Climate Change Caused California Drought

http://www.usnews.com/news/blogs/at-the-edge/2015/04/14/climate-change-and-the-california-drought

Climate change is linked to California’s drought by two mechanisms: rising temperatures and changing atmospheric patterns conducive to diminishing rains.

Climate change intensified the California drought by fueling record-breaking temperatures that evaporated critically important snowpack, converted snow to rain, and dried out soils.
Weather records tend to be broken when the trend driven by natural changes and the trend driven by climate change run in the same direction, in this case toward warmer temperatures. Drought in California has increased significantly during the past 100 years, driven by rising temperatures.