[gcheong]

Good question. I think people are betting that even with dramatically increased consumption (for example all developing countries reaching developed country levels standard of living) we will eventually reach something resembling a steady-state of population and consumption. I think it's a big bet indeed but I think it needs to be made if nothing else than just to reduce the amount of suffering around the world caused by our current system. At worst, assuming fusion succeeds, we stave off the inevitable for a while longer in the hopes something else comes along to balance the equation.