PEOPLE - By 2100, there could be 11 billion people on the planet

According to a newly-released estimate from the UN, humanity is on track to grow to a global population of 11 billion people by the end of this century.

Currently, there are 7.2 billion people on the planet and we're growing fast.

UN Population Division director John Wilmoth said in a release:

For the world as a whole, fertility has fallen rapidly in recent decades, especially since the 1960s. Several large developing countries, including China, India, Indonesia, Iran, Brazil, South Africa, and many others, have experienced a rapid fall in the average number of children per woman. This has led to a reduction in population growth rates in much of the developing world.

At the same time, many countries of Europe, East Asia, and elsewhere now have very low levels of fertility, well below their "replacement level" of around 2.1 children per woman. As a result, these populations are ageing rapidly and face challenges in providing care and support to their growing ranks of older persons. Some of these countries have seen their populations begin to decrease in recent years.

There remains, however, a group of countries with relatively high levels of fertility (more than 5 children per woman on average). Most of these are on the UN's list of 49 least developed countries, and many are located in sub-Saharan Africa - for example, Nigeria, Niger, the Democratic Republic of the Congo, Ethiopia, and Uganda, but also Afghanistan and Timor-Leste. For these populations, growth is rapid today, and rapid growth is expected to continue over the next few decades.

Image via The Guardian. Click to enlarge.

The question is, when will population expansion slow down and level off? Some demographers say these UN estimates are too high, because urban populations have extremely low reproductive rates - and the world's population, already more than 50 percent urban, is expected to be 67 percent urban by 2100.

The UN reached these figures, which are bigger estimates than ones they released two years ago, by looking at numbers of fertile women in countries with the biggest population boom - but also by assuming that greater access to birth control in those regions will slow birthrates in the future. Added Wilmoth:

Recently available data and other information have obliged us to revise upwardly our estimates of current fertility levels for several high-fertility countries, including Angola, Cameroun, the Demographic Republic of the Congo, Ethiopia, Mozambique, Niger, and Nigeria.

Our medium-variant projection continues to assume a rapid fall in future levels of fertility for these countries. We continue to calibrate the pace of future fertility decline using the historical experience of countries that underwent a major reduction of fertility levels after 1950, in an era of modern contraception.

The medium-variant projection is thus an expression of what should be possible if future patterns of behavioural change in childbearing resemble those of the past, for populations at similar levels of fertility. These future trends, however, are not guaranteed. In fact, in light of recent trends for some high-fertility countries, this middle scenario could require additional substantial efforts to make it possible.

Read more at the UN Population Division website

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