Steve Jones, the biologist who advised the BBC about science coverage, echoes the wrath of climatologists that people who don't buy the full the intergovernmental panel on climate change message on global warming sometimes get a repellently "fair" radio or TV hearing.

"Science turns on evidence. Balance in science is not the same as balance in politics, where politicians can have a voice, however their barmy ideas are. And they [the BBC] are not taking this on board. Why I don't know," he said.

Perhaps because, in a democracy, "barmy" politicians get elected and make decisions. Perhaps because 2,000 climatologists signing pieces of paper don't automatically convert a doubting public. Perhaps because – in science, in politics, in life – you need to win arguments, and thus to have them. I'm an urgent believer in doing something about global warming. But I also live in a democracy. And nothing is QED.