Great article, except that the biggest population centers are not in the US anymore. They are in Asia - India and China. The hermit kingdom (China) did implement its 1 child policy successfully but is now reversing it, while India is yet to tackle its own demographic challenge. As you can see, the developing world feels that they are already getting the short end of the stick w.r.t. carbon emissions. We are in dire need of an Intergovernmental Panel on Population Control to acknowledge that this problem merits attention!!