There used to be many more children than elders; now, for the first time in history, the old outnumber the young.
Globally, there are about 705 million people over 65, compared to only 680 million children under 5, according to United Nations research.
This article from the BBC presents some interesting information on the two main causes of the trend: women are having fewer babies, and people are living longer. Unfortunately, however, the writer casts these trends in an entirely negative light, falsely portraying elders as a drain on society. This is the sort of casual ageism that I hope will be become less acceptable in the mainstream media in the decades to come.