Our planet is home to an estimated 6.9 billion tons of plastic waste. And it will take a minimum of 450 years for it to biodegrade – though some of it may never break down. Jenna Jambeck studies the problem at the University of Georgia, and she joins us to talk about how plastic is threatening our oceans – and what we can do to curb our use of it. She’s featured in “Planet or Plastic,” a special report in the June issue of National Geographic magazine.