Tuesday, 22 July 2008

Let's Be Nice About Global Warming

The more I read about global warming / global cooling / climate change the more I see personal attacks being made on those who offer opinions and analyses. To my mind this is a very strange way to conduct a debate on something so important because personal attacks tend to detract from calm investigation of the facts. Can they have any legitimate part to play in the debate?

My approach to such a question is guided by what I know. I am a lawyer with a good few years under my belt so I look at how we conduct cases in court and, in particular, on the part personal attacks play in the effective presentation of an argument.

The facts are king in almost all cases. He who wins on the facts usually wins the case. Examination of facts is not, however, an entirely unemotive exercise. It can be observed that there are two ways to attack a witness. You can attack the story he tells and you can attack him. In other words you can say "do not believe what he says" or "do not believe him", on some occasions you have the opportunity to say both.

In order to succeed with the "do not believe what he says" argument it is necessary to attack the substance of what the witness has said. You try to expose factual errors by reference to other, known, facts. Where what the witness has said is not credible because it is inconsistent with established facts, the result is that the witness's evidence will be rejected. This does not, however, mean that the witness himself is being deceitful. Far more often than one might think, a witness is absolutely convinced that what he says is true when in fact it is false. That might be because he has deceived himself, or he saw only part of the picture, or he took something out of context. You risk doing more harm than good if you attack him and try to expose him as a liar and a cheat because he is neither of those things, he is just someone who is mistaken and examination of the facts proves that to be the case.

The "do not believe him" approach necessarily requires the witness to be attacked personally. What he says might not be open to challenge in any other way. For example, if only the witness and the Defendant were present and the witness claims the Defendant said or did something against the law there will often by no independent means of assessing the truth of his evidence. Exposing him as someone with a criminal record for dishonesty might be the only weapon in your armory, in which case you have no choice but use it and attack the man. It also works in more subtle ways, perhaps by showing the witness to be short-tempered or to overstate his case; you have ammunition to undermine the witness himself and, thereby, to undermine his evidence.

Attacking the witness personally cannot succeed, however, where there is clear independent evidence establishing that what he said is true. It is an obvious point, but "do not believe him" has no weight when the court can say "ok, we'll reject him, now what about the other 15 witnesses?"

Anyone who follows the great global warming debate will be familiar with the personal attacks thrown out by both sides of the argument. Those supporting St Al of Gore accuse those questioning the warming theory of being right wing extremists in pursuit of an ideology or in the pay of the oil industry or closed-minded bigots resistant to change. Exactly the same accusations are made against St Al and his merry men but in reverse - they are part of a socialist plot to destroy western economies, they are in it for the money, they are quasi-religious zealots. The only insult they each make in the same terms is the accusation that their opponents are too stupid to understand the science.

What I find interesting about these insults is that they are often used in a wholly irrelevant way. This irrelevance can be exposed by looking at the substance of the debate and, in particular, by remembering that the debate has two strands, the scientific and the political.

The scientific strand is concerned with facts and just facts. The starting point is the question: "how has the earth's surface temperature changed"? People collect temperature measurements from various sources, analyse it and produce averages. Questions arise about the weight to be given to various sources of data and various methods of analysis. It does not further the issue by saying "he has selected certain data only because he wants to prove warming/lack of warming". Maybe someone did select certain data because he feels they prove his preconceptions, but if the data he chose are the most accurate his motive is irrelevant and if there are better data available they can only be proved to be better by objective analysis not by insult. The same applies when examining the method of analysis applied to the data. Choosing the best possible analysis for a bad reason is the same as choosing it for a good reason and either is better than choosing a less reliable method. At this stage of the debate the personal attacks are utterly meaningless and do nothing but expose the accuser as someone unwilling or unable to be objective. The same goes for the other aspects of the debate which are purely scientific.

The political strand of the debate is a different kettle of fish, it involves forming assessments of what should be done, it is all about value-judgments. Even here, ascribing motives and hurling insults is of limited use. If the position is that the world is doomed but can be saved if, and only if, we scrap all motor cars there is no difference in substance between someone who argues for scrapping motor cars simply because it is necessary and someone who argues for scrapping motor cars because he has failed his driving test ten times and has a chip on his shoulder about motorists. The motive behind the suggested solution to the problem is wholly irrelevant. Where, however, there is more than one possible solution to a problem the motives of the person suggesting a particular solution might help us evaluate whether his argument for that option is skewed by his preconceptions or his vested interests. Knowing his motives and his interests can be relevant in making a value-judgment because the proponent of a particular course of action is, of necessity, putting forward his opinion. We cannot know how much weight to give someone's opinion unless we know whether he has a motive or a hidden agenda which causes him to argue for one result rather than another.

Too often we see people trying to discredit a piece of research or analysis by attacking the researcher or analyst. They seem not to realise that such an attack does nothing to undermine the substance of the research or analysis. If a scientist involved in the debate seeks to undermine opposing work by attacking the authors he makes a rod for his own back because the objectivity of his own work comes into question. His work will, in the end, stand or fall on its own merits but he will be known forever as a partisan scientist. "Partisan scientist" is an oxymoron, and someone carrying that label runs the risk of the last five letters of oxymoron being given more emphasis than the first three.


redwhiteandbluepinko said...

This is so true. Frequenting the skeptic's global warming sites, I am often put off by the tone of the discussion. I often summize that insult replaces substance in their argument (even tho I sincerely hope that they are right)

(linking form Watt's Up)

Paul Shanahan said...

100% in agreement, FatBigot. Well said. I think this happens when someone is totally commited to a belief that it blinds them to alternatives.