Simulating the South Asian Monsoon: A Revealing Status Update
Islam, S., Tang, Y. and Jackson P.L. 2013. Asian monsoon simulations by Community Climate Models CAM4 and CCSM4. Climate Dynamics 41: 2617-2642.
In the words of the three Canadian researchers, but with italics added, "both  CAM4 and  CAM5 poorly simulate the ENSO-monsoon teleconnection," while "over the SAM region their simulations show significant large-scale biases such as  excessive precipitation over the Arabian bay and  over the Western Ghats of India, and  reduced precipitation over the eastern Indian Ocean extending into the Bay of Bengal." In addition, they say  "CCSM4 underestimated the precipitation over the equatorial area in the Pacific Ocean," and  it "still has the double ITCZ [Intertropical Convergence Zone] problem that was also present in the previous versions of the CCSM model." Furthermore, they write  "CCSM4 showed a systematic cold bias in the simulation of SSTs over the tropical Pacific Ocean" and it  "showed problems in simulating the observed SST-precipitation relationship." And they state, last of all,  "significant cold biases over the equatorial Pacific Ocean are found in CCSM4, particularly in winter and early summer."
When all was said and done, therefore, Islam et al. acknowledge, in spite of some significant improvements over earlier versions of the three models they had studied, "many biases are still present" and the latest versions of the models "still have simulation errors that need further consideration," which facts reveal the models' still have much to improve on.