Few of us would question that the world is overpopulated. In 50 years, the human population has roughly doubled, from 4 billion to almost 8 billion. Wouldn't it be best if humanity brought down it's numbers to a sustainable level, like 4 billion again? Probably, but there is no painless way to get there. If birth rates fall, as has already happened, it leaves us with a huge excess of ailing old people and not enough active workers to support them. In many ways, government and economies are addicted to growth, and when the growth reverses, a plethora of bad effects can be expected.