This month, the number of babies born will equal the population of Portugal. The number of people who will die will equal the population of Norway. The difference between the two is equal to the population of Libya — about 6.4 million people. That is the number by which the human race will grow in 31 days.
One of these new lives will bring the world’s population to 7 billion. He or she will probably be born on October 31, in Uttar Pradesh, India.
This seven-billion moment is the culmination of an astonishing transformation in human fortunes. For in the last Ice Age, about 20,000 years ago, Homo sapiens was close to extinction. We numbered just a few tens of thousands: we were as endangered