By the year 2100, many scientists believe that the Earth's average temperature could rise by as much as six degrees Celsius. A compelling investigation explores what each rising, and critical, degree could mean for the future of our people and planet. Illustrates how global warming has already affected the reefs of Australia, the ice fields of Greenland, and the Amazonian rain forest. Explains what's real, what's still controversial, and how existing technologies and remedies could help dial back the global thermometer.