Author says oil slick only the visible tip of problem

An environmental author told an environmental summit in Tallahassee Thursday that the spreading oil slick in the Gulf of Mexico is only the most visible aspect of the nation's dependence on fossil fuels.Bill McKibben is a scholar-in-residence at Middlebury College in Vermont, founder of 350.org and author of "Deep Economy: The Wealth of Communities and the Durable Future." He was the keynote