On World Population Day, Unpacking 9.6 Billion by 2050
How do demographers devise projections for global population?
By 2050, demographers from the United Nations project that the population will reach 9.6 billion.
But that projection has changed considerably in recent years. In 2000, the UN predicted a population with 700 million fewer people than it is predicting now—only 8.9 billion people in 2050.
Other organizations, meanwhile, have slightly different 2050 projections. The United States Census Bureau projects a population of 9.4 billion. The Population Reference Bureau, a nongovernmental group that tracks U.S. demographics, has increased its projection by two million since their last estimates were published in 2010; their number now matches the UN estimate.
What explains why these figures evolve and why they don't exactly sync up?
Population projections are dynamic. While they are often reflective of the real world,