I've learned the importance of changing people's minds at the grassroots level so that whoever does run will have a much better chance of encountering public opinion that reaches a critical mass and brings about a change not only in White House policies but in the Congress and in the state legislatures and all around the world.

In a free society, there comes a time when the truth - however hard it may be to hear, however impolitic it may seem to say - must be told.

Remember that the problem is bigger than the car you drive or the types of lightbulbs in city hall. We need a fundamental shift away from dirty fossil fuels that spew carbon pollution. To make that happen, we need to put pressure on our leaders to take the bold actions necessary to move us off dirty sources of energy.

Eventually we'll use a CO2 tax offset by a reduction in taxes elsewhere alongside a cap-and-trade plan, but the degree of difficulty associated with a CO2 tax far exceeds that with a cap-and-trade plan. We're seeing it's hard to get a cap-and-trade plan and it's much easier to use as a basis for a global agreement than a CO2 tax.

I doubt nuclear power will play a much larger role than it does now.

At some point, a false belief collides with physical reality.

I was born a poor black child.