Saw an interesting documentary by an expert in the field of population, Hans Rosling, an very entertaining and informative presenter he was too. If memory serves, as countries "sort themselves out", as women get educated, as health outcomes improve, the birth rate drops dramatically. We are not being replaced by more people in the next generation. There's a "bulge" of people living longer, while in some places more are born than die. As this sorts itself out, population will level off. Basically. But with more examples and said in a much more interesting way. We'll still have to manage 10-11 b