Tonight's Simpsons episode was a rerun that begins with the revelation that Springfield Glacier has shrunk to an ice cube, probably due to global warming. At the same time, the movie Sahara led the box office. A major plot point is Sahara is that Africa used to be wetter. This plus a major storm allowed a civil war iron clad (it looked just like the Monitor/Virginia) to sail up a part of Africa that is now desert.
The movie is correct, Africa started drying up sometime in the mid-19th century. Some lakes and rivers are gone. This is causing African glaciers to shrink due to lack of moisture.
Maybe if Lisa Simpson went to more movies she would know a bit more about glaciers.