A couple of dozen give or take 2500

The National Post has an interesting article by Lawrence Solomon ( here ). In his article Mr. Solomon quotes from a paper by the climate scientist Mike Hulme titled Climate Change: what do we know about the IPCC? While the quotes were accurate, the context did not seem to be. So I decided to investigate a bit. When contacted by e-mail Professor Hulme confirmed that the "National Post article offers a meaning rather different to that intended and to that implied." (Note that this does not necessarily mean that he endorses my position. His own website has his own clarifying statements.)

Mr. Solomon claims that the IPCC misled people by saying that thousands backed its claims on manmade global warming where as Professor Hulme’s article says that only a few dozen did.

Mr. Solomanon’s argument fails on two levels. To begin with he does not define what the claim of the IPCC is which is important since IPCC makes many claims all discussed in their reports. In fact, this is one of the weaknesses of the IPCC process described by Professor Hulme – by not being specific enough it can be vulnerable to misleading statements – as we see here.

However his larger failure is based on the erroneous assumption that saying that if only few dozen can understand the details of climate science, then the rest must not support their conclusion. This is false. Professor Hulme’s article is very clear when it states that

Claims such as ‘2,500 of the world’s leading scientists have reached a consensus that human activities are having a significant influence on the climate’ are disingenuous. That particular consensus judgment, as are many others in the IPCC reports, is reached by only a few dozen experts in the specific field of detection and attribution studies; other IPCC authors are experts in other fields.

So while many scientists can say that their work supports the concepts described or that they can follow the argument, only a few are expert enough in detection and attribution studies to form an independent opinion about the human influence on climate. Of course there are another dozen or so who understand enough about oceanography to allow them to say what the influence of the ocean is on global warming and so it goes for the claims put forward by the IPCC. As we know, climate science is an interdisciplinary subject and since no one can be expected to know it all we must look to experts in each area to draw conclusions about that subject. This is becoming a very relevant point for climate science and I am reminded of the statement by Dr. Kitcher (in his article “The Climate Change Debates”) when he says “Serious democracy requires reliance on expert opinion”.

Unfortunately, instead of adding clarity to what the experts on climate say, Mr. Solomon chooses to instead further disingenuity; ironically embodying the very opposite of the point of Professor Hulme’s article.