John Kerry: “The choice we face is between an agreement that will ensure Iran's nuclear program is limited, rigorously scrutinized…”

The message is, let's find a way to be able to make sure when we fly, we're not leaving emissions that we cannot capture.

Ninety-eight percent of all the scientists in the world agree----

It's very obvious that there are huge threats here.

We are competing, but everybody has their own approach, which is one of the exciting things here.