realize that it hasn’t crumbled Western society under unbearable taxes, the issue might resolve.

  2. I can’t reference the source right now since I can’t find the book, but I seem to recall Lorenz determining that weather prediction over the long term was nearly impossible, and even a relatively short-term prediction was apt to be inaccurate. When he was perfroming weather models on an early computer in the 60′s, he discovered so-called Sensitive Dependence on Initial Conditions, where infinitesimal changes in original input data caused massive changes in long term results. I would have thought that with the advent of chaos theory, long-term weather prediction would have been doomed.

    I know that’s not really what you’re asking here, but I wanted to provide a background to my thoughts. While I don’t have the scientific knowledge to evaluate the discussions (although quickly browsing through I could easily tell which was the more negative or positive with regards to the paper), it seems to me that at this point, I would say that disinterestedness is no longer possible.

    If we take there to be two sides: the side that does not believe global warming is an issue and the side that believes it is (or better yet, replace global warming with climate change), then those who believe climate change is an issue will assume that it is a “topic of vital importance” and will believe that there is ultimately a negative consequence for the world if such climate change is not averted or dealt with in some manner. On the other hand, there are those who believe that climate change is not an issue, and therefore we need not do anything. However, these scientists are often hired by corporations, in whose interest it is (assuming they believe that climate change is not an issue) to propagate the idea that climate change is not an issue, as this will save them a great deal of money which they would otherwise need to spend in order to bring their businesses in line with the requirements of those who think climate change is an issue (emissions standards, etc).

    What I believe it comes down to is that to everyone, for whatever reason (be it paycheck or survival of our species in the long term) this has become an issue that is no longer subject to the ideal of scientific detachedness and potentially rationality. I believe this is what you were getting at in your discussion of Peirce.

    As far as the safeguarding of the disinterestedness of science is concerned, I think it would be desirable in an ideal world, but in the world we live in, it is ultimately a lost cause to try and safeguard such a thing. Only when results are (relatively) unimportant, can disinterestedness and detachment be expected. As soon as a significant number of people take interest however, factions will inevitably form. I suspect that this will be the case until AI’s are developed which rely on logic alone.

  3. Here’s what I noticed: RC’s Gavin Schmidt offered a detailed and compelling critique of the paper. CA’s Steve McIntyre barely commented, and the discussion that followed was unfocused, and contained several ad hominem attacks on RC and the mainstream consensus (e.g. a reference to “book burning”).

    The analysis of gridcell “predictions” (a misnomer) instead of downscaled regional projections renders the DK paper all but irrevelant in my view.

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