I like Obama. I don't know who could do a better job. He's got an incredibly tough situation, and a good heart and mind. I'd like to see him rally support a little better.

My son is now an 'entrepreneur.' That's what you're called when you don't have a job.

I lost 80 percent of my wealth and then gave away over half of the rest. So I'm a man of modest means now. But if you budget carefully and watch your expenditures, you can get by on a couple billion dollars.

The U.N. had such lofty goals to eliminate poverty and stop war and cure diseases and help refugees - things that no one country could do.

In a climate where much of foreign policy is a direct function of domestic politics, focusing on what one doesn't want is an easy way out of difficult conundrums for many world leaders. Expressing what one does want requires more courage.

Square Roots creates campuses of climate-controlled, indoor, hydroponic vertical farms, right in the hearts of our biggest cities.

Yes, Brazil, like the whole world, stands to lose a lot in a climate-altered world. But it's also one of the major forces determining our future: It's the home of most of the Amazon rain forest.

When I went to university, I decided that I would like to do something related to plant ecology, because I felt that plants were so beautiful. When I am studying plants, I feel like I am talking with some kind of supernatural life, like I am talking with someone who does not speak.