The weather pattern El Niño has killed hundreds of people and inflicted millions of dollars in damage this winter. From floods in California and Peru, to high winds in Florida and Mexico, and the freak ice storm that devastated eastern Canada and northern New England, the drought in South east Asia may also be linked. While El Niño is a natural phenomena, some scientists suspect that recent shifts in its pattern is a response to human-induced global warming. Steve Curwood speaks with Kevin Trenberth heads the Climate Analysis Section of the National Center for Atmospheric Research in Boulder, Colorado.