Last updated September 29, 2021

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