Soon 10 billion people?

World population growing faster than expected

(Bild: stock.adobe.com)

Under the most "realistic" scenario for the world's social, economic and climate development, more than ten billion people will be living on Earth by 2065, according to a new study. Excitingly, however, the overall higher level of education will push down birth rates in some regions of the world less than expected.

Provided that global warming does not make many areas more or less uninhabitable, the signs now point to the Earth being home to more than ten billion people for at least some time. That alone is no cause for panic, explained researcher Anne Goujon: "I'm not afraid of the number of people, but of what they do." If the world manages to live in a more sustainable, innovative, community-oriented and environmentally conscious way by then, this is feasible. "I believe in human intelligence," says the expert.

In a working paper, scientists from the International Institute for Applied Systems Analysis (IIASA) in Laxenburg near Vienna and the Wittgenstein Center for Demography and Global Human Capital (WIC) in Vienna have revised their 2013 forecast on the development of the world's population for the second time after 2018. The recently published work, entitled "WIC2023" for short, incorporates new population, education and migration data as well as the effects of the Covid-19 pandemic and the war in Ukraine.

Different scenarios
The team's calculations are based on the so-called "Shared Socioeconomic Pathways" (SSPs) in which the Intergovernmental Panel on Climate Change (IPCC) describes different development paths up to the year 2100, which then lead to different greenhouse gas concentrations in the atmosphere. The work is based on the most likely scenario from today's perspective - known as the "middle way", "continuation of previous development" or "SSP2" - in which income distribution continues to diverge worldwide, international cooperation improves only slightly, the environmental situation continues to deteriorate accordingly and the world population grows moderately. However, there are also other scenarios in which the world remains on the "fossil fuel path", for example, which would mean significantly more global warming and a correspondingly marked decrease in the world's population.

Peak expected in 2080
According to the demographers, the SSP2 assumption would lead to a slowing but long-lasting increase in the global population, starting from the current estimate of just over eight billion people. According to the forecast, just over ten billion people would live on Earth for the first time between 2065 and 2070. According to the forecast, this development will peak between 2080 and 2085 with around 10.13 billion people on the planet. A decline to around 9.88 billion people is then expected by the end of the century. Asia would then have just under 4.5 billion inhabitants, Africa over 3.5, Europe 671 million, Latin and North America 669 and 450 million respectively and Oceania 62 million. This puts the figures well above the forecast from 2013.

Child mortality on the decline
The relatively large differences compared to previous forecasts are mainly due to the fact that in many countries in the South, child mortality has fortunately been reduced more than expected. In southern Africa, for example, this is "the result of vaccination campaigns, international aid and improved hygiene", says the demographer. In addition, it was actually assumed that birth rates would fall more sharply than recently observed in many of these countries as education levels tended to rise. In some countries, little has changed: "We did not foresee this." In Pakistan, for example, a census was carried out in 2017 for the first time since the 1990s - with the result that the assumptions about the population there had to be raised by a whole 150 million by 2100, partly because the birth rates there even rose briefly.