Dispatch from the AGU Fall Meeting

I'm at the Fall Meeting of the American Geophysical Union this week in San Francisco, which is easily the largest scientific meeting I have ever attended.  I haven't been able to find an official tally, but I have been told there are 22,000 attendees and the number of talks and posters is so overwhelming that I have to block out time each evening just to strategize for the next day!

The quality of talks has thus far been outstanding and I've tried to attend as many as possible addressing topics that are of personal interest to me, but outside my area of research.  One that I enjoyed very much was by Gerard Roe, a Professor of Earth and Space Sciences at the University of Washington, who gave a talk based largely on his paper What Do Glaciers Tell Us about Climate Variability and Climate Change?

Gerard suggested using a simple model and statistical analysis that we should expect glacial excursions similar to those observed during the Little Ice Age even in a constant climate.  Substantial glacial advances (and retreats) are an intrinsic component of the year-to-year variability that is built into the climate system.

Modeled glacial response to interannual climate variability.
Source: Roe (2010)

Basically, in any particular region, the randomness within the climate system can give you a few good years or even decades for glacial buildup and advance (or vice versa) that could be construed as a change in climate.  This suggests that it is important to consider potential impacts of randomness in the climate system when interpreting geophysical evidence of glacial advance during periods such as the Little Ice Age.

There as also a great review talk by Andrew Lacis on the role of water vapor in the climate system.  The talk was recorded, so I'll hold off on talking about it until the video is available.