Bloomberg: Record rains fell in California this week. Theyre not enough to change the course of what scientists are now calling the regions worst drought in at least 1,200 years. Just how bad has Californias drought been? Modern measurements already showed its been drier than the 1930s dustbowl, worse than the historic droughts of the 1970s and 1980s. That's not all. New research going back further than the Viking conquests in Europe still can't find a drought as bad as this one. To go back that far,...