Under the most “realistic” scenario for the social, economic and climatic development of the Earth, the population will exceed the ten billion mark by 2065. This is the result of new, comprehensive forecasts by Austrian demographers.
According to the study, there will only be a slight decline by 2100. This is mainly due to the fact that an overall higher level of education will put less pressure on birth rates in some regions of the world than expected.
In their working paper, the scientists from the International Institute for Applied Systems Analysis (IIASA) in Laxenburg near Vienna and the Vienna Wittgenstein Centre for Demography and Global Human Capital (WIC) have revised their 2013 forecast on the development of the world’s population for the second time after 2018.
The new work, entitled “WIC2023” for short, incorporates the latest 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 “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.
According to the research team, based on the SSP2 assumption, there would be a slowing but long-lasting increase in the global population 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 reach its peak between 2080 and 2085 with around 10.13 billion people. 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.
Values above previous forecast
This means that the figures are well above the forecast from 2013 (“WIC2013”), when an all-time high of 9.4 billion people worldwide was expected by 2070 and around 8.9 billion by 2100. The “WIC2018” revision was somewhat higher, with a peak of 9.7 billion around 2070 and around 9.3 billion people at the end of the century.
The analysis from ten years ago was still based in many cases on statistics from 2010, so it was definitely time for a fundamental revision, according to Anne Goujon, head of the Population and Just Societies (POPJUS) program at IIASA, in an interview with APA. Since then, climate change, for example, has gained significant momentum, along with new wars and unrest that have changed migration movements and, last but not least, the Covid-19 pandemic, which has led to a noticeable increase in mortality worldwide. In the new long-term calculations, however, even Covid is only a minor dent in the overall upward trend. Life expectancy has been increasing again since then, emphasized Goujon.
Child mortality reduced
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 birth rates there even rose briefly. The mechanisms behind this are still unclear in many cases: it could be that the effect is delayed. If, for example, many women receive more education on average, but then do not find adequate jobs, this may lead to them ending up in traditional structures with many children, says Goujon.
There is also speculation about cultural factors, such as persistent ideas about the ideal number of children – “but I doubt that,” said the researcher, who also expects a decline in fertility rates in the global South in the medium term, although it is not yet possible to say how quickly this will happen.
Global warming as a factor of uncertainty
Provided that global warming does not make many areas more or less uninhabitable, the signs are now that the earth will be home to more than ten billion people for at least some time. That alone is no cause for panic, explained the researcher: “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, it is feasible. “I believe in human intelligence,” says Goujon.
– red, science.ORF.at/Agencies/picture:pixabay.com
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