ABSTRACT
Present climate models are considered to be reliable only at scales large than 1000 km due to grid resolution and limited computer capabilities. Climate changes at finer scales can be estimated through statistical downscaling models linking the large-scale atmospheric circulation to regional climates. However, this approach assumes that the climate model will reliably simulate the relevant large-scale circulation patterns and that this statistical links will also hold in a perturbed climate. We have checked these assumptions in simulations with the Hadley Center General Circulation Model (GCM) for winter precipitation in the Iberian peninsula, a region with likely unreliable climate change estimations, due to complicated orography. Surprisingly, the results show that the GCM does reproduce the main aspects of the observed link between large and local scales and that this link remains in the simulated perturbed climate. The simulations show that anthropogenic forcing will cause changes of atmospheric circulation associated with a slight decrease of precipitation in the northern coast and otherwise increases that can be considerable in the south. The historical records show a quite similar trend pattern. These results support estimations of future regional trends simulated by the climate model under future scenarios of anthropogenic forcing.