I'm a sucker for time lapses. Scenes like this one from Planet Earth have always been so fun to watch. Being able to visualize such small changes over a grand time scale really presents things in their proper perspective.
This is a gif of the Carbon Dioxide time lapse, and I highly recommend watching the others as well. These show temperature rising, ice sheets melting, and sea levels rising (this last one is a simulation).
There really is no question that there are major changes to the earth's climate underway. This CO2 visualization demonstrates the stark reality that we will need to undo the damage that's been done by emitting carbon dioxide into the atmosphere.