Telegraph: An impending crisis in America’s water supply is signalled by a study that concludes more than half of the recent decline seen in the west can be linked to human activities. Scientists have been documenting significant changes in water flow in the western United States for the past 50 years. Now it has been found that to 60 percent of the changes in river flow, snow pack and winter air temperatures in the region during this period can be attributed to human-caused climate …