Read here. This article by Dr. Hoffman is not an easy read due to the inherent complexity of the subject. With that said, we'll boil it down to the essentials: the climate is a chaotic and dynamic system, which the mathematical techniques used in climate models are incapable of producing with reliable precision. The climate models can produce a simulated result but the likelihood of their being correct is tiny due a known mathematical concept of "irreducible imprecision." And, it can't be fixed or avoided.
"Given the state of GCM and available computer resources, valid predictions of climate changes of these magnitudes simply cannot be accurately calculated. This is not a mater of opinion, it is a statement of fact based in mathematical analysis of climate models by multiple scholars. To base the future of the world's economy and possibly the course of human civilization on climate model predictions is insanity."
Do climate scientists agree with the math scholars? From a recent survey of climate scientists there is this:
"However, the Bray and von Storch survey also reveals that very few of these scientists trust climate models — which form the basis of claims that human activity could have a dangerous effect on the global climate. Fewer than 3 or 4 percent said they “strongly agree” that computer models produce reliable predictions of future temperatures, precipitation, or other weather events."
