That's probably the best we can do, says Joseph Tainter, in a forthcoming paper. Here's the passage that will make environmentalists bark at their computer screens:
Contrary to what is typically advocated as the route to sustainability, it is usually not possible for a society to reduce its consumption of resources voluntarily over the long term. To the contrary, as problems great and small inevitably arise, addressing these problems requires complexity and resource consumption to increase.
Anyone seriously engaged in sustainability can't ignore Tainter's scholarship on collapse.