CNN: President Barack Obama took part in a roundtable discussion this week on climate change, refocusing on the issue from a public health vantage point. After the event at Washington's Howard University on Tuesday, Obama sat down with me for a one-on-one interview. I asked him about the science behind climate change and public health and the message he wants the average American to take away, as well as how enforceable his action plan is. Here are five things I learned: 1. College was an eye-opener....