American democracy is in grave danger from the changes in the environment in which ideas either live and spread or wither and die.

The more deeply I search for the roots of the global environmental crisis, the more I am convinced that it is an outer manifestation of an inner crisis that is, for lack of a better word, spiritual... what other word describes the collection of values and assumptions that determine our basic understanding of how we fit into the universe?

We face the gravest threat that civilization has ever confronted. It's global in nature and requires a global solution. Increased CO2 emissions anywhere, whether from China or the United States or from one of the countries that is burning its forests like Brazil or Indonesia.

Future generations may well have occasion to ask themselves, "What were our parents thinking? Why didn't they wake up when they had a chance?" We have to hear that question from them, now.

I have a sense of mission on this climate crisis, and I'm trying to pour all the energy I have into it. And I hope that I, along with others, can catalyze the emergence of real solutions to the climate crisis. I think we're making a lot of progress. I think we're going to win this, but it matters how quickly we win it. So I'm focused on that.

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.'

When it comes to climate, we can all make a big difference. At the most basic level, don't let denial go unchallenged and win the conversation on climate.