Tim P. Barnett, David W. Pierce, Hugo G. Hidalgo, Celine Bonfils, Benjamin D. Santer, Tapash Das, Govindasamy Bala, Andrew W. Wood, Toru Nozawa, Arthur A. Mirin, Daniel R. Cayan, Michael D. Dettinger


Published date February 22, 2008

Human-Induced Changes in the Hydrology of the Western United States

  • Observations have shown that the hydrological cycle of the western United States changed significantly over the last half of the 20th century
  • Presents 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
  • Results show that up to 60% of the climate-related trends of river flow, winter air temperature, and snow pack between 1950 and 1999 are human-induced
  • These results are robust to perturbation of study variates and methods
  • Concludes that the results portend, in conjunction with previous work, a coming crisis in water supply for the western United States