U.S., September 18, 2014 (National Geographic): In a paper published Thursday in Science, demographers from several universities and the United Nations Population Division conclude that instead of leveling off in the second half of the 21st century, as the UN predicted less than a decade ago, the world’s population will continue to grow beyond 2100.
And for the first time, through the use of a “probabilistic” statistical method, the Science paper establishes a range of uncertainty around its central estimate – 9.6 billion Earthlings in 2050, 10.9 billion by 2100. There’s an 80 percent chance, the authors conclude, that the actual number of people in 2100 will be somewhere between 9.6 and 12.3 billion.
The International Institute for Applied Systems Analysis in Vienna, Austria uses a different method to calculate probable population, however, both groups foresee India becoming the world’s most populous country, with its numbers peaking around 2070 and declining to around 1.5 or 1.6 billion by 2100.