Uh oh: Scientific American blogger on climate models: "currently it seems that the rate of inclusion of new factors is higher than the rate at which those factors can be accurately calculated or measured"

Are climate change models becoming more accurate and less reliable?

Including more real-life factors in the models does not mean that all those factors are well understood or tightly measured. You are inevitably introducing some known unknowns. Ill-understood factors will introduce more uncertainty. Well-understood factors will introduce less uncertainty. Ultimately the accuracy of the models will depend on the interplay between these two kinds of factors, and currently it seems that the rate of inclusion of new factors is higher than the rate at which those factors can be accurately calculated or measured.