We need to put a price on carbon, and that's what cap-and-trade does and that's also what a CO2 tax does. As long as our current valuation in the marketplace tells us every minute of every day that it's perfectly all right to dump 90 million tons of global warming into the thin atmosphere surrounding the planet every 24 hours as if that atmosphere is an open sewer, then the individual actions are not going to solve the problem.

I'm passionate about restoring the efficacy of American democracy, making capitalism sustainable, prioritizing advances in technology, and seizing the opportunities to use that kind of innovation to help usher in a new economy that doesn't rely on carbon-spewing fossil fuels.

The heart of the security agenda is protecting lives, and we now know that the number of people who will die of AIDS in the first decade of the 21st Century will rival the number that died in all the wars in all the decades of the 20th century.

Today we're dumping 70 million tons of global-warming pollution into the environment, and tomorrow we will dump more, and there is no effective worldwide response. Until we start sharply reducing global-warming pollution, I will feel that I have failed.

My parents were true believers in the efficacy of American constitutional democracy, and I was thoroughly inculcated with reverence for what we the people are capable of doing. The complication in that simple narrative is that as I got older, the Vietnam War shook my confidence in how our democracy was working. I ended up serving in that war, but it started with a lie, and I was very proud of my father for being one of its earliest opponents.

John McCain is now openly endorsing the policies of the Bush-Cheney White House and promising to actually continue the same policies over again? Hey, I believe in recycling but that's ridiculous.

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.