Yes a bit of thread drift, but only a few countries have a positive population profile so there is hope. Research does show that better generally education of women has the most effect in reducing family size, so I believe that aid programmes should focus on female education as the first priority. Humans do have predators called virus and bacteria, if Ebola goes from a close contact to an airborne contamination route stand well back, millions will die same goes for bird flue only 3 mutation away from going pandemic and antibiotics are losing their effects so we may be heading for a big crash. Finally we need a new compact low polluting primary energy source, the only one I think, is nuclear fusion but of hydrogen and boron it converts to electricity directly with very low radiation, very safe. Google Focus Fusion. Two forty foot containers for the device a couple of buckets of water and a kilogram of Boron will produce 5 mega Watts for a year and at a million$ a copy, what's not to like would change the world.