Tuesday, 25 January 2011

Real science and Climategate

Just watched a really interesting, if somewhat depressing Horizon, in which the President of the Royal Society, Sir Paul Nurse, discusses the way in which the public perception of science has been damaged over the past few years.  I hope that if you click that link, it'll allow you to watch the programme.  What it seems to come down to is that the internet allows anyone who feels like it to publish their own point of view, whether that's based on reality or just their own particular fantasy, and search engines throw up the links without providing any clue as to which is the real science and which the fantasy.  They all appear to carry the same weight.  No wonder the public is confused.

Much of the programme is based around Climategate, and the key thing it clarified for me was the way in which that controversy arose.

Summary
Much of the data telling us about global temperatures in the past comes from tree rings, and some of the bits of wood that provide that information are very old indeed.  From the time thermometers were invented and temperatures recorded, there's a very good correlation between the dimensions of tree rings and temperature, so we can be pretty secure in deriving temperatures from wood that was growing before the invention of the thermometer.

Unfortunately, after about 1960, the correlation starts to break down, and no-one yet understands why.  So the controversy started because in preparing a graph showing global temperatures, the scientists used real temperatures, measured using thermometers, in preference to tree ring-derived temperatures.

The Telegraph journalist who latched onto this called it "apples and oranges", ie you're not comparing like with like, but that's clearly nonsense.  What the scientists were interested in was the global temperatures, and the fact that they needed to use two different techniques to measure temperature is irrelevant.  What's important is the temperature, and that's why the science was vindicated.

One of the depressing aspects of the programme was seeing the way different newspapers had reported the vindication.  Rags like the Daily Express presented it as if, despite doing poor science, the guy somehow managed to hang onto his job, which is a gross distortion of the truth.  I guess screaming headlines always did sell more papers than boring old truth.

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