Anthony Watts has another post claiming that sea ice isn’t really doing anything worth worrying about. He includes much of the usual stuff, including a picture of the U.S.S. Skate which he originally stated was surfacing at the North Pole in March of 1959 to find lots of open water. But one of his readers pointed out that the photo wasn’t from 1959 and it wasn’t at the North Pole, so he changed his post (see the end of this for some interesting information). But that’s a minor point, what’s interesting is that he finishes by stating that “Global sea ice hasn’t varied all that much in 30 years, and I for one, am just not all that worried about it.” The claim is based on this post by Jeff Condon which Watts calls an “excellent essay.”
What Condon’s essay really illustrates is how fake skeptics fool themselves into thinking they have real evidence.
The gist is a re-definition of sea ice area to include only what Condon calls “annual” or “single-year” ice area. This isn’t done by determining which ice is really 1st-year and which isn’t — it’s done by noting that every year, almost all of the Arctic sea ice south of latitude 72N melts away, so the new definition is “sea ice south of latitude 72N.” That’s for the northern hemisphere, for the southern the definition of “annual” is: all the sea ice.
That enables Condon to compute this trend for Arctic “annual” sea ice:
It has declined strongly, but not as strongly as the real Arctic sea ice area. But by combining this rather odd and incorrect definition of “annual” Arctic sea ice with Antarctic sea ice (all of it), Condon gets what he calls “global annual” sea ice. Here’s his graph of same:
It too has declined! But — and this is what Condon was really looking for all along — the decline just barely misses statistical significance. Just barely.
Condon’s closer is “… isn’t it interesting that global single-year sea ice has not shown a trend which is easily differentiable from noise in the past 34 years?”
The interesting thing is that Condon actually believes he has formed a useful definition of “single-year” sea ice by doing nothing other than ignoring most of the Arctic sea ice. He further thinks that this would be a relevant metric for sea ice behavior. And he thinks that just barely missing statistical significance for an artificial metric which is designed to ignore the bulk of sea ice in the Arctic while including all of it from the Antarctic is “interesting.”
Yes, in my opinion the really interesting thing is that Condon actually believes he has found real evidence that sea ice decline isn’t as bad as the experts are telling us. Forget about most of the Arctic, forget about multi-year ice, Condon was looking for a metric he could believe wasn’t so bad, and of course he found what he was looking for.
But it gets even better. Anthony Watts doesn’t just hint at “… isn’t it interesting?” He doesn’t even mention that it’s an artificial (and frankly, incorrect) definition of a quantity which isn’t the relevant metric for sea ice anyway. He just refers to it as “Global sea ice,” states that it “hasn’t varied all that much in 30 years,” and yes folks he actually believes it when he says, “Sea ice is a complex problem, and my personal view is that we simply don’t know enough about its behavior in the larger context to demonstrate a causal relationship with the recent global temperature increases.”
Perhaps I should inform Watts and Condon that they missed their chance. We can do better than that! Let’s take a look at sea ice extent data from the Arctic (all of it):
Note that it has declined throughout the year, although the summer/fall decline has been faster than the winter/spring decline. Let’s define the “sea ice re-freeze” or simply “annual re-freeze” as the increase in extent from one summer/fall minimum to the following winter/spring maximum. That gives us this:
Wow! The “annual refreeze” has been increasing! We can even fit a straight line by linear regression and it’s statistically significant! And we didn’t even have to leave the Arctic at all!!!
Perhaps Watts will refer to this graph as reinforcing his lack of concern about sea ice loss.