For both leaders and citizens of the G20 countries, this week’s summit in Cannes is about as welcome as a visit to an undertaker. Euro-zoned out, as most of us are by now, seeing presidents and prime ministers assemble at a moment of global crisis to issue bland communiqués and even blander group photos will tempt many to reach for their “Occupy Wall Street” signs and pitch their tents in the nearest town square. This would, however, be a mistake. For all its unwieldiness and amorphous sense of purpose, the G20 represents the beginnings of an understanding – as necessary as it is reluctant – that a global economy with new growth sources must have a new structure of governance.