Let me begin this response with an admission of incompetence. I am not qualified to comment on the scientific claims made in Alexander Cockburn’s article. But nor is Cockburn qualified to make them.
When a non-scientist attempts to dispute the findings of an entire body of science, a good deal of humility and a great deal of research is required. Otherwise he puts himself in the position of the 9/11 truthers. Though they might know nothing about physics, structural engineering, ballistics or explosives, these people still feel qualified to assert that the experts in these fields are wrong, and that the Twin Towers were in fact brought down by controlled explosions.
A prominent progressive writer recently said the following of such amateur detectives.
“[They] proffer what they demurely call “disturbing questions”, though they disdain all answers but their own. They seize on coincidences and force them into sequences they deem to be logical and significant. Like mad Inquisitors, they pounce on imagined clues in documents and photos, torturing the data - as the old joke goes about economists — till the data confess. Their treatment of eyewitness testimony and forensic evidence is whimsical. Apparent anomalies that seem to nourish their theories are brandished excitedly; testimony that undermines their theories–like witnesses of a large plane hitting the Pentagon — is contemptuously brushed aside.”
The writer was Alexander Cockburn. I charge that his treatment of climate change resembles their treatment of the events of September 11th 2001.
To sustain or to refute his argument about the link between carbon dioxide emissions and global temperatures requires a detailed knowledge of the following issues. They are all complex matters. You have to spend a great deal of time, and you must have some expertise in and understanding of climate science, to be able confidently to comment on them:
1. The measurement record for carbon dioxide emissions.
2. The measurement record for carbon dioxide concentrations in the atmosphere.
3. The possible biases in these records, and whether or not they have been recognised and allowed for by the standard climate models.
4. The possible smoothing effect of the lag between carbon emissions and averaged atmospheric concentrations.
5. Carbon concentrations in the Eocene.
6. Other factors affecting Eocene temperatures.
7. The current state of the Milankovitch cycle and its likely impact on temperatures, with and without the extra radiative forcing caused by the addition of anthropogenic CO2.
Cockburn provides no evidence that he has mastered these issues, or that his research into his chosen subject is any more extensive than that of the conspiracists he so correctly and so entertainingly derides. But this is not the only resemblance between his case and the case made by the truthers.
· The first test of whether a scientific critique carries weight is whether or not its claims can be traced to articles published in peer-reviewed journals. Cockburn provides no references of any kind. As a result it is impossible for someone who is not an expert in this field to assess his claims. Have the “papers” he refers to been published in a peer-reviewed scientific journal? Cockburn does not tell us. If they have not, they carry no scientific weight.
· He appears to rely on the testimony of one man who studied meteorology for three years a long time ago, while dismissing the work of thousands of others with greater experience and better credentials. As Cockburn must know from his work on the 9/11 conspiracists, you can find an “expert” to support just about any position on any subject. If you want to believe that HIV does not cause AIDs, you can find a professor of medicine who supports that view. If you want to claim that smoking does not cause cancer, or that black people are less intelligent than white people, you can find a self-appointed “expert”, with academic qualifications, to defend that position. The cherry-picking of experts is just what the 9/11 conspiracists have done, and this is just why their approach is unscientific.
· He provides no evidence that he has asked other climate scientists to determine whether or not Martin Hertzberg’s argument has merit. The scientific approach demands that, rather than sheltering them from criticism, you subject your beliefs to the same scrutiny and scepticism with which you treat opposing views.
· He uses arguments – such as the claim that “water is exactly that component of the earth’s heat balance that the global warming computer models fail to account for” and the claim that global temperatures were higher in the medieval period than they are today – that have long been discredited. For a discussion of these positions, see hereand here.
· He has not understood that a temperature rise initially pre-dating an increase in CO2 in the ice core record strengthens rather than weakens the standard theory. Temperatures rose as a result of changes in the Milankovic Cycle, sunspot activity or other forcing agents. They then caused the release of greenhouse gases from the biosphere, which then caused temperatures to rise further. Climate scientists warn that rising temperatures caused by carbon dioxide emissions today will cause exactly the same effect: the release of further carbon dioxide and methane by oceans, soils and forests, causing further rises in temperature. What would he expect to find – evidence of industrial civilisations 600,000 years ago?
The fact that Cockburn appears to be unaware that these arguments carry no weight lends support to the suspicion that he knows no more about this subject that the 9/11 truthers know about the thermal properties of structural steel. And yet he feels he can brush the conflicting data contemptuously aside. Where does this confidence come from?
Cockburn’s article cannot be taken seriously until we have seen his list of references, and affirmed that the key claims he makes have already been published in peer-reviewed scientific journals. This would not mean they are correct, though it does mean that they are worth discussing. Could he possibly have gone into print without first ensuring that the scientific claims on which he bases his arguments have been properly published? I find this hard to believe, for it would be the height of irresponsibility. But Cockburn now has to demonstrate, by providing his references, that he did indeed carry out this basic check.