Apopular radio comedy series in 1940s Britain featured a sketch in which two excessively polite gentlemen would find themselves unable to pass through a doorway, paralysed by their own good manners. "After you, Claude," one would say. "No, after you, Cecil," came the reply. It could go on for quite a long time.

That is exactly what negotiating international action on climate change feels like, according to David Miliband, the UK's environment minister. "It's an 'After you, Claude' situation," he says of the discussions on the international Kyoto protocol. No country wants to be first in taking action to cut their greenhouse emissions for fear that other governments will fail to follow. So they find ways to stall, while their greenhouse gas output climbs steadily skywards.