Our societies have achieved a general level of prosperity of which most of all the human beings who have ever lived could only dream. Now we need to show that we can stop continually wanting more - more money, more stuff. We must show that it is possible for people to realise that they have enough.
Nobody in the developing world is going to take, as an answer to their aspirations, the developed world's reply: 'Sorry, you can't; we've already used it all up.' To earn the right to look the developing world in the eye and start this conversation, we need a reassessment of how we live and what we want.