Untouchables Bathing in Former British Horse Watering Trough in Mumbai, India
At the birth of Jesus, the global population was an estimated 200 million. (It was probably easier then than now for the meek to inherit the Earth.) It took until the early 1800s to reach one billion. We went from six billion to seven in a veritable blink of the eye: 12 years.
In 1950, for each person 65 and older, there were more than six children under 15. By 2070, elderly people will outnumber children under 15.
—Joel E. Cohen, author of “How Many People Can the Earth Support?”Buy This Image