Climate change crystal ball clouds over

The IPCC report has miserably failed both.

The one point we shall concentrate on here is the paper’s assertion that experts don’t matter much in unaided forecasting in their area of expertise. The paper cites several studies which deal largely with marketing and business in which experts fare no better in making forecasts concerning events in their field of expertise than non-exerts. In other words, their expertise counted for little in trying to forecast what would happen in their own fields.

As noted the surveys mainly concern marketing and business and pro-greenhouses may derive some comfort from that. They may declare that this time, because scientists are involved, it is different. Well, is it different? The paper points to individual examples of scientists making forecasts that turned out to be completely wrong - Einstein declaring that atomic energy is impossible and so on.

The classic, if rather dated, example not given in the paper is that of Lord Kelvin, a famous 19th century scientist who was mostly wrong in every pronouncement he every made about possible technological advancements.

A more recent example of how scientists can be collectively wrong, just like all other kinds of experts, is the medical profession’s collective insistence that viruses do not cause peptic ulcers - a point that doctors clung to, and note, clung to collectively for many years - in the face of pioneering work by two Australian scientists Robin Warren and Barry Marshall. The medical profession had earlier decided that stress and spicy food caused such ulcers. The scientific process eventually overcame the medical profession’s conservatism.

In other words there is no reason to believe that because a group of scientists collectively insist that they are right, that we should believe them - particularly when it comes to forecasts.

Armstrong and Green also note that the tendency of experts to be wrong is made worse, if they are working together or heed each other‘s work. The initial assumptions become dogma and difficult to overturn.

Nor are they alone in belitting the role of experts in forecasts. The point is made repeatedly in the book Megamistakes: Forecasting and the Myth of Rapid Technological Change, by Steven P.Schnaars published in 1989 but still the last word on the confident area of forecasting of the 1960s and 1970s. (The IPCC forecasts are, in essence, a throw back to that era.) As well as noting that forecasts by experts in certain fields seldom seemed to do better than lay people, Schnaars points out that conservative forecasts seemed to work best. That is, the forecasts are for little or no change in the system under study. This point is echoed by Armstrong and Green.

There may always be exceptions where the experts are right, and there are no other large scale predictive efforts by scientists on which to make a comparison, but there is very little in the panel’s output which gives independent observers any confidence. As noted, the IPCC has miserably failed at least two independent reviews of aspects of its work and, in any case, it freely admits that it does not know much about the bulk of the variables which it includes in its models. (See the table on page 4 of Climate Change 2007: The Physical Science Basis, Summary for policymakers (PDF 1.25MB). The relevant page is 16 in earlier versions.) 

Other arguments often put forward when the IPCC idols are shown to have feet of clay is that first, the risk is too great that they may be right, and second, that if we leave the decision making any longer it will be too late. The first part of that counter argument involves risk analysis which is a different discipline altogether and assumes that we know enough to assess risk properly. This is doubtful. The second objection naturally raises the question of too late for what? Are we going to have global cooling or global warming? As by now should be abundantly clear, forecasting is not about wishful thinking and it’s not about politics.

Waving a bunch of computers at a set of bad assumptions will not turn them into good forecasts, but the result can be bad policy.