Watch Earth's Population Hit 8 Billion With Real-Time Tracker

The U.N. has estimated that the global population will hit 8 billion on November 15. Using data collected from all over the world, Worldometer has made it possible to track this historic milestone in real time. Worldometer collects its data from hundreds of international records and projection models. The data is then processed through an algorithm, which generates a real-time estimate of the global population. Since 1960, the global population has more than doubled. Population growth is expected to continue, albeit at a slower rate, until the 2080s, when it will probably peak at around 10.4 billion people. "In 2020, the global population growth rate fell under 1 percent per year for the first time since 1950," Bela Hovy, from the Population Division of the United Nations Department of Economic and Social Affairs, previously told Newsweek. "Based on past and recent population trajectories, the world population is projected to reach 9 billion by 2037."

While these estimates consider thousands of population censuses and demographic indicator surveys, it is still very difficult to accurately estimate how many people are actually on the planet, let alone how the population will change in the future. "We need milestones just to inform people about how many people are living on the planet roughly and what to expect in the future," Sergei Scherbov, director of demographic analysis at the Wittgenstein Center for Demography and Global Human Capital, told Newsweek. "But no one on Earth can tell what the exact number of people living today is. Those are very rough estimates. Even in the developed countries, where censuses have been conducted, they have uncertainty."

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In many other countries, censuses have not been taken for years, and basic demographic information, like births and deaths, aren't properly registered. "To make projections, we must use different tools and approaches to estimate the levels of fertility, mortality, and migration in order to come up with some population estimates in 2022," Scherbov said. "Those methods are often based on surveys and also deliver a large degree of uncertainty in the final 2022 population." In 2011, Scherbov published a paper with colleagues Wolfgang Lutz and Warren Sanderson on when we could expect to reach this milestone, and the uncertainties in these predictions. In the study, they predicted that the 8 billion day would not be reached until between 2024 and 2033.

"The differences with our forecasts in 2011, could have occurred because we started with lower estimates in the baseline population, mortality fell faster than we expected and the fertility level was higher in U.N. estimates than our projections were based on," Scherbov said. Wolfgang Lutz, a co-author on the paper and founding director of the Wittgenstein Center, explained that declines in child mortality have been a particularly unexpected, and welcome, development. "The surprising new development over the past years was that child mortality in Africa has declined more rapidly than anticipated," he told Newsweek. "This may be due to massive campaigns by the Gates Foundation and the Global Fund focusing mostly on Malaria. "While this is a great achievement to be celebrated it also contributes to accelerating population growth. "The demographic consequences of additional surviving children is the same as those of a higher birth rate, thus adding more people to the young population who will then go on and have children themselves. At the same time in some big African countries, as well as Pakistan and Afghanistan, the birth rates have declined somewhat slower than anticipated." This rapid population growth is a clear indicator of success in public health advancement, but it also poses challenges to sustainable development and social and economic progress and will further stretch the resources of our planet. Like Scherbov, Lutz emphasized that the 8 billion day is hard to pinpoint accurately. "This milestone is of largely symbolic importance," he said. "But it can help to bring population trends back to the attention of the broader public." Do you have a tip on a science story that Newsweek should be covering? Do you have a question about population growth? Let us know via science@newsweek.com.

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Reference

Scherbov S, Lutz WL, Sanderson WC, The uncertain timing of reaching 8 billion, peak world population, and other demographic milestones, Popul Dev Rev. 2011 doi: 10.1111/j.1728-4457.2011.00435.x