If you look at the numbers (if the figures I have read are accurate), it's pretty simple to see why myself and others aren't getting all freaked out about anthropogenic contributions to the greenhouse effect. There are basically 5 gases that contribute to warming:
miscellaneous (CFC's and others)
The last figures I read indicate that human-caused CO2 contributions are estimated at 3.5% of the 3.5% total CO2 emissions. That is significantly less than 0.2%. CFC's and the other miscellaneious gases are so miniscule, they don't even generally spur conversation. If humankind's 0.02% is causing climate change, and we can't control water vapor, which is reportedly the largest contributor by far (I've read figures ranging from 75-95%), then why are we getting in an uproar?