AGW "skeptics" are pushing the idea that Phil Jones' "trick to hide the decline", and the VERY ARTIFICIAL correction I discussed in a prior post are essentially evidence of tampering with the "hockey stick" reconstruction.
In reality, the artificial correction refers to rudimentary, probably temporary code (apparently marked with all-caps comments to caution CRU researchers not to use it as final code) that corrects temperatures derived from tree-ring widths, due to a problem known as "tree-ring divergence." It's highly improbable the artificial correction was ever used in any published paper.
This "hockey stick" does not require you to write any algorithms. The only "tricks" involved in producing it are the following:
- Temperature data up to 1980 comes from Mann & Jones (2003) (data made available by NOAA.)
- Temperature from 1981 onwards comes from the CRUTEM3v global data set.
- The red line is a 25-year central moving average of the temperature series.
You can try this yourself with different data sets. It's not very difficult. If you don't trust CRU temperature data, use GISSTemp. If you don't think the Mann & Jones (2003) reconstruction should be used, there are plenty of other historical reconstructions that use methods other than tree-rings. Do report back if it doesn't work. Comment moderation is never enabled here.
[Errata 11/30/2009: The post initially said the red line was a 75-year central moving average. It's actually a 25-year CMA.]