Real vs. prediction: Watch the world's climate change throughout the 20th century

Climate scientist Gavin Schmidt works for NASA and with Columbia University's Earth Institute. He put together this animation to show what actually happened to the world's temperature in the 20th century -- compared with the work of a sophisticated prediction model. "Some things aren’t the same; there's weather that’s different in both cases and you do see slightly different patterns," says Schmidt, but in the main he says he's happy that the two turned out to be so similar (showing that the model is solid). Another lesson from this comparison: "You do see climate changes emerging in both cases."