Can More Than 7 Billion People be Sustained?

In a nice coincidence of timing with the PERN cyberseminar on population and sustainability, I have been asked to write an essay for the ABC-CLIO/Greenwood Press World Geography database. The question posed is this: "Is a world population of over 7 billion sustainable?" If you've read my chapter on Population and the Environment, you'll know my answer to that question. My general position is that a population of more than seven billion people is only sustainable if we are willing to accept either continued gross inequality in standards of living around the globe, or if everyone is willing to accept a lower standard of living. I do not believe that the earth has enough resources for more than seven billion people to live sustainably like Americans or Europeans. 

So far, none of the people posting comments on the PERN cyberseminar have disagreed with this perspective. Keep in mind that I don't like to have this view of the world. I would very much like for every one of the 9-10 billion likely alive at mid-century to live sustainably at the current level of Americans an Europeans. However, all of the available evidence suggests that to do so will require a miracle...and in the meantime there is a continual push in the rich countries to somehow raise our standard of living even higher.