Just one variant of data problems. The others are even harder
Reading through this article on how climate researchers modified and adjusted actual data from the Darwin, New Zealand station confirms my belief that historical surface measurements provide little guidance as to global temperatures.
As I mentioned in my original article, the hard part is not to find five neighboring stations, particularly if you consider a station 1,500 km away as “neighboring”. The hard part is to find similar stations within that distance. We need those stations whose first difference has an 0.80 correlation with the Darwin station first difference.
(A “first difference” is a list of the changes from year to year of the data. For example, if the data is “31, 32, 33, 35, 34″, the first differences are “1, 1, 2, -1″. It is often useful to examine first differences rather than the actual data. See Peterson (PDF) for a discussion of the use of the “first-difference method” in climate science.)
Read the whole thing if climate science and statistics interests you. Basically, even if their motives were pure, climatologists face an intractable problem of bad instruments, faulty recording, bad locations and a variety of other data oddities when trying to look at past surface temperatures.
This makes sense right? Take Saturday morning… I walked out of the house, which was brisk but comfortable, drove 4 miles, and was miserably cold.
Surface weather varies widely for surface reasons. Attempts to homogenize it to create some global record just don’t make any sense.
Going forward I’m more interested in the satellite data – which by the way – shows things getting cooler.