07-09-2009, 08:16 AM
Quote:I don't think eppie should just dismiss water vapor, since it is the most significant factor in the green house effect (~ 70 to 90%). Although, he might just be talking about variation depending on temperature. Yet, it seemed like he was saying it was irrelevant.Here's Gavin Schmidt's explanation for its irrelevance, if you're interested.
In short, water vapor doesn't stay in the atmosphere for long. Its long-term values are determined by other variables. Thus, it does not drive climate change, but rather reinforces other changes, like an increase in CO2.
-Jester