By 2050 the world's population will reach 10 billion and questions about how to feed everyone will be more urgent there ever. It's an environmental dilemma that's been simmering for generations, with "wizards" who believe science will provide the answers and "prophets" who see only disaster for the planet if the population keeps growing.
Science writer Charles Mann looks at the two sides of the problem through two men from either side of the debate who wrote about the problem a century ago. His book is The Wizard and the Prophet: Two Remarkable Scientists and Their Dueling Visions to Shape Tomorrow's World.
Charles Mann Photo: Penguin/Random House
