Video Lesson

Lesson Objectives

By the end of this lesson, you will be able to:

• Explain the trend of world population growth; and
• compare and contrast the trends of population growth in MDCs and LDCs

 Brainstorming Question

How do you understand the demographic transition model?

 Why has the largest increase (growth rate) of the world population, in history, occurred when nations began to lower their fertility rates?

Key words

• Land World population;
• Growth Trends;
• More-developed countries
• Less-developed countries

Introduction

Dear Online Learner! Population geography is the branch of geography that deals with population issues. The study of population geography focuses on the size, composition, spatial distribution, and changes in population across time. Three essential processes, namely fertility, mortality, and migration, define the pattern of population growth.

THE GROWTH OF WORLD POPULATION

Dear Online Learner! According to the demographic transitional model:

In the first stage:

• Countries normally exhibit a population growth with a high level of fertility and mortality.
• Triangular-shaped pyramid used to characterize more developed countries of 17thh and 18^th C ago.

In the second stage:

• Death rates decrease, notably among children aged 0 to 5, while birth rates remain high.

Figure 4.1. Demographic transitional model in five stages

The third stage

•  Marked by a decrease in the birth rate, owing mostly to socioeconomic changes, urbanization, and widespread contraception use.
• Population growth continues at a slower pace.

In the fourth stage

• Birth rates fall to levels where they are equal to death rates, resulting in a slowly growing population.

In the fifth stage:

•  The birth rate rose again but the death rate remained low bringing stable or low population growth.

Human population growth was modest until the mid-nineteenth century when birth rates were only slightly greater than mortality rates. The human population has expanded significantly quicker than ever before in the twentieth century.

• The global population is still growing at a slower rate than it has been since 1950. From one billion in 1800 to 7.7 billion in 2019, the world’s population has increased dramatically.

Source: United Nations, Department of Economic and Social Affairs,
Population Division (2019). World Population Prospects 2019.
Figure.4.2. Population size and annual growth rate for the world.

• Close to half of the global population lives in Europe and North America, Latin America and the Caribbean, Australia/ New Zealand, and eastern and southeastern Asia, where lifetime fertility is below 2.1 births per woman (roughly the level required for populations with low mortality to have a growth rate of zero in the long run).
• Fertility remained above the global average in 2019, primarily in Sub-Saharan Africa (4.6), Oceania (3.4) and Northern Africa and Western Asia (2.9).
• Global fertility is anticipated to decline from 2.5 live births per woman in 2019 to 2.2 in 2050 and 1.9 in 2100, according to the medium-variant estimate.
• Eastern and South-Eastern Asia, Central and Southern Asia, Latin America and the Caribbean, and Europe and Northern America, on the other hand, are expected to achieve peak population and begin population decline by the end of the century.

Figure 4.3. Total fertility (births per woman) by Sustainable Devel
opment Goal region, estimates, 1950-2020, and medium-variant
projections, 2020-2100
Source: United Nations, Department of Economic and Social Affairs,
Population Division (2019). World Population Prospects 2019.

• By 2050, sustained population expansion will significantly raise food demand, particularly in Sub-Saharan Africa and South Asia.
• Adolescent fertility (births to mothers aged 15-19 years) remains high in some countries, including several in sub-Saharan Africa, Latin America, and the Caribbean.
•  India is expected to surpass China as the world’s most populated country around 2027.

Figure 4.4. Population by Sustain able Development Goal region: Estimates, 1950-2020, medium-variant projections, 2020-2100, with 80 and 95-percent prediction intervals

Population Trends in Less Developed Countries (LDCs)

• Population growth rates LDCs were relatively modest in the mid-18^th C.
• Since 1920s the rates of natural increase in LDCs rose to approach those in more developed countries, and began to exceed in the 1930s and 1940s.

Figure 4.6: Changes in total population between 2019 and 2050
based on the medium-variant projection

• Since World War II, significant progress has been made in the provision of different facilities led to a decrease in death rates.
• African LDCs had the highest population growth rate of 2.8 % per year between 1970 and 2012, which was higher than the worldwide LDC average of 2.5 %.
• Between 2019 and 2050, two-thirds of less developed nations are forecast to see population growth with 40 of them expected to rise by more than 50% and 19 likely to quadruple their population due to ongoing high fertility.
• The fast growth of many developing world cities has made it nearly hard for governments to provide appropriate infrastructure.
• Increased population density may be beneficial if it results in larger marketplaces, increased economic engagement, more intellectual exchange, and labor division.

Population Trends in more Developed Countries (MDCs)

• MDCs’ population growth rates are lower than those of LDCs.
•  Around the world, the potential support ratio is currently decreasing.
• For example, 29 countries, mostly in Europe and the Caribbean, already have support ratios of less than three.
• By 2050, 48 countries, primarily in Europe, northern America, and eastern and southeast Asia, are forecast to have potential support ratios of less than two.