When it comes to the party that is planet Earth, we might need to plan for a few extra guests, according to scientists. A new statistical projection concludes that the world population is unlikely to level off during the 21st century, leaving the planet to deal with as many as 13 billion human inhabitants—4 billion of those in Africa—by 2100. The analysis, formulated by U.N. and University of Washington (UW), Seattle, researchers, is the first of its kind to use modern statistical methods rather than expert opinions to estimate future birth rates, one of the determining factors in population forecasts. “The U.N. in the past has been criticized for not doing complete statistics on their data and now they’ve done it exactly right,” says demography researcher John Bongaarts, vice president of the Population Council in New York City, who was not involved in the […]