Global warming is just a load of confusion for most people, I think it is mostly because of the name of it.
"Global warming" would not cause immediate higher temperatures, but a destabilization of the climate. Things will get colder in some areas, warmer in others, and the temperature will fluctuate a lot. The biggest problem with the destabilization will be the extreme weather, like hurricanes. If things continue to destabilize there will be many more hurricanes like Katrina and they will be larger.
http://en.wikipedia.org/wiki/Global_warming
If you know a little about history you will know about the Little Ice Age.
As you can see from the following chart:
http://en.wikipedia.org/wiki/Image:2000 ... arison.png
The real temperature difference between the little ice age and what it normally was around 1/2 C. We've gone up almost 1 C from 1900.



