Social movements throughout history take place in people's minds. If we got 5,000 Americans who were talking about climate change to their neighbors and to their coworkers, and talking about this pledge, that would change the political and social landscape so much more than if 5,000 people got arrested for protesting a pipeline.

My grandmother is a Holocaust survivor. Some heroes of mine have long been the Jewish Partisans, these young people who just went into the woods with whatever guns and bombs and what not they could get their hands on, and just would fight Nazis, and try to help people escape.

Social movements throughout history take place in people's minds. If we got 5,000 Americans who were talking about climate change to their neighbors and to their coworkers, and talking about this pledge, that would change the political and social landscape so much more than if 5,000 people got arrested for protesting a pipeline.

Climate change has been associated so much with a peaceful mentality - obviously peace and love are good, but we need to think about climate as a threat to survival.

Online petitions are built around getting as many signatures as possible. But the experience of taking them and forgetting about them degrades the importance.

I think it's very important to invite and encourage people to talk about climate change who have a lay understanding. In general, there is a lot of confusion among climate activists about the role of science, that scientists should be social and political leaders of this movement.

While the American people have the impression that scientists are hard at work figuring out this complex matter of climate change, it's not actually that complicated.