For a layman reading the e-mails, it is hard to tell -- sometimes in private conversations academics have short-hand ways of talking about things that could be misconstrued if overheard. I'm going to contact a friend much more expert in such things than me to get his take, to see if these are innocent remarks, evidence of sloppiness, or outright nefariousness.
As regular Wordhoarders know, I've been very critical of the treatment of the Medieval Warm Period (MWP) by the National Oceanic and Atmospheric Administration (NOAA) in this country. In the past, NOAA has posted summaries of its research on their paleoclimatology page that I found misleading and at odds with the actual research cited. Until last year, NOAA's page suggested there there was no Medieval Warm Period, but they quietly began to acknowledge it (along with the Little Ice Age), but they fudge it by writing, "In summary, it appears that the late 20th and early 21st centuries are likely the warmest period the Earth has seen in at least 1200 years." Incidentally, elsewhere NOAA still calls it the "so-called Medieval Warm Period."
In any case, some of the commentary about the CRU e-mails has been regarding the Medieval Warm Period, but much of it has been redacted to just include the dirty stuff, so here I offer you the more complete context from an e-mail exchange started on June 4th, 2003:
[W]hat I had in mind were the following two figures: 1) A plot of various of the most reliable (in terms of strength of temperature signal and reliability of millennial-scale variability) regional proxy temperature reconstructions around the Northern Hemisphere that are available over the past 1-2 thousand years to convey the important point that warm and cold periods where highly regionally variable. Phil and Ray are probably in the best position to prepare this (?). Phil and I have recently submitted a paper using about a dozen NH records that fit this category, and many of which are available nearly 2K back--I think that trying to adopt a timeframe of 2K, rather than the usual 1K, addresses a good earlier point that Peck made w/ regard to the memo, that it would be nice to try to "contain" the putative "MWP", even if we don't yet have a hemispheric mean reconstruction available that far back [Phil and I have one in review--not sure it is kosher to show that yet though--I've put in an inquiry to Judy Jacobs at AGU about this]. If we wanted to be fancy, we could do this the way certain plots were presented in one of the past IPCC reports (was it 1990?) in which a spatial map was provided in the center (this would show the locations of the proxies), with "rays" radiating out to the top, sides, and bottom attached to rectanges showing the different timeseries. Its a bit of work, but would be a great way to convey both the spatial and temporal information at the same time. 2) A version of the now-familiar "spaghetti plot" showing the various reconstructions as well as model simulations for the NH over the past 1 (or maybe 2K). To give you an idea of what I have in mind, I'm attaching a Science piece I wrote last year that contains the same sort of plot.
Anyway, there you have it in fuller context for you to form your own opinion. Obviously, the dirty part people are talking about here is where the writer discusses trying to "contain" the Medieval Warm Period by consciously employing the logical fallacy of cherry picking a data set.
*I hesitated at first to post something that was illegally hacked, but I decided to press forward because 1.) the e-mails are already now fully public, and 2.) now that people know they are there, they've also been made public through legal means as well, and 3.) when in doubt, it's better to talk about the facts. My apologies to any Wordhoarders who find this ethically questionable.