Above all, though, there is the inescapable dilemma that this planet cannot sustain six-and-a-half billion people living like today's middle-class consumers in its rich north. In just a few decades, we would use up the fossil fuels that took some 400 million years to accrete - and change the earth's climate as a result. Sustainability may be a grey and boring word, but it is the biggest single challenge to global capitalism today. However ingenious modern capitalists are at finding alternative technologies - and they will be very ingenious - somewhere down the line this is going to mean richer consumers settling for less rather than more.
Marx thought capitalism would have a problem finding consumers for the goods that improving techniques of production enabled it to churn out. Instead, it has become expert in a new branch of manufacturing: the manufacture of desires. The genius of contemporary capitalism is not simply that it gives consumers what they want but that it makes them want what it has to give. It's that core logic of ever-expanding desires that is unsustainable on a global scale. But are we prepared to abandon it? We may be happy to insulate our lofts, recycle our newspapers and cycle to work, but are we ready to settle for less so others can have more? Am I? Are you?