Human-induced changes in the hydrology of the Western United States

"A regional,multivariable climate-change detection and attribution study, using a high-resolution hydrologic model forced by global climate models, focusing on the changes that have already affected this primarily arid region with a large and growing population is presented. The results show up to 60% of the climate related trends of river flow, winter air temperature and snow pack between 1950-1999 are human-induced. These results point to a coming crisis in water supply for the western United States".