Drought and Bark Beetle Blamed for Dramatic Increase in California Tree Deaths

An aerial survey of California trees by the U.S. Forest Service last month found a drastic increase in tree mortality.  Since 2014, the number of dead trees jumped from an estimated 3.3 million to about 27.6 million. Scientists say the die-off is caused by the drought and the rising numbers of bark beetles, who destroy the trees' ability to absorb food and water. We'll discuss the die-off and how it relates to an increased risk of forest fires.