Scheduled water deliveries from the Colorado River will be short 60% to 90% of the time by mid-century if human-caused climate change continues to reduce precipitation in the basin, say state researchers at Scripps Institution of Oceanography at the University of California, San Diego. “The situation is horrible,” says Tim Barnett, Scripps research marine physicist. “We’re using all the water that is there, and there is going to be less of it.” Coincidentally, on May 15, scientists at the National Center for Atmospheric Research (NCAR), Boulder, Colo., will publish a report with similar findings from a study of major rivers worldwide. Using data from 1948 to 2004, the scientists found significant changes in about a third of the world’s largest rivers, including the Colorado, China’s Yellow River, India’s Ganges and Africa’s Niger. The reports were prepared independently of each other, says Barnett. The NCAR study attributes changes to dams and water diversions as well as to climate change.