If there is to be a ban on non-scientists discussing climate change issues (which I do not, of course, support), this should in the best  tradition be an even-handed one. That is to say, they should also ban non-scientists such as energy secretary Ed Davey, Ed Miliband, Lord Deben (chairman of the government’s climate advisory committee), Lord Stern (former adviser to the government on the economics of climate change and development) and all the others who are regularly invited to appear.