On today’s episode:
Science and skeptical bloggers A small article in last week’s Science magazine frets that skeptical bloggers are teasing climate scientists over their failed predictions. Bloggers are pointing out that actual temperatures have not been friendly to climatologists, and have failed to rise as predicted. Some climate scientists respond by effectively saying: have no fear, warming is on its way—and this time we mean it!
Climate forecast failures? Since 1999, most climate model predictions have been too high by a factor of about 3. Plus, actual temperatures have been decreasing, or at least not increasing. Yet the belief in the accuracy of future forecasts—all of which predict yet more warming—have not abated. Why is this? Why, that is, do scientists believe the opposite of the evidence and is it rational to do so?
Polka! Grab a beer and listen to Yosh and Stan Schmenge sing “Cabbage Rolls and Coffee”. Yum; or, rather, Mmm, Mmm, good. This is the rare live version! My first meal out was cabbage rolls—at Sanders (pronounced saw-n-ders) on Michigan Avenue in Dearborn (Sanders disappeared for a while, but are back, incidentally).
Evidence, Faith, and Belief To be useful, all models—climate, physics, statistics, whatever—must explain, or fit, previously observed data. Fitting that old data is always the first goal of the model-building process, but it is, or should be, far from the last. Climate models do fit, in a statistical sense, old temperature data.
But that old temperature data is sparse before about thirty years ago, and from heterogeneous sources before that, and some of it is even guessed at. There should be, therefore, but is not, tremendous uncertainty that the climate models have reproduced that old data faithfully. No climate model actually predicts past temperatures exactly; they only do so statistically, by simulating climates that “look like” the old data.
Explaining old data is a necessary but not sufficient condition for a model to be valid. To meet that standard, they must also predict new data accurately. So far, climate models have failed in this. Yet the powerful belief that is induced by a model happening to fit old data is almost overwhelming. The model fits, its owners say to themselves, so therefore it is valid. It also helps to know that nearly all statistical procedures—like the kind that are used to verify climate models’ performance—are designed to give measures of how well models fit old data. Overconfidence is an all too common result.
Climate models are built with the assumption that carbon dioxide is important, but only when it operates with a positive feedback mechanism. The truth of this is asserted and the models are built and tweaked, twisted, and tuned so that they fit old data well. Forecasts are then made, which invariably pronounce warming is on its way. And this forecasted warming is—incorrectly!—taken as evidence that the carbon-positive-feedback process is true. Again, this overconfidence stems from enjoying too much the co-incidence of the models fitting (statistically) the old data.
What needs to be done is this: a fully-funded, fully-dedicated team, skeptical of the carbon-positive-feedback process builds, tweaks and tunes, a climate model that does not contain this process. Forecasts from this model are made, and then compared with actual new data and with the forecasts from the standard climate models. (I realize this description is too brief, and even partly unfair—listen to the podcast for more.)
Glenn Beck-John Coleman call global warming a scam Coleman believes that climate scientists are forced to conform to the consensus and are engaged in a “scam.” I do not agree; “scam” is far too strong a word. It might apply to some, but it does not apply to the bulk of climate scientists. I know many of these people and I can assure you that they are not actively engaged in trying to fool the world into believing something that they themselves do not also believe. Using such an inflammatory word makes your enemies shut up their ears and rightly dismiss you as cranky, if not worse.
Nothing makes a scientist’s career faster than proving something that others either did not know or believed to be false. If a young scientist could prove that the carbon-positive-feedback process is false, he would be sitting pretty. But understand: climate models are enormous undertakings, dozens to hundreds of people working on them, building them through multiple years of effort. Vast sums are efforts are involved and no one person can play more than a small part in the process. Therefore, it is almost impossible for one person to go his own way; further, because of the sheer complexity, it is likely that everybody involved will tend to believe the same things. This is why there is a rough consensus of climate model workers.
And this explains why independent people, like your author, are the skeptics.
Polka again I found the outro song on YouTube, but I am unable to rediscover its source.