Last week, the National Snow and Ice Data Center came out with the estimate that we did not quite set a record for the minimum extent of Arctic sea this year. Rather, 2011 seems to have come in a slight second to 2007.
However, another scientific group does claim that we've hit a new record. Who's right?
I don't know, but I don't think either bit of news is the most important thing to focus on. For as Skeptical Science points out, we also just learned that total sea ice volume reached a new low in 2010 (wonky hide-the-punchline paper here). And that is, to my mind, a much bigger deal than what total sea ice extent is doing on a year by year basis.
Remember, extent is a measure of area covered, and volume is a measure of total ice mass. (More clarification here.)
There is a strong case that volume matters more, because extent can be misleading. Why?