Climate change and health, WV mine blast, cyberwarfare
This week on Need to Know: The threats climate change poses to human health. The story of a deadly mine blast in West Virginia. A new super-weapon in the world of cyber-warfare. Jon Meacham considers the belief among some Christians that the world will end on May 21st. And Alison Stewart talks to John Esposito of Georgetown University about President Obama and the Arab Spring.