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Politics : Politics of Energy -- Ignore unavailable to you. Want to Upgrade?

To: TimF who wrote (74520)	1/28/2017 3:12:33 PM
From: teevee	Respond to of 86355

thermometers are all calibrated in ice water baths. There is no need to adjust historical temperature data, other than to commit some kind of fraud.

To: TimF who wrote (74520)	1/29/2017 3:57:01 PM
From: Alastair McIntosh	Read Replies (1) \| Respond to of 86355

How do you infer that I'm challenging specific adjustments from me saying I'm not doing so? I drew the inference from your clause "(in this conversation)" in the sentence where you stated that you were not challenging the adjustments that have been made. The fact that you specifically included that clause led me to my inference that you could be challenging the adjustments in other conversations. "I'm not (in this conversation) challenging the specific adjustments that have been made" Notice that the earlier adjustments (differences between the line for raw data and the other lines) are 1 - Not as directional. 2 - Smaller You are not interpreting the temperature adjustments correctly. The plot shows temperatures relative to 1900 - 1920. (As you can see, the three lines intersect at 1910.) However, the current readings from state of the art instruments are taken to be correct which requires that the adjustments be made to earlier readings. It would be better to have shown the adjustments relative to current readings instead of the 1900 - 1920 period. That would show that the large adjustments are actually in the earlier readings. EDIT: Here is a better plot: NCDC assumes that the current set of instruments recording temperature is accurate, so any time of observation changes or PHA-adjustments are done relative to current temperatures. Because breakpoints are detected through pair-wise comparisons, new data coming in may slightly change the magnitude of recent adjustments by providing a more comprehensive difference series between neighboring stations. When breakpoints are removed, the entire record prior to the breakpoint is adjusted up or down depending on the size and direction of the breakpoint. This means that slight modifications of recent breakpoints will impact all past temperatures at the station in question though a constant offset. The alternative to this would be to assume that the original data is accurate, and adjusted any new data relative to the old data (e.g. adjust everything in front of breakpoints rather than behind them). From the perspective of calculating trends over time, these two approaches are identical, and its not clear that there is necessarily a preferred option.