Climate scientist Michael Mann, best known for creating the questionable “hockey stick” graph to show the effects of so-called anthropogenic global warming after the industrial revolution spoke to CNN about the University of East Anglia climate-gate emails.
CNN: What does he mean by saying the word “trick?”
Michael Mann: Scientists, Mathematicians often use the word ‘trick’ in the sense of a clever approach to solving a problem. We had one data set that stretched way into the past, but it didn’t come up to the present. It stopped in 1980. At the same time, we had more recent data that showed how the Earth has warmed in the subsequent decades, and in order to understand the longer term data, it needs to be put in the context of the more recent data, so that the relative warmth today can be compared to the relative warmth in the past, and so the trick was simply presenting these two data sets together so that they could be compared against each other. It was completely out in the open. So, there was nothing hidden or secret. It was just what my colleague was calling a clever way to present the data.
CNN: What about the word decline? What is that referring to?
MANN: He refers to tree ring information. They were looking at the density of the wood, that formed in those annual growth bands, and it turns out that measure is highlighted with summer temperatures, where these tress grow.
(SOT describing tree ring formations)
MANN: In this email that referred to the “decline,” was simply referring to the fact that these data shouldn’t be used after 1960, because of this divergence—-because of this decline. So this was something that was completely out in the open. It wasin the published literature.
CNN: No cover up?
MANN: No cover up. It was perhaps it was a poor choice of words. Again, I imagine if my colleague, if he knew, that his personal e-mails were going to be read by the entire world, he might have been a little bit more careful in how he worded things.