There's such a wide variation in tax systems around the world, it's difficult to imagine a harmonized CO2 tax that every country agrees to. That's not in the cards in the near term. But the countries that are doing the best job, like Sweden, are already doing both of these. I think that eventually we'll use both of them but we need to get started right away and the cap-and-trade is a proven and effective tool.

Any child born into the hugely consumptionist way of life so common in the industrial world will have an impact that is, on average, many times more destructive than that of a child born in the developing world.

Most people in politics draw energy from backslapping and shaking hands and all that. I draw energy from discussing ideas.

I'm going to be focused on doing everything I possibly can to help solve the climate crisis.

I affirm my faith when I'm asked about it. But I always try to do so in a way that communicates absolute respect, not only for people who worship in a different way, but just as much respect for those who do not believe in God and who are atheists.

Someone who expresses a view that is contrary to the view of the overwhelming majority should be allowed to stand undisturbed as a monument to our commitment to free speech.

Population growth is straining the Earth's resources to the breaking point, and educating girls is the single most important factor in stabilizing that. That, plus helping women gain political and economic power and safeguarding their reproductive rights.