A new paper came out in Science just last week called Possible artifacts of data biases in the recent global surface warming hiatus, by Dr. Thomas Karl of the NOAA, which considers the so-called ‘hiatus’ in global warming in the last 17 years or so. I don’t intend to cover the paper in detail; you can read more here, here and here if you wish. The paper is available here and is not paywalled, as far as I know.
The essence of the paper, though, is that the authors identified three systematic biases in land surface and, of more significance, sea surface temperature measurements. Having identified the biases, and their contribution to measurements, Karl et al applied these to correct the global temperature record, producing a more accurate record in the process, and concluded that the warming rate since the start of the century is in line with the previous five decades. The ‘hiatus’, therefore, does not exist.
Identifying biases in data is extremely important in science. Scientists need to know whether what they are observing, and therefore interpreting, is correct. Introduced biases in the data need either to be simply acknowledged, or used to correct the data. It is simply unscientific to ignore that they exist, especially when they don’t fit your preconceptions or expectations of what the data should look like – more on that in a minute.
Examples from my own research would be the different levels of bias in pipetting fluids depending on the person doing the work: some might consistently pipette more or less fluid than another. Or there can be instrumental bias, such as the measurement of alkalinity by photometry, which in my lab results exhibit an accuracy bias of +/- 30% depending on how it is assessed!
Data bias is one thing; cognitive bias another. As mentioned, once biases in data are detected, they must be allowed for in the interpretation of the results. If one ignores the bias (assuming it’s significant, of course) because this bias changes the interpretation of the data – perhaps unfavourably – then cognitive bias is introduced. Scientists are trained, as far as is possible, to ignore this and consider only what the data tells them. Or at least they should, if they are being sufficiently sceptical and unbiased.
Going back to Karl et al 2015, the response by climate change deniers (or ‘sceptics’, if you wish) has been predictable. I have commented little, if at all, on this blog about climate change denial. It’s a phenomenon which is interesting to observe, but also immensely frustrating. The cognitive dissonance, conspiracy theorising, and lack of genuine sceptical and unbiased thinking amongst those who deny [carbon dioxide is a greenhouse gas; the Earth is rapidly warming; ice sheets are melting; extreme weather is increasing] and that humans are to blame is similar to young Earth creationists, anti-vaxxers and so on.
Various popular denial blogs cover the spectrum of denial, notably Watts Up With That, Bishop Hill, Climate Etc. and JoNova. There also many blogs dedicated to debunking denial myths and claims, the best of which are Skeptical Science and HotWhopper. However, in addition to the ‘big hitters’ of climate denial, there are many many smaller ones which get little attention. Two such blogs are written by so-called sceptics on my doorstep in Scotland: Euan Mearns is proprietor of Energy Matters, while Mike Haseler runs Scottish Sceptic. If I may be so bold, and perhaps a tad unprofessional, neither are as intelligent as they think they are, and Haseler in particular inhabits the nuttier end of the pick-n-mix bag of climate denial.
Euan launched an attack on me back on February called Green Thinking: is it science? after I dared to accept the current hypothesis of why snow cover is decreasing in spring, but increasing in winter in the Northern Hemisphere (see here, for example). He also allows himself, his co-proprietor Roger Andrews, and commentators on his blog to indulge in out-and-out denial, conspiracy theorising, claims of scientific fraud, etc. Euan didn’t believe me when I suggested this was how he behaved, and was hardly contrite when I produced the evidence.
But bringing this up to date, Euan also covered briefly the Karl et al 2015 paper. Here are some of his and Roger’s comments. See if you can spot the cognitive bias:
I find the NOAA study to be quite disturbing. Adjusting data to get the result you want or expect.
I [sic] someone like Karl really such a bad scientist or are there masters in government pulling the strings?
But Obama is allied with Gore. And so in this case Federal funds can be used to buy the nation’s scholars to support the President’s policy.
As to NOAA’s motivation, the global warming pause has now been going on for almost 18 years. Another few years of no warming and they may all find themselves out of a job.
If you think these are taken out of context then you can see the whole discussion here. Sadly Euan automatically moderates my comments so that he can filter out suggestions from myself (and others) that his comments are way off base, thus creating his own echo chamber of denial and conspiracy theories. Mike Haseler goes even further than Euan, for example this is one of his recent (and reasonably tame) comments in relation to Karl et al 2015:
You don’t have to even read the paper to know it is crap, because their behaviour is not the rational unbiased behaviour of real scientists, but instead it’s the behaviour of a bunch of conmen trying to scam people.
Cries of “scam”, “fraud”, etc. are common amongst those who seek to deny our human-induced changing climate. In Scotland, where the scientific method has a prestigious history and continues to this day, it is sad to see such rejection of science by my fellow citizens. It is ironic, of course, in claiming incompetence and prostitution regarding a paper on adjusting for biases, that those who do so fail to see their own cognitive biases in failing to recognise that our Earth continues to warm, that there is no slowdown, and that we are the cause of it.