According to data from NASA's Goddard Institute of Space Studies, the world's temperature has risen quite a bit since 1880.
But let's be honest: looking at charts and graphs isn't always the most fun thing in the world - and it may not always be the best way to get a point across.
That's what University of Minnesota student (and cello player) Daniel Crawford figured when he made this video.
Rather than just explaining how much warmer the world has gotten, Crawford turned the data into music.
The converted the average global temperature for each year into a musical note, and then played a whole composition that starts with the data for 1880 and finishes up with 2012.
If you listen to the whole thing, there are some definite peaks and valleys, but the overall impression is clear: the song's a lot higher-pitched at the end than at the start.
The final message in the video drives home Crawford's point: "Scientists predict our planet will warm by at least another 1.8 degrees Celsius by the end of the century. This additional warming would produce a series of notes beyond the range of human hearing"