Climate exerts strong controls over almost all physical and ecological processes. In particular climate regulates ecosystem fluxes of energy and matter as well as the geomorphic and biogeochemical processes underlying the distribution and structure of ecosystems (Jacobson et al., 1997; Schlesinger, 1997; Bonan, 2002). Climate also regulates the frequency and intensity of disturbances (Swetnam and Betancourt 1998), and paces the rate at which species can invade a given area (Lyford et al. 2003, Gray et al. 2006). Ecologists and ecosystem managers must in turn possess a working knowledge of climate variability and the potential for future climatic change.