In the hue and cry about the 'green economy' leading up to Rio + 20 a number of simple points have been neglected. First, the purposes of the economy have been too narrowly conceived. Second, the role of demand management is vastly underplayed. Third, the assumptions about the nature of reality are inconsistent with contemporary science. Fourth, it is mired in a complex discourse about measurement, which fails to even recognize that all economies are dependent on living within Earth's biogeochemical constraints. Fifth, it uses a conceptual framework laid down in the 18th century and tries to apply it to the Anthropocene. The simple, but to many unthinkable, fact is that you cannot get to a flourishing or even sustainable Earth if you start with the assumptions of neo-classical economics. This is not to say that some of the neo-classical tools are not useful, but that they must be deployed in a framework that it does not and cannot supply.