A teacher wants to get her class to understand the scientific method and process, particularly how it is sometimes necessary to reach provisonal conclusions on the basis of limited data.
She gives her students a can containing white marbles and black marbles, with a cover that has an aperture which allows one hand to be inserted and to remove a few marbles. The teacher instructs them to shake the can thoroughly every time before they collect a sample, and to sample the marbles five at a time (and return the marbles to the can after they have been removed and counted). The requirement is that the class give her a single report on what the can contains, after they have discussed their results.
All of the students (lets say 30) reached into the can, pulled out five marbles, and reported their results. 24 of the students pulled out five white marbles. Five of the students pulled out 4 white marbles and one black marble. One student pulled out five black marbles.
So now the class had to write its report. They selected one of their best writers to compose an initial statement. The statement said, "Based on our collections of marbles from the can, we believe that the can is filled mostly with white marbles, and a few black marbles."
But then one of the students that pulled out 4 white and 1 black said, "Wait. Somebody else pulled out five black marbles. That might indicate that there are a lot more black marbles in the can. I got one, too."
The writer of the original statement replied: "But based on what we know -- so many of our class pulled out 5 white marbles -- we have to say that we think most of the marbles are white."
Another student said, "But you don't know that for sure. What if the black marbles are heavier? What if most of the students didn't reach into the can far enough to get more heavier black marbles near the bottom? There could be as many black marbles in the can as white marbles -- we just didn't grab them properly."
The statement writer then said: "No, we don't know for sure. We can't look into the can and count all the white marbles and all the black marbles. But if I rewrite our report to say that there could be a lot more black marbles in the can, that would make it sound like we pulled out more black marbles than we actually did, doesn't it?"
The student that pulled out 5 black marbles then says, "I can't tell you if they felt any heavier, because I didn't pull out any white marbles. But it's possible that they were."
The student trying to write the statement throws up his hands in frustration and says, "OK, we're trying to write the best report we can. We should first say that most of our collections were all white marbles. That seems to show that most of the marbles in the can are white marbles. But because there was one collection with all black marbles and five others with one black marble, we'll also say that there are definitely some black marbles in the can. We can't say anything else because we didn't do anything else!"
The students think this over. One student then says, "If you don't at least mention that there could be a lot of black marbles in the can, because one student collected five black marbles, then it'll look like you're trying to hide something."
The report writer says, "Like what?
The student replies, "It'll look like you're trying to hide that there might be a lot of black marbles in the can."
The report writer says, exasperatedly, "But most of the collections were all white marbles! It has to be clear in our report that our collections showed that most of the marbles in the can are white!"
The students discuss and discuss and discuss for another hour. Finally they agree on this report:
"Each of the students in the class collected five marbles from the can. Most of these collections were five white marbles. A few students had collections with one black marble and four white marbles. One student collected five black marbles, which seemed unusual. Based on our results, we conclude that the contents of the can are primarily white marbles with a much lower number of black marbles compared to the number of white marbles."
Is that report propaganda? If so, then so also is that part of the IPCC TAR being discussed in the email messages.
(By the way, one student in the class went home and complained to his parents that the class was biased toward white marbles, because they added the part about the collection of five black marbles being unusual, which made it seem like collecting five black marbles wasn't very important, when it really was the most interesting thing that happened, and they should have said more about it!)
Interesting that no one accounted for the red marbles.
The part you don't seem to understand is how few independent proxy studies were used in the 2001 IPCC version of the hockey stick. It was mostly based on Mann PCA, shown to be flawed.