I don't think that's an accurate description of what he's saying -- he's made a point several times (e.g. [0][1]) of challenging the models, not the underlying science, comparing them to economic models, which he feels, having majored in economics (and having studied and built his own [1]) are not reliable. One may disagree with him about models and modeling, but I think it's helpful to understand what he's actually saying.
I'm putting an excerpt here from a recent blog post [0] he did which I think demonstrates my summary above to be a truer understanding of where he's coming from:
I’m not a scientist, but it seems to me that the chemistry and physics parts of climate science are probably pretty locked down. I give that stuff full credibility.
The measurements of temperature, ice, and sea levels over time are probably fairly good, but I observe disagreements among scientists on how best to measure. I’ll give the measurements an 85% credibility.
When it comes to the complex climate models, I’ve never seen a complex, iterative model – of the type that includes human assumptions and human measurements – reliably predict the future multiple years out. I don’t think it has ever been done, and perhaps it never will be. I give the complex climate models a 10% credibility rating. And I am only that generous because perhaps this is the exception to the pattern I observe that says complexity always hides the future, as opposed to predicting it.
BTW, I think the next paragraph, where he describes the psychological aspects of how people evaluate things when they don't have deep expertise or knowledge is interesting and possibly useful for understanding how to get through to people (Adams' blogs a lot about persuasion/psychology and how so often that is more important than facts in shaping people's views of things):
This is a good time to remind you that I have neither the qualifications nor the time to evaluate the climate science models on my own. So I’m stuck with using pattern recognition – which is not science, and it is not reason. And my pattern recognizer says humans use complexity of this sort to hide the truth, not to reveal it. If scientists want to change my mind, they need to show me historical examples in which things “like this” did a good job of predicting the future. You have to work on my pattern memory to change my mind, not my knowledge of climate science.
Again, you may disagree with him about models and modelling, but he's identified why some intelligent people, who are not science-deniers, may have issues with some aspects of climate-science.
[0] http://blog.dilbert.com/post/158778029326/how-to-change-my-b...
[1] http://blog.dilbert.com/post/158549646496/how-leonardo-dicap...