On October 31, 2011, we passed 7 billion people on earth. World citizen number 7 billion was symbolically designated by the UN to be the newborn girl Danica in the Philippines. She was congratulated by UN Secretary-General Ban Ki Moon and received a number of gifts. The seventh billion was passed just 13 years after the previous one in 1998. And in 2012 – Norway passed 5 million.
How long does it take before we pass the next billion?
How is population growth distributed among different land groups?
What are the key factors in getting population growth under control?
What challenges does population growth pose to humanity?
2: Population growth raises concerns
Many people are worried that the world’s population is growing so fast. They point out that many are starving (approximately 2.7 billion people live on less than $ 2 per day, according to COUNTRYAAH) and lack basic benefits. The large and rising population also leads to environmental problems such as greenhouse gas emissions , global warming and other climate change. Where will it end – many think – if all inhabitants of the world get as high a consumption of resources as an average inhabitant of developed countries?
However, it is a fact that world population growth is declining . Measured as a percentage, growth was at its peak around 1970 with a 2.1 per cent increase per year . The growth rate has now almost halved and has fallen to 1.1 per cent per year. What happened? Why are the changes so big?
3: Rapid demographic transition in particular
Population development can be described with the term the demographic transition . The transition from phase 1 to 2 began in Norway and most other European countries in the early 1800s. Then the great mortality crises disappeared due to. years, epidemics and wars, and life expectancy began to increase. In most countries in the south, the transition began in the early 1950s, i.a. as a result of modern medicine, more education and technological development.
This led to a rapid decline in mortality (in phase 2) and high population growth, which thus peaked around 1970. The high growth led to doomsday prophecies about famine and other disasters. It took quite a few years before the third phase of the demographic transition began in the south, ie a decline in the birth rate.
In 1974, fertility was high in almost all developing countries, with an average of 5.4 children per woman. Since then, this has decreased in most countries in the south, to 2.7 children per woman. This is not much above the reproduction level of 2.1 children .
However, many countries still have very high fertility, especially the least developed countries (Fig. 4). The average is now 4.4 children per woman (down from 6.7 children in the early 1970s). Sub-Saharan Africa in particular has high fertility – 5.1 children per woman. In Uganda and Niger, women still have well over 6 children on average. Another challenge is that the decline in the birth rate that began in the 1980s in some countries seems to have stopped almost completely, despite some economic development (including Kenya and Ghana).
4: Lower growth in percent
Although the percentage growth in the population has almost halved since the 1970s, the absolute growth is still large – 78 million in 2011 (Fig. 8). This may look like a small change from the top of 90 million in 1989. But the growth is on the way down. According to the UN’s latest population projections (2010–2100), the annual population increase will fall to 37 million in 2050 and 5 million in 2100.
This development is based on a hypothesis that the demographic transition will eventually be completed in all countries in the world , but at different times. Thus, the population will stabilize at just over 10 billion , a little into the next century – according to the hypothesis. Billion No. 8 will be passed in 2024, 13 years after the previous one. But then we will spend more and more time on every billion: Nr. 9 will be passed 18 years later in 2042 and No. 10 in 2082. It may be the last billion pass in human history, at least on the way up!
5: But it can go differently
However, deviations from the assumptions can have a major impact . If the number of children for women becomes ½ children higher than assumed in the intermediate alternative, the population in 2100 will be as many as 16 billion people and will continue to grow rapidly. On the other hand: If the number of children becomes ½ children lower than in the intermediate alternative, the population will reach a peak of just over 8 billion around 2040 and then fall , to 6 billion in 2100 (Fig. 2).
However, the greatest effect will be if fertility and mortality continue at the current level, as in the constant alternative . Then the population will grow to as much as 27 billion in 2100 and not long after reaching an almost astronomical – and totally unrealistic – level. In other words, a continuation of the current level will go wrong. The point, however, is that the demographic transition is well under way in almost every country in the world.
However, there are some reefs in the sea that require the world community to continue and preferably increase efforts in fields that have to do with population development, especially in reproductive health (especially care for pregnant women, obstetrics, women in childbirth and newborns). Combating poverty and strengthening the status of women , especially through education , is also very important. Women – far more than men – are often the key to better family finances, better health and education for children.
The population in the world will thus probably grow from the current 7 billion to just over 10 billion. The majority of this growth will come in sub-Saharan Africa, with more than 1 billion (Fig. 5). Also in Asia, the population will grow a lot, but there the growth rate has already fallen a lot. In Europe, the population will decline from 739 to 675 million in this century, but it will grow slightly in the developed countries as a group, from just over 1.2 billion today to just over 1.3 billion in 2100.
6: The two most populous countries
In the world’s most populous country, China, the population will reach a peak of 1.4 billion around 2025 and then decline, according to the UN’s middle alternative. The second most populous country, India, will catch up with China in 2020, but also in India the population will decline. However, this will not happen until after 2060 and from a significantly higher level, 1.7 billion. By 2100, India will therefore have about 50 percent more inhabitants than China. In 1950, the relationship was reversed (Fig. 6).
China’s one-child policy has been important for the decline in the birth rate and population growth, but other factors have also contributed strongly, such as better health care, better education and not least strong economic growth. Today, it would probably have little effect on the birth rate if the one-child policy in China was abolished.
7: The population explosion has been called off
Global population growth has slowed significantly in recent decades. There is no longer any talk of a population explosion or bomb, as there was in the 1960s and 1970s. Nevertheless, the population is growing rapidly, and in many regions population growth is so strong that it slows down social and economic development . This applies in particular to sub-Saharan Africa, where there are many countries where the fertility transition has not yet begun. Poverty is both a cause and a consequence of high population growth. There is therefore every reason to pay great attention to population issues in the years to come.
The focus on birth control was reduced after the international conference on population and development in Cairo in 1994. Instead, an investment was made in the broader concept of reproductive health, which i.a. includes health checks and safe births. This has been an important change of course, which has benefited many women in developing countries. But it is unfortunate that assistance with family planning has declined significantly since 1994, both in absolute and relative terms.
8: Fertility – birth rate – fertility
Fertility has declined in most countries in the world (Figure 4). However, it is not always obvious that this is due to social and economic development. In Bangladesh – as a prime example – fertility has declined without significant social and economic development. In several countries, the decline in the birth rate seems to have stopped despite despite some economic development (including Kenya, Botswana, Ghana and Turkey). It is especially in sub-Saharan Africa that fertility is still high, which means very large population growth now and in the years to come.
Education is among the single factors that have meant the most to the decline in fertility. The UN (2004) reports that at the country level there is a clear negative correlation between the overall fertility level and the average length of education for adults. Education affects fertility in a number of different ways, via how many children you want, income and salary, ambitions, knowledge of contraceptive methods, etc. Not only do women’s own education have an effect on fertility, it has also been found that the environment’s educational level has a negative effect on the number of children.
However, it is a question of whether the increase in the level of education in the poorest countries will happen quickly enough for the demographic transition to be completed in this century, as the UN assumes. In sub-Saharan Africa, contraceptive use has increased by ½ percentage points per year since 1994. However, it is estimated that if African women are to achieve a satisfactory level of contraceptive use – 60–70 per cent for women – use must increase by 1½ percentage points per year. This requires increased efforts from both rich countries and the African countries themselves.
9: Life expectancy and mortality
From 1950 to 2010 , global life expectancy increased by as much as 20 years, from 48 (in 1950−1955) years to 68 years (in 2005−2010). This is “a remarkable achievement for mankind”, as the head of the UN Population Office put it. This is partly due to a sharp reduction in infant mortality (from 180 to 57 per 1,000 births since 1950). Here, both better living conditions (food, housing, etc.), better public services (water, rubbish, toilets, etc.) and modern medicine (vaccines, antibiotics, etc.) have played a major role.
There are only a few exceptions where mortality has increased: After the fall of communism, the life expectancy of men in Eastern Europe fell. And in southern Africa, life expectancy declined due to the HIV / AIDS epidemic. But these setbacks seem to be temporary. For developing countries as a whole, even for the least developed, the UN reckons that life expectancy will continue to increase.
In general, the decline in mortality has occurred significantly faster in most developing countries than in the industrialized countries . Norway and Sweden spent 150 years coming from a life expectancy of 40-50 years to 80 years. Indonesia and Vietnam spent only 50 years on the same thing. Nevertheless, life expectancy is still increasing significantly in the rich countries.
Many demographers and others have thought that life expectancy would soon reach a maximum and then stabilize, but there is little to suggest that. However, some researchers believe that life expectancy for women may exceed 100 years in this century. Others are skeptical of this and emphasize that there are a number of signs that life expectancy growth may decline in the years to come and even become negative, e.g. due to a more unhealthy lifestyle, obesity and diabetes.
