The United Nations Population Division has no clear idea how many people there will be in the world, even within the next 50 years.
One projection says the world’s population could actually drop by a billion people within the next half century. Yet family planning programmes continue even though in many countries, such as Nigeria, there are far fewer people than was originally thought and accurate census statistics are difficult to obtain.
According to a Globe and Mail report (June 6, 1992) population demographers can know only one thing about their findings: “mainly that all their assumptions may be suspect.”
Joseph Grinblat, a UN demographer, says there is no way population reports can see ahead and predict what the population will be.
“We can’t tell the future,” he says. “There is a wide range of possibilities.”
As an example of this, the U.S. census bureau predicted in 1958 that by the mid 1970s the American population would be as much as 243.9 million people. In fact, there were 213.1 million. David Heer, who worked for the U.S. Census Bureau at the time, said predictions are made based on the premise that trends do not change.