David Beasley, the director of the United Nations World Food Programme, told CNN’s Becky Anderson on Tuesday that a “one-time” donation from the top 400 billionaires in the US could help save the lives of 42 million people this year. If the world’s top 400 billionaires chipped in, Beasley said, all it would take to prevent famine is .36% of their total net worth increases.