When you have the facts on your side, argue the facts. When you have the law on your side, argue the law. When you have neither, holler.

When you talk about President Trump, the cable networks turned over so many hours of prime time to him. Why? Because he was entertaining, but also because it drove ratings. And that is different from what the news media is supposed to focus on.

A day will come when our children and grandchildren will look back and they'll ask one of two questions. Either they will ask: "what in God's name were they doing?" or they may look back and say: "how did they find the uncommon moral courage to rise above politics and redeem the promise of American democracy?"

Unless we act boldly and quickly to deal with the underlying causes of global warming, our world will undergo a string of terrible catastrophes.

I think the cost of energy will come down when we make this transition to renewable energy.

Of all the works of civilization that interfere with the natural water distribution system, irrigation has been by far the most pervasive and powerful.

The truth is that we're at a critical juncture in the history of our species and if we don't act soon, we could inhabit a world we don't recognize anymore. But the most important truth is that we are capable of stopping climate change before the worst of its consequences are locked in. The solutions exist - all we need is the will to do something about it.