Quick Fact: Hannity advances falsehood about CRU email to claim scientists were "fudging" data
On his Fox News show, Sean Hannity falsely claimed that emails reportedly stolen from the Climate Research Unit at the University of East Anglia (CRU) show that the scientists "were certainly fudging" climate data; as an example, Hannity read from an email from CRU scientist Phil Jones in which he employed the word "trick" to describe his methods. In fact, the word "trick" has been grossly misinterpreted and refers to unreliable tree-ring data, not actual temperature readings.
Hannity cites "Mike's Nature trick" email to claim scientists "were certainly fudging" data
From the December 3 edition of Fox News' Hannity:
HANNITY: The climate change emails uncovered at the University of East Anglia shed serious doubts on the science of global warming.
And if they weren't dumping data, well, they were certainly fudging it. Another email between these colleagues from nine years prior shows the dishonesty was long in the works. It reads, quote, "I've just completed Mike's Nature trick of adding in the real temps for each series for the last 20 years, i.e., from 1981 onwards, you know, to hide the decline." Well, that would be the decline in global temperatures.
So could it be any more clear that the so-called climate scientists are hoodwinking the entire world community?
FACT: Scientists say the word "trick" has been misinterpreted; it is not evidence Jones was "fudging" climate data
Several scientists have stated that the word "trick" is being misinterpreted. Phil Jones' email  states, "I've just completed Mike's Nature trick of adding in the real temps to each series for the last 20 years (ie from 1981 onwards) amd [sic] from 1961 for Keith's to hide the decline." The (UK) Guardian reported  in a November 20 article that Bob Ward , director of policy and communications at the Grantham Research Institute on Climate Change and the Environment at the London School of Economics, said of Jones' email: "It does look incriminating on the surface, but there are lots of single sentences that taken out of context can appear incriminating. ... You can't tell what they are talking about. Scientists say 'trick' not just to mean deception. They mean it as a clever way of doing something -- a short cut can be a trick." RealClimate.org also explained  that "the 'trick' is just to plot the instrumental records along with reconstruction so that the context of the recent warming is clear. Scientists often use the term 'trick' to refer to ... 'a good way to deal with a problem', rather than something that is 'secret', and so there is nothing problematic in this at all."
"Hide the decline" refers to unreliable tree-ring data, not actual temperature readings. In a November 26 article , The Morning Call of Allentown, Pennsylvania, reported that Penn State scientist Michael Mann -- whose "trick" was referenced in Jones' email  -- "said his trick, or 'trick of the trade,' for the Nature chart was to combine data from tree-ring measurements, which record world temperatures from 1,000 years ago until 1960, with actual temperature readings for 1961 through 1998" because "scientists have discovered that, for temperatures since 1960, tree rings have not been a reliable indicator." Jones has also stated  that it is "well known" that tree-ring data "does not show a realistic trend of temperature after 1960," and CRU has said that "[t]he 'decline' in this set of tree-ring data should not be taken to mean that there is any problem with the instrumental temperature data." In a November 20 post, RealClimate.org's staff , which is comprised of several working climate scientists, including Mann, similarly stated :
As for the 'decline', it is well known that Keith Briffa's maximum latewood tree ring density proxy diverges from the temperature records after 1960 (this is more commonly known as the "divergence problem"-see e.g. the recent discussion in this paper ) and has been discussed in the literature since Briffa et al in Nature in 1998 (Nature, 391, 678-682). Those authors have always recommend not using the post 1960 part of their reconstruction, and so while 'hiding' is probably a poor choice of words (since it is 'hidden' in plain sight), not using the data in the plot is completely appropriate, as is further research to understand why this happens.