Hope and optimism aren't just attitudes, they are life strategies.

Scientists tend to focus on what they don't know more than what they do know. And there are a lot of things we still don't know about the climate. But we know the difference between climate variability and climate change, and right now the amount of carbon in the atmosphere is well outside the variability pattern - and that's quite quantifiable.

We need to become energy independent or at least aspire to that.

I think no country is going to be immune from the Arab awakening because the Arab awakening is driven by deep human longing for dignity, for justice and for freedom. I think that applies to young people in Saudi Arabia as much as to young people in Egypt, Tunisia, or Yemen, or Libya, or Syria. If I were in Saudi Arabia, I would be getting ahead of this and looking for ways to appreciate those aspirations and align my country with them.

I would say that in 2000, we understand as much about how today's system of globalization is going to work as we understood about how the Cold War system was going to work in 1946.

I firmly believe that the next great breakthrough in bioscience could come from a 15-year-old who downloads the human genome in Egypt.

No, most of our political elite has not realized that the world is flat.