The McIntyre factor is the amount that you have to multiply the size of an adjustment in the GISS US temperatures by to get the number of words in the resulting Steve McIntyre post. Empirical evidence puts the McIntyre factor at 125,000. You see, on Sep 10 GISS made some small changes:
We switched to the current version of USHCN data set which includes data through 2005. The effect of this change is shown by the following graphs. Also see tables of comparisons for globe and US-only.
In the US, 1998 and 1934 each changed by just 0.01 degrees C. So naturally Steve McIntyre wrote a 2,500 word post about how the changes were part of some NASA conspiracy to … ah, heck, if I summarized him you might wonder if I was being unfair, so in his own words:
This new leaderboard is really something else. I’m going to post on this: but if the SHAP version was what they used for the past decade, it’s a little – shall we say – “convenient” to decide in Sept 2007 that they are going to switch to the FILNET version (without announcing it on their website) and then, surprise, surprise, 1998 is now tied for the warmest year. This is going to send shivers up the spine of any readers familiar with accounting principles. …
So while the difference between 1934 and 1998 may have been “statistically insignificant”. Hansen was obviously quite annoyed by the attention paid to 1934 being called the “warmest year” even in the U.S. and the change in rankings must have stuck in his craw. Was that motivation in the change from SHAP to FILNET accounting? I certainly hope not. Perhaps long before the Y2K error re-arranged things, NASA had already made long-standing plan to shift from SHAP accounting to FILNET accounting. But if this was not the case, then the timing of the change, especially with the all too “convenient” restoration of 1998 to the top of the leaderboard is certainly unfortunate.
This is precisely the type of situation that would have been avoided by NASA adhering to GAAP principles. Companies cannot change accounting procedures on a whim. Auditors will not permit companies to change methods merely to enhance reported earnings. And if a company changed accounting procedures without any disclosure, it would be viewed very seriously by regulatory agencies – whether or not the company said that it “mattered”. If the change from SHAP to FILNET accounting didn’t “matter”, then Hansen shouldn’t have done it. If it did matter, he still shouldn’t have done it right now just when he was archiving source code for the first time – and to do so without either formal disclosure or a re-statement of prior results simply boggles the imagination.
So McIntyre reckons that NASA changed their procedure to put 1998 on top of the leaderboard. But NASA doesn’t publish a leaderboard of warmest years in the US. And not only that they’ve never reported that 1998 was the warmest year in the US.
The fact is, that 1998 and 1934 are so close in the GISS temperatures that any new set of numbers has a good chance of changing their ranking. Since 2005, the relative rankings have changed from 1934 warmest, to tied, to 1998 warmest, to 1934 warmest and to tied again. None of these changes means anything — it’s just noise, but the result of this noise is more noise from McIntyre. If 1934 hits the front he can post about how 1998 is no longer the warmest year and if 1998 edges ahead, he can post about how NASA is cooking the books.
And just as he intended, McIntyre’s post was picked up by denialist blogs like Noel Sheppard, who accused NASA of cooking the books like Enron. Charming.