Eight billion people: Where is the world's population heading?

New York - Whether the world's population will actually break the eight billion mark on November 15 is questionable.

However, as it is impossible to keep track of hundreds of thousands of births and deaths per day, the United Nations has chosen the middle of the month for the human milestone. 8,000,000,000 - never before have so many people lived on Earth. But an end to the increase is in sight.

How did humanity get to this point?

According to current knowledge, Homo sapiens appeared around 300,000 years ago. Over the past millennia, the number of people has risen steadily - apart from phases of major pandemics such as the plague. The increase gradually accelerated and by the year 0 there were around 190 million people.

With longer life expectancy, the curve rose much more steeply from around the year 1700 - and the first billion was probably reached shortly after 1800. It took less than 100 years from a world population of two billion in 1928 to today's eight billion people. And it only took eleven years to grow from seven to eight billion.

A reason to celebrate - or cause for concern?

For the head of the United Nations Population Fund, Natalia Kanem, the current figure contains many positive aspects. After all, she says, it reflects a fundamental leap: "Eight billion people is a significant milestone for humanity. And it is the combination of longer life expectancy, lower maternal and child mortality and increasingly effective healthcare systems," said Kanem at a recent UN expert meeting.

According to Kanem, the fact that many people are worried about overpopulation is unfounded: "I am here to make it clear that the sheer number of human lives is not a cause for fear."

According to the UN, there are sufficient resources - it is a matter of correct and fair distribution.

Frank Swiaczny from the Federal Institute for Population Research adds with regard to global warming: "More people do not necessarily mean a larger ecological footprint."

Almost half of global CO2 emissions are caused by the ten percent of the world's population with the highest incomes, while the contribution of the poorest half is negligible.

Perpetual growth? On the contrary

"The pace of global population growth is slowing," explains UN expert Rachel Snow. The highest annual growth rate was reached in 1964 at 2.2 percent per year. "But now we are growing at less than one percent per year."

According to the latest studies, this trend is set to continue - until the world population is forecast to stop growing in 2080. The number of people will then be 10.4 billion.

Which regions of the world are developing and how?

Particular attention is being paid to developments in Asian countries with particularly large populations. China, the - still - most populous country in the world, is facing huge challenges, as the birth rate in this country of 1.4 billion people is low following the one-child policy.

Experts explain this by saying that many people who grew up as only children consider it normal to have just one child.

India, with over 1.3 billion people, has a higher birth rate and is likely to overtake China in the coming year. However, growth is also slowing in India - which is linked to the improved availability of contraceptives.

Meanwhile, in no other part of the world will the population increase as much in the foreseeable future as in parts of Africa. "According to current forecasts, sub-Saharan Africa will continue to grow significantly. Much of the future growth in the world's population will take place in this region and in some countries in Asia," says expert Swiaczny.

According to the German Foundation for World Population, around 1.4 billion people currently live in Africa. By 2050, the population is expected to rise to around 2.5 billion. By the end of the century, there will be around three times as many people living in Africa as there are today, almost 4.3 billion - around 40 percent of the world's population.

In contrast, high-income countries such as Japan are currently slipping into a negative population trend. For a stable growth rate, countries like Germany would therefore have to rely on migration. The UN advises in a report: "All countries, regardless of whether they are experiencing a net inflow or outflow of migrants, should take steps to facilitate orderly, safe, regular and responsible migration."

And the next milestone?

Of course, even with nine and ten billion people on the planet, there will still be a stir. But the United Nations does not expect a real turning point until the year 2100. Experts believe that the world's population will steadily decline from around then.

However, as with weather forecasts, predictions for population development become more uncertain with increasing time.