Nov 252009
 

I’m still trying to digest this… the meaning of recently released e-mails that suggest, to put it mildly, questionable behavior on behalf of some of the world’s leading climate researchers.

One e-mail that’s most hotly debated is about this:

mbh99smooth_no_inst

This plot contains two types of data: long-term reconstructed temperatures from the fossil record, and shorter term instrumental temperatures. Now the trouble is, the smoothed curve (green) based on the reconstructed temperatures alone points slightly downward… no dramatic warming trend. In contrast, the instrumental temperatures show an upward trend. This apparent disagreement is purely a mathematical artifact; anyone who ever attempted to fit, for instance, a polynomial curve to some data knows that the fit tends to diverge near the ends of the data interval. But it wouldn’t look good on a report that is designed to influence world opinion and global policy to show a downward trend, would it. So there’s a neat “trick”: the apparent downward trend can be eliminated by using the instrumental temperatures to pad the reconstructed temperature data set, and produce an upward trend.

Note that this doesn’t mean that there is a downward trend. The planet may very well be warming, due to what people are doing to it. Unfortunately, the information content of manipulated graphs is zero, or less than zero even… they can generate skepticism towards genuine future results and delay a necessary public response.

There are many other questionable e-mails in the lot, including e-mails that suggest the hiding of data from freedom-of-information requests, e-mails that suggest efforts to block the publication of research by climate change skeptics, and at least one eyebrow-raising comment cheering at the death of a climate change skeptic, leading to calls for a researcher to resign.

I’m still digesting this, but it reinforces my conviction that phrases like “standard model” or “scientific consensus”, far from reassuring, should be a clear indication that the science might be shaky, and that an attempt is being made to substitute authority in place of convincing data and firm logic.

 Posted by at 4:35 am

  One Response to “Climate change?”

  1. […] in different ways. True. But that is no excuse to discard the raw data. Not to mention that the data manipulation that caught so many people’s attention in the Climategate e-mails was not about fixing up raw […]