I am delighted that David Cameron has made plain his views on aeroplanes in the current issue of GQ magazine. He rejects the notion that it’s wrong for ordinary people to take a cheap holiday overseas, something the negative environmentalists claim. Instead, and consistent with his views on positive environmentalism, he says: “I don’t want to make air travel the preserve of the rich.” He’s right: we of course, need to use technology to cut emissions, such as by creating a prize fund to reward new advances in this area, but let’s have both the aeroplanes and the cleaner environment.