The global warming deniers persist in this air of unreality. After all, the entire north polar icecap, which has been there for most of the last 3 million years, is disappearing before our eyes. Forty percent is already gone. The rest is expected to go completely within the next decade. What do they think is causing this?

Airplane travel is nature's way of making you look like your passport photo.

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

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.

I am a passionate advocate of getting special interest money out of politics.

We are in an unusual predicament as a global civilization. The maximum that is politically feasible, even the maximum that is politically imaginable right now, still falls short of the minimum that is scientifically and ecologically necessary.

The survival of the United States of America as we know it is at risk. And even more — if more should be required — the future of human civilization is at stake.