Six Degrees Could Change the World. National Geographic. In a special broadcast event, National Geographic explores the startling theory that Earths average temperature could rise six degrees Celsius by the year 2100. In this amazing and insightful documentary, National Geographic illustrates, one poignant degree at a time, the consequences of rising temperatures on Earth. Also, learn how existing technologies and remedies can help in the battle to dial back the global thermometer. Great models and clips.