Climate projections are the numerical output of climate model simulations. For example, a projection could be a monthly time series of temperature values for an area average or values at a particular model grid cell. Global climate models (GCMs) have relatively coarse spatial resolution. Downscaled (fine-scale) climate projections are developed from regional climate models (RCMs) that typically simulate physical processes in greater detail or statistics can be applied to GCM output to create more spatial detail. Some climate projections include historical climate simulations as well as future simulations.