There’s been a lively debate on Twitter recently about climate change, and the IPCC. Believe it or not, there are people out there who think the IPCC is a panel of 2,500 scientists who all support Al Gore’s orthodoxy. Michael Mole tells me that “The work of the IPCC is contributed to by thousands of scientists from all over the world”. They say it’s a “scientific consensus”, but nothing could be further from the truth.
Not all scientists: First of all, a fair number of the panel members are actually not scientists at all. They are environmental activists. That’s why many of the claims in the IPCC’s TAR4 (described as peer-reviewed science) turned out to be little more than quotes from NGO propaganda. There are also a lot of bureaucrats and civil servants involved in the project.
Not all relevant: Not all of the IPCC’s “scientists” are involved in relevant disciplines. Some are involved in related disciplines – for example economists (Is an economist a scientist – discuss!), epidemiologists and so on. I think particularly of IPCC reviewer Hans Labohm, a distinguished economist with whom I have worked. He is one of the IPCC’s 2,500 panellists, but he is a passionate campaigner against the Al Gore Theory. These disciplines have something to contribute after we’ve agreed about AGW, but not necessarily specific expertise in the subject itself. I think we should perhaps hear more from statisticians and astronomers, who have much to contribute, but don’t seem to figure largely in the IPCC’s conclusions. (It was a mathematician, Steve McIntyre, who with Ross McKitrick debunked Michael Mann’s Hockey Stick – Mann may or may not know about climate, but his statistics were way off beam). Some are from totally unrelated disciplines. IPCC Chairman Ravendra Pachauri, for example, is a railway engineer.
Not all agree: Paul Reiter, an epidemiologist and expert in tropical diseases from the French Pasteur Institute, actually had to threaten legal action to get his name removed from an IPCC report. He had repeatedly advised them that malaria was not a disease of hot climates (the worst recorded outbreak having been in Siberia) but they refused to correct the text, and initially refused to withdraw his name. He told me this story as we shared a cab a few years ago to Chicago’s O’Hare airport – we’d been attending a Heartland climate conference. My good friend Fred Singer, one of the USA’s most distinguished climatologists, was an IPCC panellist and has the Nobel lapel pin to prove it. His best line: “The IPCC accepts my corrections to its punctuation. But not to its science”.
The IPCC has in fact been hi-jacked by a small group of a couple of dozen scientists, known as “The Hockey Team”, after the infamous graph (now dropped even by the IPCC). These guys were exposed by the ClimateGate e-mails. They work together. They peer-review each other’s papers from a common perspective. They know that the predictions of their climate theory are failing, and they cooperate to “hide the decline” (in their famous phrase).
My Twitter interlocutors have a touching faith in the peer-review process (although as we’ve seen, it can be subverted by a determined group working together). And they have a weird view that all the peer-reviewed science supports the IPCC. Someone called Jonathan Waxman asks “Is there ANY peer-reviewed literature that challenges the IPCC’s position?”. Answer: A great deal. Read any decent climate realist book – Fritz Vahrenholt’s “The Neglected Sun” is a recent and fine example – and you will find literally hundreds of references to peer-reviewed science. Equally, read Fred Singer’s alternative take on the subject, his NIPCC Report, and you will find that he actually relies on much of the IPCC material. But he interprets it differently.
Someone Tweeted that the IPCC was “a meta-study of thousands of scientific papers”. It is no such thing. A meta-analysis takes hard data from a range of smaller-scale studies and aggregates them into a much larger sample. The IPCC quotes many peer-reviewed papers, but it then makes assumptions and guesses and estimates to process the science into climate models (which don’t seem able to predict either forwards or backwards). Absolutely notable is first of all their assessment that the Sun can largely be ignored, because solar irradiance is fairly constant. They ignore wide variations in segments of the spectrum, especially UV. And they ignore large and cyclical variations in the solar magnetic field. Svensmark came up with a mechanism to explain this effect: a strong solar magnetic field protects the earth, partially, from cosmic rays. This reduces cloud formation in the atmosphere, reduces albedo, and results in warming, and vice-versa. Originally proposed as a theory, Svensmark now has convincing experimental evidence from CERN and elsewhere that cosmic rays do indeed engender cloud formation.
If Svensmark is right, it follows that the Sun is primarily responsible for climate change, and the rôle of CO2 is marginal at best. And indeed over the longer term, earth’s climate correlates rather well with solar cycles, and rather poorly with CO2 levels. Indeed the whole climate scare is really based on the period 1975/1998, when a longer term (1000 year) and a shorter term (c 60 year) solar cycle coincided and reinforced each other. Atmospheric CO2 also rose between 1945 and 1970, but global temperatures dropped slightly.
The other prominent area of doubt and debate is the climate sensitivity of CO2. Most climatologists agree that other things being equal, a doubling of atmospheric CO2 would cause about 1oC of warming. Note that I say “doubling”. This is a geometric (actually negative logarithmic) relationship, not an arithmetic one. So the higher the current level of CO2, the more extra CO2 you need for a given increase. It’s a law of diminishing returns – another reason not to panic. The IPCC however works on an alarming figure of 3oC per doubling. They seek to justify that by appealing to “positive feedbacks” — primarily but not solely water vapour. Water vapour, of course, increases the greenhouse effect. But it also increases cloud formation, so it may have a cooling effect. The IPCC has not demonstrated its mechanism. Meantime studies by Richard Lindzen of MIT suggest that the net feed-back effect may be negative, with a CO2 doubling leading to a fraction of a degree temperature increase.
The IPCC shows graphs representing the tropical hot-spot in the troposphere predicted by all the climate models, but fails to explain why observation shows that no such hot spot exists in reality.
So the IPCC may quote peer-reviewed science, but it is highly selective, taking only those papers that support its position, and it builds assumptions on the back of them which are not always justified by the research itself – to the extent that Fred Singer can make the sceptic case using much of the same research.
Finally, an observation about the philosophy of science. Nicholas Petrie asks “Is David Attenborough misled when he warns of climate change?”. One thing we avoid in science, Nicholas, is the “argument from authority”. In 1600 the Church burned Giordano Bruno at the stake, because they accepted the argument from authority that the world was flat, and rejected Bruno’s observational evidence that it was round. Forgive me for repeating an old story, but I love the one about Einstein, asked if he knew that a thousand physicists rejected his General Theory of Relativity. He replied: “If I were wrong, one would be enough”. Science is driven by evidence, not authority, nor majorities, nor consensus. Science deals in falsifiable hypotheses. The hypothesis of man-made climate change has been tested by observation over time, and is demonstrably false.