MarkH has made a case study of Alexander Cockburn’s crankish nonsense on global warming, but there is a bit left over for me to comment on. Cockburn’s main scientific authority is some guy he met on a cruise who worked as a meteorologist for a whole three years, but he does quote on other person on the science. Look:

As Richard Kerr, Science magazine’s man on global warming remarked, “Climate modelers have been ‘cheating’ for so long it’s become almost respectable.”

It takes a few seconds to find the source of the quote. You need a subscription to read the whole article, but the bit you get for free is enough to tell you that one doing the cheating is Cockburn:

Climate Change: Model Gets It Right–Without Fudge Factors
Science 16 May 1997: 1041

To keep their computer models from drifting off into climates quite unlike today’s, climate modelers have gotten in the habit of fiddling with fudge factors, arbitrary “flux adjustments.” But now researchers at the National Center for Atmospheric Research in Boulder, Colorado, have developed a model that gets it right without flux adjustments. The first results from this model imply that future greenhouse warming may be milder than some other models have suggested–and may take decades to reveal itself.

So Kerr’s article tells you that ten years ago modelers stopped ‘cheating’, but Cockburn rips a quote out of context to make it look as if they were still doing it.

Here’s the quote in context:

Climate modelers have been “cheating” for so long it’s almost become respectable. The problem has been that no computer model could reliably simulate the present climate. Even the best simulations of the behavior of the atmosphere, ocean, sea ice, and land surface drift off into a climate quite unlike today’s as they run for centuries. So climate modelers have gotten in the habit of fiddling with fudge factors, so-called “flux adjustments,” until the model gets it right.

No one liked this practice (Science, 9 September 1994, p. 1528). “If you can’t simulate the present without arbitrary adjustments, you have to worry,” says meteorologist and modeler David Randall of Colorado State University (CSU) in Fort Collins. But now there’s a promising alternative. Thirty researchers at the National Center for Atmospheric Research (NCAR) in Boulder, Colorado, have developed the first complete model that can simulate the present climate as well as other models do, but without flux adjustments. The new NCAR model, says Randall, “is an important step toward removing some of the uneasiness people have about trusting these models to make predictions of future climate” (see main text).

The NCAR modelers built a host of refinements into their new Climate System Model (CSM). But the key development, says CSM co-chair Byron Boville, was finding a better way to incorporate the effects of ocean eddies, swirling pools of water up to a couple of hundred kilometers across that spin off strong currents. Climate researchers have long known that the eddies, like atmospheric storms, help shape climate by moving heat around the planet. But modelers have had a tough time incorporating them into their simulations because they are too small to show up on the current models’ coarse geographic grid. The CSM doesn’t have a finer mesh, but it does include a new “parameterization” that passes the effects of these unseen eddies onto larger model scales, using a more realistic means of mixing heat through the ocean than any earlier model did, says Boville.

Even when run for 300 model “years,” the CSM doesn’t drift away from a reasonably realistic climate, says NCAR’s Climate and Global Dynamics director Maurice Blackmon. “Being able to do this without flux corrections gives you more credibility,” he says. “For better or worse, we’re not biasing the results as was necessary before.”


  1. #1 Zeno
    June 2, 2007

    In a previous life, before I got my faculty appointment, I spent a few years in an agency that computed revenue and expenditure forecasts for the state of California. We used a system based on an econometric model created by the UCLA Business Forecasting Project (if I remember the name correctly). My fellow civil servants were responsible for tweaking and adjusting the model before we published our periodic forecasts. I recall that the adjustments were called “add factors” rather than “fudge factors”, but the idea was the same. Forecasting was an odd mix of science and art, the deterministic econometric model able to go only so far, after which the experienced forecasters fiddled with the “add factor” knobs on the model to get it to “fit better”. The add factors weren’t purely arbitrary, but there was always an element of educated guesswork in selecting them. I doubt that econometric forecasting will ever be able to do entirely without them, but that’s not my area of expertise.

  2. #2 Alex
    June 3, 2007

    Cockburn has always been a fact-lite crank, but the important difference here is that he has now begun to be crankish and fact-lite about an issue his staple audience cares about.

  3. #3 ajit
    June 7, 2007

    He is just on an ego trip…He is pretty good on every other subject.

  4. #4 Munin
    June 12, 2007

    George Monbiot rips into Cockburn’s Counterpunch articles on his website.

    The rest of the “debate” (more of an artillery exchange) is archived here.