Hot air

It is always enjoyable to poke fun at politicians' poor grasp of science and Sir Ron Oxburgh, president of the British Association, has provided the latest example. In his presidential address to the BA's Birmingham meeting he mentioned a "senior and well-educated MP" who responded to a constituent grumbling about car exhaust emissions by saying: "In any case, I am told that one Porsche produces no more carbon dioxide than seven joggers."