Paper Reviewed
Zhao, L., Xu, J., Powell Jr., A.F. and Jiang, Z. 2015. Uncertainties of the global-to-regional temperature and precipitation simulations in CMIP5 models for past and future 100 years. Theoretical and Applied Climatology 122: 259-270.

As reported by Zhao et al. (2015), the four authors of this important paper examined global-to-regional surface temperature and precipitation trends of the past 100 years, as both measured and hindcast by historical simulations of CMIP5 climate models. And what did their analyses reveal by so doing?

For starters, Zhao et al. report that (1) the model historical simulations have large uncertainties in their geographic distributions, especially over the Arctic, Antarctic and other high north latitudes such as Russia, that (2) this spread increased as the climate warmed, creating (3) an even more striking inconsistency among the models, such that compared to observations, (4) most of the models underestimate precipitation on both global and sub-region scales, that (5) there are striking spread differences for regional and sub-regional trends," such that (6) "regional-scale atmospheric processes and the distribution of the impacts need improvement."

In light of these several observations, Zhao et al. thus conclude by posing an important question: "If the models cannot reasonably simulate the historical and present conditions, how much can we trust their future climate projections?" Very little would appear to be a reasonable answer.