In case you haven't noticed the BBC are running a massive experiment on Climate Change. Part of the experiment involves using everybody's computer. Click here for details.
When you sign up the Beeb download a program that runs in the background while you have your computer on and will collect all the data at some point in the future. I don't know if it will stop global warming, I think that people are too attacted to their cars for that to happen.
Anyway I now have a Screen Saver that is running through world climate changes from 1920 right up to 2080 in half hour jumps. So far it has got to May 1921. More interesting than the countdown to the Doctor Who Christmas Special that was there before.