World's Population To Top 11 Billion by 2100

7-21-15 NASA DSCOVR Whole Earth
Earth, as seen on July 6 from a distance of 1 million miles by a NASA scientific camera aboard the Deep Space Climate Observatory spacecraft. NASA

The population total will grow to 11.2 billion worldwide by the end of the 21st century, the United Nations Department of Economic and Social Affairs is predicting.

The current world population, at 7.3 billion, will increase to 9.7 billion by 2050 before rising to more than 11 billion five decades later, the department's Population Division director, John R. Wilmoth, explained in a presentation Monday at the 2015 Joint Statistical Meetings in Seattle.

Though population projections are by nature uncertain, the division can estimate with 95 percent confidence that the total will sit between 9.5 billion and 13.3 billion by 2100. Population projections on global, continental and national levels are important tools for leaders and policymakers weighing long-term decisions, Wilmoth said, according to a press release from the American Statistical Association.

The division's "World Population Prospects" report (2015 revision) explains, for example, that "the concentration of population growth in the poorest countries will make it harder for those governments to eradicate poverty and inequality, combat hunger and malnutrition, expand education enrollment and health systems, improve the provision of basic services and implement other elements of a sustainable development agenda to ensure that no-one is left behind."

According to the report, Africa will account for more than half of the world's projected population growth through 2050, with the continent producing 1.3 billion of the 2.4 billion people expected to be added by mid-century. The continent is also the only major area where significant population growth is predicted to continue beyond 2050. Its share of the global population will rise over the next several decades while that of Asia—the most populous continent—declines.

India will become the world's most populous country, the U.N. predicts, passing China in the early 2020s. Likewise, the division predicts that Nigeria's population will surpass that of the U.S. by roughly 2050, making it the world's third most populous country. The U.S. is projected to add an average of 1.5 million people per year to reach 450 million by the end of the century.

In contrast, several countries' populations are expected to shrink by 15 percent or more by mid-century: Bosnia and Herzegovina, Bulgaria, Croatia, Hungary, Japan, Latvia, Lithuania, the Republic of Moldova, Romania, Serbia and Ukraine.

The report points out that fertility has declined in most parts of the world, though there are still large variations. Close to half of the world's population is in countries with "low fertility," where women have on average fewer than 2.1 children (like the U.S., China, Brazil, and all of Europe). A similar portion lives in countries with "intermediate fertility," with an average of 2.1 to 5 children (like India, Indonesia, Mexico and the Philippines). The remaining 9 percent live in the 21 countries (including Nigeria, Democratic Republic of Congo and Afghanistan) where the fertility rate is higher than 5. The global fertility rate is expected to decline from 2.5 in recent years to 2.25 in 2045-2050 and 2.0 in 2095-2100. Any variation on these predictions could obviously have a significant impact on the world's population.

Another consequence of a fertility decline is an aging population. The number of people in the world over the age of 60, which currently stands at roughly 901 million, is expected to more than double by mid-century and more than triple by its end. Even more drastic: The number of people over 80 is expected to more than triple by 2050, and by 2100 it is expected to be more than seven times what it is today.

World's Population To Top 11 Billion by 2100 | World