How to cope with the growing global population

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A view of Busan, the Republic of Korea’s second largest city

© UN Photo/Kibae Park

The number of people living on earth is truly enormous: 7 billion people, hard to grasp. If those 7 billion people stood shoulder to shoulder, they would cover 1,554 km², about half of the province of West Flanders.

Another image: let’s divide these billions of people into groups of four, the average family size in Belgium. If you give each family a detached, ground floor house of 120 m² and a garden of 125 m², all these 1.75 billion families will occupy 428,750 km², approximately the total surface area of Germany, Belgium and the Netherlands.

That seems surprisingly little, but this half a million square kilometres would not get us far. People consume food, goods and energy, for which extra land is needed: for agriculture, factories, office buildings, shops, roads. Moreover, not every piece of land is habitable, and nature too has a right to its place in the sun. Both images show that space is not the biggest problem: the need for water, food, energy and raw materials is.

The figures

First the good news: we live longer than ever before. In the early 1950s, each newborn had an average life expectancy of 48 years. By 2011, life expectancy had risen to 70 years. Moreover, the ‘fertility’ rate, the number of children a woman has on average, has fallen sharply, from 6 in the 1950s to 2,5 today. For a stable population - which neither increases nor decreases - women should have an average of 2.1 (to 2.3) children, the so-called 'replacement level'.


Yet the population continues to grow. Table 1 shows how many people there will be in 2050 and in 2100. Of course, we cannot predict with 100% certainty how, for example, the size of families in Africa will evolve, but it is possible to make estimations based on current figures and trends. The three variants - low, medium and high - leave a little room for margin. Usually the medium variant is used. In the low variant fertility rate is 0.5 lower than in the medium variant, in the high variant it is 0.5 higher. This results in major differences: the 2100 population estimates vary from 6.2 to 15.8 billion people, although it is assumed that the population will have stabilised at around 10 billion by then.

Estimated world’s population (in billions)

Estimated world’s population (in billions)













Fertility rate

The world’s population shows important differences with regard to fertility. For the sake of convenience, we distinguish regions with low, medium and high fertility (see figure). In countries with low fertility rates (below 2.1), the population will peak around 2030. Almost all European countries belong to this category, next to countries such as Brazil, China, Tunisia, Thailand, Iran and Vietnam. Today, the low-fertility countries account for 42% of the world’s population.

40% of the world’s population lives in countries with medium fertility rates (between 2.1 and 3), where the population will reach its peak in 2065. The most populated countries belonging to this category are India, the US, Indonesia, Bangladesh, Mexico and Egypt.

In countries with high fertility rates (more than 3), the population will continue to increase until 2100. Today, 18% of the population (1.2 billion people) lives in these countries, a number that is expected to rise to 4.2 billion by 2100. The most populated countries belonging to this category are Pakistan, Nigeria, Philippines, Ethiopia, DR Congo and Tanzania. Most newborns will come from black Africa, where almost all countries have high fertility rates.

Increase of the world’s population and fertility rate

Increase of the world’s population and fertility rate




% of increase




+ 119 %




- 2 %

North America



+ 36 %

Latin America & the Caribbean



+ 25 %

Asia (without China)



+ 38 %




- 2 %




+ 68 %

Growth stages

Table 2 shows some figures of countries belonging to different fertility categories, illustrating the traditional growth stages a population goes through. Starting with high birth and death rates (DR Congo), the death rate gradually decreases, and with some delay, the birth rate will follow, until it gradually reaches the replacement level of 2.1 (India). In the final stage, both birth and death rates are very low (Belgium). The population is ageing and growth is (mainly) due to migration.

Three countries in various fertility categories (2011)

Three countries in various fertility categories (2011)


DR Congo (high)

India (medium)

Belgium (low)

Population 2011

67.8 million

1.241 billion

11 million

Population 2050

148.5 million

1.691 billion

12.5 million

Population younger than 15

46 %

33 %

17 %

Population older than 65

3 %

5 %

17 %

Birth rate per 1,000




Death rate per 1,000




Child mortality per 1,000 live births




Life expectancy

49 years

64 years

80 years

Population living on less than 2 USD per day

80 %

76 %


Married women between 15 and 49 using contraceptives

18 %

54 %

75 %

Fertility rate




Population in urbanised areas

36 %

29 %

99 %

Problems and opportunities

Rapid population growth in the poorest countries

The vast majority of population growth is seen in the poorest countries, making it even more difficult to lift the people in those countries out of poverty. For example, black Africa’s population (currently 883 million) will amount to over 2 billion in 2050. In other words, the birth rate in this part of the world will be very high. In order to absorb this growth, the number of midwives must at least double, while health centres and schools will have to accommodate more people. Food supply is another major concern. The population in Niger and Zambia will more than triple by 2050.

Opportunity: The large number of young people provides the poorest countries with an enormous workforce that could allow them to make a leap forward. That is, if they manage to find a job. In other words, there is a need for more education and employment opportunities, and less corruption. If young people do not get opportunities, they risk becoming a time bomb.


In the more developed countries - Europe, Japan, Australia, Canada... - the population is ageing rapidly. Today, there are still 4 working adults per elderly person; by 2050, there will only be 2, whereas one in three people will be over 60 years old. Measures are needed to keep society going, including keeping older people active for longer. Migration from countries with high fertility rates will be more than welcome. Eventually, the entire world's population will age.

Opportunity: Elderly people are - perhaps - wiser, greener and more moderate, less prone to consumption whims.


214 million people already live outside their home country. A population explosion in the poorest countries will inevitably have an important effect in attracting people to the richer countries. Often the highly educated leave the poor countries because they cannot find a decent job there: brain drain.

Opportunity: Today, Europe prefers to keep migrants out. However, for an ageing population, migrants will be indispensable to make up for the shortage of labour. For poor countries, "compatriots who made it abroad" can also be beneficial. In 2010, they sent home 262 billion euros, in addition to bringing inspiring ideas.


Today, half of the world’s population already lives in urbanised areas. This does not necessarily mean that all these people live in mega-cities. The majority of 'urban dwellers' live in small towns and villages, which explains why 99% of people in Belgium live in urbanised areas. In India, which has mega-cities like Mumbai and Delhi, more than 70% still live in rural areas.

The largest population growth occurs in rural areas. At the same time, rural inhabitants are leaving en masse. In India, less than 50% will be living in rural areas by 2050, while China and Nigeria will see their urban population increase from 50% today to over 70% in 2050.

Rural inhabitants’ life often becomes miserable when they end up in slums, where they easily catch contagious diseases due to lack of sanitation facilities. Today, 828 million people live in slums. The number of 'slum dwellers' will continue to rise, but at a slower rate than the total urban population.

Opportunity: People in cities spontaneously practise birth control as women in cities need a job to survive, which leaves less time to take care of children. Moreover, they no longer need children to work in the field. Despite the misery, people continue to choose living in cities because they find it easier to find a job there. Besides, cities are more appropriate to service provision (health care...) close to the people.


More people means higher consumption of water, food, energy and raw materials. However, the population is growing fastest in the poorest countries, where people consume little. The big consumers are the rich industrial countries. Emerging countries such as China, Brazil and India are rapidly achieving the level of these rich countries. More consumption usually means more pollution and greenhouse gases such as carbon dioxide (CO2). Even now, many cities in China are barely livable due to air pollution. CO2 emissions are driving climate change. Today, 7% of the world’s population - the richest half a billion people - is responsible for half of the CO2 emissions. The poorest 50% only account for 7% of the emissions.


Slowing down population growth

China's one-child policy was a form of forced birth control, but nowadays, it is believed that only voluntary family planning really works. Women are the main target group: if all women could decide for themselves how many children they want, fertility rate would spontaneously drop below the replacement level of 2.1.

There is a need for :

  1. Sound primary and secondary education for girls (and boys), including sex education. The better educated, the more critical women will be in making their own choices. They should be able to make their own decisions without facing pressure from their husband, family or society. Authorities must promote birth control.
  2. Affordable and available contraceptives to facilitate family planning. Young people should also have access to them. In many African countries, 14-16 year olds are sexually active, or are already getting married. However, they can only get contraceptives from a doctor if they are accompanied by a parent.
  3. Adequate health care that can reduce infant and maternal mortality. The lower infant mortality rate initially increases the population, but it does encourage women to have fewer children. A lower infant mortality rate is an excellent incentive to reduce the number of births.
  4. Economic development in the South. In many countries, increasing prosperity was accompanied by a falling birth rate, although there does not necessarily exist a causal link between them. For example, a poor country like Bangladesh already has a low fertility rate because women have access to education and contraceptives.
  5. Financial support from donors. In recent years, donors have given less support to family planning. In any case, Belgium continues to support the activities of the UN Population Fund (UNFPA). In 2011, our country donated 5.5 million euros.

Promoting different and ecologically acceptable consumption

The South is entitled to development, although it should be ‘ecologically acceptable’. The North must consume in a radically different way: less waste, more recycling, renewable alternatives. It is imperative to use food, water, energy and raw materials sparingly. This is the only way the earth will be able to support the expected 10 billion people.

The world's population reached 7 billion on 31 October 2011

© UN Photo/Rick Bajornas