Some segments of the Internet are abuzz with the claim by climate change skeptic Steven Goddard (Tony Heller) over at his Real Science blog that NASA/NOAA have been jiggering the numbers so that they can claim that warmest years in the continental United States occurred recently, not back in the 1930s. Folks, please watch out for confirmation bias.
Via email, I asked Anthony Watts, proprietor of WattsUpWithThat, what he thinks of Goddard's claims. He responded…
…while it is true that NOAA does a tremendous amount of adjustment to the surface temperature record, the word "fabrication" implies that numbers are being plucked out of thin air in a nefarious way when it isn't exactly the case.
"Goddard" is wrong is his assertions of fabrication, but the fact is that NCDC isn't paying attention to small details, and the entire process from B91's to CONUS creates an inflated warming signal. We published a preliminary paper two years ago on this which you can read here: http://wattsupwiththat.com/2012/07/29/press-release-2/
About half the warming in the USA is due to adjustments. We' received a lot of criticism for that paper, and we've spent two years reworking it and dealing with those criticisms. Our results are unchanged and will be published soon.
In his email, Watts also cites the strong criticisms of Goddard's earlier claims over at the Blackboard blog:
Goddard made two major errors in his analysis, which produced results showing a large bias due to infilling that doesn't really exist. First, he is simply averaging absolute temperatures rather than using anomalies. Absolute temperatures work fine if and only if the composition of the station network remains unchanged over time. If the composition does change, you will often find that stations dropping out will result in climatological biases in the network due to differences in elevation and average temperatures that don't necessarily reflect any real information on month-to-month or year-to-year variability. Lucia covered this well a few years back with a toy model, so I'd suggest people who are still confused about the subject to consult her spherical cow.
His second error is to not use any form of spatial weighting (e.g. gridding) when combining station records. While the USHCN network is fairly well distributed across the U.S., its not perfectly so, and some areas of the country have considerably more stations than others. Not gridding also can exacerbate the effect of station drop-out when the stations that drop out are not randomly distributed.
I note that Watts commented on the, hmmm, accuracy of Goddard's work over at the Blackboard as well:
I took Goddard to task over this as well in a private email, saying he was very wrong and needed to do better. I also pointed out to him that his initial claim was wronger than wrong, as he was claiming that 40% of USCHN STATIONS were missing.
Predictably, he swept that under the rug, and then proceeded to tell me in email that I don't know what I'm talking about. Fortunately I saved screen caps from his original post and the edit he made afterwards.
Note the change in wording in the highlighted last sentence.
In case you didn't know, "Steve Goddard" is a made up name. Supposedly at Heartland ICCC9 he's going to "out" himself and start using his real name. That should be interesting to watch, I won't be anywhere near that moment of his.
This, combined with his inability to openly admit to and correct mistakes, is why I booted him from WUWT some years ago, after he refused to admit that his claim about CO2 freezing on the surface of Antarctica couldn't be possible due to partial pressure of CO2.
And then when we had an experiment done, he still wouldn't admit to it.
And when I pointed out his recent stubborness over the USHCN issues was just like that…he posts this:
He's hopelessly stubborn, worse than Mann at being able to admit mistakes IMHO.
In his email to me, Watts details the sort of bureaucratic bungling that produces what he thinks is a significant artificial warming signal in the lower 48 temperature records from which he concludes:
It is my view that while NOAA/NCDC is not purposely "fabricating" data, their lack of attention to detail in the process has contributed to a false warming signal in the USA, and they don't much care about it because it is in line with their expectations of warming. The surface temperature record thus becomes a product of bureaucracy and not of hard science…Never ascribe malice to what can be explained by simple incompetence.
See my earlier reporting on Watts et al.'s U.S. temperature data paper in my article, "Everyone Freaks Out About Two New Climate Change Studies." In response to criticism of that paper Watt and his colleagues have, as noted above, recrunched the data and will release a new paper soon.