Stabalize....says who.  Homo Sapiens are a breeing machine that know no boundaries and we will to populate more and more, like any species that has no predator to keep them in check.

Where does the 9 billion come from....what group hypothesized this number?  I would be most interested.

SInce the Industrial Revolution, our numbers have gone straight up and I see no barrier in keeping us in check as we have become very efficient in eliminating all competition.  The only competition will be mother nature and thats coming sooner than later.