"How long until we stop rebuilding cities?" When the value capitalists can extract from a rebuilt city declines below the investment needed, in the time frame that it gets destroyed again. Hurricane Andrew cost $25 billion in damages and Homestead was 70% rebuilt in 2 - 3 years. That value has definitely been extracted. However, Miami now stands at a $1.5 Trillion evaluation. If 100 year events become decadal, the potential damage can not be extracted (with profit of course) in 10 years. The resulting financial cascade will (is going to - only a matter of time) dwarf anything we have seen.