The 28gate seminar's finding that global warming science is settled and that "due balance" requires dissenting views to be seen and heard less is insidious. In this post I'm going to try to set out why.
What is the consensus? That carbon dioxide is a greenhouse gas? Yup. That man's activities are increasing carbon dioxide levels? Certainly. That temperatures went up at the end of the twentieth century and have not gone up since? Definitely. That human beings can affect the climate? Without a shadow of doubt.
Anything else? I don't think so. Even simple questions like whether observed temperature rises are anything out of the ordinary remain hugely controversial. The extent to which mankind has affected and will affect temperatures is likewise unknown, a great amphitheatre of ignorance dimly illuminated by a handful of aged CFLs - the climate models that scientists have pinned their hopes on - and little else. That these models are wrong is not in doubt - all models are wrong after all - but how wrong and how useful they are as tools to guide public policy is just another mystery. How can there possibly be consensus in these circumstances?
The impacts of climate change and the economics of climate change and policy responses to climate change are likewise entirely up in the air, with new hypotheses flown every day and shot down every evening and a mishmash of often contradictary empirical observations lending colour to the chaos. A glance tells you that there is no consensus.
So let us be clear, we don't even know if we have a big problem or a small one.
Yet the seminar has decided that sceptic input is not required in any of these areas. When did you last hear it put on the BBC that climate sensitivity might be low and that we were getting worked up about nothing? When did you last hear the Stern report or decarbonisation challenged on the BBC? 2007? I certainly can't recall any recent outings for views like this: they are sceptic views and are not to be aired. Yet these are all areas in which there is precisely no academic consensus. Indeed in the case of Stern one could probably make the case that there is something approaching consensus that the noble lord is talking out of his hat.
The concepts of mainstream and sceptic, upholder and dissentient, warmist and denier are profoundly unhelpful in the climate debate. The range of questions at issue mean that it is simply preposterous to divide everyone into two camps as the BBC has done - it's simply not logical.
Of course, given that the seminar was run for the benefit of green pressure groups, it's clear that logic had nothing to do with it. The BBC has used the seminar to minimise criticism of any aspect of climate science, climate economics and climate policy.
Quentin Cooper, the presenter of the BBC's Material World radio programme, asked on a recent show why he had never heard about the problems with biofuels. Frankly I'm amazed that he can't work it out.