Here's the raw truth:
All the computer models are wrong. They have not only failed to predict the future, they can't even predict that past.
That is, when you run their software with the data from, say, the 1970s or 1980s, and project what should happen in the 1990s or 2000s, they project results that have absolutely nothing to do with the known climate data for those decades.
In other words, the models don't work. The only way to make them "work" is to take the known results and then fiddle with the software until it finally produces them. That's not how honest science is done.-- Orson Scott Card
You can read the whole thing here, and very good it is: