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On the credibility of climate predictions
D. KOUTSOYIANNIS, A. EFSTRATIADIS, N. MAMASSIS & A. CHRISTOFIDES
Department of Water Resources, Faculty of Civil Engineering, National Technical University of Athens, Heroon Polytechneiou 5, GR-157 80 Zographou, Greece
http://www.atypon-link.com/IAHS/doi/pdf/10.1623/hysj.53.4.671?cookieSet=1

" ...On the other hand, in recent decades, numerous hydrological studies have attempted to cast projections of the impacts of hypothesized anthropogenic climate change on freshwater resources and their management, adaptation and vulnerabilities (Kundzewicz et al., 2008). All these studies are essentially based on the explicit or tacit assumptions that climate is deterministically predict-able in the long term and that the climate models (or general circulation models, GCMs) can give credible predictions of future climate for horizons of 50, 100 or more years (e.g. Alcamo et al., 2007). Less effort has been put into falsifying or verifying such assumptions. However, the wide-spread use of statistical downscaling methods in hydrological studies may be viewed as an indirect falsification of the reliability of climatic models: for this downscaling refers in essence to tech-niques that modify the climate model outputs in an area of interest in order to reduce their large departures from historical observations in the area, rather than techniques to scale down the coarse-gridded GCM outputs to finer scales."

also here - http://www.atypon-link.com/IAHS/doi/abs/10.1623/hysj.53.4.671