There is another version at Skeptical Science
You can take a test at National Geographic
Whatever, it’s pretty obvious that global warming is happening, but some people will deny anything.
You can read the Economist Article, Climate change: Mail-strom (Nov 26th 2009) here. There is a related Economist article–Climate change: A heated debate (Nov 26th 2009) as well that you can read here.
Another method is in this super video, but you need to watch it all the way through.
Just remember what Douglas Adams said in “the Hitchhiker’s Guide to the Galaxy“:
People who argue that black is white get killed at the first zebra crossing