The World Population Just Hit 8 Billion and Here’s How It Will Continue to Grow

The World Population Just Hit 8 Billion and Here’s How It Will Continue to Grow

According to the models of the United Nations (UN), the world’s population will reach 8 billion today–a mere 12 years since it passed 7 billion, and less than a century after the planet supported just 2 billion people.

The latest UN population update, released in July this year, also revises its long-term projection down from 11 billion people to 10.4 billion by 2100.

Demographers will never be sure if 15 November really was the Day of Eight Billion, as the UN has named it, but they do agree on one thing. Despite the rapid growth of the human population, it is slowing down and, in a few decades, Earth will see a decrease in its population.

“It’s a crude approximation, but it’s more of a symbol finding,” says Patrick Gerland who heads demographic work at UN Population Division in New York City. “We may have passed it or it may come a little later, however, it’s around this point that humanity is reaching 8 million .”

.

Although it is an estimate, this could be the most reliable estimate the UN has made so far. The UN recently changed the way it analyzes data, moving from five-year intervals to annual intervals. In recent decades, many countries have seen a steady increase in their ability to collect statistics.

There are still significant blind spots, especially for countries in humanitarian crises or conflicts like Somalia, Yemen, and Syria. Gerland states that the accuracy of the empirical information is not always accurate around the globe.

Differing estimates

The rapid increase in the world’s population over the past century (see “People of the world”) was a result of advances in medicine and public health, which allowed more children to live to adulthood. In lower-income countries, fertility rates, which is the number of children per mother, remained high.

Demographers are particularly interested in fertility rates and how they will change. These factors help to predict what will happen to the world’s population in the future. Differences in assumed fertility rates have been an important reason behind a notable diversion in what various models had previously forecast for the world’s population in 2100, for example. Those results suggested a spread ranging from 8.8 billion to nearly 11 billion by the end of the century.

alt
Credit: Nature

“If you make even relatively small adjustments in these fertility-rate trajectories it accumulates, and suddenly a big country can have 100 million people more 80 years from now,” says Tomas Sobotka, a population researcher at the Vienna Institute of Demography.

In 2018, the International Institute for Applied Systems Analysis (IIASA) in Vienna forecast that global population would be about 9.5 billion in 2100. The institute is now preparing an update, which will raise that estimate to between 10 billion and 10.1 billion. Sobotka says the change is due to higher survival rates for children living in lower-income countries. Another factor is the higher fertility rates in large countries like Pakistan, according to Sobotka.

More reliable data

The most significant factor behind the UN’s updated forecast is that data from China has been more reliable since the end of the country’s one-child policy in 2015.

” “There was always a mismatch between the different sources of information coming from China during that policy,” Gerland states. He says that some parents, especially if they had a daughter, did not register their first birth. Many children didn’t appear in official statistics until they started school. He says, “We had to rely upon education statistics for more precise information.”

The UN predicts that China’s population will shrink year-on-year, and then peak, by the end of this century.

” The Chinese statistics suggest that there are more deaths than births in China. In that situation, Gerland states.

This article is reproduced with permission and was first published on November 15 2022.

Read More