Global warming/hockey stick/deception

anonymous
...the data used for temperatures further back than about 100 years represent long term averages (100-1000 years) and are based on things like Deuterium concentrations, organism distributions and other factors that change slowly. Temperatures from about 100 to 30 years ago are sparsely sampled surface temps and grossly homogenized while temperatures up to 30 years ago tend to be either sparse, highly homogenized data (Mann's tree rings, Hansen's GISS temp, etc.) or satellite data, both of which are representative of shorter term averages. It should be clear to anyone who understands statistical analysis that a short term averages change more rapidly and have more p-p variability than long term averages. If you applied the same multi century averaging to all of the data, the hockey stick would completely disappear. Mixing long term averages with short term averages is a common trick used in these hockey stick plots which as far as I can tell is done for no other reason than to confuse you into believing fiction. &mdash; email quoted in a comment here

Orson Scott Card

 * 2007-03-04 All in a Good Cause (alt) by Orson Scott Card: the story of the Hockey stick controversy, in somewhat simplified and dramaticized form, with links to a couple of books for supporting evidence (but nothing online). OSC's claim (which repeats what has been said elsewhere) is that all the claims of global warming are based on this one heavily-biased faulty analysis.
 * Like many of Card's essays, this one draws a very strong conclusion from a long chain of facts that are difficult to confirm. His main argument seems to be that all of the so-called "consensus" on the existence of global warming is based on one single paper whose conclusions he throws into serious doubt. In defense of this position, he offers links to two books, neither of which appear to be online (i.e. you have to buy the books just to follow to the next link in the chain -- which may or may not yield actual data or solid arguments). My first reaction is that I am extremely skeptical of this; you just don't get a global scientific consensus based entirely on one paper, much less one whose conclusions are so easily shot down. Card's argument is also a sort of ad hominem in that it doesn't actually offer specific counter-arguments but merely tries to discredit the source. However, as usual, Card is performing a useful service by at least showing some of the basis behind the claims that GW is pseudo-scientific; some progress can now be made in understanding those claims.
 * On a very brief reading of the Wikipedia article, it looks like the "hockey stick" conclusion probably exaggerated the data somewhat but still came to the correct conclusion.

responses

 * 2007-08-10 slashdot has a point-by-point response

Defenses
I think the most critical point to remember, if you are researching this in the context of determining the validity of AGW theory, is that this row is about a single study that was published 8 years ago. This is starting to be ancient history. If you feel it is tainted (as I prefer to just assume, because as I said I do not want to put the required effort into unraveling it all for myself) then simply discard it.
 * The Hockey Stick is Broken, part of an FAQ refuting GW skepticism, says:

The fact is there are dozens of other reconstructions. These other reconstructions do tend to show some more variability than MBH98, ie the handle of the hockey stick is not as straight, but they *all* support the general conclusions that the IPCC TAR came to in 2001: the late 20th century warming is anomalous in the last one or two thousand years and the 1990's are very likely warmer than any other time in the last one or two thousand years.