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.

Sandy was particularly destructive because it was prevented from moving back out to sea by a "blocking pattern" associated with the jet stream. There's debate about this, but one recent study suggested that melting sea ice in the Arctic may lead to such blocking.

If the U.S. wants to help people in tsunami-hit countries like Sri Lanka and Indonesia - not to mention other poor countries in Africa - there's one step that would cost us nothing and would save hundreds of thousands of lives. It would be to allow DDT in malaria-ravaged countries.

The photos were taken by African Union soldiers. People in Congress saw them. I thought if people could see them, there would be public outcry. No one would be able to say, We just didn't know what was going on there.

Most of the villagers were hiding in the bush, where they were dying from bad water, malaria and malnutrition

America's education system has become less a ladder of opportunity than a structure to transmit inequity from one generation to the next.

Neither left nor right has focused adequately on maternal health