Even assuming a limit exists, without hard numbers this discussion is a waste of time. There is a huge practical difference between a limit of 8 billion and one

Even assuming a limit exists, without hard numbers this discussion is a waste of time. There is a huge practical difference between a limit of 8 billion and one of 20 billion; especially as these same UN population models, which the author mentions, predict that world population may stabilize, or even start declining, by 2050 (http://www.un.org/esa/population/publications/popnews/Newsltr_87.pdf http://www.un.org/esa/population/publications/popnews/Newslt...)