If you just try to make rational arguments about why people should care about Congo and how 5 million people have died, then people tend not to be receptive. But once you've created a connection of empathy, rational arguments can play a supportive role.

The way you get leaders to care about issues of conscience is to apply political pressure. It's less a question of persuading leaders directly and more trying to build a social movement that holds their feet to the fire.

Solar power is one of the most hopeful technologies but still produces about 0.01 percent of U.S. electricity. The U.S. allocates just $159 million for solar research per year - about what we spend in Iraq every nine hours.

Laws matter, but typically changing the law by itself accomplishes little.

There seems to be this sense among even well-meaning Americans that Africa is this black hole of murder and mutilation that can never be fixed, no matter what aid is brought in.

The bulk of the emails tend to come after a column. I can get about 2,000 after a column.

One of the things that really got to me was talking to parents who had been burned out of their villages, had family members killed, and then when men showed up at the wells to get water, they were shot