The bottom line is that CO2 is absolutely, positively, and without question, the single most important greenhouse gas in the atmosphere. (dotearth.blogs.nytimes.com)
Is water a far more important a greenhouse gas than carbon dioxide, as some claim? (newscientist.com)
Second, they need to come up with an explanation for why a 35 % increase in the second most important greenhouse gas does not affect the global temperature. (grist.org)