Quite how much this changes the larger picture I’m really not sure: the news is too new and not enough other, brighter than I, people have chewed it over for me to know. But, fascinating all the same.
We’re all used to the cry that 1998 was the warmest year ever? Or warmest in 100/400/1,000 years, take your pick? It appears not. 1934 was, at least for the United States. Further, that there’s (again for the U.S. only) been some reordering of which were the other hottest years:
1934, 1998, 1921, 2006, 1931, 1999, 1953, 1990, 1938, 1939
That’s the new listing. Now, no, this does not prove that the whole thing is hype, nor that it’s mistaken. It’s long been known that there was cooling from the 40s to the 70s as a result of the sulphates pumped into the atmosphere and that as we cleaned up industrial emissions this effect declined, the underlying warming coming through. What it does show though is that by no means is this a settled question. For what is it that has caused this revision?
Steve McIntyre (whose Climate Audit site seems to be down, rumoured to be a result of a DOS attack: how strange on a day he releases this sort of information) was puzzled by a seeming anomaly in some of the temperature recordings (I’m going to keep it very simple here) and suspected that there was a bug in some of the software. Having informed the people at NASA who tend to such records, they then changed the listings as above.
So, over and above the interesting, but not crucial (except in terms of rhetoric), fact that 1998 was not the warmest year, even in the last century, we’ve found that there are indeed errors in the temperature records. Which I think is indeed very interesting, and again, while not crucial in and of itself, could be: it depends upon how many others there are.
Which leads to the conclusion that, really, we ought to go and find out, don’t you think? Before we commit ourselves to trillions of dollars of expenditure and wealth foregone on the basis of what we now know to be, to put it kindly, dodgy figures? Why, we might ask those who have been correcting the temperature figures (and yes, they do need correcting, for things like urban heat effects, replacement or moving of measurement stations etc.) exactly how they have been correcting those temperatures: can we see your data and assumptions please? Perhaps your code?
It’s just about possible to say “We’re scientists, we know what we’re doing” and insist that no mere retired mining executive is ever going to find anything wrong. However, when that very mere retired mining executive does find something wrong that’s a stance that’s not really going to work.
Gentlemen, time for you to show your workings, please.