Population. How many do we need? My humble opinion suggests that each couple can have two children. This view solves two problems. The first problem solved is that a limit has been placed on the population of the earth and secondly, the ageing population problem is eradicated. China has a one child policy but also an ageing population.Me, humbly suggest, that China changes its policy to a two child policy and it may change the demographics of China. If it works, then China's policy can be adopted by the rest of the world.
Again, Just a few thoughts.
Adrian T.