Four planets required.

Recent World Bank work in their Eco2 Cities project explains that between now and 2030 we will build as much urban space again as existed in 2001. The growth of course will be mostly in the developing and emerging world, and in its 2030 form will consume some 16% of the land mass. Regretably with current estimated footprints these cities will require a mere four planets to support them.My questions are as follows:
1. What might trigger our collective awareness of the future tsunami we are building?
2. What frameworks might help assist decison makers and planners to urgently reduce city footprints and the level of 'lock in' that comes when we just put up the same old infrastructure today and tomorrow?
3. Given that 76% of all economic activity takes place in cities, why isn't the alarm sounding in our more foresightful organizations?
4. Where are the repositories of smart ideas that can be easily adapted and imitated by the cities of the world - or does each of them have to reinvent the wheel themselves?
5. Finally what role do we who think about the future and its weak signals have in creating awareness of this critical future issue?

Oh and by the way, Hawkins, Lovins, et al. talked as long ago as the 90's about Factor 4 and Factor 10 as a core discipline for strategy. By my thinking Factor 4 would see our cities live within the limits of one planet with not much room for anything else, while Factor 10 would see them live within limits equal to their future land mass.