Why is this a big deal? Lets let the lead author, Ben Santer, explain the key findings (from new media Science Daily):
Our key findings were as follows:And the reason this is important from Dr. Santer:
1. Despite the relatively short length (19 years) of the observed water vapor data, we were able to identify a "fingerprint" of human activities in this observational record.
2. Unlike most previous "fingerprint" work, our study used results from virtually all of the world's major climate models. We showed that our identification of a human "fingerprint" in satellite-based water vapor records was robust to current uncertainties in climate models.
3. The model results enabled us to "disentangle" the contributions of different factors to the overall increase in water vapor. We found that in climate models, this increase in water vapor was primarily due to human-caused increases in greenhouse gases.
4. Bottom line: our results suggest that there is an emerging signal of human activities in the moisture content of Earth's atmosphere. The climate system is telling us a consistent story. The observed changes in temperature, moisture, and atmospheric circulation fit together in an internally- and physically consistent way.
One persistent criticism of the "discernible human influence" findings of previous IPCC assessments is that such conclusions were largely based on "fingerprint" studies which relied heavily on surface temperature changes.
The thrust of the criticism was this:
"If there really is a signal of human activities lurking in the climate system, it should be manifest in many different climate variables, and not in surface temperature alone."
Our study helps to refute this criticism, and shows that we have now moved well beyond "temperature only" fingerprint studies.
Here's the press release from Lawrence Livermore National Lab.
About all I can find is coverage in the San Jose Mercury News and brief mention in United Press International. This would have been great to mention during the Bush and U.N. meeting's coverage the following week.