Sunday, November 29, 2009

Data, we don't need no stinking data.

Admitted the title is a paraphrase of a film quip, or more precisely, a paraphrase that combines two lines from the same film. But it seems to capture some of the attitudes at the Climate Research Unit regarding the data they used, as one of the key centers in the world, to determine whether or not their has been warming.

Raw data is collected. That data then goes through a process of adjustment where the scientist makes certain assumptions about how the data should be manipulated in order to take into account various factors, such as the "heat island" effect, changes in location of the reporting station, etc. Of course, the assumptions one makes can change the results by a considerable amount.

The raw data, however, is obviously critical if one is to verify the results. Would other scientists, using the same data sets, get the same results. Both the data and the assumptions used need to be available for that verification process to work. I personally would argue it "ain't science" until it can be replicated by others, using the same data. Of course, there is also legitimate debate regarding what assumptions were created to massage the data.

But now the Evironmental Editor of the London Sunday Times, Jonathan Leake, reports:
SCIENTISTS at the University of East Anglia (UEA) have admitted throwing away much of the raw temperature data on which their predictions of global warming are based. It means that other academics are not able to check basic calculations said to show a long-term rise in temperature over the past 150 years.

...The admission follows the leaking of a thousand private emails sent and received by Professor Phil Jones, the CRU’s director. In them he discusses thwarting climate sceptics seeking access to such data.

In a statement on its website, the CRU said: “We do not hold the original raw data but only the value-added (quality controlled and homogenised) data.”

The CRU is the world’s leading centre for reconstructing past climate and temperatures. Climate change sceptics have long been keen to examine exactly how its data were compiled. That is now impossible.

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