At a time when there is more reason than ever to doubt that human activity is causing dangerous climate change, the IPCC’s launch of its Fifth Assessment Report has been a triumph of spin over rational enquiry.
Whatever the strange and very lengthy[1] Working Group 1 (The Physical Science Basis) Summary For Policymakers (SPM) may say, there is no doubt that over the past decade and a half, atmospheric Co2 has risen significantly and global average temperature has failed to do the same. This fact contradicts everything that the IPCC has told us in previous reports. It therefore undermines the alarmism, exaggeration and downright misrepresentation that characterise the IPCC process. So how is it that the world’s media has swallowed the scientist’s tale of woe so completely without questioning their extraordinary claim (p12) that they are now more certain than ever, rather than far less certain, that humans are changing the climate.
The answer is quite simple. The document that was so assiduously leaked and spun throughout last week, and finally published on Friday morning when the media agenda had been well and truly established – presumably to the satisfaction of the political representatives overseeing the final draft in the Swedish capital – is not a really a scientific document at all. It is a proselytising opinion piece that provides no clue as to whose opinions are being represented or precisely what evidence they are relying on.
The key statement in the SPM, and the one that the media has – understandably – focused on, is the near certainty that human influence has been the dominant cause of any observed warming since the mid-20th century:
Human influence has been detected in warming of the atmosphere and the ocean, in changes in the global water cycle, in reductions in snow and ice, in global mean sea level rise, and in changes in some climate extremes (Figure SPM.6 and Table SPM.1). This evidence for human influence has grown since AR4. It is extremely likely that human influence has been the dominant cause of the observed warming since the mid-20th century. {10.3–10.6, 10.9}
Now read that again, leaving out the words extremely likely. We are left with two assertions. Firstly, that mankind’s fingerprints are all over changes in global temperature, snow and ice melt, and sea levels. These are all perfectly unsurprising characteristics of the minor temperature rise that took place during the last century or so. Secondly, there is an assertion that, during a period when no statistically significant warming has taken place at all, the evidence supporting notions of anthropogenic climate change has increased. This is a claim that clearly invites ridicule, rather than the strait-faced apocalyptic headlines we have seen in recent days.
We now all know, unless our heads have been firmly buried in the sand recently, that extremely likely is IPCC speak for ‘We’re ninety-five precent certain, so boo sucks to you!’. In scientific terms this is about the highest level of certainty you can claim, but it still doesn’t raise what the SPM has to say above the level of an assertion. No! it just makes it all sound more portentous. Anyone with a scrap of scepticism to their name is going to ask, ‘Who says?, and ‘How can we be that certain?’, and ’and ‘Why should we share your certainty?’. But those questions are stifled once you reinsert the words extremely likely.
The process we are talking about here is what is called expert judgement, and it has been a matter of concern for some time. The problem is that most of the scariest prognostications of the IPCC have contained terms like very likely or high confidence, but without anyone in the real world knowing whose judgement is being relied on, how impartial they might be, or precisely what evidence they have considered. Without such knowledge, it is impossible to know with what integrity, competence and impartiality these expert judgements have been reached.
Back in late 2009 and early 2010, the IPCC was so concerned about its image in the wake of the collapse of the Copenhagen climate talks, the Climategate scandal, and revelations about gross exaggeration and the use of ‘grey literature’ in the last assessment report, that they called in a panel from a highly respected scientific institution, the InterAcademy Council, to review their procedures and make recommendations. One of the things that this panel of wise men focused on was the IPCC’s treatment of confidence levels and the likelihood of the predictions in their report coming true. Here are a few – damning – excerpts from their report:
The evolving nature of climate science, the long timescales involved, and the difficulties of predicting human impacts on and responses to climate change mean that many of the results presented in IPCC reports have inherently uncertain components. To inform policy decisions properly, it is important for uncertainties to be characterized and communicated clearly and coherently.
IPCC authors are tasked to review and synthesize available literature rather than to conduct original research. This limits the authors’ abilities to formally characterize uncertainty in the assessment reports. As a result, IPCC authors must rely on their subjective assessments of the available literature to construct a best estimate and associated confidence intervals.
In addition to characterizing uncertainty using confidence intervals and probability distributions, Working Group I [in the For the Assessment Report] used a combination of the confidence and likelihood scales to characterize the certainty of their conclusions. Virtually every statement in the Summary for Policy Makers is characterized using the terms employed by one of these scales.
The IPCC uncertainty guidance urges authors to provide a traceable account of how authors determined what ratings to use to describe the level of scientific understanding (Table 3.1) and the likelihood that a particular outcome will occur (Table 3.3). However, it is unclear exactly whose judgments are reflected in the ratings that appear in the Fourth Assessment Report or how the judgments were determined. How, exactly, a consensus was reached regarding subjective probability distributions needs to be documented. The uncertainty guidance for the Third Assessment Report required authors to indicate the basis for assigning a probability to an outcome or event (Moss and Schneider, 2000), and this requirement is consistent with the guidance for the Fourth Assessment
Report.
Recommendation: Chapter Lead Authors should provide a traceable account of how they arrived at their ratings for level of scientific understanding and likelihood that an outcome will occur.Emphasis in the original
Page 37
(my emphasis throughout)
Or in other words, if you’re going to spice up your report by attributing confidence and probability levels to your own work, you need to be up front about it. That means an audit trail so that those who are interested can see who took the decisions and how they took them. Emotive terms allocating certainty – but rarely if ever uncertainty – to the reports findings are just as common in the current SPM as they were in the last one, but this report is much, much longer. (I wonder why?)
Just like the 2007 SPM, the impact of what the IPPC are saying now has as much to do with the levels of certainty that the authors award to their own judgement as with the actual research findings that they are assessing. The situation at the moment is that no audit trail is available.
Although at the end of most paragraphs there are figures in curly brackets which provide references to sections of the main report that are the basis for the finding, the main report has not yet been published so there is no way to check up on what the authors are saying. Nor is there any way to determine whose expert judgement is being relied on or what measure of agreement there was among those [A.G.F1] involved. Such information may be contained in the main report, but there is no way of knowing until it is published. This really does matter as there can be serious conflicts of interest where an author’s own research findings are material being assessed. The InterAcademy Council had much to say, and made recommendations, about this problem too.
So it would seem that the IPCC has learned nothing from its dark days of 2009-10, and that the recommendations of the InterAcademy Council have been ignored. All we have in the SPM – and the vast PR forces that have been deployed to dragoon an increasingly sceptical public into believing in anthropogenic global warming – is what I have already described as an opinion piece, with no means for anyone to check up on what they are being told.
Until this problem has been addressed neither the IPCC, nor the press coverage, nor the usual suspects who have lined up to say, ‘Hey! These scientists really know what they’re talking about even if we can’t check up on them’ can really have any credibility.
In the mid-seventeenth century, the Royal Society emerged as the world’s leading, and groundbreaking, scientific institution with the motto nullius in verba; ‘nothing in words’. This heralded a new era in which our understanding of the natural world would be based on observation, experimentation and empirical evidence, not on wisdom that had percolated down via the words of authority attributed to great men. On the back of this revolution in thinking our modern technological world developed.
So far as the IPCC is concerned, it would seem the words of authority, and particularly ones like high confidence and extremely likely are all that count, and a huge number of politicians, activists and bureaucrats who are in a position to shape our economy and the course of our day to day lives are very willing to play along with them.
So far a climate science is concerned at least, empiricism is dead!
UPDATE:30/09/2013: See Alex Cull’s comment below for a link to his transcript of the speach which is interesting, but perhaps not in the way that Blair might wish.
[1] Previous summaries for policymakers have been much shorter.
there is no doubt that over the past decade and a half, atmospheric Co2 has risen significantly and global average temperature has failed to do the same.
So, if just for a moment, and for the sake of argument, we accept that to be true, you would therefore say that this shows that CO2 emissions have no significant effect on the climate?
I wonder if you’d agree with the following statement which uses the same logic.
There is no doubt that in the last five years UK government debt has risen significantly.(its just about doubled). And yet, prices have risen less in last five years than they did in the previous five. Therefore this shows that the level of government debt has no significant effect on inflation.
I suspect you may say ‘ah but that’s different. There are other factors involved’. And yes, that would be a good point. There are always other factors involved.
Quite agree but to be nit picking Nullius in Verba means on the word of nobody – i.e. evidence not authority. Sorry, I think you do a marvellous job generally. The incompetence of journalists to probe any deeper is staggering.