Back in mid-2011, Chip Knappenberger treated us to his brand of shallow thinking about temperature data for the U.S.A. We discussed it soon after. In spite of the fact that 2011 wasn’t even over yet, Knappenberger said this:
… 2011 will mark the continued return of U.S. national temperatures to conditions much closer to the 20th century mean, down from the unusually elevated temperatures that characterized the 1998–2010 period.
Chip began with this graph:
Despite its being mid-2011, Knappenberger left out everything after 1997 — because what came after didn’t fit his conception of the US temperature trend.
What came after was higher temperature in the USA. When he showed this, his version included the average anomaly for the first half of 2011 only:
He also put in his estimated likely range, and a pair of trend lines — one using data through 2007, the other omitting everything after 1997 (because what came after didn’t fit his conception of the US temperature trend). He also concluded that the decade of elevated US temperature was just a fluke:
Now, after three relatively near-normal years, the 10-yr warm period from 1998-2007 was starting to look to be out of place, rather than the new norm…
But the last three years, 2008–2010, and now the projections for 2011, lie much closer to an extension of the 1895–1997 trend line than the 1895-2007 trend line (Figure 6).
Let’s sum up: Knappenberger prefers a trend estimate which leaves out the recent hot years. He justifies this by saying that three years is enough to conclude that the trend without the hot years is the “real” one. Curious that 3 years reveals the true trend but 10 years is just a fluke.
If 2011 ultimately turns out to come in in-line with the central projections in Figure 5, it will strengthen the suggestion that the unusually high temperature that characterized the 10-yr period from 1998–2007, were just that, unusual, and do not best represent either the expected trend or the climate state of the U.S. for the next several decades to come.
It turned out that 2011 did not conform to Knappenberger’s expectation of being cooler than 2010 in the USA.
The really telling part of all this is that even if it had, that doesn’t justify leaving out the hot years when estimating a trend. That’s not just cherry-picking, it’s wishful thinking of the worst kind — the kind that puts other folks (you and me) in danger.
There’s no doubt that fluctuations occur — real data are the combination of trend and fluctuations. Hot years might be a fluctuation, nothing more. That’s why we apply statistics to get the best estimate. One of the important rules of honest statistics is you’re not allowed to leave out data just because it contradicts what you want to believe. Yet that is exactly what Chip Knappenberger did.
Knappenberger not only considered it possible, he actually stated as a conclusion that the hot years were just due to fluctuations. He never mentioned the possibility that the three-year period 2007-2010 might be cooler because of fluctuations. According to Knappenberger, when temperature fluctuates up it’s “unusual” but when it fluctuates down it’s “near-normal.”
That’s one of Chip Knappenberger’s brands of shallow thinking. I was originally going to append the adjective “unique,” but that would be a mistake. This kind of so-shallow approach to looking at what has been happening to the world is pervasive among the fake “skeptics” who deny the danger of global warming. Like Anthony Watts crowing about record December snow cover without even mentioning the real trends. Or even worse: Watts and co. have now decided to crowdsource their cherrypicking under the fake name “analysis.”
Fluctuations can go both ways, down and up. When a “down” fluctuation combines with an “up” trend, it gives what Chip Knappenberger and Anthony Watts and lots of other fake skeptics call “normal.” But when an “up” fluctuation combines with an “up” trend, you get USA temperature for 2012:
The impact of this year’s heat and drought on our corn crop was not pretty.
The temperature fluctuation in 2012 was quite high, but by no means extraordinary:
It was the combination of fluctuation and trend which made 2012 so bad. Fluctuations will continue to come, some up, some down. The “up” ones will bring about a repeat of disastrous conditions. And since the trend keeps rising, those future disasters will be even worse.
The “down” fluctuations will bring about a repeat of fake skeptics crowing about “return to normal.”