The Arab awakening was like watching elephants fly: something you didn't expect, something you haven't seen before, "Wow, elephants fly."

Everything I’ve ever gotten in life is largely due to the fact that I was born in this country, America, at this time with these opportunities for its citizens. It is the primary obligation of our generation to turn over a similar America to our kids.

You always have to remember that Mother Nature is a lot like your body. If your temperature goes from 98.6 to 100.6, you don't feel so good. If it goes from 100.6 to 102.6, well, you call the doctor. If it goes from 102.6 to 104.6, you're in the emergency room at a hospital. The same with Mother Nature - small changes in global average temperatures have a huge climate effect.

My mom enlisted in the U.S. Navy in World War II, and my parents actually bought our home thanks to the loan she got through the GI Bill.

The Arab world had a big problem of frankly venal elites. That is why these revolutions happen, because people didn't think the opportunities were being shared fairly.

America is the greatest engine of innovation that has ever existed, and it can't be duplicated anytime soon, because it is the product of a multitude of factors: extreme freedom of thought, an emphasis on independent thinking, a steady immigration of new minds, a risk-taking culture with no stigma attached to trying and failing, a noncorrupt bureaucracy, and financial markets and a venture capital system that are unrivaled at taking new ideas and turning them into global products.

So what am I? I guess I would call myself a sober optimist...If you are not sober about the scale of the challenge, then you are not paying attention. But if you are not an optimist, you have no chance of generating the kind of mass movement needed to achieve the needed scale.