Back on Feb. 15, George Will wrote an op-ed in the The Washington Post in which he claimed:
As global levels of sea ice declined last year, many experts said this was evidence of man-made global warming. Since September, however, the increase in sea ice has been the fastest change, either up or down, since 1979, when satellite record-keeping began. According to the University of Illinois’ Arctic Climate Research Center, global sea ice levels now equal those of 1979.
This set off a major controversy that continues to this day. (For example, see here and here.) As the master of hyperbole Joe Romm points out with delight, the Post actually contradicted Will by name in a news piece, which is quite unorthodox.
This blog does not tackle the huge issues of sea ice and whether we should be terrified or not. (Dan Simmons alerts us to this response to the latest fretting.) In truth, particular data points are rather irrelevant; someone who believes in the need for immediate curbs on carbon emissions could plausibly argue, “It is the long-term trends, not volatile blips, that matter.”
However, in this blog post I will give a qualified defense of Will, because (a) as he himself said in his original op-ed, it was the alarmists who were making much of momentary blips in the data–specifically, the drastic collapse in sea ice in the 3rd quarter of 2008. And I also want to partially defend Will because (b) his erroneous statement about the long-term change in sea ice is largely due to a statistical quirk that no other commentator has noticed (to my knowledge).
First, let’s review Will’s alleged sin. His article on Feb. 15 claimed that the amount (technically, the surface area, not the thickness) of global sea ice was the same as in 1979. But that wasn’t true, because if you go to this graph–hosted by the very same group Will cites as his source–you will see that in February 1979 on the bottom chart, the red line is well above the average (the black line) while in February 2009 the red line is well below the average. That led the Arctic Climate Research Center to issue this statement:
We do not know where George Will is getting his information, but our data shows that on February 15, 1979, global sea ice area was 16.79 million sq. km and on February 15, 2009, global sea ice area was 15.45 million sq. km. Therefore, global sea ice levels are 1.34 million sq. km less in February 2009 than in February 1979. This decrease in sea ice area is roughly equal to the area of Texas, California, and Oklahoma combined.
Now what happened is that Will–whether due to his own research or trusting someone who tipped him off to the “fact”–was relying on somewhat dated information. Just a few weeks earlier, in December 2008 it was true that global sea ice area was roughly the same as it had been on the same day in December 1979. See for yourself on that same chart.
So those favoring the IPCC policy positions etc. are laughing over Will’s apparent blunder. One of them wrote: “Of course, [Will’s readers] probably assumed that by “now,” Will had mean[t] “now,” as opposed to “two months ago.” Silly readers.”
So here is my modest point in all of this: The climate alarmists are giving the impression that the rolling 29-year decline in sea ice collapsed by the same area as several US states, all in the matter of a few weeks. And the silly George Will, ignorant of this volatility, didn’t realize he needed to check his data more frequently before penning an op-ed.
But that’s actually not what happened. The real reason that Will was caught in this embarrassing situation was that the year changed from 2008 to 2009. If you go back once again to the chart, you will see what’s really going on here: Because the participants in this debate are using the odd criterion of “current sea ice relative to the same calendar date in 1979,” the 29-year lookback (from Dec. 2008 to Dec. 1979) suddenly jumps to a 30-year lookback when we compare Feb. 2009 to Feb. 1979.
In other words, it’s not so much that the long-term change suddenly got much worse in a few weeks, but rather that sea ice declined a lot from early 1979 to late 1979.
Incidentally, for what it’s worth–and I’m just eyeballing the chart–it seems that as of this writing, the (now 30-year) change is once again about flat: In other words, the ice area as of today looks to be just about the same as it was on the same date back in 1979. The overall trend still goes down, and so the alarmists can still say their models are consistent with the data.
But in the grand scheme, Will’s original point is quite valid: Isn’t it rather surprising that we have to squint really hard to see the change in sea ice over a 30-year period? Isn’t it surprising that this series is so volatile that it still quite often completely swamps whatever the underlying trend may be, so that we still get the result that there has been no net decline since 1979?
George Will is obviously not a professional climatologist (nor am I), and there is always a danger when amateurs come into a complex field that they will botch a few details. But I for one was very surprised to learn that there are still days when global sea ice is the same as it was on the same calendar day in 1979, inasmuch as I have been bombarded with all the “news” that man-made warming is melting all of the ice caps etc.
To repeat, George Will did not say, “The IPCC models are obviously wrong because global sea ice is the same today as in 1979.” On the contrary, he was responding to alarmists who were claiming that the particular levels in (say) July 2008 showed that the IPCC models were obviously right.
If it is the case (as I suspect) that the professional climatologists who form the “consensus” are exaggerating the degree to which the available evidence confirms their predictions and their declarations that immediate and drastic government action is needed to avert catastrophe, then it will be necessary for outsiders to say the emperor has fewer clothes than he himself maintains. (This is not to say the IPCC emperor is naked, mind you.)
So yes, an op-ed writer in the Washington Post said something that was incorrect, and he deserves to be criticized for it, both by alarmists and skeptics alike. But his important point was largely lost because of his goof. When we look into exactly what happened, and why the “change since 1979” shifted so much from the time Will did his research to the time he penned his op-ed, his mistake is much more excusable than his harshest critics believe.