President Obama is heading to Fresno, California, tomorrow, in the midst of the state's historic drought and a political fight over how to handle it.
Berkeley professor B. Lynn Ingram says the drought may be the most severe since the 1500s, based on research on tree rings. She says we may be entering a drier period that may last decades.
- B. Lynn Ingram, professor of earth and planetary science at the University of California, Berkeley. She's also co-author of "The West without Water: What Past Floods, Droughts, and Other Climatic Clues Tell Us about Tomorrow."
This segment aired on February 13, 2014.