Friday, January 18th 2013, 1:51 PM EST
Alterations to temperature record 1881-2008
I ran a post yesterday, showing how the latest version of GISSTEMP had changed from using Hadley/Reynolds to ERSST for ocean temperatures, with the result that about 0.03C had been added to recent warming.
However, this is not the only change they have made to the historical temperature record in recent years. Climate4You, fortunately, archived the GISS data in May 2008. Comparing this dataset with today’s version, we can see that about 0.10C of warming, or more, has been added to temperatures in the last decade, compared to data up to about 1950.
It must be remembered that these are only changes made by GISS since 2008. As I pointed out, prior to 2008, other adjustments of about 0.03C had already been added to the numbers originally declared just a few years earlier. These adjustments must, therefore, also be added on to the adjustments made since.
An adjustment of 0.10C or so may not seem a lot, but the latest GISS anomaly, against the baseline of 1951-80, is 0.44C. These adjustments make up about a quarter of this figure.
I have also done some digging on the original numbers GISS declared for 1998, which seem much different to what they now show. News on this later.