This description comes from onearth.org:

From our friends at NASA comes this amazing 26-second video, depicting how temperatures around the globe have warmed since 1880. That year is what scientists call the beginning of the “modern record.” You’ll note an acceleration of those temperatures in the late 1970s as greenhouse gas emissions from energy production increased worldwide. The data comes from NASA’s Goddard Institute for Space Studies in New York, which monitors global surface temperatures. As NASA notes, “in this animation, reds indicate temperatures higher than the average during a baseline period of 1951-1980, while blues indicate lower temperatures than the baseline average.”