What are some interesting facts about the greenhouse effect?

Answer:
The information used about CO2 levels is taken from ice cores in polar areas. The data for CO2 levels for the past few years has been from next to a volcano in the Caribbean. Chance of different levels of CO2 at different locations giving wrong impression? Surely not.

I'm not trying to be prejudiced but it's true, if you're going to change this answer then don't remove the fact.
First answer by Kittsville. Last edit by Kittsville. Contributor trust: 14 [recommend contributor recommended]. Question popularity: 1 [recommend question].