I think we can assume that climate scientists are aware of chaos theory, considering their field was one of the first to recognize the value in modeling things

I think we can assume that climate scientists are aware of chaos theory, considering their field was one of the first to recognize the value in modeling things as dynamic non-linear systems. While there are large error margins due to that non-linearity, literally all of our evidence (including causative models, e.g. grade school greenhouse science experiments) indicates bad things. Those may not come to pass, or they may not be human related -- nothing is certain -- but there's precious little evidence in the other direction. Outcomes may vary, you are right. Yet nearly all available evidence suggests we should accept AGW as the most likely situation, while accepting there may be other, more accurate predictions. We should change our behavior only once new evidence comes in indicating a different conclusion.