This is one of Peter Sinclair’s best videos.  It does a fabulous job of explaining the science behind the issue and debunking the skeptic argument.  He addresses what has for some time been a favorite page in the skeptic playbook: the bogus argument that AGW is refuted by the fact that at the termination of recent ice ages, increases in temperature initially lag behind increases in CO2.  This argument is a straw man; nobody is denying that this patterns occurs.  But this observation, and the fact that temperature can indeed have strong effects on CO2 conc., in no way undercuts the science behind AGW.   The simple explanation for this is that we know that many other factors influence global temperature.  And ice ages are thought to be controlled by Milankovitch cycles and not by changes in atmospheric CO2.  That doesn’t mean that CO2 does not also influence global temperature or that it isn’t the major driver of recently observed global warming.

IOW as John Cook pokes fun at this illogical argument:  “Chickens do not lay eggs, because they have been observed to hatch from them”.

There are better written explanations of this issue by far more knowledgeable people than me here and here.  And Peter’s video is a great place to start:

[youtube=http://www.youtube.com/watch?v=hWJeqgG3Tl8&w=425&h=344]