Although demographers can never be sure, it was announced in the media that on November 15, Humanity reached the figure of eight billion individuals. Beyond the number, which appears as impressive as it is uncertain, what does it mean? Very little, since what matters is the growth trend which, as already predicted in the past, is actually decreasing.
How far will the global population increase?
This is a complex question as until now researchers have relied on estimates that have since turned out to be incorrect. Absurdly, the figure of eight billion could be the most reliable that the UN has produced so far. The organization recently changed the way it analyzes data from five-year intervals to yearly intervals. In particular, there has been a steady improvement over the last few decades in the ability of many countries to collect statistical values. If this is true for the most industrialized countries, it cannot be equally reliable for countries experiencing humanitarian crises and conflicts, such as Somalia, Yemen and Syria.
Different estimates but that was to be expected
Rapid population growth throughout the XNUMXth century was driven by advances in public health and medicine, allowing more children to survive into adulthood. At the same time, fertility rates (defined as the average number of children per woman) have decreased in the most industrialized countries, but have increased or remained high in third world countries.
Demographers are particularly interested in accurately determining fertility rates, because these factors can predict what will happen to the global population in the future. The differences in fertility rates created a large percentage deviation from what various models had previously predicted for world population in 2100 which suggested a spread between 8,8 billion and almost 11 billion. Interesting is the higher life expectancy in the most industrialized countries which, however, have at the same time a lower fertility.
Among the most incisive countries in terms of demographics we have China, and one wonders when the peak of the Chinese population will be reached. On the basis of United Nations forecasts, data from China are now more reliable since the end of the "one child" policy which took place in 2015. In fact, it emerged that many families, especially with the birth of a girl, did not register the birth, as a result, many children were not included in official statistics until they started attending compulsory schooling. According to Nature, UN forecasts suggest that China's population has already reached its peak and will shrink year on year, at least until the end of the century.
For other countries the trend could be very different
The change is due to observed survival rates which are increasing in low-income countries thanks to lower infant mortality. Another factor to consider are the fertility rates, which are rising in some large countries, including Pakistan. In the next ten years, India's population will exceed that of China which, as stated, will tend to decrease.
In fact, Asia is today the most populous continent, home to about 60% of the Earth's inhabitants but which could be reached by 2100 from Africa. To give an idea: today about a sixth of the world's population lives in Africa, in 2050 the quota will be a quarter and at the end of the century, one inhabitant out of three in the world will be African. In practice out of three, one will be Asian, one African and the last divided into Europe and the American continent. North American and European populations will tend to decline from 2030.
In 2018, theInternational Institute for Applied Systems Analysis (IIASA) in Vienna had predicted that the world population would have been around 9,5 billion in 2100. The Institute is now preparing an update, which will most likely change this estimate between 10 and 10,1 billion and then start a phase of reduction. This is essential, not only to provide a solid basis from which to project into the distant future, but also to develop current policies in planning the tools to be adopted following future emergencies. Just think of the recent pandemic, in which the evaluation of vaccine stocks was wrong. Furthermore, for the necessary assessment of the distribution of resources and the medium and long-term forecast of work in certain sectors (education, health, tertiary, etc.).
Last but not least, the distribution of resources to try to mitigate uncontrolled phenomena of mass migrations from areas in need of support to the more fortunate countries, effectively creating destabilizing social phenomena. There are no definitive answers but it is believed that the migratory phenomenon will mainly affect India, Nigeria, Congo, Pakistan, Ethiopia, Tanzania, Uganda and Indonesia where strong demographic growth is expected. This migration, if not controlled, will lead to a drastic reduction of resources with a high possibility of social conflicts. And… the first line of battle will take place on the sea.
Charts: World Population Prospects 2017
(article originally published on https://www.ocean4future.org)