Guidelines for constructing climate scenarios

Scientists and others from academia, government, and the private sector increasingly are using climate model outputs in research and decision support. For the most recent assessment report of the Intergovernmental Panel on Climate Change, 18 global modeling centers contributed outputs from hundreds of simulations, coordinated through the Coupled Model Intercomparison Project Phase 3 (CMIP3), to the archive at the Program for Climate Model Diagnostics and Intercomparison (PCMDI; http: //pcmdi3. llnl. gov) Meehl et al. , 2007. Many users of climate model outputs prefer downscaled data—i. e. , data at higher spatial resolution—to direct global climate model (GCM) outputs; downscaling can be statistical e. g. , Meehl et al. , 2007 or dynamical e. g. , Mearns et al. , 2009. More than 800 users have obtained downscaled CMIP3 results from one such Web site alone (see http: //gdo‐dcp. ucllnl. org/downscaled cmip3ₚrojections/, described by Meehl et al. , 2007).