In case anyone is actually interested in the data, the ice tracking website The Cryospher Today has published a pdf on the issue.

Read it carefully, because it CONFIRMS the core assertion in question made at Daily Tech (the source material for Will). It then SHIFTS THE ARGUMENT to point to the FACT that Northern Hemisphere sea ice is between 500K sq miles and 1M sq miles below that measured in 1979.

They spend much of the pdf describing why GLOBAL sea ice concentrations (which are, in fact, the same within margin of error of that measured in 1979) should not be used to discuss global warming, but rather one should look at the Northern Hemisphere data.

In science, this is called “cherry picking data to support your biases.” Be that as it may, the core assertion at Daily Tech has not been refuted.

And Carl Zimmer does a dishonest job of dodging the issue altogether in his counter attack - he simply unleashes a series of cleverly disguised ad-hominems and then makes naked re-assertions.

Net is this - Will did not lie. He relied on a source that proved to be accurate. Whether he should have relied on that source in the first place is a matter for a different debate.