7 billionth baby born on Halloween — we think

The United Nations Population Division declared Oct. 31 as the day that the world’s population bumped up to 7 billion, adding to the exponential growth that added 1 billion people in just the last 12 years.

Although population scientists will never know when the exact date of the 7 billionth baby will be born, the UN declared Oct. 31 as the symbolic date. The UN said today’s calculation comes with about a 1-2 percent margin of error – which means the population could be about 56 million people higher or lower.

Regardless, the world’s population is expected to grower at an even faster pace in the future, reaching up to 10 billion by the end of the century.

Most of the growth is expected in developing countries in Asia, Latin America and Africa.

In America, the growth rate has remained relatively flat at about 1.8 percent a year. Because the birth rate in the United States is at population replacement levels of about two children per mother, the increase is mainly attributed to high immigration.