Will IPCC climate models make accurate predictions?

The question "Will IPCC climate models make accurate predictions?" is based upon a false premise. This premise is that the IPCC models make predictions.

The IPCC does not claim that its models make predictions. What it claims is that they make "projections" ( see http://icecap.us/images/uploads/SPINNING_THE_CLIMATE08.pdf ). There is a significant difference between the two.

An IPCC "projection" is a mathematical function that maps the time to the computed average global temperature. A "prediction" is a proposition that states the outcome of a statistical event.

A model that makes predictions is falsifiable, thus lying within science under Karl Popper's criterion for differentiation of scientific from non-scientific models. A model that makes only projections is not falsifiable, thus lying outside science. It follows that the IPCC's advice to the world's policy makers lacks a basis in science.

The IPCC's 2007 report contains a description of the scientific method of inquiry together with the implication that the IPCC follows this method. This implication, however, is false.

Interesting quote from Roy Spencer: "....[The IPCC should] have put just as much work into model formulations that predicted very little warming. If those models could not be made to act as realistically as those that do produce a lot of warming, then their arguments would carry more weight."

At least he's admitting models are in principle useful! But his suggestion is odd, when you consider that additionally constraining a model to output a desired result can only make it harder for that model to act realistically (i.e. in accordance with all known observations). Essentially he's suggesting that some modelers should assume a future result as part of the input to the model. But isn't that exactly what he's against? It would suggest that modelers should pick and choose elements in the model on the basis of whether it caused a particular metric of the output (i.e. Global Temperature) to be a particular value. But that's backwards. You don't want to assume your hypothesis in the evaluation of whether to accept or reject each element in the model. Roy Spencer is concerned - and that's a good thing - that modelers have an implicit systemic bias in favor of AGW, but his suggestion to build a model that introduces an explicit systemic bias against AGW won't prove anything other than if you're biased you can prove anything.

I agree with Roy Spencer that auditing models for any bias that would favor warming is worthwhile, but I don't think that anyone following Roy Spencer's scientific philosophy will contribute anything useful to this. This comment in his article, which early on advises his readers of the importance to "stick to science rather than hyperbole" reveals why:

"As a result of all this uncertainty, the IPCC starts talking in meaningless probabilistic language that must make many professional statisticians cringe. These statements are nothing more than pseudo-scientific ways of making their faith in the models sound more objective, and less subjective"

Please. Probabilistic language is exactly what we need to make sense of such assessments.

Interesting background on the peer-review process for Patrick Frank's article "A Climate of Belief" published in Skeptic magazine, run by Michael Shermer:

Pat Frank says here:

"Michael Shermer then sent [my article] to two further climate scientists of his choice. I was required to respond in detail to their critical comments, and did so. I can tell you as a well-published scientist myself and as an experienced reviewer, that the article went through a very valid peer-review"

Yet, this is what one of those climate scientists, Tapio Schneider, has to say here:

"In September 2007, Michael Shermer, the publisher of the magazine, sent me Frank’s submitted article (an earlier but essentially similar version thereof), asking me what I think of it. This was not a request to review it but an informal email among acquaintances. I pointed Shermer to some of the most glaring errors in Frank’s article. ... After pointing this and other errors and distortions out to Shermer–all of which are common conceptual errors of the sort repeatedly addressed on this site, with the presentation in Frank’s article just dressed up with numbers etc. to look more “scientific” – I had thought this was the last I had seen of this article. ... Indeed, I was surprised by the decision to publish it given the numerous errors."

If one is a firm believer in GIGO (garbage in, garbage out) and that, therefore, computer models are faulty, and specifically that computer models that predict a significant global warming in the 21st century due to humans are faulty, then it also follows that computer models are faulty for proving the opposite point of view: that there is no significant global warming or that humans contribute negligibly. In other words, one is in a "you cannot prove god exists, you cannot prove god does not exist" situation.

I thought I could do a simple search online for computer models that might offer a different prediction than the ones currently recognized internationally, which predict significant global warming caused by humans.

Every time I find any counter website, the website reveals its anti-socialist, pro-capitalism political bias. Moreover, they completely discredit themselves with their irrationality, because they never logically consistently apply the fact that - if computer models are faulty at predicting future - or even past - cause and effect - from some arbitrarily chosen initial condition - and computer models merely include the ideas we humans put into them, then it follows that humans - without the help of computers - are far LESS capable of logically consistently determining cause and effect with their single-variable mind and extremely limited ability to hold massive amounts of data in their memory, compared to a computer.