Results/Conclusions At least three different types of problems constrain models estimating climate change driven extinction risk. First, the distinction between a species fundamental and realized niche is a chronic problem for distribution modeling. Species distribution models must assume that the actual distribution reflects environmental constraints on potential distribution, and this is simply not likely the case for many narrowly distributed, and hence, vulnerable species. Biotic interactions and dispersal limitation can play a strong role in species distributions and are rarely incorporated into species models. Cases where there is a clear physiological range limit mechanism remain the exception, not the norm. Second, the mechanics of species distribution modeling remains problematic. Broadly distributed species often model poorly because of habitat generality. In contrast, narrowly distributed species may return high model fit, but often suffer from a lack of power to adequately capture the entirety of a species' niche. Finally, climate change is occurring against a backdrop of numerous other environmental changes that may impact species responses, and within the context of natural selection and the capacity for species to alter their relationship to climate. Emerging studies have demonstrated remarkable capacity for rapid response and unpredictable synergies amongst covarying environmental change.