Distorted view through the climate gates
Much has been written - not least on this website - and much more surely will be written over the coming months about supposed inconsistencies, errors, misjudgements and poor practice among climate scientists.
How many "scandals" do we now have with the suffix "-gate" attached to them? At least five, by my count, with the most embarrassing surely being the projection that the mighty Himalayan glaciers could largely be gone within a human generation.
The latest -gate - detailed in a series of articles in The Guardian by environment journalist Fred Pearce - concerns a set of temperature data from China that was used in a 1990 paper in Nature to estimate the likely impact of progressive urbanisation on temperatures recorded at weather stations.
The paper is one of several cited by the Intergovernmental Panel on Climate Change (IPCC) in reaching its conclusion that:
"Urban heat island effects are real but local, and have not biased the large-scale trends."
The implication of The Guardian's article is that Chinese scientists contributing data for that paper had not taken as much care as they should have done to document and allow for the fact that some of the weather stations had been relocated over the course of the study period, possibly affecting their readings; and that at some stage the paper's lead author, Professor Phil Jones, had been made aware of the issue by an independent UK researcher, Douglas Keenan, but did not seek to publicise or remedy it.
As anyone following the -gate trail will know, Professor Jones is the scientist at the centre of the original "Climategate" - November's e-mail theft from the University of East Anglia.
The point of this post isn't to go once more over well-trodden ground, but to raise a simple but crucial point.
Like all the other noisy -gates, this latest one throws up two questions: was scientific best practice followed, and is there anything here that affects the basic picture of climate science?
Whatever the answers to those may be - and Professor Jones' University of East Anglia has issued a rebuttal covering key points of The Guardian's article - the important point to make is that they are separate questions.
In some circles, every single -gate "relevation" has been followed by a ritualised fanfare claiming that the picture of climate warming through rising greenhouse gases concentrations has now been "fatally undermined", or some similar phrase.
Journalists with an eye for old-fashioned concepts such as balance, like Fred Pearce, are careful to avoid making that conclusion.
He writes that this latest episode...
"...does not change the global picture of temperature trends. There is plenty of evidence of global warming, not least from oceans far from urban influences. A review of recent studies published online in December by David Parker of the Met Office concludes that, even allowing for Jones's new data, 'global near-surface temperature trends have not been greatly affected by urban warming trends'."
He could also have cited the body of evidence from the satellite record, which also shows a clear warming trend.
In a paper published in the journal Energy and Environment [pdf link] in which he detailed his concerns about the 1990 conclusions, Doug Keenan made the same point:
"None of this means that the conclusion of the IPCC is incorrect."
In an interview with the Press Association (PA) about The Guardian's article, Phil Jones says he stands by the conclusion of the 1990 paper, not least because it was backed up by other studies, including papers in 2007 and 2008 that used a more detailed Chinese dataset.
Below is a graph comparing the 1990 (Jones et al) and 2007 (Li et al) graphs.
He goes on to say:
"It makes me quite worried people are beginning to doubt the climate has warmed up."
And clearly some people do doubt that - many of you tell me so, in great detail, on every post I write, whatever it deals with - and judging by your comments, that's partly because some of you believe that all climate scientists are as bent as a... well, a hockey stick might be a good simile here.
It is a free world; and if you really do hold that view, then presumably it makes sense to jump the divide between the two questions I raised earlier, and conclude that as all climate scientists are dodgy, so is all climate data.
But I would argue that keeping the questions separate is of absolute and vital importance.
How scientists and the institutions of science behave is an important issue, no doubt about it - for evidence, look no further than the latest developments on the MMR saga, which sees The Lancet retracting the decade-old paper that sparked all the fuss - and Phil Jones tells PA in his interview:
"We do need to make more of the data available, I fully accept that."
But what matters far, far more than the nuances of climate scientists' behaviour is whether the climate is warming, and if it is, what is driving that warming.
Those are questions crucial for humanity's future, because if the IPCC's projections become reality, substantial swathes of the global population will find themselves living in much more straitened circumstances than they face at present.
If the scientific case for greenhouse warming crumbles, so be it; but I'd suggest we should beware of assuming it is crumbling simply because a few scientists or a few scientific papers or a few IPCC reviewers have been seen to fall short of the highest standards.