Traditionally the United States has been the natural leader of the world. That's not just pride as an American speaking; it's just the reality. Without the U.S. being involved in Paris Climate Agreement, it's hard for the world community to move forward as effectively.

In the end, we must restore a balance within ourselves between who we are and what we are doing. Each of us must take a greater personal responsibility for this deteriorating global environment; each of us must take a hard look at the habits of mind and action that reflect - and have led to - this grave crisis.

There's no such thing as clean coal. It's non-existent. Theoretically, it might be possible, many years from now, to come up with a way to clean it as it's burnt. But there's not a single demonstration project in the United States. [...] Clean coal doesn't exist.

The warnings about global warming have been extremely clear for a long time. We are facing a global climate crisis. It is deepening. We are entering a period of consequences.

I remember as a boy when the conversation on civil rights was won in the South. I remember a time when one of my friends made a racist joke and another said, 'Hey man, we don't go for that anymore.'

As many know, the Chinese expression for "crisis" consists of two characters side by side. The first is the symbol for "danger," the second the symbol for "opportunity."

Incredibly, while these 18 to 20 year-olds cannot legally buy a beer, cannot purchase a bottle of wine and cannot order a drink in a bar, right now they can walk into any gun shop, any pawn shop, any gun show, anywhere in America and buy a handgun.