To be a scientific fraud, they'd need to be aware they lying. Having seen theoretical physics spend 40 years getting nowhere because they were all doing string theory and telling each other it would solve all the open problems, when, in fact, it never yielded a testable prediction and was only useful to get rid of some double counting in Feynman diagrams, I am inclined toward applying Hanlon's razor and holding that the climatologists have fallen into the same form of stupidity as the physicists: they all do the same thing (build models based on the assumption that the primary driver of global temperature is greenhouse gas concentrations), all try to make everything fit their theory, ignore any competing theories, the same way the physicists did with string theory.
Of course, string theory didn't interact with politics by giving the Left an excuse to seize control of the energy economy. If some faction in government had a vested interest in string theory, the way the Left has a vested interest in anthropogenic global warming, the physicists would still all be doing it.
